Composition for forming light-emitting layer of organic electroluminescent device, organic electroluminescent device, organic EL display device and organic EL lighting

Abstract

A composition for forming a luminescent layer of an organic electroluminescent element that includes a polycyclic heterocyclic compound represented by formula (1), a compound represented by formula (20), and an organic solvent. Provided is an organic electroluminescent element with a long drive life that has a luminescent layer containing a polycyclic heterocyclic compound that contains boron. (Ring a, ring b, and ring c are aromatic hydrocarbon rings or aromatic heterocycles. Y is O, N-R, or S. R is an aromatic hydrocarbon ring group, aromatic heterocyclic group, or an alkyl group. R may bond with a carbon atom adjacent to an atom bonded to Y in at least one of rings a-c by -O-, -S-, -C(-Ra)2-, or a single bond. Ra is a hydrogen atom or an alkyl group.) (Ar21-Ar35 are a hydrogen atom or a structure in which one or 2-10 benzene ring structures are unbranched or branched and linked.)

Description

[Technical Field]

[0001] The present invention relates to a composition for forming a light-emitting layer of an organic electroluminescent device, and to an organic electroluminescent device, an organic EL display device, and an organic EL lighting device using the same. [Background technology]

[0002] In recent years, organic electroluminescent devices using organic thin films have been developed instead of those using inorganic materials as thin-film electroluminescent devices. Organic electroluminescent devices (OLEDs) usually have a hole injection layer, hole transport layer, organic light-emitting layer, electron transport layer, etc. between an anode and a cathode, and materials suitable for each of these layers are being developed, and development is also progressing for each of the emitted colors: red, green, and blue.

[0003] Methods for forming the organic layers of organic electroluminescent devices include vacuum deposition and wet film-forming (coating) methods. Vacuum deposition has the advantage of being easy to form layers, improving charge injection from the anode and / or cathode, and facilitating the confinement of excitons in the light-emitting layer. On the other hand, wet film-forming has the advantages of not requiring a vacuum process, being easy to scale up, and being able to easily form layers containing multiple materials with various functions by using a coating liquid that mixes multiple materials with various functions. For this reason, research and development of organic electroluminescent devices using wet film-forming methods has been actively conducted in recent years.

[0004] Patent Documents 1 to 5 discuss organic electroluminescent devices in which a light-emitting layer containing a light-emitting material having a polycyclic heterocyclic compound skeleton containing boron and nitrogen is formed by a wet film-forming method. However, there is a demand for a further increase in the operating life of the element. Furthermore, there is a demand for devices that can be driven at a lower voltage and have improved luminous efficiency.

[0005] [Patent Document 1] International Publication No. 2016 / 152418 [Patent Document 2] International Publication No. 2019 / 198699 [Patent Document 3] International Publication No. 2019 / 235452 [Patent Document 4] International Publication No. 2018 / 062278 [Patent Document 5] International Publication No. 2018 / 186404 Summary of the Invention

[0006] An object of the present invention is to provide an organic electroluminescent device which has a light-emitting layer containing a polycyclic heterocyclic compound containing boron, which exhibits excellent device characteristics, and in particular, has a long operating life. Another object of the present invention is to provide an organic electroluminescent device that has an emitting layer containing a boron-containing polycyclic heterocyclic compound, exhibits excellent device characteristics, is driven at a low voltage, has high luminous efficiency, and has a long driving life.

[0007] The gist of the present invention is as follows [1] to

[23] .

[0008] [1] A composition for forming a light-emitting layer of an organic electroluminescent device, comprising: a polycyclic heterocyclic compound represented by the following formula (1); at least one of the following compounds I, II, III, and IV; and an organic solvent.

[0009] [ka]

[0010] (In formula (1), ring a, ring b, and ring c each independently represent an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent; Y is independently O, NR, or S; R represents an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is a ring selected from the group consisting of the ring a, the ring b, and the ring c, and a carbon atom adjacent to the atom bonded to the Y, and -O-, -S-, -C(-R a ) may be linked by a double or single bond, R a is a hydrogen atom or an alkyl group, the adjacent carbon atom is not a carbon atom constituting the central fused two-ring structure of formula (1) containing B and the Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Compound I: a compound represented by the following formula (20): Compound II: a compound represented by the following formula (200): Compound III: one or more compounds selected from the group consisting of a compound represented by the following formula (210), a compound represented by the following formula (220), and a compound represented by the following formula (230): Compound IV: A compound represented by the following formula (240):

[0011] [ka]

[0012] (In formula (20), Ar 21 ~Ar 35 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0013] [ka]

[0014] (In formula (200), each W independently represents CH or N, and at least one W is N; Xa 1 , Ya 1 , and Za 1each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, Xa 2 , Ya 2 and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent; g11, h11, and j11 each independently represent an integer of 0 to 6; At least one of g11, h11, and j11 is an integer of 1 or greater, If g11 is 2 or more, multiple Xa 1 may be the same or different, If h11 is 2 or more, multiple Ya 1 may be the same or different, j If 11 is 2 or more, there are multiple Za 1 may be the same or different, R 31 represents a hydrogen atom or a substituent, and four R 31 may be the same or different, However, if g11, h11, or j11 is 0, the corresponding Xa 2 , Ya 2 , Za 2 is not a hydrogen atom.)

[0015] [ka]

[0016] (In formula (210), formula (220) and formula (230), Ar 41 , Ar 42 , Ar 43each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, R 21 , R 22 , R 23 each independently represents a hydrogen atom or a substituent, X 21 , X 22 are each independently O, S, or N-Ar 44 represents Ar 44 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, n21, n22, and n23 each independently represent 1 or 2; n24 represents an integer from 1 to 4, If n24 is 2 or more, multiple R 21 may be the same or different.)

[0017] [ka]

[0018] (In formula (240), Ar 611 , Ar 612 each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R 611 , R 612 each independently represents a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent; n611 , n 612 are each independently an integer of 0 to 4.

[0019] [2] The composition for forming a light-emitting layer of an organic electroluminescent device according to [1], wherein Y in the formula (1) is NR.

[0020] [3] In the formula (20), Ar 22 , Ar 23 , Ar 24 , Ar 27 , Ar 28 , Ar 29 , Ar 32 , Ar 33 and Ar 34 The composition for forming a light-emitting layer of an organic electroluminescent device according to [1] or [2], wherein at least one of the following is a structure represented by the following formula (21) or the following formula (22):

[0021] [ka]

[0022] (In formulas (21) and (22), Ar 36 ~Ar 39 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 8 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0023] [4] In the formula (20), Ar 22 , Ar 23 and Ar 24 One of the following and Ar 27 , Ar 28 and Ar 29 One of the following and Ar 32 , Ar 33 and Ar 34 The composition for forming a light-emitting layer of an organic electroluminescent device according to [3], wherein any one of the above is a structure represented by the formula (21) or the formula (22).

[0024] [5] In the formula (20), Ar22 , Ar 27 and Ar 32 The composition for forming a light-emitting layer of an organic electroluminescent device according to [4], wherein the compound is a structure represented by the formula (21) or the formula (22).

[0025] [6] The composition for forming a light-emitting layer of an organic electroluminescent element according to any one of [3] to [5], wherein the structure represented by formula (21) is a structure represented by the following formula (21-1), (21-2), (21-3), (21-4), or (21-5), and the structure represented by formula (22) is a structure represented by the following formula (22-1), (22-2), (22-3), or (22-4).

[0026] [ka]

[0027] [7] The composition for forming a light-emitting layer of an organic electroluminescent device according to [1] or [2], wherein at least two of the three Ws in the formula (200) are N.

[0028] [8] The composition for forming a light-emitting layer of an organic electroluminescent device according to [7], wherein all of W in the formula (200) are N.

[0029] [9] Ar in the formula (210), the formula (220), and the formula (230) 41 , Ar 42 and Ar 43 is a group represented by any one of the following formulas (20-1) to (20-13):

[0030] [ka]

[0031] (In the above formula, * represents a bonding position, Ar 45is an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group in which 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent are linked together.

[0032]

[10] A method for producing an organic electroluminescent element, comprising the step of applying and drying the composition for forming an emitting layer of an organic electroluminescent element according to any one of [1] to [9] to form an emitting layer.

[0033]

[11] A method for manufacturing an organic EL display device, including the method for manufacturing the organic electroluminescent device according to

[10] .

[0034]

[12] A method for manufacturing an organic electroluminescent lighting device, including the method for manufacturing an organic electroluminescent device according to

[10] .

[0035]

[13] An organic electroluminescent device having an anode, a cathode, and a light-emitting layer provided between the anode and the cathode, the light-emitting layer containing a polycyclic heterocyclic compound represented by the following formula (1) and at least one of the following compounds I, II, III, and IV:

[0036] [ka]

[0037] (In formula (1), ring a, ring b, and ring c each independently represent an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent; Y is independently O, NR, or S; R represents an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is a ring selected from the group consisting of the ring a, the ring b, and the ring c, and a carbon atom adjacent to the atom bonded to the Y, and -O-, -S-, -C(-R a) may be linked by a double or single bond, R a is a hydrogen atom or an alkyl group, the adjacent carbon atom is not a carbon atom constituting the central fused two-ring structure of formula (1) containing B and the Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Compound I: a compound represented by the following formula (20): Compound II: a compound represented by the following formula (200): Compound III: one or more compounds selected from the group consisting of a compound represented by the following formula (210), a compound represented by the following formula (220), and a compound represented by the following formula (230): Compound IV: A compound represented by the following formula (240):

[0038] [ka]

[0039] (In formula (20), Ar 21 ~Ar 35 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0040] [ka]

[0041] (In formula (200), each W independently represents CH or N, and at least one W is N; Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, Xa 2 , Ya2 and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent; g11, h11, and j11 each independently represent an integer of 0 to 6; At least one of g11, h11, and j11 is an integer of 1 or greater, If g11 is 2 or more, multiple Xa 1 may be the same or different, If h11 is 2 or more, multiple Ya 1 may be the same or different, j If 11 is 2 or more, there are multiple Za 1 may be the same or different, R 31 represents a hydrogen atom or a substituent, and four R 31 may be the same or different, However, if g11, h11, or j11 is 0, the corresponding Xa 2 , Ya 2 , Za 2 is not a hydrogen atom.)

[0042] [ka]

[0043] (In formula (210), formula (220) and formula (230), Ar 41 , Ar 42 , Ar 43 each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, R 21 , R 22 , R 23each independently represents a hydrogen atom or a substituent, X 21 , X 22 are each independently O, S, or N-Ar 44 represents Ar 44 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, n21, n22, and n23 each independently represent 1 or 2; n24 represents an integer from 1 to 4, If n24 is 2 or more, multiple R 21 may be the same or different.)

[0044] [ka]

[0045] (In formula (240), Ar 611 , Ar 612 each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R 611 , R 612 each independently represents a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent; n 611 , n 612 are each independently an integer of 0 to 4.

[0046]

[14] The organic electroluminescent device according to

[13] , wherein Y in the formula (1) is NR.

[0047]

[15] In the formula (20), Ar 22 , Ar23 , Ar 24 , Ar 27 , Ar 28 , Ar 29 , Ar 32 , Ar 33 and Ar 34 The organic electroluminescent device according to

[13] or

[14] , wherein at least one of the above is a structure represented by the following formula (21) or the following formula (22):

[0048] [ka]

[0049] (In formulas (21) and (22), Ar 36 ~Ar 39 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 8 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0050]

[16] In the formula (20), Ar 22 , Ar 23 and Ar 24 and Ar 27 , Ar 28 and Ar 29 and Ar 32 , Ar 33 and Ar 34 The organic electroluminescent device according to

[15] , wherein either one of the above is a structure represented by the formula (21) or the formula (22).

[0051]

[17] In the formula (20), Ar 22 , Ar 27 and Ar 32 The organic electroluminescent device according to

[16] , wherein the structure is represented by the formula (21) or the formula (22).

[0052]

[18] The organic electroluminescent device according to any one of

[15] to

[17] , wherein the structure represented by the formula (21) is a structure represented by the following formula (21-1), (21-2), (21-3), (21-4) or (21-5), and the structure represented by the formula (22) is a structure represented by the following formula (22-1), (22-2), (22-3) or (22-4).

[0053] [ka]

[0054]

[19] The organic electroluminescent device according to

[13] or

[14] , wherein at least two of the three Ws in the formula (200) are N.

[0055]

[20] The organic electroluminescent device according to

[19] , wherein all of W in the formula (200) are N.

[0056]

[21] Ar in the formula (210), the formula (220), and the formula (230) 41 , Ar 42 and Ar 43 is a group represented by any one of the following formulas (20-1) to (20-13):

[0057] [ka]

[0058] (In the above formula, * represents a bonding position, Ar 45 is an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group in which 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent are linked together.

[0059]

[22] An organic EL display device comprising the organic electroluminescent device according to any one of

[13] to

[21] .

[0060]

[23] An organic EL lighting device comprising the organic electroluminescent device according to any one of

[13] to

[21] . [Effects of the Invention]

[0061] The composition for forming a light-emitting layer and the organic electroluminescent device of the present invention can provide an organic electroluminescent device that exhibits excellent device characteristics, particularly a long driving life. Furthermore, the composition for forming a light-emitting layer and the organic electroluminescent device of the present invention can provide an organic electroluminescent device that exhibits excellent device characteristics and has particularly high luminous efficiency. Furthermore, the composition for forming a light-emitting layer and the organic electroluminescent device of the present invention can provide an organic electroluminescent device that exhibits excellent device characteristics and is particularly effective in reducing voltage. Furthermore, the composition for forming a light-emitting layer and the organic electroluminescent device of the present invention can provide an organic electroluminescent device that exhibits excellent device characteristics, is driven at a low voltage, has high luminous efficiency, and has a long driving life. [Brief explanation of the drawings]

[0062] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the structure of an organic electroluminescent device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0063] The following describes in detail embodiments of the composition for forming the light-emitting layer of an organic electroluminescent element of the present invention, the organic electroluminescent element, an organic EL display device including the organic electroluminescent element, and an organic EL lighting device including the organic electroluminescent element. The following description is one example (typical example) of the embodiment of the present invention, and the present invention is not limited to these contents as long as it does not deviate from the gist of the invention.

[0064] [Composition for forming a light-emitting layer of an organic electroluminescent element] The light-emitting layer of an organic electroluminescent device contains at least a material having light-emitting properties (light-emitting material), and preferably contains one or more host materials. The host material is usually a charge-transporting material, but a material with low charge-transporting properties may be blended to adjust the charge-transporting properties. The composition for forming a light-emitting layer of an organic electroluminescent device of the present invention (hereinafter referred to as "the composition for forming a light-emitting layer of the present invention") contains a polycyclic heterocyclic compound represented by the following formula (1) as a light-emitting material, and contains at least one of the following compounds I, II, III, and IV as a host material, and further contains an organic solvent.

[0065] [ka]

[0066] (In formula (1), ring a, ring b, and ring c each independently represent an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent; Y is independently O, NR, or S; R represents an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is a ring selected from the group consisting of the ring a, the ring b, and the ring c, and a carbon atom adjacent to the atom bonded to the Y, and -O-, -S-, -C(-R a ) may be linked by a double or single bond, R a is a hydrogen atom or an alkyl group, the adjacent carbon atom is not a carbon atom constituting the central fused two-ring structure of formula (1) containing B and the Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Compound I: a compound represented by the following formula (20): Compound II: a compound represented by the following formula (200): Compound III: one or more compounds selected from the group consisting of a compound represented by the following formula (210), a compound represented by the following formula (220), and a compound represented by the following formula (230): Compound IV: A compound represented by the following formula (240):

[0067] [ka]

[0068] (In formula (20), Ar 21 ~Ar 35 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0069] [ka]

[0070] (In formula (200), each W independently represents CH or N, and at least one W is N; Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, Xa 2 , Ya 2 and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent; g11, h11, and j11 each independently represent an integer of 0 to 6; At least one of g11, h11, and j11 is an integer of 1 or greater, If g11 is 2 or more, multiple Xa 1 may be the same or different, If h11 is 2 or more, multiple Ya1 may be the same or different, j If 11 is 2 or more, there are multiple Za 1 may be the same or different, R 31 represents a hydrogen atom or a substituent, and four R 31 may be the same or different, However, if g11, h11, or j11 is 0, the corresponding Xa 2 , Ya 2 , Za 2 is not a hydrogen atom.)

[0071] [ka]

[0072] (In formula (210), formula (220) and formula (230), Ar 41 , Ar 42 , Ar 43 each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, R 21 , R 22 , R 23 each independently represents a hydrogen atom or a substituent, X 21 , X 22 are each independently O, S, or N-Ar 44 represents Ar 44 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, n21, n22, and n23 each independently represent 1 or 2; n24 represents an integer from 1 to 4, If n24 is 2 or more, multiple R 21 may be the same or different.)

[0073] [ka]

[0074] (In formula (240), Ar 611 , Ar 612 each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R 611 , R 612 each independently represents a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent; n 611 , n 612 are each independently an integer of 0 to 4.

[0075] In the light-emitting layer formed using the composition for forming a light-emitting layer of the present invention, the polycyclic heterocyclic compound represented by formula (1) functions as a light-emitting material, and Compound I, Compound II, Compound III, and Compound IV function as host materials. In this specification, at least one of Compound I, Compound II, Compound III, and Compound IV may be referred to as "Compounds I to IV" or "first host material." In addition, the composition for forming a light-emitting layer of the present invention may be referred to as "first composition."

[0076] [Reasons why the present invention is effective] <Compound I> In an organic electroluminescent device using the composition for forming an emission layer of the present invention, the emission layer contains, as a host material, Compound I represented by Formula (20), which is a compound having a structure in which multiple benzene rings are linked. This appropriately adjusts the charge transport properties within the emission layer, suppresses deterioration of the polycyclic heterocyclic compound represented by Formula (1), which is the emission material, and is believed to extend the device's operating life. In particular, Compound I has the effect of suppressing charge transport properties. When an anthracene-based host material with high electron transport properties represented by Formula (30), which will be described later, is used as the second host material, it is believed that the electron transport properties within the emission layer are suppressed to prevent the emission material from being excessively reduced and degraded, thereby extending the device's operating life.

[0077] <Compound II> In an organic electroluminescent device using the composition for forming an emission layer of the present invention, the emission layer contains, as a host material, Compound II represented by Formula (200), which is a compound having a structure in which a nitrogen-containing six-membered heteroaromatic ring and a benzene ring are linked. This appropriately adjusts the charge transport properties within the emission layer, lowering the voltage required, improving the emission efficiency, and suppressing deterioration of the polycyclic heterocyclic compound represented by Formula (1), which is the emission material. This is believed to result in a longer operating life. In particular, when Compound II has a triazine structure in which all Ws in Formula (200) are nitrogen atoms, the LUMO is relatively deep, providing electron transport properties as well as moderate electron trapping properties. This prevents excessive electron supply to the emission material, improving the durability of the emission material and, as a result, extending the operating life of the organic electroluminescent device. In particular, it is believed that electrons can enter the vacant p orbital of the boron atom in the polycyclic heterocyclic compound represented by Formula (1), which is the emission material, and thereby suppressing deterioration of the emission material. In addition, Compound II has a high electron-transporting property because it has a six-membered aromatic ring with a nitrogen atom at the center. Therefore, when Compound II is used as the first host, it is thought that the voltage can be further reduced, the luminous efficiency can be improved, and the operating life can be extended by further using a host material with high hole-transporting property.

[0078] <Compound III> The compound III, which is any one of the compounds represented by the formula (210), the compounds represented by the formula (220), and the compounds represented by the formula (230) contained in the composition for forming a light-emitting layer of the present invention and the light-emitting layer of the organic electroluminescent device formed from the composition for forming a light-emitting layer, always has an aromatic ring bonded to the 3-position of the benzene ring to which two or three phenylene groups bonded to the nitrogen atom of the amine are linked. 41 , Ar 42 , Ar 43 or a structure represented by a benzene ring. With such a structure, the number of benzene rings bonded to the nitrogen atom of the amine at the para position becomes 2 or 3, and the HOMO is distributed appropriately, improving hole transportability and lowering voltage. Furthermore, the balance between electrons and holes in the light-emitting layer improves, improving luminous efficiency, improving durability, and extending the operating life of the device. Furthermore, Ar 41 , Ar 42 , Ar 43 It is believed that the presence of such a structure will lead to lower voltage, higher luminous efficiency, and longer life, as well as improved solubility in organic solvents of the compound. 41 , Ar 42 , Ar 43 It is believed that durability can be improved by appropriately selecting the structure. Furthermore, in cases where the light-emitting material directly accepts holes injected from the anode layer and becomes oxidized, which could lead to degradation, Compound III possesses hole-transporting properties and readily accepts holes from the cathode layer, making the light-emitting material less susceptible to direct oxidation and suppressing degradation. Conversely, in cases where the light-emitting material directly accepts electrons injected from the cathode and becomes reduced, which could lead to degradation, it is believed that Compound III rapidly transports holes to the light-emitting material, allowing the light-emitting material to recombine and emit light, thereby suppressing degradation. Because Compound III is a hole-transporting host with a triphenylamine structure, using Compound III as the first host and a highly electron-transporting material as the second host material could reduce voltage, improve luminous efficiency, and provide an organic electroluminescent device with a long operating life.

[0079] <Compound IV> The light-emitting layer-forming composition of the present invention and the organic electroluminescent device formed therefrom contain, as a host material in the light-emitting layer, compound IV represented by formula (240), which is a compound containing a structure having two carbazole rings. This appropriately adjusts the charge transport properties within the light-emitting layer, lowering the voltage, improving the luminous efficiency, and suppressing the deterioration of the polycyclic heterocyclic compound represented by formula (1), which is the light-emitting material, thereby extending the operating life. In cases where the light-emitting material would directly receive holes injected from the anode layer and become oxidized, and this could lead to degradation, compound IV has hole-transport properties and readily accepts holes from the cathode layer, thereby preventing the light-emitting material from being directly oxidized and suppressing degradation. Conversely, in cases where the light-emitting material would easily receive electrons injected from the cathode and become reduced, this is likely due to the rapid transport of holes from compound IV to the light-emitting material, which then recombines and emits light, thereby suppressing degradation. Furthermore, because Compound IV has two highly planar carbazole ring structures, it is believed that the hole transport property to the light-emitting material, which is a highly planar polycyclic heterocyclic compound represented by Formula (1), is improved. At this time, electrons are rapidly supplied to the light-emitting material, which is believed to rapidly recombine and emit light, and to suppress deterioration of the light-emitting material. Therefore, by using Compound IV as the first host and a material with high electron transport properties as the second host material, it is believed that an organic electroluminescent device can be obtained that operates at a lower voltage, has improved luminous efficiency, and has a long operating life.

[0080] [Polycyclic heterocyclic compounds] The composition for forming a light-emitting layer of the present invention contains a polycyclic heterocyclic compound represented by the formula (1). The polycyclic heterocyclic compound represented by the formula (1) is preferably a light-emitting material.

[0081] <Ring a, ring b and ring c> Ring a, ring b, and ring c are each independently an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent.

[0082] The substituent that the aromatic hydrocarbon ring or aromatic heterocycle may have is preferably a group selected from the following substituent group α.

[0083] Furthermore, the aromatic hydrocarbon ring or aromatic heterocycle preferably has a 5- or 6-membered ring that shares a bond with the central fused bicyclic structure in formula (1) composed of B and Y (hereinafter, sometimes referred to as the "central fused bicyclic structure"), and more preferably has a 6-membered ring that shares a bond with the central fused bicyclic structure.

[0084] (Formula (1')) Here, the "central fused two-ring structure" refers to a structure in which two saturated hydrocarbon rings, each containing B and two Ys, are fused together, as shown in the center of formula (1). Specifically, it is a structure in which rings d and e in the following formula (1') are fused together.

[0085] [ka]

[0086] (In formula (1'), rings a to c and Y have the same meanings as in formula (1).)

[0087] Furthermore, the case where there is a "six-membered ring sharing a bond with the central fused two-ring structure" means, for example, when ring a is a benzene ring (six-membered ring). Yoshi The phrase "an aromatic hydrocarbon ring or an aromatic heterocycle has this six-membered ring" means that ring a is formed by this six-membered ring alone, or that ring a is formed by condensing another ring or the like to this six-membered ring so as to include this six-membered ring. The same explanation applies to "ring b," "ring c," and "five-membered ring."

[0088] (aromatic hydrocarbon ring) Examples of the aromatic hydrocarbon ring in ring a, ring b, and ring c in formula (1) include aromatic hydrocarbon rings having 6 to 30 carbon atoms, preferably aromatic hydrocarbon rings having 6 to 16 carbon atoms, more preferably aromatic hydrocarbon rings having 6 to 12 carbon atoms, and particularly preferably aromatic hydrocarbon rings having 6 to 10 carbon atoms.

[0089] Specific examples of aromatic hydrocarbon rings include a monocyclic benzene ring, a bicyclic ...

[0090] (aromatic heterocycle) Examples of the aromatic heterocycle in ring a, ring b, and ring c in formula (1) include aromatic heterocycles having 2 to 30 carbon atoms, preferably aromatic heterocycles having 2 to 25 carbon atoms, more preferably aromatic heterocycles having 2 to 20 carbon atoms, still more preferably aromatic heterocycles having 2 to 15 carbon atoms, and particularly preferably aromatic heterocycles having 2 to 10 carbon atoms. Preferred examples of the aromatic heterocycle include heterocycles containing, as ring-constituting atoms other than carbon atoms, 1 to 5 heteroatoms selected from oxygen atoms, sulfur atoms, and nitrogen atoms.

[0091] Specific examples of the aromatic heterocycle include a pyrrole ring, an oxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, a thiadiazole ring, a triazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a naphthyridine ring, a carbazole ring, an acridine ring, a phenoxazine ring, a phenothiazine ring, a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, and a dibenzothiophene ring.

[0092] (substituent group α) Substituent group α consists of a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted diheteroarylamino group, a substituted or unsubstituted arylheteroarylamino group (an amino group having an aromatic hydrocarbon group and an aromatic heterocyclic group), a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, and a halogen atom.

[0093] The substituents that the group selected from the substituent group α other than halogen atoms may have are the following substituent group β.

[0094] Examples of the aromatic hydrocarbon group or aryl structure in Substituent Group α include aromatic hydrocarbon ring groups in Rings a, b, and c. Specific and preferred structures of the aromatic hydrocarbon rings are also similar. A benzene ring is preferred as the aromatic hydrocarbon group in Substituent Group α.

[0095] Examples of the aromatic heterocyclic group or heteroaryl structure in the substituent group α include aromatic heterocyclic groups in rings a, b, and c. Specific and preferred structures of the aromatic heterocyclic ring are also similar. The aromatic heterocyclic group in the substituent group α is preferably a triazine ring, a benzimidazole ring, a benzothiazole ring, a pyrimido[5,4-d]pyrimidine ring, or a benzo[1,2-d:4,5-d]diimidazole ring.

[0096] The alkyl group in Substituent group α may be either linear or branched, and examples thereof include linear alkyl groups having 1 to 24 carbon atoms or branched alkyl groups having 3 to 24 carbon atoms. As the alkyl group, linear alkyl groups having 1 to 18 carbon atoms or branched alkyl groups having 3 to 18 carbon atoms are preferred, linear alkyl groups having 1 to 12 carbon atoms or branched alkyl groups having 3 to 12 carbon atoms are more preferred, linear alkyl groups having 1 to 6 carbon atoms or branched alkyl groups having 3 to 6 carbon atoms are even more preferred, and linear alkyl groups having 1 to 4 carbon atoms or branched alkyl groups having 3 to 4 carbon atoms are particularly preferred.

[0097] Specific examples of the alkyl group 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 isopentyl group, a neopentyl group, a tert-pentyl group, an n-hexyl group, a 1-methylpentyl group, a 4-methyl-2-pentyl group, a 3,3-dimethylbutyl group, a 2-ethylbutyl group, an n-heptyl group, a 1-methylhexyl group, an n-octyl group, and a tert-octyl group. A part of H in the alkyl group in the substituent group α may be replaced with F.

[0098] Examples of the alkoxy group in Substituent group α include linear alkoxy groups having 1 to 24 carbon atoms or branched alkoxy groups having 3 to 24 carbon atoms. The alkoxy group is preferably a linear alkoxy group having 1 to 18 carbon atoms or a branched alkoxy group having 3 to 18 carbon atoms, more preferably a linear alkoxy group having 1 to 12 carbon atoms or a branched alkoxy group having 3 to 12 carbon atoms, still more preferably a linear alkoxy group having 1 to 6 carbon atoms or a branched alkoxy group having 3 to 6 carbon atoms, and particularly preferably a linear alkoxy group having 1 to 4 carbon atoms or a branched alkoxy group having 3 to 4 carbon atoms.

[0099] Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, and an octyloxy group.

[0100] Examples of the halogen atom in the substituent group α include a fluorine atom, a chlorine atom, and a bromine atom. As the halogen atom, a fluorine atom and a chlorine atom are preferred, and among these, a fluorine atom is more preferred.

[0101] (substituent group β) Substituent group β consists of an aromatic hydrocarbon group which may be substituted with an aralkyl group, an aromatic heterocyclic group which may be substituted with an aralkyl group, an alkyl group, and a halogen atom. Examples of the aromatic hydrocarbon group, aromatic heterocyclic group, alkyl group, aralkyl group, and halogen atom in substituent group β include those similar to those in substituent group α, and preferred structures are also similar to those in substituent group α. From the viewpoint of improving stability and solubility, the substituent group β is preferably an aromatic hydrocarbon group which may be substituted with an aralkyl group, an aromatic heterocyclic group which may be substituted with an aralkyl group, an alkyl group, or an aralkyl group. In the substituent group β, the aralkyl group, the aralkyl group which may substitute an aromatic hydrocarbon group, and the aralkyl group which may substitute an aromatic heterocyclic group are preferably aralkyl groups having 7 to 30 carbon atoms, and preferably have a structure in which a benzene ring is bonded to an alkyl group.

[0102] (Y) In formula (1), Y is O, NR, or S.

[0103] (R) R is an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group which may have a substituent. In addition, the two Ys in formula (1) may be the same or different, but are preferably the same. The two Ys are preferably NR.

[0104] Examples of the aromatic hydrocarbon ring group and aromatic heterocyclic group for R in formula (1) include the aromatic hydrocarbon ring group and aromatic heterocyclic group in ring a, ring b, and ring c in formula (1). As the aromatic hydrocarbon ring group and aromatic heterocyclic group, particularly preferred are aromatic hydrocarbon ring groups having 6 to 10 carbon atoms (e.g., phenyl group, naphthyl group, etc.) and aromatic heterocyclic groups having 2 to 15 carbon atoms (e.g., carbazolyl group, etc.). When R in formula (1) is an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent, it is the same as the aromatic hydrocarbon ring group which may have a substituent or the aromatic heterocyclic group which may have a substituent in rings a, b, and c of formula (1). The specific structure and preferred structure are also the same as the aromatic hydrocarbon ring group which may have a substituent or the aromatic heterocyclic group which may have a substituent in rings a, b, and c of formula (1). When R in formula (1) is an aromatic hydrocarbon ring group which may have a substituent or an aromatic heterocyclic group which may have a substituent, formula (1) is represented by the following formula (21). The formula (1) is preferably a structure represented by the following formula (21).

[0105] Examples of the alkyl group in R in formula (1) include the alkyl groups in the above-mentioned substituent group α. As the alkyl group, alkyl groups having 1 to 4 carbon atoms (such as methyl and ethyl groups) are particularly preferred.

[0106] R is a ring selected from the group consisting of the ring a, the ring b, and the ring c, and a carbon atom adjacent to the atom bonded to the Y, and -O-, -S-, -C(-R a ) may be bonded by a 2- or single bond, where R a is a hydrogen atom or an alkyl group.

[0107] R a Examples of the alkyl group in the above include the alkyl groups in the above-mentioned Substituent Group α. As the alkyl group, an alkyl group having 1 to 4 carbon atoms is particularly preferred, such as a methyl group or an ethyl group.

[0108] The adjacent carbon atoms are not carbon atoms that constitute the central fused two-ring structure. Furthermore, at least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium.

[0109] (Formula (21)) [ka]

[0110] (In formula (21), ring a, ring b, ring c, ring d, and ring e are the same as those in formula (1'), ring f and ring g are the same as ring a, ring b, or ring c in formula (1'), and each independently represents an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent; Ring f is a ring in which the carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b is bonded to a carbon atom bonded to -O-, -S-, -C(-R a ) may be linked by a double or single bond, Ring g is a ring in which the carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c is bonded to a carbon atom bonded to N, and -O-, -S-, -C(-R a ) may be linked by a double or single bond, R a is a hydrogen atom or an alkyl group, However, the adjacent carbon atom is not a carbon atom constituting the ring d and the ring e containing B and N, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium.

[0111] As the aromatic hydrocarbon ring group and aromatic heterocyclic group in ring f and ring g, aromatic hydrocarbon ring groups having 6 to 10 carbon atoms (such as a phenyl group or a naphthyl group) and aromatic heterocyclic groups having 2 to 15 carbon atoms (such as a carbazolyl group) are particularly preferred.

[0112] The substituents that rings f and g, which are aromatic hydrocarbon rings or aromatic heterocycles, may have are the same as those for rings a, b and c, and are preferably groups selected from the aforementioned substituent group α.

[0113] (Formula (22)) The formula (21) is preferably a structure represented by the following formula (22).

[0114] [ka]

[0115] In formula (22), the rings a, b, c, d, and e in formula (21) all have a benzene ring structure, and the rings a, b, c, d, and e may have a substituent; Ring f is a ring in which the carbon atom adjacent to the atom bonded to N in at least one of ring a and ring b is bonded to a carbon atom bonded to -O-, -S-, -C(-R a ) may be linked by a double or single bond, Ring g is a ring in which the carbon atom adjacent to the atom bonded to N in at least one of ring a and ring c is bonded to a carbon atom bonded to N, and -O-, -S-, -C(-R a ) may be linked by a double or single bond, R a is a hydrogen atom or an alkyl group, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (22) may be substituted with a halogen atom or deuterium.

[0116] The substituents which the ring a, the ring b, the ring c, the ring d, and the ring e may have are the same as the substituents which the ring a, the ring b, the ring c, the ring d, and the ring e in the formula (21) may have, and the specific structures and preferred structures are also the same.

[0117] The polycyclic heterocyclic compound represented by the formula (22) is also preferably a polycyclic heterocyclic compound TD1 represented by the formula (71) described below, or a polycyclic heterocyclic compound TD2 represented by the formula (81) described below. The polycyclic heterocyclic compound represented by the formula (1) is also preferably a polycyclic heterocyclic compound TD1 represented by the formula (71) described below, or a polycyclic heterocyclic compound TD2 represented by the formula (81) described below.

[0118] <Specific examples of polycyclic heterocyclic compounds represented by formula (1)> The polycyclic heterocyclic compound represented by formula (1) is not particularly limited, but examples thereof include the following compounds.

[0119] [ka]

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] <Polycyclic heterocyclic compound TD1> The polycyclic heterocyclic compound represented by formula (1) is also preferably a polycyclic heterocyclic compound represented by the following formula (71): In the present invention, the polycyclic heterocyclic compound represented by the following formula (71) may be referred to as polycyclic heterocyclic compound TD1.

[0124] [ka]

[0125] (In equation (71), A1 to A7 each independently represent a hydrogen atom, a fluorine atom, an alkyl group which may have a substituent, a heteroaryl group which is an electron-accepting substituent, a nitro group, or a cyano group, or an aromatic hydrocarbon group or aromatic heterocyclic group which has, as a substituent, a heteroaryl group which is an electron-accepting substituent, a nitro group, or a cyano group; R 71 ~R 78 each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, an electron-donating substituent, or a combination thereof; A dotted line represents a single bond or no bond.)

[0126] In the polycyclic heterocyclic compound represented by formula (71), the electron cloud of the LUMO is localized at the position where A1 to A7 are bonded to the phenyl group. Therefore, by making at least one selected from A1 to A7 an electron-accepting substituent, the electron cloud expands, the energy level of the LUMO is stabilized, and the energy difference between the HOMO and LUMO is reduced. As a result, the polycyclic heterocyclic compound represented by formula (71) can obtain an emission spectrum with a longer wavelength.

[0127] (A1~A7) A1 to A7 each independently represent a hydrogen atom, a fluorine atom, an alkyl group which may have a substituent, a heteroaryl group which is an electron-accepting substituent, a nitro group, or a cyano group, or an aromatic hydrocarbon group or aromatic heterocyclic group which has, as a substituent, a heteroaryl group which is an electron-accepting substituent, a nitro group, or a cyano group. Preferably, at least one selected from A1 to A7 is an electron-accepting substituent, and A1 to A7 other than the electron-accepting substituent are each independently a hydrogen atom, a fluorine atom, or an alkyl group which may have a substituent. It is preferable that at least one selected from A1 to A7 is an electron-accepting substituent, since the emission wavelength can be adjusted by the number and type of A1 to A7. An electron-accepting substituent is a substituent of a chemical structure that is chemically bonded to an adjacent chemical structure and tends to withdraw electrons from the adjacent chemical structure, resulting in an excess of electrons.

[0128] Examples of the electron-accepting substituent include a heteroaryl group, a nitro group, a cyano group, an aromatic hydrocarbon group or an aromatic heterocyclic group having the above-mentioned substituent, etc. Among these, a heteroaryl group is preferred from the viewpoint of increasing the wavelength.

[0129] The heteroaryl group is an aryl group having at least one atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of the heteroaryl group include groups having polycyclic aromatic heteroaryls having 1 to 4 rings containing carbon atoms, nitrogen atoms, oxygen atoms, sulfur atoms, etc.

[0130] Furthermore, the electron-accepting substituent is preferably a group whose absolute value (hereinafter sometimes referred to as "absolute value α") of the sum of the HOMO energy level and the LUMO energy level divided by 2 is 3 eV or more. When the absolute value α is 3 eV or more, the electron-accepting property of the substituent is empirically improved.

[0131] The absolute value α of the electron-accepting substituent is preferably 3.1 eV or more, more preferably 3.5 eV or more, and even more preferably 4.0 eV or more. There is no particular upper limit for the absolute value α of the electron-accepting substituent, but it is generally 7.0 eV or less.

[0132] The HOMO and LUMO energy levels of an electron-accepting substituent are the HOMO and LUMO molecular orbital energy levels obtained as follows: In formula (71), the single bond between the electron-accepting substituent and the adjacent phenyl group is deleted, and a hydrogen atom is added. The molecular structure of the resulting electron-accepting substituent can then be optimized using density functional calculations in the molecular orbital calculation software Gaussian 16, with the functional B3LYP and basis set 6-31G(d).

[0133] The electron-accepting substituent is preferably a group represented by the following formula (5), a group represented by the following formula (6), a group represented by the following formula (7), or a group represented by the following formula (8).

[0134] [ka]

[0135] In formulas (5) to (8), R 732 ~R 745 are each independently a hydrogen atom, an alkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

[0136] Examples of the alkyl group include linear, branched, or cyclic alkyl groups having 1 or more and 24 or less carbon atoms, such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, and dodecyl group.

[0137] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 or more and 60 or less carbon atoms. Specific examples include monovalent groups of 6-membered monocyclic rings or 2- to 5-condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring.

[0138] R 732 ~R 745 The substituent that may be possessed by may be selected from the substituent group Z2 described below.

[0139] Specific examples of the above formulas (5) to (8) include the following formulas (2-1) to (2-7).

[0140] [ka]

[0141] In the above formulas (2-1) to (2-7), the absolute value α obtained by calculation is as follows:

[0142] Group represented by formula (2-4): 4.35 eV Group represented by formula (2-6): 4.18 eV Group represented by formula (2-3): 4.17 eV Group represented by formula (2-7): 4.12 eV Group represented by formula (2-5): 4.10 eV Group represented by formula (2-2): 3.73 eV Group represented by formula (2-1): 3.13 eV

[0143] That is, when the same number of groups represented by the above formula (2-4), the above formula (2-6), the above formula (2-3), the above formula (2-7), the above formula (2-5), the above formula (2-2), or the above formula (2-1) are introduced into the same positions of A1 to A7 in the above formula (71), the effect of lengthening the emission wavelength can be obtained in the order of the above formula (2-4) > the above formula (2-6) > the above formula (2-3) > the above formula (2-7) > the above formula (2-5) > the above formula (2-2) > the above formula (2-1).

[0144] Among these, the electron-accepting substituent is preferably a group represented by the above formula (5) from the viewpoint of increasing wavelength and ease of production by organic synthesis.

[0145] The group represented by the formula (5) has a relatively large absolute value α and little steric hindrance with the adjacent phenyl group in the formula (71). Therefore, there is little twisting of the π plane between the adjacent phenyl group and the group represented by the formula (5), and the effect of extending the wavelength of the large emission can be obtained. In addition, the group represented by the formula (5) can be produced relatively easily in organic synthesis, and even when it is desired to improve solubility in a solvent, R 732 , R 733 It is relatively easy to introduce a long-chain alkyl group (for example, 4 or more carbon atoms) into the

[0146] R 732 , R 733 In addition, an alkyl group which may have a substituent is preferable because it can easily obtain a long wavelength emission wavelength by increasing the absolute value α, and also from the viewpoint of solubility in a solvent. 732 and R 733It is more preferable that at least one selected from the above is a phenyl group having a tert-butyl group.

[0147] In addition, from the viewpoint of solubility in solvents and emission wavelength Narrow From the viewpoint of half-value width, R 732 and R 733 and the other is an optionally substituted aromatic hydrocarbon group. The substituent that the aromatic hydrocarbon group may have can be selected from the substituent group Z2.

[0148] Furthermore, A1 to A7 other than the electron-accepting substituents are each independently a hydrogen atom, a fluorine atom, or an alkyl group which may have a substituent.

[0149] Examples of the alkyl group include linear, branched, or cyclic alkyl groups having 1 or more and 24 or less carbon atoms, such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, and dodecyl group.

[0150] The substituents that A1 to A7 may have can be selected from the substituent group Z2 described below.

[0151] When A1 to A7 are each independently a fluorine atom or an alkyl group which may have a substituent, the emission wavelength becomes slightly shorter or longer than when A1 to A7 are each a hydrogen atom due to their electron-accepting properties. Therefore, it is preferable to select the substituent according to the target wavelength.

[0152] When a wet film-forming method is used, A1 to A7 are preferably each independently a long-chain alkyl group for the purpose of improving solubility in a solvent.

[0153] The degree of localization of the LUMO electron cloud varies among A1 to A7, and varies depending on the position. Therefore, the positions where the electron-accepting substituents have the greatest effect on wavelength increase are A4 > A1 = A7 > A3 = A5 > A2 = A6. That is, the effect of electron-accepting substituents on wavelength increase is most pronounced in A4.

[0154] Therefore, at least one selected from A1, A4, and A7 is preferably an electron-accepting substituent, and more preferably a group represented by formula (5).

[0155] When both A1 and A7 are electron-accepting substituents, the effect of lengthening the wavelength is approximately the same as when only A4 is the same electron-accepting substituent. In addition, it is preferable that two or more selected from A1 to A7 are electron accepting substituents, as this will result in a longer wavelength, and it is preferable that two or more selected from A1 to A7 are electron accepting substituents and at least one A4 is an electron accepting substituent, as this will result in an even longer wavelength.

[0156] In formula (71), it is preferable that the single bonds connecting A1 to A7 to the adjacent phenyl groups are twisted so that the π-planes of the adjacent phenyl groups and the main aromatic hydrocarbon groups of the electron-accepting substituents are not twisted. This is because such twisting makes it difficult for the adjacent phenyl groups and the electron-accepting substituents to smoothly exchange charges, making it difficult to shift the emission wavelength of formula (71) to a longer wavelength.

[0157] (R 71 ~R 78 ) R 71 ~R 78 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, an electron-donating substituent, or a combination thereof.

[0158] Examples of the alkyl group include linear, branched, or cyclic alkyl groups having 1 or more and 24 or less carbon atoms, such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, and dodecyl group.

[0159] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 or more and 60 or less carbon atoms. Specific examples include monovalent groups of 6-membered monocyclic rings or 2- to 5-condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring.

[0160] The aromatic heterocyclic group is preferably an aromatic heterocyclic group having 3 to 60 carbon atoms. Specific examples thereof include monovalent groups of 5- or 6-membered rings, such as a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, and an azulene ring.

[0161] R 71 ~R 78 The substituent that may be possessed by may be selected from the substituent group Z2 described below.

[0162] Also, R 71 ~R 78From the viewpoint of increasing the wavelength, it is preferable that at least one selected from the following be an electron donating substituent. The electron-donating substituent is a substituent of a chemical structure that is chemically bonded to an adjacent chemical structure and thus tends to become electron deficient by donating electrons from the adjacent chemical structure.

[0163] In the polycyclic heterocyclic compound represented by the formula (71), R 71 ~R 78 The electron cloud of the HOMO is localized and gathered at R 71 ~R 78 By using at least one selected from the following as an electron-donating substituent, the electron cloud of the HOMO tends to spread outward, the energy level of the HOMO becomes unstable, and the energy difference between the HOMO and the LUMO becomes smaller. As a result, the polycyclic heterocyclic compound represented by the formula (71) can obtain an emission spectrum with a longer wavelength.

[0164] The electron-donating substituent is preferably a group having an absolute value α of less than 3 eV. When the absolute value α is less than 3 eV, the electron-donating property of the substituent is empirically improved.

[0165] The absolute value α of the electron-donating substituent is more preferably less than 2.97 eV, even more preferably less than 2.8 eV, and particularly preferably less than 2.6 eV, from the viewpoint of increasing the wavelength. Although there is no particular lower limit for the absolute value α of the electron-donating substituent, it is generally 1 eV or more.

[0166] The HOMO and LUMO energy levels of an electron-donating substituent are the HOMO and LUMO molecular orbital energy levels obtained as follows: In formula (71), the single bond between the electron-donating substituent and the adjacent phenyl group is deleted, and a hydrogen atom is added. The molecular structure of the resulting electron-donating substituent can then be optimized using density functional theory in the molecular orbital calculation software Gaussian 16, with the functional B3LYP and basis set 6-31G(d).

[0167] The electron-donating substituent is preferably a group represented by the following formula (2), a group represented by the following formula (3), or a group represented by the following formula (4).

[0168] [ka]

[0169] In formulas (2) to (4), R 709 ~R 731 are each independently an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a hydrogen atom.

[0170] Examples of the alkyl group include linear, branched, or cyclic alkyl groups having 1 or more and 24 or less carbon atoms, such as a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, and dodecyl group.

[0171] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 or more and 60 or less carbon atoms. Specific examples include monovalent groups of 6-membered monocyclic rings or 2- to 5-condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring.

[0172] R 709 ~R 731 The substituent that may be possessed by may be selected from the substituent group Z2 described below.

[0173] Specific examples of the above formulas (2) to (4) include the following formulas (4-1) to (4-3).

[0174] [ka]

[0175] In the above formulas (4-1) to (4-3), the absolute value α obtained by calculation is as follows:

[0176] Group represented by formula (4-3): 2.96 eV Group represented by formula (4-2): 2.91 eV Group represented by formula (4-1): 2.46 eV

[0177] That is, R in the above formula (71) 71 ~R 78 When the same number of groups represented by the above formula (4-3), the above formula (4-2), or the above formula (4-1) are introduced into the same positions among these, the effect of shifting the emission wavelength to longer wavelength can be obtained in the order of the above formula (4-1) > the above formula (4-2) > the above formula (4-3). Also, R 71 ~R 78 It is preferable that two or more selected from the above be electron donating substituents, since this will result in a longer wavelength.

[0178] Among these, the electron donor substituent is preferably a group represented by the above formula (2) from the viewpoint of a balance between longer wavelength, ease of production by organic synthesis, and structural stability.

[0179] The group represented by the above formula (2) has a relatively small absolute value α, and can achieve the effect of lengthening the emission wavelength. In addition, the group represented by the above formula (2) can be produced relatively easily in organic synthesis, and even when it is desired to improve solubility in a solvent, R 709 ~R 716 It is relatively easy to introduce a long-chain alkyl group into the

[0180] R 709 ~R 716 From the viewpoints of solubility in a solvent and ease of synthesis, at least one selected from the above is preferably a tert-butyl group.

[0181] In addition, R 71 ~R 78are each independently an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a combination thereof, R 71 ~R 78 The emission wavelength becomes slightly shorter or longer than when is a hydrogen atom, so it is preferable to select the substituent in accordance with the desired wavelength.

[0182] In addition, when a wet film formation method is used, R 71 ~R 78 is preferably each independently a long-chain alkyl group for the purpose of improving solubility in a solvent.

[0183] R 71 ~R 78 The degree to which the HOMO electron cloud is localized is not uniform, and varies depending on the position. 71 ~R 78 Among these, the position where the effect of the electron donor substituent on wavelength increase is most pronounced is R 74 =R 75 >R 71 =R 78 >R 73 =R 76 >R 72 =R 77 That is, R 74 and R 75 The effect of electron donor substituents on the wavelength increase is most pronounced in the .GAMMA..

[0184] <dotted line> In formula (71), the dotted line may represent a single bond or no bond. The dotted line is preferably a single bond. When the dotted line is a single bond, the electron cloud expands and the emission wavelength becomes slightly longer. In addition, when the dotted line is a single bond, the electron-accepting substituents in A1 to A7 and R 71 ~R 78 This makes it easy to introduce electron-donating substituents into the

[0185] <Symmetry of Polycyclic Heterocyclic Compounds> The polycyclic heterocyclic compound of the formula (71) is preferably asymmetric because it has the effect of narrowing the half-width of the emission wavelength. It is believed that the reduced symmetry of the asymmetric structure makes it difficult for the polycyclic heterocyclic compounds to associate with each other, reducing the interaction between the polycyclic heterocyclic compounds, thereby narrowing the half-width of the emission spectrum.

[0186] The polycyclic heterocyclic compound being asymmetric means that, when the line connecting the bond axis of B and A4 in the formula (71) is taken as the rotation axis, the compound does not have the same structure when rotated 180° around the rotation axis, or does not have mirror symmetry with respect to a plane perpendicular to the plane formed by the polycyclic heterocycles of the compound of the formula (71) and including the bond axis.

[0187] Specifically, a structure that satisfies at least one of the following (i) and (ii) is preferred. (i) A1 to A7, R 71 ~R 78 However, when rotated 180° about the bond axis, the structure does not become the same. (ii) A1 and A7 are different, A2 and A6 are different, A3 and A5 are different, R 71 and R 78 are different or R 72 and R 77 are different or R 73 and R 76 are different, or R 74 and R 75 But the structure is different.

[0188] <Substituent group Z2> Examples of the substituent group Z2 include the following groups. A linear, branched, or cyclic alkyl group having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, carbon atoms; for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, a dodecyl group, etc. an alkenyl group having typically 2 or more carbon atoms and typically 24 or less, preferably 12 or less carbon atoms; for example, a vinyl group, an alkynyl group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less carbon atoms; for example, an ethynyl group, etc. an alkoxy group having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms; for example, a methoxy group, an ethoxy group, etc. an aryloxy group or heteroaryloxy group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a phenoxy group, a naphthoxy group, a pyridyloxy group, etc. an alkoxycarbonyl group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms; for example, a methoxycarbonyl group, an ethoxycarbonyl group, etc. a dialkylamino group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less carbon atoms; for example, a dimethylamino group, a diethylamino group, etc. a diarylamino group having usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a diphenylamino group, a ditolylamino group, an N-carbazolyl group, etc. an arylalkylamino group having usually 7 or more carbon atoms and usually 36 or less, preferably 24 or less carbon atoms; for example, a phenylmethylamino group, etc. An acyl group having usually 2 or more carbon atoms, usually 24 or less, preferably 12 or less carbon atoms; for example, an acetyl group, a benzoyl group, etc. Halogen atoms; for example, fluorine atoms, chlorine atoms, etc. a haloalkyl group having usually 1 or more, usually 12 or less, preferably 6 or less carbon atoms; for example, a trifluoromethyl group, etc. an alkylthio group having usually 1 or more and usually 24 or less, preferably 12 or less carbon atoms; for example, a methylthio group, an ethylthio group, etc. an arylthio group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a phenylthio group, a naphthylthio group, a pyridylthio group, etc. A silyl group having usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a trimethylsilyl group, a triphenylsilyl group, etc. A siloxy group having a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less; for example, a trimethylsiloxy group, a triphenylsiloxy group, etc. An aromatic hydrocarbon group having a carbon number of usually 6 or more and usually 36 or less, preferably 24 or less; for example, a phenyl group, a naphthyl group, etc. Aromatic heterocyclic groups having usually 3 or more, preferably 4 or more, and usually 36 or less, preferably 24 or less carbon atoms; for example, a thienyl group, a pyridyl group, etc. Aralkyl groups having 7 or more, preferably 8 or more, and 40 or less, preferably 30 or less, and more preferably 20 or less carbon atoms; for example, 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 1,1-di(n-hexyl)-1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, 4-phenylcyclohexyl group, etc. a heteroaralkyl group having 2 or more, preferably 4 or more, and 40 or less, preferably 30 or less, and more preferably 20 or less carbon atoms; a 1,1-dimethyl-1-(2-pyridyl)methyl group, a 1,1-di(n-hexyl)-1-(2-pyridyl)methyl group, a (2-pyridyl)methyl group, a (2-pyridyl)ethyl group, a 3-(2-pyridyl)-1-propyl group, a 4-(2-pyridyl)-1-n-butyl group, a 1-methyl -1-(2-pyridyl)ethyl group, 5-(2-pyridyl)-1-n-propyl group, 6-(2-pyridyl)-1-n-hexyl group, 6-(2-pyrimidyl)-1-n-hexyl group, 6-(2,6-diphenyl-1,3,5-triazin-4-yl)-1-n-hexyl group, 7-(2-pyridyl)-1-n-heptyl group, 8-(2-pyridyl)-1-n-octyl group, 4-(2-pyridyl)cyclohexyl group, etc. Among these, an alkyl group, an alkoxy group, an aryloxy group, an aromatic hydrocarbon group, or an aralkyl group is preferred.

[0189] <Specific examples of polycyclic heterocyclic compound TD1> The structure of the polycyclic heterocyclic compound TD1 represented by formula (71) is not particularly limited, but examples thereof include the following structures.

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] [ka]

[0195] <Polycyclic heterocyclic compound TD2> The polycyclic heterocyclic compound represented by formula (1) is also preferably a polycyclic heterocyclic compound represented by the following formula (81): In the present invention, the polycyclic heterocyclic compound represented by the following formula (81) may be referred to as polycyclic heterocyclic compound TD2.

[0196] [ka]

[0197] (In formula (81), R 81 and the four R's 82 each independently represents a hydrogen atom, an alkyl group having 10 or less carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have a substituent. A 81 represents a structure represented by the following formula (82). a80, b80, c80, and d80 each independently represent an integer of 0 to 2, and at least one of a80 to d80 is an integer of 1 or greater. In equation (81), A 81 If there are multiple A 81 may be the same or different.)

[0198] [ka]

[0199] (In formula (82), an asterisk (*) represents a bond, R F represents a fluoroalkyl group having 5 or less carbon atoms, R 83 represents an alkyl group having 10 or less carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have a substituent. e80 represents an integer from 0 to 5. The two R in equation (82) F may be the same or different. 83 If there are multiple R 83 may be the same or different.)

[0200] (Reason why Equation (81) is preferred) The polycyclic heterocyclic compound TD2 represented by the formula (81) has a basic skeleton of a fused heterocyclic skeleton containing a boron atom and a nitrogen atom, and is characterized in that at least one quaternary carbon atom substituted with two fluoroalkyl groups and a benzene ring, represented by the formula (82), is connected to this basic skeleton.

[0201] If a fluorine atom is directly substituted into the basic skeleton, the emission wavelength will be shortened, but the ionization potential and electron affinity of the compound will change significantly. Therefore, when the compound is applied as a light-emitting material for an organic electroluminescent device, the charge balance of the device will be disrupted, making it difficult to achieve excellent device characteristics.

[0202] In contrast, in the polycyclic heterocyclic compound TD2, a fluorine atom, which is a strong electron-withdrawing group, is not directly substituted on the basic skeleton. This makes it possible to shorten the emission wavelength without significantly changing the ionization potential and electron affinity, which have a significant effect on the device characteristics of organic electroluminescent devices.

[0203] Furthermore, the quaternary carbon atom in formula (82) connected to the basic skeleton has an asymmetric structure in which two fluoroalkyl groups and a benzene ring are bonded, so polycyclic heterocyclic compound TD2 has excellent solubility in organic solvents. Therefore, the film formed by the wet film-forming method has high uniformity and is suitable as a light-emitting material for organic electroluminescent devices.

[0204] <R 81 and R 82 > R in equation (81) 81 and the four R's 82each independently represents a hydrogen atom, an alkyl group having 10 or less carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have a substituent.

[0205] Examples of alkyl groups having 10 or less carbon atoms include methyl, ethyl, branched, straight-chain, or cyclic propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl, and adamantyl groups. 1 When is an alkyl group having 10 or less carbon atoms, from the viewpoint of the stability of the compound, a methyl group, a branched, linear or cyclic propyl group, or a butyl group is preferred, and a branched butyl group is particularly preferred.

[0206] Examples of aromatic hydrocarbon groups having 6 to 20 carbon atoms include monovalent groups such as a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, a chrysene ring, a pyrene ring, a benzanthracene ring, and a perylene ring. From the viewpoint of the solubility of the compound, a phenyl group, which is a monovalent group of a benzene ring, is preferred.

[0207] Examples of aromatic heterocyclic groups having 3 to 20 carbon atoms include monovalent groups such as pyridine ring, quinoline ring, benzofuran ring, and carbazole ring.

[0208] R 81 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a t-butyl group.

[0209] R 82 is preferably a hydrogen atom.

[0210] <a80~d80> In formula (81), a80, b80, c80, and d80 each independently represent an integer of 0 to 2, and at least one of a80 to d80 is an integer of 1 or greater. From the viewpoint of a short emission wavelength of the compound, a80+b80+c80+d80 is preferably 2 or greater, and particularly preferably a80+b80+c80+d80 is 4 or greater.

[0211] <R F > In equation (82), R F represents a fluoroalkyl group having 5 or less carbon atoms. Examples of fluoroalkyl groups having 5 or less carbon atoms include a trifluoromethyl group, a pentafluoroethyl group, and perfluoroalkyl groups such as a branched, linear, or cyclic perfluoropropyl group, a perfluorobutyl group, and a perfluoropentane group. From the viewpoint of the film-forming properties of the compound, a trifluoromethyl group and a pentafluoroethyl group are preferred, and a trifluoromethyl group is particularly preferred.

[0212] <R 83 > In equation (82), R 83 represents an alkyl group having 10 or less carbon atoms, which may have a substituent, an aromatic hydrocarbon group having from 6 to 20 carbon atoms, which may have a substituent, or an aromatic heterocyclic group having from 3 to 20 carbon atoms, which may have a substituent. Examples of alkyl groups having 10 or less carbon atoms include a methyl group, an ethyl group, and a branched, linear, or cyclic propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, and a decyl group. From the viewpoint of the solubility of the compound, a branched or linear propyl group, a butyl group, a pentyl group, or a hexyl group is preferred, and a branched or linear butyl group, or a branched, linear, or cyclic hexyl group is particularly preferred.

[0213] Examples of aromatic hydrocarbon groups having 6 to 20 carbon atoms include monovalent groups such as a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, a chrysene ring, a pyrene ring, a benzanthracene ring, and a perylene ring. From the viewpoint of the solubility of the compound, a phenyl group, which is a monovalent group of a benzene ring, is preferred.

[0214] Examples of aromatic heterocyclic groups having 3 to 20 carbon atoms include monovalent rings such as pyridine ring, quinoline ring, benzofuran ring, and carbazole ring. Based on Examples include:

[0215] <R 81 ~R 83Substituents that may be present in R 81 , R 82 , R 83 is an alkyl group having 10 or less carbon atoms which may have a substituent, an aromatic hydrocarbon group having from 6 to 20 carbon atoms which may have a substituent, or an aromatic heterocyclic group having from 3 to 20 carbon atoms which may have a substituent, the substituent that the alkyl group, aromatic hydrocarbon group, or aromatic heterocyclic group may have can be selected, for example, from Substituent Group W1 which will be described later.

[0216] Among these, alkyl groups having 10 or less carbon atoms, aromatic hydrocarbon groups or aromatic heterocyclic groups having 20 or less carbon atoms, and aralkyl groups having 30 or less carbon atoms are preferred, and alkyl groups having 10 or less carbon atoms, aromatic hydrocarbon groups having 20 or less carbon atoms, and aralkyl groups having 30 or less carbon atoms are more preferred.

[0217] Examples of the alkyl group having 10 or less carbon atoms as a substituent include a methyl group, an ethyl group, and branched, linear, or cyclic propyl, butyl, pentyl, hexyl, octyl, nonyl, and decyl groups. From the viewpoint of compound stability, a methyl group, an ethyl group, a branched, linear, or cyclic propyl group, or butyl group is preferred, and a branched propyl group is particularly preferred.

[0218] Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms as a substituent include monovalent groups such as a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, a chrysene ring, a pyrene ring, a benzanthracene ring, and a perylene ring. From the viewpoint of the solubility of the compound, a phenyl group, which is a monovalent group of a benzene ring, is preferred.

[0219] Examples of the aromatic heterocyclic group having 3 to 20 carbon atoms as a substituent include monovalent groups such as a pyridine ring, a quinoline ring, a benzofuran ring, and a carbazole ring.

[0220] Examples of aralkyl groups having 30 or less carbon atoms as a substituent include benzyl, 2-phenylethyl, 2-phenylpropyl-2-yl, 2-phenylbutyl-2-yl, 3-phenylpentyl-3-yl, 3-phenyl-1-propyl, 4-phenyl-1-butyl, 5-phenyl-1-pentyl, 6-phenyl-1-hexyl, 7-phenyl-1-heptyl, and 8-phenyl-1-octyl groups.

[0221] <Substituent group W1> Examples of the substituent group W1 include the following groups. For example, a linear, branched, or cyclic alkyl group having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, or a dodecyl group; For example, an alkenyl group having typically 2 or more carbon atoms and typically 24 or less, preferably 12 or less, such as a vinyl group; For example, an alkynyl group having typically 2 or more carbon atoms and typically 24 or less, preferably 12 or less, such as an ethynyl group; For example, aralkyl groups having 30 or less carbon atoms, such as a benzyl group, a 2-phenylethyl group, a 2-phenylpropyl-2-yl group, a 2-phenylbutyl-2-yl group, a 3-phenylpentyl-3-yl group, a 3-phenyl-1-propyl group, a 4-phenyl-1-butyl group, a 5-phenyl-1-pentyl group, a 6-phenyl-1-hexyl group, a 7-phenyl-1-heptyl group, or an 8-phenyl-1-octyl group; For example, an alkoxy group having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a methoxy group or an ethoxy group; For example, an aryloxy group or heteroaryloxy group having usually 4 or more, preferably 5 or more, carbon atoms and usually 36 or less, preferably 24 or less, such as a phenoxy group, naphthoxy group, or pyridyloxy group; For example, an alkoxycarbonyl group having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a methoxycarbonyl group or an ethoxycarbonyl group; For example, dialkylamino groups having usually 2 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a dimethylamino group or a diethylamino group; For example, diarylamino groups having usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less carbon atoms, such as a diphenylamino group, a ditolylamino group, or an N-carbazolyl group; For example, an arylalkylamino group having usually 7 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a phenylmethylamino group; For example, acyl groups such as an acetyl group and a benzoyl group, each of which usually has 2 or more carbon atoms and usually has 24 or less, preferably 12 or less, carbon atoms; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, haloalkyl groups having typically 1 or more carbon atoms and typically 12 or less, preferably 6 or less, such as a trifluoromethyl group; For example, alkylthio groups having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a methylthio group or an ethylthio group; For example, an arylthio group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less, carbon atoms, such as a phenylthio group, a naphthylthio group, or a pyridylthio group; For example, a silyl group having usually 2 or more, preferably 3 or more, carbon atoms and usually 36 or less, preferably 24 or less, such as a trimethylsilyl group or a triphenylsilyl group; For example, a siloxy group having usually 2 or more, preferably 3 or more, carbon atoms and usually 36 or less, preferably 24 or less, such as a trimethylsiloxy group or a triphenylsiloxy group; cyano group; For example, aromatic hydrocarbon groups having usually 6 or more carbon atoms and usually 36 or less, preferably 24 or less, such as a phenyl group or a naphthyl group; For example, aromatic heterocyclic groups having usually 3 or more, preferably 4 or more, carbon atoms and usually 36 or less, preferably 24 or less, such as thienyl and pyridyl groups.

[0222] Among the above-mentioned substituent group W1, an alkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group is preferable, and an alkyl group or an aromatic hydrocarbon group is more preferable. From the viewpoint of charge transport properties, it is more preferable that the compound has no substituent.

[0223] Each of the substituents in the above-mentioned substituent group W1 may further have a substituent, and as the substituent, the same substituents as those in the above-mentioned substituent group W1 can be used.

[0224] <Preferable polycyclic heterocyclic compound TD2> The polycyclic hetero compound TD2 represented by the formula (81) preferably has a structure represented by the following formula (83).

[0225] [ka]

[0226] (In formula (83), R 81 , R 82 , A 81 is R in Eq. (81) 81 , R 82 , A 81 is synonymous with a83, b83, c83 and d83 each independently represent 0 or 1, and at least one of them represents 1.

[0227] That is, in the formula (81), A 81 In the basic skeleton where the nitrogen atom is not substituted, the HOMO is distributed on the carbon atom at the para position of the nitrogen atom (= the meta position of the boron atom), so that carbon atom has a structure represented by formula (83). A 81 When the substituent is replaced by, the effect of shortening the wavelength is large, which is preferable. From this viewpoint, it is preferable that all of a83 to d83 are 1 in the above formula (83).

[0228] <Specific examples of polycyclic heterocyclic compounds TD2> Specific examples of the polycyclic heterocyclic compound TD2 of the present invention represented by formula (81) are shown below, but the present invention is not limited to these.

[0229] [ka]

[0230] The composition for forming a light-emitting layer of the present invention may contain only one type of polycyclic heterocyclic compound represented by the formula (1), or may contain two or more types.

[0231] [Compound I: Compound represented by formula (20)] In one embodiment, the composition for forming a light-emitting layer of the present invention contains a compound I represented by the following formula (20).

[0232] [ka]

[0233] (In formula (20), Ar 21 ~Ar 35 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0234] In formula (20), Ar 21 ~Ar 35 In the case where the benzene ring structure is an optionally substituted benzene ring structure or a structure in which 2 to 10 optionally substituted benzene ring structures are linked in an unbranched or branched manner, the substituent that the benzene ring may have is preferably an alkyl group.

[0235] <Alkyl group as a substituent> The alkyl group as a substituent is a linear, branched, or cyclic alkyl group having usually 1 or more and 12 or less carbon atoms, preferably 8 or less, further preferably 6 or less, and even more preferably 4 or less carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, and a 2-ethylhexyl group.

[0236] <Equation (21), Equation (22)> In the formula (20), Ar 22 , Ar 23 , Ar 24 , Ar 27 , Ar 28 , Ar 29 , Ar 32 , Ar 33 and Ar 34 At least one of the above is preferably a structure represented by the following formula (21) or (22).

[0237] [ka]

[0238] (In formulas (21) and (22), Ar 36 ~Ar 39 each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 8 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

[0239] In formula (21) and formula (22), Ar 36 ~Ar 39 In the case where the benzene ring has a structure in which 2 to 10 benzene ring structures which may have a substituent or 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner, the substituent which the benzene ring may have is preferably an alkyl group as the substituent.

[0240] In the formula (20), Ar 22 , Ar 23 and Ar 24One of the following and Ar 27 , Ar 28 and Ar 29 and Ar 32 , Ar 33 and Ar 34 Preferably, any one of the above is a structure represented by the formula (21) or the formula (22), and Ar 22 , Ar 27 and Ar 32 is more preferably a structure represented by the formula (21) or the formula (22).

[0241] Furthermore, the structure represented by the formula (21) is preferably a structure represented by the following formula (21-1), (21-2), (21-3), (21-4) or (21-5), and the structure represented by the formula (22) is preferably a structure represented by the following formula (22-1), (22-2), (22-3) or (22-4). These structures may be substituted with an alkyl group as the substituent. From the viewpoint of improving solubility, substitution with an alkyl group is preferred. From the viewpoint of charge transport properties and durability during device operation, it is preferred that the structure has no substituent.

[0242] [ka]

[0243] Among these, the structure represented by the formula (21) is preferably a structure represented by the formula (21-1), (21-3), (21-4), or (21-5), and the structure represented by the formula (22) is more preferably a structure represented by the formula (22-1), and it is particularly preferable that at least one of the structures represented by the formula (21) or the formula (22) includes a structure represented by the formula (21-1) or a structure represented by the formula (22-3).

[0244] It is believed that the inclusion of such a structure in the compound represented by formula (20) allows for appropriate adjustment of the charge transport property in the light-emitting layer, thereby increasing the light-emitting efficiency, and also leads to excellent solubility and durability during device operation.

[0245] <Molecular weight> Compound I represented by formula (20) is a low molecular weight material, and its molecular weight is preferably 3,000 or less, more preferably 3,000 or less, particularly preferably 2,000 or less, and most preferably 1,500 or less. The lower limit of the molecular weight of Compound I is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0246] <Specific examples of compound I represented by formula (20)> The compound I represented by formula (20) is not particularly limited, but examples thereof include the following compounds.

[0247] [ka]

[0248] [ka]

[0249] The composition for forming a light-emitting layer of the present invention may contain only one type of compound I represented by the formula (20) above, or may contain two or more types.

[0250] [Compound II: Compound represented by formula (200)] In one embodiment, the composition for forming a light-emitting layer of the present invention contains a compound II represented by the following formula (200).

[0251] [ka]

[0252] (In formula (200), each W independently represents CH or N, and at least one W is N; Xa 1 , Ya 1 , and Za 1 each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, Xa 2 , Ya 2 and Za 2 each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent; g11, h11, and j11 each independently represent an integer of 0 to 6; At least one of g11, h11, and j11 is an integer of 1 or greater, If g11 is 2 or more, multiple Xa 1 may be the same or different, If h11 is 2 or more, multiple Ya 1 may be the same or different, j If 11 is 2 or more, there are multiple Za 1 may be the same or different, R 31 represents a hydrogen atom or a substituent, and four R 31 may be the same or different, However, if g11, h11, or j11 is 0, the corresponding Xa 2 , Ya 2 , Za 2 is not a hydrogen atom.)

[0253] The compound II represented by the above formula (200) is preferably a charge transport compound, that is, a charge transport host material.

[0254] <w> In the formula (200), W represents CH or N, and at least one of them is N. From the viewpoint of electron transport properties and electron durability, it is preferable that at least two of them are N, and it is more preferable that all of them are N.

[0255] <Xa 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 , Za 2 > In the formula (200), Xa 1 , Ya 1 , Za 1 is a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, and Xa 2 , Ya 2 , Za 2 When the aromatic hydrocarbon group having 6 to 30 carbon atoms optionally having a substituent is a 6-membered monocyclic ring or 2 to 5 condensed rings, the aromatic hydrocarbon ring of the aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably a 6-membered monocyclic ring or 2 to 5 condensed rings. Specific examples include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, a fluoranthene ring, and an indenofluorene ring. Among these, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, or a fluorene ring is preferred, a benzene ring, a naphthalene ring, a phenanthrene ring, or a fluorene ring is more preferred, and a benzene ring, a naphthalene ring, or a fluorene ring is even more preferred.

[0256] In the formula (200), Xa 1 , Ya 1 , Za 1 is a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, and Xa 2 , Ya 2 , Za 2 When is an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, the aromatic heterocyclic ring of the aromatic heterocyclic group having 3 to 30 carbon atoms is preferably a 5- or 6-membered monocyclic ring or 2 to 5 condensed rings. Specific examples thereof include a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, an indolocarbazole ring, an indenocarbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a perimidine ring, a quinazoline ring, and a quinazolinone ring. Among these, a thiophene ring, a pyrrole ring, an imidazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, an indolocarbazole ring, a phenanthroline ring, or an indenocarbazole ring is preferred, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring is more preferred, and a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring is even more preferred.

[0257] Xa in the formula (200) 1 , Ya 1 , Za 1 , Xa 2 , Ya 2 , and Za 2 In the above, particularly preferred aromatic hydrocarbon rings are a benzene ring, a naphthalene ring, or a phenanthrene ring, and particularly preferred aromatic heterocycles are a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring.

[0258] <g11、h11、j11> g11, h11, and j11 each independently represent an integer of 0 to 6, and at least one of g11, h11, and j11 is an integer of 1 or greater. From the viewpoint of charge transport properties and durability, it is preferred that g11 is 2 or greater, or at least one of h11 and j11 is 3 or greater.

[0259] Furthermore, the compound represented by the formula (200) preferably has a total of 8 to 18 of these rings, including the ring having three central Ws, from the viewpoints of charge transportability, durability, and solubility in organic solvents.

[0260] <R 31 > R when it is a substituent 31 is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. From the viewpoint of improving durability and charge transportability, an aromatic hydrocarbon group which may have a substituent is more preferred. When R is a substituent, 31 When there are a plurality of groups, they may be different from each other.

[0261] The substituents that the aromatic hydrocarbon group having 6 to 30 carbon atoms may have, the substituents that the aromatic heterocyclic group having 3 to 30 carbon atoms may have, and the substituent R 31 The substituent that may be possessed by can be selected from the following substituent group Z.

[0262] <Substituent group Z> The substituent group Z is a group consisting of alkyl groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, alkoxycarbonyl groups, dialkylamino groups, diarylamino groups, arylalkylamino groups, acyl groups, halogen atoms, haloalkyl groups, alkylthio groups, arylthio groups, silyl groups, siloxy groups, cyano groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. These substituents may have any of a linear, branched, and cyclic structure.

[0263] More specifically, the substituent group Z includes the following structures. For example, a linear, branched, or cyclic alkyl group having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, more preferably 8 or less, and even more preferably 6 or less, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, or a dodecyl group; s an alkoxy group having usually 1 or more carbon atoms and usually 24 or less, preferably 12 or less, such as a methoxy group or an ethoxy group; For example, an aryloxy group or heteroaryloxy group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less, carbon atoms, such as a phenoxy group, naphthoxy group, or pyridyloxy group; For example, alkoxycarbonyl groups having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms, such as a methoxycarbonyl group or an ethoxycarbonyl group; For example, dialkylamino groups having usually 2 or more and usually 24 or less, preferably 12 or less carbon atoms, such as a dimethylamino group or a diethylamino group; For example, diarylamino groups such as diphenylamino groups and ditolylamino groups, each of which has usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less carbon atoms; For example, an arylalkylamino group having typically 7 carbon atoms, typically 36 or less, and preferably 24 or less, such as a phenylmethylamino group; For example, acyl groups such as an acetyl group and a benzoyl group, each of which usually has 2 carbon atoms, usually 24 or less, and preferably 12 carbon atoms; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, haloalkyl groups having typically 1 or more carbon atoms and typically 12 or less, preferably 6 or less, such as a trifluoromethyl group; For example, alkylthio groups having usually 1 or more and usually 24 or less, preferably 12 or less carbon atoms, such as a methylthio group or an ethylthio group; For example, an arylthio group having usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less, carbon atoms, such as a phenylthio group, a naphthylthio group, or a pyridylthio group; For example, a silyl group having usually 2 or more, preferably 3 or more, carbon atoms and usually 36 or less, preferably 24 or less, such as a trimethylsilyl group or a triphenylsilyl group; For example, a siloxy group having a carbon number of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less, such as a trimethylsiloxy group or a triphenylsiloxy group; cyano group; For example, aromatic hydrocarbon groups such as phenyl and naphthyl groups, each having a carbon number of usually 6 or more and usually 36 or less, and preferably 24 or less; For example, aromatic heterocyclic groups having usually 3 or more, preferably 4 or more, carbon atoms and usually 36 or less, preferably 24 or less, such as a thienyl group or a pyridyl group.

[0264] Among the above-mentioned substituent group Z, alkyl groups, alkoxy groups, diarylamino groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups are preferred. From the viewpoint of charge transportability, aromatic hydrocarbon groups or aromatic heterocyclic groups are preferred as the substituent, more preferably aromatic hydrocarbon groups, and even more preferably no substituent. From the viewpoint of improving solubility, alkyl groups or alkoxy groups are preferred as the substituent.

[0265] Each of the substituents in the above-mentioned substituent group Z may further have a substituent. Examples of such a substituent include the same as those in the above-mentioned substituents (substituent group Z). Each of the substituents that may be contained in the above-mentioned substituent group Z is preferably an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group, and from the viewpoint of charge transportability, it is more preferable that each of the substituents in the above-mentioned substituent group Z does not have any further substituent.

[0266] <Molecular weight> Compound II represented by formula (200) is a low-molecular-weight material, and its molecular weight is preferably 3,000 or less, more preferably 3,000 or less, particularly preferably 2,000 or less, and most preferably 1,500 or less. The lower limit of the molecular weight of compound II is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0267] <Specific examples of compound II represented by formula (200)> The compound II represented by the formula (200) is not particularly limited, but examples thereof include the following compounds.

[0268] [ka]

[0269] [ka]

[0270] The composition for forming a light-emitting layer of the present invention may contain only one type of compound II represented by the formula (200), or may contain two or more types.

[0271] [Compound III: Compounds represented by formula (210), formula (220), and formula (230)] In one embodiment, the composition for forming an emitting layer of the present invention contains one or more compounds III selected from the group consisting of a compound represented by the following formula (210), a compound represented by the following formula (220), and a compound represented by the following formula (230):

[0272] [ka]

[0273] (In formula (210), formula (220) and formula (230), Ar 41 , Ar 42 , Ar 43 each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, R 21 , R 22 , R 23 each independently represents a hydrogen atom or a substituent, X 21 , X 22 are each independently O, S, or N-Ar 44 represents Ar 44 represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, n21, n22, and n23 each independently represent 1 or 2; n24 represents an integer from 1 to 4, If n24 is 2 or more, multiple R 21 may be the same or different.)

[0274] The compound III represented by the formula (210), (220), or (230) is preferably a charge transport compound, that is, a charge transport host material.

[0275] <Ar 41 , Ar 42 , Ar 43 , Ar 44 , X 21 , X 22 > Ar in the formula (210), the formula (220) and the formula (230) 41 , Ar 42 , Ar 43 and Ar 44 The aromatic hydrocarbon group having 6 to 30 carbon atoms that can be used is preferably a monovalent group of a 6-membered monocyclic ring or 2 to 5 condensed rings. Specific examples include monovalent groups such as a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, fluoranthene ring, and indenofluorene ring. A monovalent group of a benzene ring, naphthalene ring, phenanthrene ring, fluorene ring, or indenofluorene ring is more preferred, a monovalent group of a benzene ring, naphthalene ring, or fluorene ring is more preferred, and a monovalent group of a benzene ring or naphthalene ring is most preferred.

[0276] Ar in the formula (210), the formula (220) and the formula (230) 41 , Ar 42 , Ar 43 and Ar 44 The aromatic heterocyclic group having 3 to 30 carbon atoms that can be used is preferably a monocyclic group having 5 or 6 members or a monovalent group having 2 to 5 condensed rings. Specific examples include monovalent groups such as a furan ring, a benzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, an indolocarbazole ring, an indenocarbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzisoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a perimidine ring, a quinazoline ring, and a quinazolinone ring. Of these, a thiophene ring, a pyrrole ring, an imidazole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, an indolocarbazole ring, a phenanthroline ring, or an indolocarbazole ring is preferred, a monovalent group of a pyridine ring, a pyrimidine ring, a triazine ring, a quinoline ring, a quinazoline ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, an indolocarbazole ring, or an indenocarbazole ring is more preferred, and a monovalent group of a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, an indolocarbazole ring, or an indenocarbazole ring is even more preferred.

[0277] Ar 41 , Ar 42 , Ar 43 or Ar 44 However, when the aromatic hydrocarbon group and aromatic heterocyclic group are monovalent groups formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms, which may have a substituent, and an aromatic heterocyclic group having 3 to 30 carbon atoms, which may have a substituent, the aromatic hydrocarbon group and aromatic heterocyclic group can be selected from these monovalent groups and combined. The number of links is preferably 2 or 3, and more preferably 2.

[0278] Ar 44 is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a group in which 2 to 5 aromatic hydrocarbon groups having 6 to 30 carbon atoms which may have a substituent are linked together.

[0279] X 21 is preferably O or N-Ar 44 and X 22 is preferably O or S, and more preferably O. The substituents that these groups may have can be selected from the aforementioned substituent group Z in compound II.

[0280] Ar 41 , Ar 42 and Ar 43 Preferred groups include groups represented by the following formulae (20-1) to (20-13), and these groups may further have a substituent.

[0281] [ka]

[0282] (In the above formula, * represents a bonding position, Ar 45 is an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group in which 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent are linked together.

[0283] Ar 45 is the Ar 44 The same monovalent groups as those applicable to the above can be applied. Preferably, the aromatic hydrocarbon group has 6 to 30 carbon atoms and may have a substituent, or a monovalent group in which 2 to 5 aromatic hydrocarbon group structures having 6 to 30 carbon atoms and may have a substituent are linked together.

[0284] The substituent is preferably selected from the above-mentioned substituent group Z. Preferred substituents are also as described in the above-mentioned substituent group Z.

[0285] <R 21 , R 22 , R 23 > R when it is a substituent 21 , R 22 and R 23 can be independently selected from the above-mentioned substituent group Z. Preferably, it is an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent. From the viewpoint of improving durability and charge transportability, it is more preferably an aromatic hydrocarbon group which may have a substituent. When R is a substituent, 21 When there are a plurality of groups, they may be different from each other.

[0286] R when it is a substituent 21 , R 22 and R 23 The substituent that may be possessed by can be selected from the above-mentioned group Z of substituents.

[0287] <Molecular weight> Compound III represented by formula (210), formula (220), or formula (230) is a low-molecular-weight material, and its molecular weight is preferably 3,000 or less, more preferably 3,000 or less, particularly preferably 2,000 or less, and most preferably 1,500 or less. The lower limit of the molecular weight of compound III is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0288] <Specific examples of compound III represented by formula (210), formula (220), or formula (230)> The compound III represented by the formula (210), (220) or (230) is not particularly limited, but examples thereof include the following compounds.

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292] [ka]

[0293] [ka]

[0294] The composition for forming a light-emitting layer of the present invention may contain only one type of compound represented by the formula (210) as compound III, or may contain two or more types. The composition for forming a light-emitting layer of the present invention may contain only one type of compound represented by the formula (220) as compound III, or may contain two or more types. The composition for forming a light-emitting layer of the present invention may contain only one type of compound represented by the formula (230) as compound III, or may contain two or more types. Furthermore, the composition for forming a light-emitting layer of the present invention may contain, as compound III, one or more types of compounds represented by the formula (210) and one or more types of compounds represented by the formula (220), one or more types of compounds represented by the formula (210) and one or more types of compounds represented by the formula (230), one or more types of compounds represented by the formula (220) and one or more types of compounds represented by the formula (230), or one or more types of compounds represented by the formula (210), one or more types of compounds represented by the formula (220), and one or more types of compounds represented by the formula (230).

[0295] [Compound IV: Compound represented by formula (240)] In one embodiment, the composition for forming a light-emitting layer of the present invention contains a compound IV represented by the following formula (240).

[0296] [ka]

[0297] (In formula (240), Ar 611 , Ar 612 each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R 611 , R 612 each independently represents a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent; n 611 , n 612 are each independently an integer of 0 to 4.

[0298] <Ar 611 , Ar 612 > Ar 611 , Ar 612 each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 50, more preferably 6 to 30, and even more preferably 6 to 18. Specific examples of the aromatic hydrocarbon group include monovalent groups of aromatic hydrocarbon structures, such as benzene rings, naphthalene rings, anthracene rings, tetraphenylene rings, phenanthrene rings, chrysene rings, pyrene rings, benzanthracene rings, and perylene rings, each having a carbon number of typically 6 or more and typically 30 or less, preferably 18 or less, and more preferably 14 or less, or monovalent groups of structures in which multiple structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, typically, a structure in which 2 to 8 rings are linked is used, and a structure in which 2 to 5 rings are linked is preferred. When multiple aromatic hydrocarbon rings are linked, the linked rings may be the same structure or different structures.

[0299] Ar 611 , Ar 612 are preferably each independently phenyl group, a monovalent group in which multiple benzene rings are bonded in a chain or branched manner, a monovalent group in which one or more benzene rings and at least one naphthalene ring are bonded in a linear or branched manner, a monovalent group in which one or more benzene rings and at least one phenanthrene ring are bonded in a linear or branched manner, or a monovalent group in which one or more benzene rings and at least one tetraphenylene ring are bonded in a linear or branched manner; and more preferably a monovalent group in which a plurality of benzene rings are bonded in a chain or branched form, and in either case the order of bonding does not matter.

[0300] As described above, the number of linked benzene rings, naphthalene rings, phenanthrene rings, and tetraphenylene rings is usually 2 to 8, and preferably 2 to 5. Among these, preferred are a monovalent structure in which 1 to 4 linked benzene rings are bonded, a monovalent structure in which 1 to 4 linked benzene rings and a naphthalene ring are bonded, a monovalent structure in which 1 to 4 linked benzene rings and a phenanthrene ring are bonded, or a monovalent structure in which 1 to 4 linked benzene rings and a tetraphenylene ring are bonded.

[0301] These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically, can be selected from the substituent group Z. Preferred substituents are the preferred substituents in the substituent group Z.

[0302] Ar 611 , Ar 612 From the viewpoint of the solubility and durability of the compound, it is preferable that at least one of the above has at least one partial structure selected from the following formulae (72-1) to (72-7).

[0303] [ka]

[0304] In each of the above formulas (72-1) to (72-7), * represents a bond to an adjacent structure or a hydrogen atom, and at least one of the two * represents the bonding position to the adjacent structure. In the following description, * has the same definition unless otherwise specified.

[0305] More preferably, Ar 611 , Ar 612 At least one of the above has at least one partial structure selected from the formulae (72-1) to (72-4) and (72-7). More preferably, Ar 611 , Ar 612 Each of these has at least one partial structure selected from the formulae (72-1) to (72-3) and (72-7). Particularly preferably, Ar 611 , Ar 612 Each of these has at least one partial structure selected from the formula (72-1), the formula (72-2), and the formula (72-7).

[0306] Formula (72-2) is preferably the following formula (72-2-2).

[0307] [ka]

[0308] More preferably, formula (72-2) is the following formula (72-2-3).

[0309] [ka]

[0310] In addition, from the viewpoint of the solubility and durability of the compound, Ar 611 , Ar 612 The partial structure that is preferably contained in at least one of the above includes a partial structure represented by formula (72-1) and a partial structure represented by formula (72-2).

[0311] <(R 611 , R 612 > R 611 , R 612 are each independently a deuterium atom, a halogen atom such as a fluorine atom, or a monovalent aromatic hydrocarbon having 6 to 30 carbon atoms which may have a substituent. The aromatic hydrocarbon group is preferably a monovalent group having an aromatic hydrocarbon structure with 6 to 30 carbon atoms, more preferably 6 to 18 carbon atoms, and even more preferably 6 to 10 carbon atoms. These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically, can be selected from the substituent group Z. Preferred substituents are the preferred substituents in the substituent group Z.

[0312] <n 611 , n 612 > n 611 , n 612 are each independently an integer of 0 to 4, preferably 0 to 2, and more preferably 0 or 1.

[0313] <Substituent> Ar 611 , Ar 612 , R 611 , R 612 When is a monovalent or divalent aromatic hydrocarbon group, the substituent that may be possessed is preferably a substituent selected from the substituent group Z in the compound II.

[0314] <g> G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent.

[0315] The number of carbon atoms in the aromatic hydrocarbon group of G is preferably 6 to 50, more preferably 6 to 30, and even more preferably 6 to 18. Specific examples of the aromatic hydrocarbon group include divalent groups of aromatic hydrocarbon structures, such as benzene rings, naphthalene rings, anthracene rings, tetraphenylene rings, phenanthrene rings, chrysene rings, pyrene rings, benzanthracene rings, and perylene rings, each having a carbon number of typically 6 or more and typically 30 or less, preferably 18 or less, and more preferably 14 or less, or divalent groups of structures in which multiple structures selected from these structures are linked in a chain or branched manner. When multiple aromatic hydrocarbon rings are linked, typically, a structure in which 2 to 8 rings are linked can be mentioned, and a structure in which 2 to 5 rings are linked is preferred. When multiple aromatic hydrocarbon rings are linked, the linked rings may be the same structure or different structures.

[0316] G is preferably single bond, a phenylene group, a divalent group in which multiple benzene rings are bonded in a chain or branched manner, a divalent group in which one or more benzene rings and at least one naphthalene ring are bonded in a linear or branched manner, a divalent group in which one or more benzene rings and at least one phenanthrene ring are bonded in a linear or branched manner, or a divalent group in which one or more benzene rings and at least one tetraphenylene ring are bonded in a linear or branched manner, and more preferably a divalent group in which a plurality of benzene rings are bonded in a chain or branched form, and in either case the order of bonding does not matter.

[0317] As described above, the number of linked benzene rings, naphthalene rings, phenanthrene rings, and tetraphenylene rings is usually 2 to 8, and preferably 2 to 5. Among these, more preferred are a divalent structure in which 1 to 4 linked benzene rings are bonded, a divalent structure in which 1 to 4 linked benzene rings and a naphthalene ring are bonded, a divalent structure in which 1 to 4 linked benzene rings and a phenanthrene ring are bonded, or a divalent structure in which 1 to 4 linked benzene rings and a tetraphenylene ring are bonded.

[0318] These aromatic hydrocarbon groups may have a substituent. The substituent that the aromatic hydrocarbon group may have is as described above, and specifically, can be selected from the substituent group Z in the compound II described above. Preferred substituents are the preferred substituents in the substituent group Z in the compound II described above.

[0319] <Specific examples of compound IV represented by formula (240)> Preferred specific examples of the compound IV represented by the formula (240) are shown below, but the present invention is not limited to these.

[0320] [ka]

[0321] [Organic solvents] The organic solvent contained in the composition for forming a light-emitting layer of the present invention is a volatile liquid component used for forming a layer containing the polycyclic heterocyclic compound represented by the formula (1) and compounds I to IV by wet film formation.

[0322] The organic solvent is not particularly limited as long as it is an organic solvent that can well dissolve the polycyclic heterocyclic compound represented by formula (1), compounds I to IV, and the second host material described below, which are solutes.

[0323] Preferred organic solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin, and methylnaphthalene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; and aromatic hydrocarbons such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether. aromatic ethers; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; alicyclic ketones such as cyclohexanone, cyclooctanone, and fenchone; alicyclic alcohols such as cyclohexanol and cyclooctanol; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; aliphatic alcohols such as butanol and hexanol; and aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA).

[0324] Among these, from the viewpoint of viscosity and boiling point, alkanes, aromatic hydrocarbons, and aromatic esters are preferred, and aromatic hydrocarbons and aromatic esters are particularly preferred.

[0325] These organic solvents may be used alone or in any combination of two or more in any ratio.

[0326] The boiling point of the organic solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower. If the boiling point of the organic solvent is below this range, evaporation of the solvent from the composition for forming an emitting layer during wet film formation may reduce film formation stability. If the boiling point of the organic solvent is above this range, residual solvent may remain after wet film formation, reducing film formation stability.

[0327] In particular, it is considered that a more uniform coating film can be easily formed by combining two or more organic solvents having a boiling point of 150° C. or higher, which is preferable.

[0328] [Second host material] The composition for forming a light-emitting layer of the present invention preferably further contains a second host material.

[0329] The second host material is preferably a charge-transporting host material, and may be a material conventionally used for organic electroluminescent devices. Examples include pyridine, carbazole, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthene, benzophenanthrene, fluorene, acetonaphthofluoranthene, coumarin, p-bis(2-phenylethenyl)benzene and derivatives thereof, quinacridone derivatives, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran)-based compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, fused aromatic ring compounds substituted with an arylamino group, and styryl derivatives substituted with an arylamino group.

[0330] These may be used alone or in any combination of two or more in any ratio.

[0331] Of these, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthene, benzophenanthrene, fluorene, acetonaphthofluoranthene, and derivatives thereof are preferred, and anthracene derivatives are more preferred. The anthracene derivative is preferably a compound represented by the following formula (30): The anthracene derivative represented by the following formula (30) has excellent electron transport properties, and when used as a host material in the light-emitting layer of an organic electroluminescent device, it functions as an electron-transporting host.

[0332] <Anthracene derivatives>

[0333] [ka]

[0334] In the above formula (30), Ar 241 , Ar 242 are each independently a structure represented by the following formula (31), and Ar 243 represents a substituent, and Ar 243 If there are multiple Ar 243 may be the same or different, and n 43 is an integer between 0 and 8.

[0335] [ka]

[0336] In the above formula (31), Ar 244 , Ar 245 each independently represents an aromatic hydrocarbon structure which may have a substituent, or a heteroaromatic ring structure which may have a substituent; Ar 244 , Ar 245 If there are multiple of each, multiple Ar 244 , Ar 245 may be the same or different, and n 44 is an integer between 1 and 5, n 45 is an integer between 0 and 5.

[0337] Ar 244 is preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 30 carbon atoms and which may have a substituent, and more preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 12 carbon atoms and which may have a substituent. Specifically, the aromatic hydrocarbon structure is more preferably a benzene ring structure, a naphthalene structure, an anthracene structure, or a phenanthrene structure, and even more preferably a benzene ring structure.

[0338] Ar 245 is preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 30 carbon atoms and which may have a substituent, or an aromatic heterocyclic structure which is a fused ring having 6 to 30 carbon atoms and which may have a substituent, and more preferably an aromatic hydrocarbon structure which is a monocyclic or fused ring having 6 to 12 carbon atoms and which may have a substituent, or an aromatic heterocyclic structure which is a fused ring having 12 carbon atoms and which may have a substituent. Specific examples of the aromatic hydrocarbon structure include a benzene ring structure, a naphthalene structure, an anthracene structure, and a phenanthrene structure, and more preferably a benzene ring structure, a naphthalene structure, or a phenanthrene structure. Specific examples of the aromatic heterocyclic structure include a dibenzofuran structure, a dibenzothiophene structure, and a phenanthroline structure, and more preferably a dibenzofuran structure or a phenanthroline structure.

[0339] n 44 is preferably an integer of 1 to 3, and more preferably 1 or 2. n 45 is preferably an integer of 0 to 3, and more preferably an integer of 0 to 2.

[0340] (Ar 243 , Ar 244 , Ar 245 (substituents of The substituent Ar 243 , Ar 244 and Ar 245 The substituent that may be possessed by is preferably a group selected from the substituent group Z in the compound II, more preferably an alkyl group or an aromatic hydrocarbon group included in the substituent group Z, and even more preferably an aromatic hydrocarbon group included in the substituent group Z. 243 , Ar 244 and Ar 245 The substituent that may be contained in the group Z may further contain a substituent, and examples of the further substituent that may be contained include the same as those in the group Z of substituents described above, and are preferably an alkyl group having 8 or less carbon atoms, an alkoxy group having 8 or less carbon atoms, or a phenyl group, and more preferably an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, or a phenyl group. From the viewpoint of charge transport properties, it is more preferable that each of the substituents in the group Z of substituents described above does not contain any further substituent.

[0341] (molecular weight) The compound represented by the formula (30) is a low-molecular-weight material, and its molecular weight is preferably 3,000 or less, more preferably 2,500 or less, particularly preferably 2,000 or less, and most preferably 1,500 or less, and is usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0342] (Specific examples of anthracene derivatives represented by formula (30)) The anthracene derivative represented by the formula (30) is not particularly limited, but examples thereof include the following compounds:

[0343] [ka]

[0344] [ka]

[0345] [ka]

[0346] [ka]

[0347] [Content] The content of the polycyclic heterocyclic compound represented by formula (1) contained in the composition for forming an emitting layer of the present invention is usually 0.001% by mass or more, preferably 0.01% by mass or more, and usually 30.0% by mass or less, preferably 20.0% by mass or less. The content of Compounds I to IV in the composition for forming a light-emitting layer of the present invention is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30.0% by mass or less, preferably 20.0% by mass or less. By setting the contents of the polycyclic heterocyclic compound represented by formula (1) and compounds I to IV within these ranges, holes and electrons can be efficiently injected from an adjacent layer (e.g., a hole transport layer or a hole blocking layer) into the light-emitting layer, thereby reducing the driving voltage. The polycyclic heterocyclic compound represented by formula (1) may be contained in the composition for forming a light-emitting layer either alone or in a combination of two or more thereof. The compounds I to IV may also be contained in the composition for forming a light-emitting layer either alone or in a combination of two or more thereof.

[0348] When the composition for forming an emitting layer of the present invention contains the second host material, the content thereof is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30.0% by mass or less, preferably 20.0% by mass or less. By setting the content of the second host material in the composition for forming an emitting layer within the above range, it is thought that the electron transportability in the emitting layer is improved, resulting in a lower voltage, and the balance between electrons and holes in the emitting layer is improved, thereby improving the luminous efficiency.

[0349] From the viewpoint of improving the luminous efficiency, the total content of the compounds I to IV and the second host material contained in the composition for forming an emitting layer of the present invention is usually 1,000 parts by mass or less, preferably 100 parts by mass or less, and more preferably 50 parts by mass or less, relative to 1 part by mass of the polycyclic heterocyclic compound represented by formula (1) in the composition for forming an emitting layer, and is usually 0.01 part by mass or more, preferably 0.1 part by mass or more, and more preferably 1 part by mass or more.

[0350] From the viewpoint that charge transfer within the light-emitting layer is appropriately suppressed, the balance between electrons and holes is further improved, the light-emitting efficiency is improved, and the driving life of the device is thought to be extended, the content of Compounds I to IV relative to 100 parts by mass of the total content of Compounds I to IV and the second host material contained in the composition for forming a light-emitting layer of the present invention is usually 100 parts by mass or less, preferably 70 parts by mass or less, and more preferably 50 parts by mass or less, and usually 1 part by mass or more, preferably 3 parts by mass or more, and more preferably 10 parts by mass or more.

[0351] The content of the organic solvent contained in the composition for forming an emitting layer of the present invention is usually 10% by mass or more, preferably 50% by mass or more, particularly preferably 80% by mass or more, and usually 99.95% by mass or less, preferably 99.9% by mass or less, particularly preferably 99.8% by mass or less. If the content of the organic solvent is equal to or more than the lower limit, the composition has an appropriate viscosity and improves coatability, while if it is equal to or less than the upper limit, a uniform film is easily obtained and film-formability is good.

[0352] [Other ingredients] The composition for forming a light-emitting layer of the present invention may further contain other compounds in addition to the above-mentioned compounds, as necessary. Preferred examples of the other compounds include phenols such as dibutylhydroxytoluene and dibutylphenol, which are known as antioxidants.

[0353] [Film forming method] The method for forming a light-emitting layer using the light-emitting layer-forming composition of the present invention is a wet film-forming method. The wet film-forming method involves applying a composition to form a liquid film, which is then dried to remove the organic solvent, thereby forming a light-emitting layer film. Examples of the application method include wet film-forming methods such as spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet printing, nozzle printing, screen printing, gravure printing, and flexographic printing, and the applied film is then dried to form a film. Among these film-forming methods, spin coating, spray coating, inkjet printing, and nozzle printing are preferred. When manufacturing an organic EL display device equipped with an organic electroluminescent element using the light-emitting layer-forming composition of the present invention, the inkjet method or nozzle printing method is preferred, with the inkjet method being particularly preferred.

[0354] The drying method is not particularly limited, and natural drying, drying under reduced pressure, heat drying, or drying under reduced pressure while heating can be appropriately used. Heat drying may be performed after natural drying or drying under reduced pressure in order to further remove residual organic solvent. In the drying under reduced pressure, the pressure is preferably reduced to or below the vapor pressure of the organic solvent contained in the composition for forming a light-emitting layer. When heating, the heating method is not particularly limited, but heating on a hot plate, heating in an oven, infrared heating, etc. can be used. temperature The temperature is usually 80°C or higher, preferably 100°C or higher, more preferably 110°C or higher, and is preferably 200°C or lower, more preferably 150°C or lower. The heating time is usually 1 minute or more, preferably 2 minutes or more, and usually 60 minutes or less, preferably 30 minutes or less, more preferably 20 minutes or less.

[0355] [Organic electroluminescent element] An organic electroluminescent device according to one embodiment of the present invention includes an anode, a cathode, and an emitting layer formed between the anode and the cathode using the emitting layer-forming composition according to the present invention. The emitting layer-forming composition according to one embodiment of the present invention includes a polycyclic heterocyclic compound represented by formula (1) as an emitting material, and at least one of compound I, compound II, compound III, or compound IV as a host material, and further includes an organic solvent. The emitting layer-forming composition according to one embodiment of the present invention preferably includes the second host material, and the second host material is preferably a compound represented by formula (30). The emitting material contained in the emitting layer-forming composition according to one embodiment of the present invention is preferably the polycyclic heterocyclic compound represented by formula (1) alone, and more preferably the host material is at least one of compound I, compound II, compound III, or compound IV, and the compound represented by formula (30) alone. An organic electroluminescent device according to another aspect of the present invention has an anode, a cathode, and an emitting layer provided between the anode and the cathode, and the emitting layer preferably contains the polycyclic heterocyclic compound represented by formula (1) and at least one of compounds I to IV, and the emitting layer further contains the second host material, and the second host material is preferably a compound represented by formula (30). The emitting material contained in the emitting layer of the organic electroluminescent device according to another aspect of the present invention is preferably the polycyclic heterocyclic compound represented by formula (1) alone, and it is more preferable that the host material consists of at least one of compounds I, II, III, and IV, and the compound represented by formula (30).

[0356] Furthermore, since the host material contains a material having an electron-transporting property and a material having a hole-transporting property, the charge balance between electrons and holes in the light-emitting layer can be easily improved. Therefore, it is preferable that the electron-transporting host material contains at least one of the compound represented by formula (30) as the second host material and the compound II, and that the hole-transporting host material contains at least one of the compound III and the compound IV.

[0357] The organic electroluminescent device of the present invention preferably further comprises a second organic layer, other than the light-emitting layer, between the anode and the light-emitting layer. The second organic layer is more preferably a hole-injection layer or a hole-transport layer, and even more preferably a hole-transport layer. Furthermore, as described below, the second organic layer preferably comprises a polymer having a triarylamine structure as a repeating unit (hereinafter, the polymer contained in the second organic layer may be referred to as a "second polymer"). More preferably, the polymer does not comprise a crosslinking group. The second polymer is preferably a polymer comprising a repeating unit represented by formula (50) below, more preferably a polymer comprising a repeating unit represented by formula (54), formula (55), formula (56), formula (57), or formula (60).

[0358] The second organic layer is preferably formed by a wet film-forming method using the second composition described below. The second composition is insolubilized by heating after application. Therefore, the second organic layer can be suitably used for laminating organic electroluminescent devices.

[0359] The second organic layer contained in the organic electroluminescent device of the present invention will be described below. The structure of the organic electroluminescent device of the present invention will be described later.

[0360] [Second organic layer] The second organic layer preferably contains a second polymer having a triarylamine structure as a repeating unit as a hole transport material, and the polymer may have a crosslinking group, but more preferably does not contain a crosslinking group. The reason why it is preferable that the crosslinking group is not contained is as follows. Generally, polycyclic heterocyclic compounds containing boron have an empty p-orbital on the boron, which makes them susceptible to reaction with various reactive groups. If the hole transport layer in contact with the light-emitting layer is made of a material that does not have a crosslinking group, the unreacted crosslinking group will not chemically react with the polycyclic heterocyclic compound containing boron when the device is operating, which is thought to improve stability.

[0361] [Second polymer used in the second organic layer] The second polymer having a triarylamine structure as a repeating unit contained in the second organic layer preferably contains the triarylamine structure in the main chain of the polymer.

[0362] The polymer contained in the second organic layer preferably has a triarylamine structure as a repeating unit, and the triarylamine structure is preferably contained in the main chain of the polymer. A polymer having a triarylamine structure as a repeating unit, which is preferred as a polymer contained in the second organic layer, will be described below. In the following description, unless otherwise specified, the substituent is a substituent selected from the substituent group Z in the compound II described above, or a crosslinking group described below. The repeating unit of the triarylamine structure is represented by the following formula (50):

[0363] [ka]

[0364] (In formula (50), Ar 51 represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a group in which a plurality of groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked together; Ar 52 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of at least one group selected from the group consisting of the divalent aromatic hydrocarbon groups and the divalent aromatic heterocyclic groups are linked together directly or via a linking group. Ar 51 and Ar 52 may form a ring via a single bond or a linking group.

[0365] (Ar 51 : side chain) In the repeating unit represented by the above formula (50), Ar 51 represents an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a group in which a plurality of groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked together.

[0366] The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, and specific examples thereof include monovalent groups of 6-membered monocyclic rings or 2 to 5 condensed rings, such as a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, and fluorene ring, or groups in which multiple of these are linked together. Note that, for example, a "monovalent group of a benzene ring" means a "benzene ring having a single free valence," i.e., a phenyl group.

[0367] The aromatic heterocyclic group preferably has 3 or more and 60 or less carbon atoms, and specific examples thereof include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, a benzoyl ... Examples of the 5- or 6-membered ring include a monovalent group of a 5- or 6-membered monocyclic ring or a monovalent group of 2- to 4-fused rings, such as an isoxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, and an azulene ring, or a group in which a plurality of these rings are linked together.

[0368] Ar 51 is preferably an aromatic hydrocarbon group which may have a substituent, from the viewpoints of excellent charge transport properties and excellent durability, and among these, a monovalent group of a benzene ring or fluorene ring which may have a substituent, i.e., a phenyl group or fluorenyl group which may have a substituent, is more preferred, a fluorenyl group which may have a substituent is still more preferred, and a 2-fluorenyl group which may have a substituent is particularly preferred.

[0369] Ar 51 The substituents that the aromatic hydrocarbon group and aromatic heterocyclic group may have are not particularly limited, as long as they do not significantly impair the properties of the present polymer. Preferred examples of the substituents include groups selected from the above-mentioned substituent group Z, with alkyl groups, alkoxy groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups being more preferred, and alkyl groups being even more preferred.

[0370] Ar 51 In terms of solubility in a coating solvent, a fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms is preferred, and a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms is particularly preferred. Furthermore, a 9-alkyl-2-fluorenyl group in which the 9-position of the 2-fluorenyl group is substituted with an alkyl group is preferred, and a 9,9-dialkyl-2-fluorenyl group substituted with two alkyl groups is particularly preferred.

[0371] The fluorenyl group substituted with an alkyl group at at least one of the 9- and 9'-positions tends to improve the solubility in solvents and the durability of the fluorene ring. Furthermore, the fluorenyl group substituted with an alkyl group at both the 9- and 9'-positions tends to further improve the solubility in solvents and the durability of the fluorene ring.

[0372] Also, Ar 51 is also preferably a spirobifluorenyl group from the viewpoint of solubility in a coating solvent.

[0373] (Other preferred Ar 51 ) The polymer may include a repeating unit represented by the formula (50) 51 At least one of the above is preferably a group containing a monovalent or divalent group in which 2 to 5 optionally substituted benzene rings are linked, a fluorenyl group which may have a substituent, a group represented by the following formula (51), a group represented by the following formula (52), or a group represented by the following formula (53).

[0374] (Formula (51))

[0375] [ka]

[0376] (In formula (51), * represents a bond to the nitrogen atom of the main chain of formula (50), Ar 53 , Ar 54 each independently represent a divalent aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent or aromatic heterocyclic groups which may have a substituent are linked together directly or via a linking group; Ar 55 represents an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a monovalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or aromatic heterocyclic groups are linked together directly or via a linking group, Ar 56 represents a hydrogen atom or a substituent.

[0377] Here, the substituents that each aromatic hydrocarbon group and each aromatic heterocyclic group may have, and Ar when they are substituents, 56 may have a crosslinking group. As the crosslinking group, a group selected from the group T of crosslinking groups described below can be used.

[0378] (Ar 53 , Ar 54 ) In the repeating unit represented by the formula (51), Ar 53 , Ar 54 each independently represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have a substituent or aromatic heterocyclic groups which may have a substituent are linked directly or via a linking group. A divalent aromatic hydrocarbon group which may have a substituent or a group in which a plurality of divalent aromatic hydrocarbon groups which may have a substituent are linked together is preferred. The substituents which the aromatic hydrocarbon group and the aromatic heterocyclic group may have may have a crosslinking group, and are preferably the same groups as those in the group Z of substituents. As the crosslinking group, a group selected from the group T of crosslinking groups may be used.

[0379] Ar 53 and Ar 54 The aromatic hydrocarbon group and aromatic heterocyclic group are 52 The same aromatic hydrocarbon groups and aromatic heterocyclic groups as those mentioned above can be used.

[0380] The divalent group in which a plurality of optionally substituted aromatic hydrocarbon groups or optionally substituted aromatic heterocyclic groups are linked directly or via a linking group may be a group in which a plurality of the same groups are linked, or a group in which a plurality of different groups are linked.

[0381] When a plurality of the above divalent groups are linked together, examples include divalent groups with 2 to 10 linked groups, and divalent groups with 2 to 5 linked groups are preferred.

[0382] Ar 53 is preferably a group in which 1 to 6 optionally substituted divalent aromatic hydrocarbon groups are linked together, more preferably a group in which 2 to 4 optionally substituted divalent aromatic hydrocarbon groups are linked together, and among these, a group in which 1 to 4 optionally substituted phenylene rings are linked together is more preferred, and biphenylene in which 2 optionally substituted phenylene rings are linked together is particularly preferred.

[0383] When a plurality of such divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked, the group is preferably one in which the plurality of linked divalent aromatic hydrocarbon groups are bonded so as not to be conjugated. Specifically, it is preferable that the group contains a 1,3-phenylene group or a group having a substituent and forming a twisted structure due to the steric effect of the substituent.

[0384] Ar 53 The substituents that Ar may have are preferably the same as those in the substituent group Z. 53 has no substituents.

[0385] Ar 54 From the viewpoints of excellent charge transport properties and durability, the divalent aromatic hydrocarbon group is preferably a group in which one or more divalent aromatic hydrocarbon groups, which may be the same or different, are linked together, and the divalent aromatic hydrocarbon group may have a substituent. When multiple groups are linked together, the number of linked groups is preferably 2 to 10, more preferably 6 or less, and particularly preferably 3 or less from the viewpoint of film stability. Preferred aromatic hydrocarbon structures are benzene rings, naphthalene rings, anthracene rings, and fluorene rings, and more preferably benzene rings and fluorene rings. Preferred groups in which multiple groups are linked together are groups in which one to four phenylene rings, which may have a substituent, are linked together, or groups in which a phenylene ring, which may have a substituent, and a fluorene ring, which may have a substituent, are linked together. From the viewpoint of a wider LUMO, biphenylene, in which two phenylene rings, which may have a substituent, are linked together, is particularly preferred.

[0386] Ar 54 The substituent that may be possessed by may be any of the substituents in the above-mentioned group Z, or a combination thereof. The substituent is preferably other than an N-carbazolyl group, an indolocarbazolyl group, or an indenocarbazolyl group, and more preferably a phenyl group, a naphthyl group, or a fluorenyl group. It is also preferable that the group has no substituent.

[0387] (Ar 55 ) Ar 55 is a monovalent group in which a plurality of groups selected from an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked together directly or via a linking group. Preferably, it is a group in which a plurality of optionally substituted monovalent aromatic hydrocarbon groups or optionally substituted monovalent aromatic hydrocarbon groups are linked together.

[0388] The substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group may have may have a crosslinking group, and are preferably the same groups as those in the above-mentioned group Z of substituents. As the crosslinking group, a group selected from the group T of crosslinking groups described below can be used.

[0389] When a plurality of aromatic hydrocarbons are linked, they are preferably divalent groups of 2 to 10 linked rings, and more preferably monovalent groups of 2 to 5 linked rings. 51 The same aromatic hydrocarbon groups and aromatic heterocyclic groups as those mentioned above can be used.

[0390] Ar 55 It is preferable that the compound has a structure represented by any one of the following schemes 2. Furthermore, from the viewpoint of distributing the LUMO of the molecule, it is preferable that the compound has a structure represented by any one of a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e - 1~e - Further, from the viewpoint of promoting the broadening of the LUMO of the molecule by having an electron-withdrawing group, a-1 to a-4, b-1 to b-9, d-1 to d-12, and e - 1~e - Further, from the viewpoint of the effect of confining excitons formed in the light-emitting layer, which have a high triplet level, a-1 to a-4, d-1 to d-12, and e - 1~e - 4 is preferred. In addition, from the viewpoint of easy synthesis and excellent stability, d-1 and d-10 are more preferred, and the benzene ring structure of d-1 is particularly preferred. Furthermore, these structures may have a substituent. In the figure, "-*" represents Ar 54 If there are multiple "-*", one of them must be Ar 54 represents the bonding position with

[0391] [ka]

[0392] [ka]

[0393] [ka]

[0394] <R 31 and R 32 > R in Scheme 2 31 and R 32 are each independently preferably a linear, branched, or cyclic alkyl group which may have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 to 6, more preferably 3 or less, and further preferably a methyl group or an ethyl group.

[0395] R 31 and R 32 may be the same or different, but all R 31 and R 32 are preferably the same groups.

[0396] Ar 55 As the substituent that may be possessed by Ar, any one of the substituents in the above-mentioned group Z or a combination thereof can be used. 54 It is preferable that the substituents are selected from the same substituents that may be possessed by the group.

[0397] (Ar 56 ) Ar 56 represents a hydrogen atom or a substituent. 56 When Ar is a substituent, it is not particularly limited, but is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. 53 ~Ar 54 It is a monovalent structure similar to the aromatic hydrocarbon structure and aromatic heterocyclic structure mentioned above.

[0398] Ar 56 When is a substituent, it may have a crosslinking group. As the crosslinking group, a group selected from the group T of crosslinking groups described below can be used.

[0399] Ar 56 When Ar is a substituent, it is preferably bonded to the 3-position of carbazole from the viewpoint of improving durability. 56 is preferably a hydrogen atom from the viewpoint of ease of synthesis and charge transport properties. 56 From the viewpoint of improving durability and charge transportability, is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and more preferably an aromatic hydrocarbon group which may have a substituent.

[0400] Ar 56 is preferably a hydrogen atom from the viewpoint of ease of synthesis and charge transport properties.

[0401] Ar 56 When is an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, the substituents are the same as those exemplified in the above-mentioned substituent group Z, the preferred substituents are also the same, and the substituents that these substituents may further have are also the same.

[0402] (Formula (52)) In addition, the polymer may contain Ar in the repeating unit represented by the above formula (50). 51 At least one of the groups is preferably a group represented by the following formula (52): The reason for this is thought to be that in the two carbazole structures in the following formula (52), the LUMOs are distributed in the aromatic hydrocarbon group or aromatic heterocyclic group between the nitrogen atoms, thereby suppressing the influence on the main chain amine in formula (50) and improving the durability of the main chain amine against electrons and excitons.

[0403] [ka]

[0404] (In formula (52), Ar 61 and Ar 62 each independently represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent, Ar 63 ~Ar 65 are each independently a hydrogen atom or a substituent. * indicates the bonding position to the nitrogen atom in formula (50).

[0405] (Ar 63 ~Ar 65 ) Ar 63 ~Ar 65 each independently represents a hydrogen atom or a substituent. 63 ~Ar 65 When Ar is a substituent, the substituent is not particularly limited, but is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Preferred structures of the aromatic hydrocarbon group and the aromatic heterocyclic group include the above-mentioned Ar 51 The groups are the same as those listed above.

[0406] Ar 63 ~Ar 65 is a substituent, Ar 63 ~Ar 65 is preferably bonded to the 3- or 6-position of each carbazole structure from the viewpoint of improving durability.

[0407] Ar 63 ~Ar 65 is preferably a hydrogen atom from the viewpoint of ease of synthesis and charge transport properties.

[0408] Ar 63 ~Ar 65 From the viewpoint of improving durability and charge transportability, is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and more preferably an aromatic hydrocarbon group which may have a substituent.

[0409] Ar 63 ~Ar 65 When is an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, the substituents are the same as those exemplified in the above-mentioned substituent group Z, the preferred substituents are also the same, and the substituents that these substituents may further have are also the same.

[0410] (Ar 62 ) Ar 62 is a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent.

[0411] The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, more preferably 10 to 50 carbon atoms, and particularly preferably 12 to 40 carbon atoms. Specific examples of the aromatic hydrocarbon group include divalent groups of 6-membered monocyclic or 2- to 5-condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, or groups in which multiple such groups are linked together. When multiple such groups are linked together, the multiple linked divalent aromatic hydrocarbon groups are preferably conjugated.

[0412] The aromatic heterocyclic group preferably has 3 to 60 carbon atoms, and specific examples thereof include a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienothiophene ring, a furopyrrole ring, a furofuran ring, a thienofuran ring, and a benzoiso Examples thereof include a divalent group of a 5- or 6-membered monocyclic ring or a 2- to 4-condensed ring such as an oxazole ring, a benzisothiazole ring, a benzimidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a phenanthridine ring, a benzimidazole ring, a perimidine ring, a quinazoline ring, a quinazolinone ring, or an azulene ring, or a group in which a plurality of these rings are linked together.

[0413] The substituents that these aromatic hydrocarbon groups or aromatic heterocyclic groups may have include the alkyl groups, aralkyl groups, and aromatic hydrocarbon groups of the above-mentioned substituent group Z. 62 In the case where the structure of Ar is twisted, it is preferable to have no substituents. 62 In the case where the structure does not become distorted, it is preferable that the group has a substituent.

[0414] Ar 62 Preferred groups are divalent groups of a benzene ring, a naphthalene ring, an anthracene ring, or a fluorene ring, or groups in which multiple such groups are linked together, more preferably divalent groups of benzene rings or groups in which multiple such groups are linked together, particularly preferably 1,4-phenylene groups in which benzene rings are linked together at the divalent positions of the 1 and 4, 2,7-fluorenylene groups in which fluorene rings are linked together at the divalent positions of the 2 and 7, or groups in which multiple such groups are linked together, and most preferably a group containing "1,4-phenylene group-2,7-fluorenylene group-1,4-phenylene group-".

[0415] In these preferred structures, the phenylene group does not have a substituent other than the linking position, which is due to the steric effect of the substituent. 62 In addition, it is preferable that the fluorenylene group has substituents at the 9,9' positions from the viewpoint of improving the solubility and durability of the fluorene structure.

[0416] (Ar 61 ) Ar 61 is a divalent group that connects to the nitrogen atom of the main chain amine in formula (52). Ar 61 is a divalent aromatic hydrocarbon group which may have a substituent or a divalent aromatic heterocyclic group which may have a substituent.

[0417] Ar 61 The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, more preferably 10 to 50 carbon atoms, and particularly preferably 12 to 40 carbon atoms. Specific examples of the aromatic hydrocarbon group include divalent groups of a 6-membered monocyclic ring or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, or groups in which multiple of these are linked together.

[0418] Ar 61 The aromatic heterocyclic group preferably has 3 to 60 carbon atoms. Specific examples thereof include a 5- or 6-membered monocyclic or 2- to 4-fused ring divalent group, such as a furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, and azulene ring, or a group in which a plurality of these are linked together.

[0419] The substituents which these aromatic hydrocarbon groups or aromatic heterocyclic groups may have include the alkyl groups, aralkyl groups and aromatic hydrocarbon groups of the above-mentioned substituent group Z.

[0420] When a plurality of such divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked, the plurality of linked divalent aromatic hydrocarbon groups are preferably linked so as not to be conjugated. Specifically, it is preferable that the group contains a 1,3-phenylene group or a group having a substituent and forming a twisted structure due to the steric effect of the substituent.

[0421] (Formula (53)) Ar in the repeating unit represented by the formula (50) 51 At least one of the above is preferably a group represented by the following formula (53):

[0422] [ka]

[0423] In formula (53), * represents a bond to the nitrogen atom of the main chain of formula (50), Ar 71 represents a divalent aromatic hydrocarbon group which may have a substituent, Ar 72 and Ar 73 each independently represent an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a monovalent group in which two or more groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups are linked together directly or via a linking group; Ring HA is an aromatic heterocycle containing a nitrogen atom, X 2 , Y 2 each independently represents a carbon atom or a nitrogen atom; X 2 and Y 2 When at least one of the groups is a carbon atom, the carbon atom may have a substituent.

[0424] <Ar 71 > Ar 71 is the Ar 53 is a group similar to Ar 71 As the divalent aromatic hydrocarbon group, one optionally substituted divalent hydrocarbon group or a group in which 2 to 10 optionally substituted divalent aromatic hydrocarbon groups are linked together is preferred, one optionally substituted divalent aromatic hydrocarbon group or a group in which 2 to 8 optionally substituted divalent aromatic hydrocarbon groups are linked together is more preferred, and among these, a group in which two or more optionally substituted divalent aromatic hydrocarbon groups are linked together is preferred.

[0425] Ar 71 As the alkyl group, a group in which 2 to 6 benzene rings which may have a substituent are linked is particularly preferred, and a quaterphenylene group in which 4 benzene rings which may have a substituent are linked is most preferred.

[0426] Also, Ar 71 preferably contains at least one benzene ring linked at the 1,3-position, which is a non-conjugated moiety, and more preferably contains two or more.

[0427] Ar 71 In the case where a plurality of divalent aromatic hydrocarbon groups which may have a substituent are linked together, it is preferred that all of them are linked together by direct bonding from the viewpoint of charge transport properties or durability.

[0428] For this reason, Ar 71 Preferred structures linking the nitrogen atom in the main chain of the polymer and the ring HA in the formula (53) are as shown in Scheme 2-1 and Scheme 2-2 below. "-*" represents the bonding site with the nitrogen atom in the main chain of the polymer or the ring HA in the formula (53). Either of the two "-*"s may be bonded to the nitrogen atom in the main chain of the polymer or to the ring HA.

[0429] [ka]

[0430] [ka]

[0431] Ar 71 The substituents that Ar may have include any one of the substituents in the above-mentioned group Z or a combination thereof. 71 The preferred range of the substituents that may be possessed by G is the same as the substituents that may be possessed when G is an aromatic hydrocarbon group.

[0432] <X 2 and Y 2 > X 2 and Y 2 each independently represents a C (carbon) atom or an N (nitrogen) atom. 2 and Y 2 When at least one of them is a C atom, it may have a substituent.

[0433] X is chosen to localize the LUMO more easily around the HA ring. 2 and Y 2 are preferably all N atoms.

[0434] X 2 and Y 2 When at least one of X is a C atom, the substituent that may be present may be any one of the substituents in the above-mentioned group Z or a combination thereof. 2 and Y 2 More preferably, has no substituent.

[0435] <Ar 72 and Ar 73 > Ar 72 and Ar 73 are each independently an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group in which two or more groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent are linked together directly or via a linking group.

[0436] From the viewpoint of distributing the LUMO of the molecule, Ar 72 and Ar 73 each independently have a structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e-1 to e-4 shown in Scheme 2 above.

[0437] Furthermore, from the viewpoint of promoting the broadening of the LUMO of the molecule by having an electron-withdrawing group, structures selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-12, and e-1 to e-4 are preferred.

[0438] Furthermore, from the viewpoint of a high triplet level and the effect of confining excitons formed in the light-emitting layer, structures selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4 are preferred.

[0439] In order to prevent aggregation of molecules, structures selected from d-1 to d-12 and e-1 to e-4 are more preferred. 72 =Ar 73 = d-1 or d-10 is preferred, and the benzene ring structure of d-1 is particularly preferred.

[0440] These structures may also have a substituent. "-*" represents the binding site to the cyclic HA. When there are multiple "-*", any one of them represents the binding site to the cyclic HA.

[0441] Ar 72 and Ar 73 As the substituent that may be possessed by the compound, any one of the substituents in the substituent group Z or a combination thereof can be used. From the viewpoint of durability and charge transport properties, the substituent is preferably a group similar to the substituent group Z.

[0442] (Ar 52 ) Ar 52 Aromatic hydrocarbon groups and aromatic heterocycle The group is Ar of formula (50). 51 In addition, Ar 52 Aromatic hydrocarbon groups and aromatic heterocycle The substituents that the group may have are preferably the same as those in the group Z of substituents.

[0443] [Bridging group] A crosslinking group is a group that reacts with another crosslinking group located in the vicinity of the crosslinking group upon exposure to heat and / or active energy rays to form a new chemical bond. In this case, the reactive group may be the same as or different from the crosslinking group.

[0444] Examples of the crosslinking group include a group containing an alkenyl group, a group containing a conjugated diene structure, a group containing an alkynyl group, a group containing an oxirane structure, a group containing an oxetane structure, a group containing an aziridine structure, an azide group, a group containing a maleic anhydride structure, a group containing an alkenyl group bonded to an aromatic ring, a cyclobutene ring fused to an aromatic ring, etc. Specific examples of the crosslinking group include groups selected from the following group T of crosslinking groups.

[0445] (Bridging group T) [ka]

[0446] [ka]

[0447] In the above-mentioned bridging group T, R XL represents a methylene group, an oxygen atom, or a sulfur atom; R 100 represents a hydrogen atom or an alkyl group which may have a substituent, n XL represents an integer from 0 to 5. XL When there are multiple, they may be the same or different, and n XL When there are multiple R groups, they may be the same or different. *1 indicates the bonding position. These bridging groups may have a substituent. When R is an alkyl group or a bridging group, 100 The substituents which may be possessed by are preferably those described in the above-mentioned substituent group Z.

[0448] <Preferred repeating unit represented by formula (50)> Hereinafter, as more preferred repeating units of the above formula (50), repeating units of the following formulas (54), (55), (56), (57), and (60) will be described in detail.

[0449] It is also preferable that the polymer having a triarylamine structure as a repeating unit contains a plurality of repeating units of different structures in each of the repeating units represented by these formulas.

[0450] <Repeating unit represented by formula (54)> [ka]

[0451] (In formula (54), Ar 51 is Ar in the formula (50). 51 is the same as X is -C(R 207 )(R 208 )-, -N(R 209 )- or -C(R 211 )(R 212 )-C(R 213 )(R 214 )- and R 201 , R 202 , R 221 and R 222 each independently represents an alkyl group which may have a substituent, R 207 ~R 209 and R 211 ~R 214 each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group, a and b each independently represent an integer of 0 to 4, c is an integer from 0 to 3, d is an integer from 0 to 4, R 201 If there are multiple R 201 may be the same or different, R 202 If there are multiple R 202 may be the same or different, R 221 If there are multiple R 221 may be the same or different, R 222 If there are multiple R 222 may be the same or different, i and j are each independently an integer of 0 to 3.

[0452] (R 201 , R 202 , R 221 , R 222 ) R in the repeating unit represented by the above formula (54) 201 , R 202 , R 221 and R 222 are each independently an alkyl group which may have a substituent.

[0453] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more, and is preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. The alkyl group is more preferably a methyl group or an ethyl group.

[0454] R 201 If there are multiple R 201 may be the same or different, and R 202 If there are multiple R 202 may be the same or different. All R 201 and R 202 are preferably the same groups.

[0455] R 221 If there are multiple R 221 may be the same or different, and R 222 If there are multiple R 222 may be the same or different. Since the charge can be uniformly distributed around the nitrogen atom and synthesis is easy, all R 221 and R 222 are preferably the same groups.

[0456] (R 207 ~R 209 and R 211 ~R 214 ) R 207 ~R 209 and R 211 ~R 214 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

[0457] The alkyl group is not particularly limited, but since this tends to improve the solubility of the polymer, the number of carbon atoms is preferably 1 or more, and is preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less. The alkyl group may have a linear, branched, or cyclic structure.

[0458] Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, a cyclohexyl group, and a dodecyl group.

[0459] The aralkyl group is not particularly limited, but preferably has 5 or more carbon atoms, and preferably 60 or less, more preferably 40 or less, since this tends to improve the solubility of the polymer.

[0460] Specific examples of the aralkyl group include a 1,1-dimethyl-1-phenylmethyl group, a 1,1-di(n-butyl)-1-phenylmethyl group, a 1,1-di(n-hexyl)-1-phenylmethyl group, a 1,1-di(n-octyl)-1-phenylmethyl group, a phenylmethyl group, a phenylethyl group, a 3-phenyl-1-propyl group, a 4-phenyl-1-n-butyl group, a 1-methyl-1-phenylethyl group, a 5-phenyl-1-n-propyl group, a 6-phenyl-1-n-hexyl group, a 6-naphthyl-1-n-hexyl group, a 7-phenyl-1-n-heptyl group, an 8-phenyl-1-n-octyl group, and a 4-phenylcyclohexyl group.

[0461] The aromatic hydrocarbon group is not particularly limited, but preferably has 6 or more carbon atoms, and preferably 60 or less, more preferably 30 or less, since this tends to improve the solubility of the polymer.

[0462] Specific examples of the aromatic hydrocarbon group include monovalent groups of 6-membered monocyclic rings or 2 to 5 condensed rings such as a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring, or groups in which a plurality of these are linked together.

[0463] From the viewpoint of improving charge transport properties and durability, R 207 and R 208 is preferably a methyl group or an aromatic hydrocarbon group, and R 207 and R 208 is more preferably a methyl group, and R 209 is more preferably a phenyl group.

[0464] R 201 , R 202 , R 221 , R 222 alkyl group, R 207 ~R 209 and R 211 ~R 214 The alkyl group, aralkyl group and aromatic hydrocarbon group may have a substituent. 207 ~R 209 and R 211 ~R 214 Examples of the alkyl group, aralkyl group and aromatic hydrocarbon group include those mentioned above as preferred groups.

[0465] R 201 , R 202 , R 221 , R 222 alkyl group, R 207 ~R 209 and R 211 ~R 214 From the viewpoint of reducing the voltage, it is most preferable that the alkyl group, aralkyl group and aromatic hydrocarbon group have no substituent.

[0466] (a, b, c and d) In the repeating unit represented by the above formula (54), a and b are each independently an integer of 0 to 4. Preferably, a+b is 1 or greater, and each of a and b is preferably 2 or less, with both a and b being 1 being more preferred. Here, a being 1 or greater means that c is 1 or greater, and b being 1 or greater means that d is 1 or greater. When b is 1 or greater, d is also preferably 1 or greater. When c is 2 or greater, multiple a's may be the same or different, and when d is 2 or greater, multiple b's may be the same or different.

[0467] When a+b is 1 or more, the aromatic rings in the main chain are twisted due to steric hindrance, resulting in excellent solubility of the polymer in solvents, and the coating film formed by a wet film-forming method and heat-treated tends to be excellent insolubility in solvents. Therefore, when a+b is 1 or more, when another organic layer (e.g., a light-emitting layer) is formed on this coating film by a wet film-forming method, elution of the polymer into the organic solvent-containing composition for forming the light-emitting layer used in the present invention is suppressed. As a result, it is thought that the formed light-emitting layer is less affected, and the operating life of the organic electroluminescent device is further extended.

[0468] In the repeating unit represented by the above formula (54), c is an integer of 0 to 3, and d is an integer of 0 to 4. It is preferable that c and d are each 2 or less, more preferably c and d are equal, and particularly preferably that both c and d are 1 or both c and d are 2.

[0469] In the repeating unit represented by the above formula (54), when both c and d are 1 or both c and d are 2, and both a and b are 2 or 1, R 201 and R 202 are most preferably bonded at positions symmetrical to each other.

[0470] where R 201 and R 202 and are bonded at positions symmetric to each other means that R 201 and R 202 In this case, a 180-degree rotation around the main chain is considered to be the same structure.

[0471] R 221 and R 222 When present, each of R is preferably independently located at the 1st, 3rd, 6th, or 8th position relative to the carbon atom of the benzene ring to which X is bonded. 221 and / or R 222 The existence of R 221 and / or R 222 is bonded to a fused ring and the adjacent benzene ring on the main chain are twisted due to steric hindrance, and the polymer has excellent solubility in solvents, and a coating film formed by a wet film-forming method and heat-treated tends to have excellent insolubility in solvents, which is preferable.

[0472] (i and j) In the repeating unit represented by the above formula (54), i and j are each independently an integer of 0 to 3. i and j are each independently preferably an integer of 0 to 2, more preferably 0 or 1. i and j are preferably the same integer. i and j are preferably 1 or 2 in order to twist the main chain of the polymer, and R 221 and / or R 222 is preferably bonded to the 1st and / or 3rd positions of the benzene ring. From the viewpoint of ease of synthesis, it is preferable that i and j are 0. The bonding position to the benzene ring is the carbon atom adjacent to the carbon atom to which X is bonded, and R 221 or R 222 The carbon atom to which the molecule can be bonded is the first position, and the carbon atom that is bonded to the adjacent structure as the main chain is the second position.

[0473] (Ar 51 ) In the repeating unit represented by the above formula (54), Ar 51 is Ar in the formula (50). 51 and is a group in which a plurality of groups selected from an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, and an aromatic heterocyclic group which may have a substituent are linked together.

[0474] Examples of the group in which a plurality of groups selected from an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, and an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked include Ar 51 The same substituents and preferred structures as those of Ar in the formula (50) are also included. 51 The same as in the case of

[0475] (Other preferred Ar 51 ) Ar in the repeating unit represented by the above formula (54) 51 It is more preferable that at least one of the above is a group represented by the formula (51), the formula (52), or the formula (53). In the two carbazole structures in the formula (51), the LUMO is distributed in the aromatic hydrocarbon group or aromatic heterocyclic group between the nitrogen atoms, which is thought to tend to improve durability against electrons and excitons.

[0476] (X) X in the above formula (54) is -C(R 207 )(R 208 )- or -N(R 209 )-, and -C(R 207 )(R 208 )- is more preferred.

[0477] In addition, in the polymer containing the repeating unit represented by the above formula (54), Ar 51 , R 201 , R 202 , R 221 , R 222 When there are a plurality of X's, they may be the same or different. Preferably, the polymer contains a plurality of repeating units represented by formula (54) having the same structure. In this case, when the polymer contains a plurality of repeating units having the same structure, the HOMO and LUMO of the repeating units are the same, so that charges are not concentrated at a specific shallow level to form traps, and it is thought that this results in excellent charge transport properties.

[0478] (Preferred repeating unit) The repeating unit represented by the above formula (54) is particularly preferably a repeating unit represented by any one of the following formulae (54-1) to (54-8).

[0479] [ka]

[0480] [ka]

[0481] In the above formula, R 201 and R 202 are identical and R 201 and R 202 are bonded at symmetric positions to each other.

[0482] [Specific examples of the main chain of the repeating unit represented by formula (54)] The main chain structure excluding the nitrogen atom in the above formula (54) is not particularly limited, but examples include the following structures.

[0483] [ka]

[0484] [ka]

[0485] [ka]

[0486] [ka]

[0487] [ka]

[0488] [ka]

[0489] [ka]

[0490] [ka]

[0491] [Content of repeating unit represented by formula (54)] In the polymer contained in the second organic layer, the content of the repeating unit represented by formula (54) is not particularly limited, but the repeating unit represented by formula (54) is usually contained in the polymer in an amount of 10 mol % or more, preferably 30 mol % or more, more preferably 40 mol % or more, and even more preferably 50 mol % or more.

[0492] The polymer contained in the second organic layer may be composed solely of the repeating unit represented by formula (54), but for the purpose of balancing various performances when formed into an organic electroluminescent device, it may also contain a repeating unit other than formula (54). In this case, the content of the repeating unit represented by formula (54) in the polymer is usually 99 mol % or less, preferably 95 mol % or less.

[0493] [Terminal group] In this specification, the term "terminal group" refers to the structure of the terminal portion of the polymer formed by an endcapping agent used at the end of polymerization of the polymer. In the second organic layer, the terminal group of the polymer containing the repeating unit represented by formula (54) is preferably a hydrocarbon group. From the viewpoint of charge transportability, the hydrocarbon group preferably has 1 to 60 carbon atoms, more preferably 1 to 40 carbon atoms, and even more preferably 1 to 30 carbon atoms.

[0494] Examples of the hydrocarbon group include: a linear, branched, or cyclic alkyl group having usually 1 or more, preferably 4 or more, and usually 24 or less, preferably 12 or less, carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, a cyclohexyl group, or a dodecyl group; a linear, branched, or cyclic alkenyl group, such as a vinyl group, which usually has 2 or more carbon atoms and usually has 24 or less carbon atoms, preferably 12 or less carbon atoms; a linear or branched alkynyl group, such as an ethynyl group, having typically 2 or more carbon atoms and typically 24 or less, and preferably 12 or less, carbon atoms; Examples include aromatic hydrocarbon groups having usually 6 or more carbon atoms and usually 36 or less, and preferably 24 or less, such as a phenyl group and a naphthyl group.

[0495] These hydrocarbon groups may further have a substituent, and the optional substituent is preferably an alkyl group or an aromatic hydrocarbon group. When there are a plurality of these optional additional substituents, they may be bonded to each other to form a ring.

[0496] From the viewpoint of charge transportability and durability, the terminal group is preferably an alkyl group or an aromatic hydrocarbon group, and more preferably an aromatic hydrocarbon group.

[0497] <Repeating unit represented by formula (55)>

[0498] [ka]

[0499] (In formula (55), Ar 51 is Ar in the formula (50) or the formula (54). 51 is the same as R 303 and R 306 each independently represents an alkyl group which may have a substituent, R 304 and R 305 each independently represents an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group, l is 0 or 1; m is 1 or 2; n is 0 or 1 p is 0 or 1; q is 0 or 1.

[0500] (R 303 , R 306 ) R in the repeating unit represented by the above formula (55) 303 and R 306 are each independently an alkyl group which may have a substituent. The alkyl group is R in the formula (54). 201 and R 202 The substituents that may be present and preferred structures are the same as those of R 201 and R 202 The same can be mentioned. R 303 If there are multiple R 303 may be the same or different, and R 306 If there are multiple R 306 may be the same or different.

[0501] (R 304 , R 305 ) R in the repeating unit represented by the above formula (55) 304 and R 305 are each independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group, preferably an optionally substituted alkyl group. R 304 and R 305 are preferably the same.

[0502] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 or more, and is preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less, since this tends to improve the solubility of the polymer.

[0503] Specific examples include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, an n-octyl group, a cyclohexyl group, and a dodecyl group.

[0504] The alkoxy group is not particularly limited, and may be an alkoxy group (-OR 10 )R 10 The group may have a linear, branched, or cyclic structure, and preferably has 1 or more carbon atoms, preferably 24 or less, and more preferably 12 or less, since this tends to improve the solubility of the polymer.

[0505] Specific examples include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, a hexyloxy group, a 1-methylpentyloxy group, and a cyclohexyloxy group.

[0506] The aralkyl group is not particularly limited, but preferably has 5 or more carbon atoms, and preferably has 60 or less, and more preferably has 40 or less carbon atoms, since this tends to improve the solubility of the polymer.

[0507] Specific examples include a 1,1-dimethyl-1-phenylmethyl group, a 1,1-di(n-butyl)-1-phenylmethyl group, a 1,1-di(n-hexyl)-1-phenylmethyl group, a 1,1-di(n-octyl)-1-phenylmethyl group, a phenylmethyl group, a phenylethyl group, a 3-phenyl-1-propyl group, a 4-phenyl-1-n-butyl group, a 1-methyl-1-phenylethyl group, a 5-phenyl-1-n-propyl group, a 6-phenyl-1-n-hexyl group, a 6-naphthyl-1-n-hexyl group, a 7-phenyl-1-n-heptyl group, an 8-phenyl-1-n-octyl group, and a 4-phenylcyclohexyl group.

[0508] (l, m and n) l represents 0 or 1, and n represents 0 or 1.

[0509] l and n are each independent, and l+n is preferably 1 or more, more preferably 1 or 2, and even more preferably 2. When l+n is within the above range, the solubility of the polymer contained in the second organic layer tends to be increased, and precipitation from the composition for organic electroluminescent elements containing the polymer tends to be suppressed.

[0510] m represents 1 or 2, and is preferably 1, since the organic electroluminescent device of the present invention can be driven at a low voltage and hole injection ability, transport ability, and durability tend to be improved.

[0511] (p and q) p represents 0 or 1, and q represents 0 or 1. When l is 2 or greater, the multiple p's may be the same or different. When n is 2 or greater, the multiple q's may be the same or different. When l = n = 1, p and q cannot be 0 at the same time. When p and q are not 0 at the same time, the solubility of the polymer contained in the composition of the present invention is increased and precipitation from a second composition containing the polymer tends to be suppressed. Furthermore, when p + q is 1 or greater, the aromatic rings in the main chain are twisted due to steric hindrance, which improves the solubility of the polymer in solvents, and the coating film formed by a wet film-forming method and heat-treated tends to be insoluble in solvents. Therefore, when another organic layer (e.g., a light-emitting layer) is formed on this coating film by a wet film-forming method, elution of the polymer into the composition for forming the other organic layer, which contains an organic solvent, is suppressed.

[0512] (Ar 51 ) In the repeating unit represented by the above formula (55), Ar 51 is Ar in the formula (50) or the formula (54). 51 and is a group in which a plurality of groups selected from an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, and an aromatic heterocyclic group which may have a substituent are linked together.

[0513] Examples of the group in which a plurality of groups selected from an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, and an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked include Ar 51 The same substituents and preferred structures as those of Ar in the formula (50) are also included. 51 The same as in the case of

[0514] [Specific examples of the main chain of the repeating unit represented by formula (55)] The main chain structure excluding the N atom of the repeating unit represented by formula (55) is not particularly limited, but examples thereof include the following structures.

[0515] [ka]

[0516] [ka]

[0517] [ka]

[0518] [ka]

[0519] [ka]

[0520] [ka]

[0521] [ka]

[0522] [ka]

[0523] [Content of repeating unit represented by formula (55)] In the polymer contained in the second organic layer, the content of the repeating unit represented by formula (55) is not particularly limited, but the repeating unit represented by formula (55) is usually contained in the polymer in an amount of 10 mol % or more, preferably 30 mol % or more, more preferably 40 mol % or more, and particularly preferably 50 mol % or more.

[0524] The polymer contained in the second organic layer may be composed solely of the repeating unit represented by formula (55), but for the purpose of balancing various performances when formed into an organic electroluminescent device, it may also contain a repeating unit other than formula (55). In this case, the content of the repeating unit represented by formula (55) in the polymer is usually 99 mol % or less, preferably 95 mol % or less.

[0525] [Terminal group] In the polymer contained in the second organic layer, the end group of the polymer containing the repeating unit represented by formula (55) is preferably a hydrocarbon group, similar to the end group of the polymer containing the repeating unit represented by formula (54). Preferred hydrocarbon groups and the substituents that may be possessed are also similar to those of the end group of the polymer containing the repeating unit represented by formula (54).

[0526] <Repeating unit represented by formula (56)> [ka]

[0527] (In formula (56), Ar 51 is Ar in the formula (50), the formula (54) or the formula (55). 51 is the same as Ar 41 represents a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is linked together directly or via a linking group, R 441 and R 442 each independently represents an alkyl group which may have a substituent, t is 1 or 2; u is 0 or 1; r and s are each independently an integer of 0 to 4.

[0528] (R 441 , R 442 ) R in the repeating unit represented by the above formula (56) 441 , R 442 are each independently an alkyl group which may have a substituent.

[0529] The alkyl group is a linear, branched, or cyclic alkyl group which may have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the number of carbon atoms is preferably 1 or more, and is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. The alkyl group is more preferably a methyl group or a hexyl group.

[0530] R 441 and R 442 When there are a plurality of repeating units represented by the above formula (56), R 441 and R 442 may be the same or different.

[0531] (r, s, t and u) In the repeating unit represented by formula (56), r and s each independently represent an integer of 0 to 4. When t is 2 or greater, multiple r's may be the same or different, and when u is 2 or greater, multiple s's may be the same or different. r+s is preferably 1 or greater, and each of r and s is preferably 2 or less. When r+s is 1 or greater, the operating life of the organic electroluminescent device is thought to be further extended.

[0532] In the repeating unit represented by the above formula (56), t is 1 or 2, and u is 0 or 1. t is preferably 1, and u is preferably 1.

[0533] (Ar 51 ) In the repeating unit represented by the above formula (56), Ar 51 is Ar in the formula (50), the formula (54) or the formula (55). 51 and is a group in which a plurality of groups selected from an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, and an aromatic heterocyclic group which may have a substituent are linked together.

[0534] The aromatic hydrocarbon group which may have a substituent or the aromatic heterocyclic group which may have a substituent includes Ar in the formula (50). 51 The same substituents and preferred structures as those of Ar in the formula (50) are also included. 51 The same as in the case of

[0535] (Ar 41 ) Ar 41 is a divalent aromatic hydrocarbon group which may have a substituent, a divalent aromatic heterocyclic group which may have a substituent, or a divalent group in which a plurality of at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is linked together directly or via a linking group.

[0536] Ar 41 Aromatic hydrocarbon groups and aromatic heterocycle The group is Ar in the formula (50). 52 In addition, aromatic hydrocarbon groups and aromatic heterocycle The substituents that the group may have are preferably the same as those in the group Z of substituents, and the substituents that the group may further have are preferably the same as those in the group Z of substituents.

[0537] [Specific examples of repeating units represented by formula (56)] Specific examples of the main chain of the repeating unit represented by formula (56) are shown below.

[0538] [ka]

[0539] [Content of repeating unit represented by formula (56)] In the polymer contained in the second organic layer, the content of the repeating unit represented by formula (56) is not particularly limited, but the repeating unit represented by formula (56) is usually contained in the polymer in an amount of 10 mol % or more, preferably 30 mol % or more, more preferably 40 mol % or more, and particularly preferably 50 mol % or more.

[0540] The polymer contained in the second organic layer may be composed solely of the repeating unit represented by formula (56), but for the purpose of balancing various performances when formed into an organic electroluminescent device, it may also contain a repeating unit other than formula (56). In this case, the content of the repeating unit represented by formula (56) in the polymer is usually 99 mol % or less, preferably 95 mol % or less.

[0541] [Terminal group] In the polymer contained in the second organic layer, the end group of the polymer containing the repeating unit represented by formula (56) is preferably a hydrocarbon group, similar to the end group of the polymer containing the repeating unit represented by formula (54). Preferred hydrocarbon groups and the substituents that may be possessed are also similar to those of the end group of the polymer containing the repeating unit represented by formula (54).

[0542] <Repeating unit represented by formula (57)> [ka]

[0543] (In formula (57), Ar 51 is Ar in the formula (50), the formula (54), the formula (55) or the formula (56). 51 is the same as R 517 ~R 519 each independently represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aralkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent; f, g, and h each independently represent an integer of 0 to 4; e represents an integer of 0 to 3; However, if g is 1 or greater, e is 1 or greater.)

[0544] (R 517 ~R 519 ) R 517 ~R 519 The aromatic hydrocarbon group and aromatic heterocyclic group in each of the Ar 51 The substituents which these groups may have are preferably the same as those in the above-mentioned group Z of substituents.

[0545] R 517 ~R 519 The alkyl group and aralkyl group in the R 207 The same groups as those listed in R are preferred, and the substituents that may further be contained are also the same as those listed in R 207 Groups similar to the following are preferred.

[0546] R 517 ~R 519 The alkoxy group in the formula (I) is preferably the alkoxy group exemplified in the above-mentioned group Z of substituents, and the substituents that may be further substituted are also the same as those in the above-mentioned group Z of substituents.

[0547] (f, g, h) f, g, and h each independently represent an integer of 0 to 4. When e is 2 or more, the multiple g's may be the same or different. It is preferable that f+g+h is 1 or more. f+h is preferably 1 or greater, It is more preferable that f+h is 1 or more, and f, g, and h are 2 or less. It is more preferable that f+h is 1 or more, and f and h are 1 or less. Most preferably, f and h are both 1.

[0548] When f and h are both 1, R 517 and R 519 are preferably bonded at positions symmetrical to each other. Also, R 517 and R 519 are preferably identical to

[0549] More preferably, g is 2. If g is 2, then two R 518 are most preferably linked to each other in the para position, If g is 2, then two R 518 are most preferably the same.

[0550] where R 517 and R 519 are bonded at positions symmetrical to each other, the bond positions shown below are used. However, for the purposes of notation, a 180-degree rotation around the main chain axis is considered to be the same structure.

[0551] [ka]

[0552] When the polymer of this embodiment contains a repeating unit represented by formula (57), the ratio of the compound represented by formula (1) to the repeating unit represented by formula (57), (number of moles of repeating units represented by formula (57)) / (number of moles of the compound represented by formula (1)), is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, even more preferably 0.9 or more, and particularly preferably 1.0 or more. The ratio is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less.

[0553] The repeating unit represented by the formula (57) is preferably a repeating unit represented by the following formula (58).

[0554] [ka]

[0555] In the case of the repeating unit represented by the formula (58), it is preferable that g=0 or 2. When g=2, the bonding positions are the 2nd and 5th positions. When g=0, that is, R 518 When there is no steric hindrance due to the presence of two R 518 When the bond is diagonal to the benzene ring, R 517 and R 519 and can be bonded at positions symmetrical to each other.

[0556] Furthermore, the repeating unit represented by the formula (58) is more preferably a repeating unit represented by the following formula (59) in which e=3.

[0557] [ka]

[0558] In the case of the repeating unit represented by the formula (59), it is preferable that g=0 or 2. When g=2, the bonding positions are the 2nd and 5th positions. When g=0, that is, R 518 When there is no steric hindrance due to g = 2 and the bonding positions are 2 and 5, that is, when there is no steric hindrance due to two R 518 When the bond is diagonal to the benzene ring, R 517 and R 519 and can be bonded at positions symmetrical to each other.

[0559] <Specific examples of the main chain of the repeating unit represented by formula (57)> The main chain structure of the repeating unit represented by formula (57) is not particularly limited, but examples thereof include the following structures.

[0560] [ka]

[0561] It is preferable that the repeating unit represented by any of formulas (50) to (59) does not have a crosslinking group. When the repeating unit does not have a crosslinking group, it is preferable because the polymer chain is less likely to be distorted by heat drying or baking (heat baking) after wet film formation. This is because a volume change may occur when the crosslinking group reacts, resulting in polymer chain distortion. Furthermore, polymer chain distortion may occur even if no volume change occurs.

[0562] <Repeating unit represented by formula (60)> [ka]

[0563] (In formula (60), Ar 51 is Ar in the formula (50). 51 is the same as n 60 represents an integer from 1 to 5.)

[0564] (n 60 ) n 60 represents an integer of 1 to 5, preferably an integer of 1 to 4, and more preferably an integer of 1 to 3.

[0565] [Preferred repeating units] When the functional material used in the composition of the present invention is a polymer having a repeating unit represented by formula (50), the repeating unit represented by formula (50) is more preferably a repeating unit represented by formula (54), a repeating unit represented by formula (55), a repeating unit represented by formula (56), a repeating unit represented by formula (57), or a repeating unit represented by formula (60).

[0566] Among these, A repeating unit represented by formula (54) containing a partial structure represented by formula (61): A repeating unit represented by the formula (55) containing a partial structure represented by the following formula (61): A repeating unit represented by the formula (56) containing a partial structure represented by the following formula (61): Alternatively, it is preferably a polymer containing a repeating unit represented by the formula (57) which contains a partial structure represented by the following formula (61).

[0567] [ka]

[0568] (In formula (61) and formula (61'), R 601 is R in Eq. (54) 201 or R 202 , R in Eq. (55) 303 , R 304 , R 305 , or R 406 , R in Eq. (56) 441 or R+, R in formula (57) 517 , R 518 or R 519 and -* represents a bond to the adjacent atom. When formula (61) is a partial structure of formula (54) or a partial structure of formula (56), Ring B may be part of a fused ring. The partial structures represented by formula (61) and formula (61') are R 601 In addition, when Ring A and Ring B are a partial structure of formula (54), R 201 or R 202 , if it is a partial structure of formula (55), R 303 , R 304 , R 305 , or R 406 , if it is a partial structure of formula (56), R 441 or R 442 , if it is a partial structure of formula (57), R 517 , R 518 or R 519 It may have.) Incidentally, since the formula (61) and the formula (61') can be regarded as being the same, the formula (61) will be used in the following explanations when necessary.

[0569] The partial structure represented by the formula (61) is a substantially planar structure of Ring A and Ring B formed by π conjugation, which is represented by R 601 The main chain is distorted by the steric hindrance of the π-conjugated bond, resulting in a twisted structure compared to that of a normal π-conjugated bond. In other words, it has a twisted structure that inhibits conjugation. Therefore, the singlet excitation energy level and the triplet excitation energy level are increased, which makes it possible to block excitons in the adjacent light-emitting layer, and this tends to increase the luminous efficiency of the light-emitting element, which is preferable.

[0570] (Formula (62)) The repeating unit of the formula (54) is particularly preferred. The composition of the present invention more preferably contains a solvent compound represented by the formula (1) and a polymer having this repeating unit. The repeating unit of the formula (54) is preferably a repeating unit represented by the following formula (62):

[0571] [ka]

[0572] (In formula (62), Ar 51 , X, R 201 , R 202 , R 221 , R 222 , a, b, c, and d are Ar in the formula (54). 51 , X, R 201 , R 202 , R 221 , R 222 , a, b, c, d are the same, a 1 , a 2 , b 1 , b 2 , i 1 , i 2 , j 1 , j 2 are each independently 0 or 1. However, either of the following conditions (1) or (2) must be met. (1)a 1 , a 2 and a are each independently 1 or greater, b 1 , b 2 and b are each independently 1 or greater, c and d are each independently 1 or more; If c is 1, then a 1 or a 2 at least one of is 1, If d is 1, then b 1 or b 2 At least one of them is 1. (2)i 1 , i 2 , j 1 and j 2 are independent and at least one is 1. Ring B1 is R 201 and Ring B2 is R 201 a divalent group having c-1 benzene rings linked together, which may have the formula: Ring B3 refers to a divalent fused ring in which a biphenyl structure is further bonded via X. Ring B4 is R 202 a divalent group having d-1 benzene rings linked together, which may have the formula: Ring B5 is R 202 It refers to a divalent benzene ring which may have

[0573] Here, a in formula (54) being 1 or more means that a 1 , a 2 and a are equal to or greater than 1, and b being equal to or greater than 1 in formula (54) means that b 1 , b 2 and at least one of b is 1 or greater.

[0574] As shown below, the formula (62) contains the formula (61) as a partial structure. a 1 , a 2 and at least one of a is 1 or greater, a 1 or a 2 If at least one of is 1, when c is 2 or more, Ring B1 and Ring B2 contain the formula (61) as a partial structure; when c is 1, Ring B1 and Ring B3 each contain the formula (61) as a partial structure; When a is 1 or more and c is 2, Ring B2 and Ring B1, or Ring B2 and Ring B3, contain the formula (61) as a partial structure, When a is 1 or more and c is 3 or more, in addition to the above possibilities, Ring B2 may contain the above formula (61) as a partial structure.

[0575] Similarly, b 1 , b 2 It can be seen that when at least one of and b is 1 or more, the formula (61) is included as a partial structure.

[0576] Also, i 1 , i 2 , j 1 and j 2 If at least one of is 1, i 1 and i 2 If either or both of these are 1, then R in Ring B3 221 and the benzene ring of Ring B2 or Ring B1 form a partial structure represented by formula (61), j 1 and j 2 If either or both of these are 1, then R in Ring B3 222 It can be seen that the ring to which is bonded and the benzene ring of Ring B4 or Ring B5 form the partial structure of formula (61). That is, it can be seen that Ring B3 and Ring B2 or Ring B1, or Ring B3 and Ring B4 or Ring B5 have a twisted structure.

[0577] Therefore, formula (62) is preferable because the aromatic ring of the main chain has a twisted structure that inhibits conjugation.

[0578] [Molecular weight of polymer] The molecular weight of the polymer contained in the second organic layer will be described below.

[0579] The weight-average molecular weight (Mw) of the polymer containing the repeating unit represented by formula (54) is usually 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 200,000 or less, and particularly preferably 100,000 or less. The weight-average molecular weight is usually 2,500 or more, preferably 5,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and particularly preferably 17,000 or more.

[0580] When the weight-average molecular weight of the polymer is equal to or less than the upper limit, the polymer tends to have good solubility in a solvent and excellent film-forming properties. When the weight-average molecular weight of the polymer is equal to or greater than the lower limit, the polymer may have improved heat resistance because the glass transition temperature, melting point, and vaporization temperature are prevented from decreasing.

[0581] The number average molecular weight (Mn) of the polymer containing the repeating unit represented by formula (54) is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and particularly preferably 100,000 or less, and is usually 2,000 or more, preferably 4,000 or more, more preferably 6,000 or more, and even more preferably 8,000 or more.

[0582] Furthermore, the dispersity (Mw / Mn) of the polymer containing the repeating unit represented by formula (54) is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. Since the smaller the dispersity, the better, the lower limit is ideally 1. When the dispersity of the polymer is equal to or less than the above upper limit, purification is easy, and the solubility in solvents and charge transport ability are good.

[0583] The weight average molecular weight (Mw) of the polymer containing the repeating unit represented by formula (55) or formula (56) is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 17,000 or more. The weight average molecular weight is preferably 2,000,000 or less, more preferably 1,000,000 or less, and particularly preferably 100,000 or less.

[0584] When the weight-average molecular weight of the polymer is equal to or less than the upper limit, the increase in molecular weight of impurities is suppressed, and purification tends to be easy. On the other hand, when the weight-average molecular weight of the polymer is equal to or more than the lower limit, the decrease in the glass transition temperature, melting point, vaporization temperature, etc. is suppressed, and heat resistance tends to be improved.

[0585] The number average molecular weight (Mn) of the polymer containing the repeating unit represented by formula (55) or formula (56) is preferably 1,000,000 or less, more preferably 800,000 or less, and even more preferably 500,000 or less, and is preferably 4,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more.

[0586] Furthermore, the dispersity (Mw / Mn) of the polymer containing the repeating unit represented by formula (55) or formula (56) is preferably 3.5 or less, more preferably 3.0 or less, even more preferably 2.4 or less, particularly preferably 2.1 or less, and most preferably 2 or less. The dispersity of the polymer is preferably 1 or more, more preferably 1.1 or more, and even more preferably 1.2 or more. When the dispersity of the polymer is the above upper limit or less, purification becomes easy, and a decrease in solubility in solvents and a decrease in charge transport ability tend to be suppressed.

[0587] The weight-average molecular weight and number-average molecular weight of a polymer are usually determined by SEC (size exclusion chromatography) measurement. In SEC measurement, the higher the molecular weight component, the shorter the elution time, and the lower the molecular weight component, the longer the elution time. The weight-average molecular weight and number-average molecular weight are calculated by converting the elution time of the sample into molecular weight using a calibration curve calculated from the elution time of polystyrene (standard sample) with known molecular weight.

[0588] (Content of repeating unit represented by formula (50)) In the polymer, the content of the repeating unit represented by formula (50) is not particularly limited, but the repeating unit represented by formula (50) is usually contained in an amount of 10 mol % or more, preferably 30 mol % or more, more preferably 40 mol % or more, and even more preferably 50 mol % or more, based on 100 mol % of all repeating units in the polymer.

[0589] The polymer may be composed solely of the repeating unit represented by formula (50), but for the purpose of balancing various performances when made into an organic electroluminescent device, the polymer may contain a repeating unit other than the repeating unit represented by formula (50). In this case, the content of the repeating unit represented by formula (50) in the polymer is usually 99 mol % or less, preferably 95 mol % or less.

[0590] <Repeating unit represented by formula (50-2)> The polymer of the present invention containing an arylamine structure as a repeating unit may further contain a structure represented by the following formula (50-2) in the main chain.

[0591] [ka]

[0592] (In the formula, R 81 , R 82 R each independently represents a hydrogen atom, an alkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group. 81 , R 82 When there are multiple p, they may be the same or different. 80 represents an integer from 1 to 5.)

[0593] R 81 , R 82 When is an alkyl group, the alkyl group may be a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more, and is preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. The alkyl group is more preferably a methyl group or an ethyl group.

[0594] R 81 , R 82 When is an aromatic hydrocarbon group or an aromatic heterocyclic group, the structures described above in the "Definition" section are preferred.

[0595] R 81 , R 82 may have a substituent and / or a crosslinking group. The substituent is preferably a substituent selected from the above-mentioned substituent group Z. The crosslinking group is preferably a crosslinking group selected from the above-mentioned crosslinking group group Z.

[0596] From the viewpoint of polymer durability and charge transport property, 80 is preferably 3 or less, more preferably 2 or less, and most preferably 1.

[0597] By including the structure represented by formula (50-2), the conjugation of the main chain of the polymer is broken, and the S1 energy level and the T1 energy level of the polymer are increased. When a composition containing this polymer is used in a hole transport layer of an organic electroluminescent device, it is thought that excitons in the light-emitting layer are less likely to be deactivated, and the light-emitting efficiency is increased, which is preferable.

[0598] (Preferable repeating unit structure of polymer) Here, the specific structure of the repeating unit represented by each formula is referred to as the "repeat unit structure." The specific structure is a structure obtained by substituting specific structures or numerical values ​​for all symbols in the general formula. That is, a polymer having an arylamine structure as a repeating unit may contain only one repeating unit structure among the repeating unit structures represented by formula (54), the repeating unit structure represented by formula (55), the repeating unit structure represented by formula (56), the repeating unit structure represented by formula (57), and the repeating unit structure represented by formula (60), or may contain two or more repeating unit structures. When two or more repeating unit structures are contained, these two or more repeating units may be repeating unit structures represented by the same general formula or repeating unit structures represented by different general formulas. From the viewpoint of charge transport properties and durability, it is more preferable that the polymer having an arylamine structure as a repeating unit is a polymer that contains one or two of the specific repeating unit structures represented by each of these formulas and does not contain any other repeating unit structures.

[0599] [Specific example] Specific examples of polymers containing the repeating unit represented by formula (54) are shown below, but the polymers used in the present invention are not limited to these. The numbers in the chemical formulas represent the molar ratios of the repeating units, and n represents the number of repeats.

[0600] These polymers may be any of random copolymers, alternating copolymers, block copolymers, graft copolymers, etc., and there are no limitations on the sequence of the monomers.

[0601] [ka]

[0602] A polymer containing a repeating unit represented by formula (55) and Ar of the repeating unit represented by formula (55) 51 Specific examples of polymers having a structure represented by formula (52) are shown below, but the polymers used in the present invention are not limited to these. The numbers in the chemical formula represent the molar ratio of repeating units. n represents the number of repeats.

[0603] These polymers may be any of random copolymers, alternating copolymers, block copolymers, graft copolymers, etc., and the sequence of the monomers is not limited.

[0604] [ka]

[0605] [ka]

[0606] [ka]

[0607] [ka]

[0608] Specific examples of polymers containing the repeating unit represented by formula (56) are shown below, but the polymers used in the present invention are not limited to these. The numbers in the chemical formula represent the molar ratio of the repeating unit. n represents the number of repeats.

[0609] These polymers may be any of random copolymers, alternating copolymers, block copolymers, graft copolymers, etc., and there are no limitations on the sequence of the monomers.

[0610] [ka]

[0611] [ka]

[0612] <Method for producing the second polymer> The method for producing the second polymer contained in the second organic layer is not particularly limited and may be any method, such as a polymerization method based on the Suzuki reaction, a polymerization method based on the Grignard reaction, a polymerization method based on the Yamamoto reaction, a polymerization method based on the Ullmann reaction, or a polymerization method based on the Buchwald-Hartwig reaction.

[0613] In the case of the polymerization method using the Ullmann reaction and the polymerization method using the Buchwald-Hartwig reaction, for example, an aryl dihalide represented by the following formula (54a) (Z represents a halogen atom such as I, Br, Cl, or F) is reacted with a primary amino aryl represented by the following formula (54b) to synthesize a second polymer containing a repeating unit represented by the formula (54).

[0614] [ka]

[0615] (In the above reaction scheme, Ar 51 , R 201 , R 202 , X, and a to d have the same meanings as in the formula (2).

[0616] In the polymerization method using the Ullmann reaction and the polymerization method using the Buchwald-Hartwig reaction, for example, a polymer containing a repeating unit represented by formula (55) is synthesized by reacting an aryl dihalide represented by formula (55a) (Z represents a halogen atom such as I, Br, Cl, or F) with a primary amino aryl represented by formula (55b).

[0617] [ka]

[0618] (In the above reaction scheme, Ar 51 , R 303 ~R 306 , l to n, p, and q have the same meanings as in the formula (55).

[0619] In the above polymerization method, the reaction for forming the N-aryl bond is usually carried out in the presence of a base such as potassium carbonate, sodium tert-butoxide, triethylamine, etc. Alternatively, it can be carried out in the presence of a transition metal catalyst such as a copper or palladium complex.

[0620] [Second Composition] The second composition that forms the second organic layer will now be described. The second composition contains a second polymer and a solvent (organic solvent). This second composition is usually used to form an organic layer of the organic electroluminescent device of the present invention by a wet film-forming method. The organic layer is preferably a hole transport layer adjacent to the light-emitting layer formed from the light-emitting layer-forming composition of the present invention. The second composition may contain one type of second polymer, or two or more types in any combination and in any ratio.

[0621] (Content of second polymer) The content of the second polymer in the second composition is usually 0.01% by mass to 70% by mass, preferably 0.1% by mass to 60% by mass, and more preferably 0.5% by mass to 50% by mass. When the content of the second polymer is within the above range, defects are unlikely to occur in the formed organic layer, and thickness unevenness is unlikely to occur, which is preferable.

[0622] (solvent) The second composition usually contains a solvent. This solvent is preferably one that dissolves the second polymer. Specifically, a solvent that dissolves the second polymer in the second composition at room temperature is suitable, typically 0.05% by mass or more, preferably 0.5% by mass or more, and more preferably 1% by mass or more.

[0623] Specific examples of the solvent include aromatic solvents such as toluene, xylene, mesitylene, cyclohexylbenzene, and methylnaphthalene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, and 3-methoxytoluene. Examples of organic solvents include ether-based solvents such as aromatic ethers such as benzene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole; aliphatic ester-based solvents such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; and ester-based solvents such as aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, isopropyl benzoate, propyl benzoate, and n-butyl benzoate; as well as organic solvents used in the composition for forming a hole injection layer and the composition for forming a hole transport layer, which will be described later.

[0624] The solvent may be used alone or in any combination of two or more in any ratio.

[0625] The surface tension of the solvent at 20° C. is usually less than 40 dyn / cm, preferably 36 dyn / cm or less, more preferably 33 dyn / cm or less.

[0626] The vapor pressure of the solvent at 25° C. is usually 10 mmHg or less, preferably 5 mmHg or less, and usually 0.1 mmHg or more. By using such a solvent, it is possible to prepare a second composition that is suitable for the process of producing an organic electroluminescent device by a wet film-forming method and that is suited to the properties of the second polymer.

[0627] Specific examples of such solvents include the above-mentioned aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene, ether solvents, and ester solvents.

[0628] Moisture can cause performance degradation of organic electroluminescent devices, particularly accelerating a decrease in brightness during continuous operation. Therefore, in order to reduce the amount of moisture remaining during wet film formation as much as possible, the water solubility of the solvent at 25°C is preferably 1% by mass or less, more preferably 0.1% by mass or less.

[0629] The content of the solvent in the second composition is usually 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 80% by mass or more. By ensuring that the solvent content is equal to or greater than the lower limit, the flatness and uniformity of the formed layer can be improved.

[0630] [Electron-accepting compounds] In order to reduce the resistance, the second composition preferably further contains an electron-accepting compound. In particular, when the second composition is used to form a hole injection layer, the second composition preferably contains an electron-accepting compound.

[0631] The electron-accepting compound is preferably a compound having oxidizing power and the ability to accept one electron from the second polymer contained in the second organic layer. Specifically, a compound having an electron affinity of 4 eV or more is preferred, and a compound having an electron affinity of 5 eV or more is more preferred.

[0632] The second composition may contain one type of electron-accepting compound as described above, or may contain two or more types in any combination and ratio.

[0633] When the second composition contains an electron-accepting compound, the content of the electron-accepting compound in the second composition is usually 0.0005% by mass or more, preferably 0.001% by mass or more, and usually 20% by mass or less, preferably 10% by mass or less.

[0634] The ratio of the electron accepting compound to the second polymer in the second composition is usually 0.5% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, and is usually 80% by mass or less, preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0635] When the content of the electron-accepting compound in the second composition is equal to or greater than the lower limit, the electron acceptor accepts electrons from the second polymer, thereby reducing the resistance of the formed organic layer. When the content of the electron-accepting compound in the second composition is equal to or less than the upper limit, the formed organic layer is less likely to have defects and less likely to have uneven thickness.

[0636] [Cation radical compounds] The second composition may further contain a cation radical compound. The cation radical compound is preferably an ionic compound consisting of a cation radical, which is a chemical species obtained by removing one electron from a hole-transporting compound, and a counter anion. However, when the cation radical is derived from a hole-transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

[0637] The cation radical is preferably a chemical species obtained by removing one electron from a hole transport compound described below, which is preferable in terms of amorphousness, visible light transmittance, heat resistance, solubility, etc.

[0638] The cation radical compound can be generated by mixing a hole transporting compound (described later) with the electron accepting compound described above. By mixing the hole transporting compound and the electron accepting compound, electrons are transferred from the hole transporting compound to the electron accepting compound, and a cation ion compound consisting of a cation radical of the hole transporting compound and a counter anion is generated.

[0639] When the second composition contains a cation radical compound, the content of the cation radical compound in the second composition is usually 0.0005% by mass or more, preferably 0.001% by mass or more, and usually 40% by mass or less, preferably 20% by mass or less. A content of the cation radical compound equal to or greater than the lower limit is preferred because the resistance of the formed organic layer is low, while a content of the cation radical compound equal to or less than the upper limit is preferred because defects are less likely to occur in the formed organic layer and film thickness unevenness is less likely to occur.

[0640] In addition to the above components, the second composition may contain components contained in the composition for forming a hole injection layer or the composition for forming a hole transport layer, which will be described later, in the amounts described later.

[0641] [Structure of organic electroluminescent device] As an example of the structure of the organic electroluminescent device of the present invention, Fig. 1 shows a schematic diagram (cross section) of an example of the structure of an organic electroluminescent device 8. In Fig. 1, 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light-emitting layer, 6 represents an electron transport layer, and 7 represents a cathode.

[0642] <Substrate> The substrate 1 serves as a support for the organic electroluminescent element, and is typically made of a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like. Of these, a glass plate or a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferred. The substrate is preferably made of a material with high gas barrier properties, as this makes it less likely for the organic electroluminescent element to deteriorate due to exposure to the outside air. Therefore, when using a material with low gas barrier properties, such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve the gas barrier properties.

[0643] <Anode> The anode 2 has the function of injecting holes into the layer on the light-emitting layer 5 side.

[0644] The anode 2 is usually made of a metal such as aluminum, gold, silver, nickel, palladium, or platinum; a metal oxide such as indium and / or tin oxide; a metal halide such as copper iodide; carbon black, or a conductive polymer such as poly(3-methylthiophene), polypyrrole, or polyaniline.

[0645] The anode 2 is usually formed by a dry method such as sputtering or vacuum deposition. When forming the anode using metal fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc., the anode can be formed by dispersing the material in an appropriate binder resin solution and applying it to the substrate. In the case of a conductive polymer, a thin film can be formed directly on the substrate by electrolytic polymerization, or the anode can be formed by applying the conductive polymer to the substrate (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0646] The anode 2 usually has a single layer structure, but may have a laminated structure as appropriate. When the anode 2 has a laminated structure, a different conductive material may be laminated on the first layer of the anode.

[0647] The thickness of the anode 2 may be determined depending on the required transparency, material, etc. When particularly high transparency is required, a thickness that provides a visible light transmittance of 60% or more is preferred, and a thickness that provides a visible light transmittance of 80% or more is more preferred. The thickness of the anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. When transparency is not required, the thickness of the anode 2 may be arbitrarily determined depending on the required strength, etc., in which case the anode 2 may have the same thickness as the substrate.

[0648] When another layer is formed on the surface of the anode 2, it is preferable to perform a treatment with ultraviolet light / ozone, oxygen plasma, argon plasma, or the like before the film formation to remove impurities on the anode 2 and adjust its ionization potential to improve hole injection properties.

[0649] <Hole injection layer> A layer that transports holes from the anode 2 side to the light-emitting layer 5 side is usually called a hole injection transport layer or hole transport layer. When there are two or more layers that transport holes from the anode 2 side to the light-emitting layer 5 side, the layer closer to the anode side may be called the hole injection layer 3. The hole injection layer 3 is preferably formed in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5 side. When the hole injection layer 3 is formed, the hole injection layer 3 is usually formed on the anode 2.

[0650] The thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[0651] The hole injection layer may be formed by vacuum deposition or wet film formation, but is preferably formed by wet film formation in terms of excellent film formability.

[0652] A general method for forming a hole injection layer will be described below: In the organic electroluminescent device of the present invention, the hole injection layer is preferably formed by a wet film formation method using a composition for forming a hole injection layer.

[0653] (Hole transporting compound) The hole injection layer-forming composition typically contains a hole transport compound that will become the hole injection layer 3. In the case of a wet film formation method, the hole injection layer-forming composition typically further contains a solvent. The hole injection layer-forming composition preferably has high hole transport properties and can efficiently transport injected holes. For this reason, it is preferable that the hole injection layer-forming composition has high hole mobility and is less likely to generate impurities that become traps during production or use. It is also preferable that the composition has excellent stability, a small ionization potential, and high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable that the composition does not quench the light emission from the light-emitting layer or that does not form exciplexes with the light-emitting layer to reduce the light-emitting efficiency.

[0654] From the viewpoint of the charge injection barrier from the anode to the hole injection layer, the hole transport compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV. Examples of the hole transport compound include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which a tertiary amine is linked via a fluorene group, hydrazone compounds, silazane compounds, and quinacridone compounds.

[0655] Among the above-mentioned exemplary compounds, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, from the viewpoints of amorphousness and visible light transmittance. Here, the aromatic tertiary amine compounds are compounds having an aromatic tertiary amine structure and also include compounds having a group derived from an aromatic tertiary amine.

[0656] The type of aromatic tertiary amine compound is not particularly limited, but it is preferable to use a polymer compound (polymerizable compound having a series of repeating units) having a weight-average molecular weight of 1,000 or more and 1,000,000 or less, since uniform light emission is easily obtained due to the surface smoothing effect.

[0657] (Formation of hole injection layer by wet film formation method) When forming the hole injection layer 3 by a wet film formation method, a composition for film formation (hole injection layer formation composition) is usually prepared by mixing the material for the hole injection layer with a soluble solvent (hole injection layer solvent). This hole injection layer formation composition is applied to a layer corresponding to the layer below the hole injection layer (usually the anode) to form a film, and then dried to form the hole injection layer 3.

[0658] The concentration of the hole transport compound in the composition for forming a hole injection layer may be any concentration as long as it does not significantly impair the effects of the present invention, but a lower concentration is preferable in terms of uniformity of the film thickness, and a higher concentration is preferable in terms of preventing defects from occurring in the hole injection layer. Specifically, the concentration is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.5% by mass or more, and is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0659] Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents.

[0660] Examples of ether solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

[0661] Examples of ester solvents include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0662] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene.

[0663] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

[0664] In addition to these, dimethyl sulfoxide and the like can also be used.

[0665] The hole injection layer 3 is usually formed by a wet film formation method by preparing a composition for forming the hole injection layer, applying the composition to a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2), and then drying the composition. After the hole injection layer 3 is formed, the coated film is usually dried by heating, drying under reduced pressure, or the like.

[0666] (Formation of hole injection layer by vacuum deposition method) When forming the hole injection layer 3 by vacuum deposition, one or more types of materials constituting the hole injection layer 3 are usually placed in a crucible installed in a vacuum chamber (when two or more types of materials are used, each is usually placed in a separate crucible), and the inside of the vacuum chamber is vacuumed by a vacuum pump for 10 -4 The chamber is evacuated to approximately 100 Pa. The crucible is then heated (when two or more materials are used, each crucible is usually heated) and the materials in the crucible are evaporated while controlling their evaporation rates (when two or more materials are used, each material is usually evaporated while controlling its evaporation rate independently), forming a hole injection layer on the anode on the substrate placed opposite the crucible. When two or more materials are used, a mixture of the materials can also be placed in the crucible and heated to evaporate to form the hole injection layer.

[0667] The degree of vacuum during deposition is not limited as long as it does not significantly impair the effects of the present invention. -6 Torr (0.13 × 10 -4 Pa) or more, 9.0×10 -6 Torr (12.0 × 10 -4 The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The film formation temperature during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10°C or more and 50°C or less.

[0668] The hole injection layer 3 may be crosslinked.

[0669] <Hole transport layer> The hole transport layer 4 is a layer that transports holes from the anode 2 side to the light-emitting layer 5 side. In the organic electroluminescent device of the present invention, the hole transport layer 4 is preferably formed in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is formed, it is usually formed between the anode 2 and the light-emitting layer 5. When the above-mentioned hole injection layer 3 is present, the hole transport layer 4 is formed between the hole injection layer 3 and the light-emitting layer 5.

[0670] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0671] The hole transport layer 4 may be formed by vacuum deposition or wet film formation, but is preferably formed by wet film formation in terms of excellent film formability.

[0672] A general method for forming a hole transport layer will be described below. In the organic electroluminescent device of the present invention, the hole transport layer is preferably formed by a wet film formation method using the second composition described above as a composition for forming a hole transport layer.

[0673] The hole transport layer 4 usually contains a hole transport compound. The hole transport compound contained in the hole transport layer 4 is preferably the second polymer contained in the second organic layer.

[0674] In addition to the second polymer, there are also known hole transporting compounds, aromatic diamines containing two or more tertiary amines and having two or more condensed aromatic rings substituted on the nitrogen atom, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (JP-A-5-234681), aromatic amine compounds having a starburst structure such as 4,4',4"-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., vol. 72-74, p. 985, 1997), and aromatic amine compounds consisting of a tetramer of triphenylamine (Chem. Commun., p. 2175, 1996). Preferred examples of the compound include spiro compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), and carbazole derivatives such as 4,4'-N,N'-dicarbazolebiphenyl. The hole transport layer 4 may also contain, for example, polyvinylcarbazole, polyvinyltriphenylamine (JP-A-7-53953), or polyarylene ether sulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, p. 33, 1996).

[0675] (Formation of hole transport layer by wet film formation method) When the hole transport layer is formed by a wet film formation method, it is usually formed using a composition for forming a hole transport layer instead of the composition for forming a hole injection layer, in the same manner as when the hole injection layer described above is formed by a wet film formation method.

[0676] When the hole transport layer is formed by a wet film formation method, the composition for forming the hole transport layer usually further contains a solvent. The solvent used in the composition for forming the hole transport layer can be the same as the solvent used in the composition for forming the hole injection layer described above.

[0677] The concentration of the hole transporting compound in the composition for forming a hole transport layer can be set to the same range as the concentration of the hole transporting compound in the composition for forming a hole injection layer.

[0678] The hole transport layer can be formed by a wet film formation method in the same manner as the above-mentioned hole injection layer formation method.

[0679] (Formation of hole transport layer by vacuum deposition method) When forming the hole transport layer by vacuum deposition, it can be formed in the same manner as when forming the hole injection layer by vacuum deposition, except that the hole transport layer-forming composition is used instead of the hole injection layer-forming composition. The film formation conditions, such as the degree of vacuum, deposition rate, and temperature during deposition, can be the same as those for the vacuum deposition of the hole injection layer.

[0680] <Light-emitting layer> The light-emitting layer 5 is a layer that is excited by the recombination of holes injected from the anode 2 and electrons injected from the cathode 7 when an electric field is applied between the pair of electrodes, and thus emits light. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 7. When a hole injection layer is present on the anode, the light-emitting layer is formed between the hole injection layer and the cathode. When a hole transport layer is present on the anode, the light-emitting layer 5 is formed between the hole transport layer and the cathode. The organic electroluminescent device of the present invention preferably has an emitting layer containing, as an emitting material, the polycyclic heterocyclic compound represented by the formula (1), and, as a host material, at least one of the compounds I, II, III, and IV. Furthermore, since the host material preferably contains a material having an electron-transporting property and a material having a hole-transporting property, it is preferable that the electron-transporting host material contains at least one of the compound represented by formula (30) as the second host material and the compound II, and that the hole-transporting host material contains at least one of the compound III and the compound IV. When the light-emitting layer of the organic electroluminescent device of the present invention contains the compound represented by the formula (30) as the second host, the preferred blending ratio (mass ratio) is as follows. The amount of compound I to be blended relative to the total amount of the compound represented by formula (30) and compound I (100) is preferably 50 or less, more preferably 40 or less, even more preferably 30 or less, particularly preferably 25 or less, preferably 5 or more, more preferably 10 or more, and particularly preferably 20 or more. The amount of compound II to be blended relative to the total amount of the compound represented by formula (30) and compound II (100) is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, particularly preferably 5 or less, preferably 1 or more, and even more preferably 3 or more. The amount of compound III to be blended relative to the total amount of the compound represented by formula (30) and compound III (100) is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, particularly preferably 5 or less, preferably 1 or more, and even more preferably 3 or more. The amount of compound IV to be blended relative to the total amount of the compound represented by formula (30) and compound IV (100) is preferably 70 or less, more preferably 50 or less, particularly preferably 30 or less, most preferably 20 or less, preferably 1 or more, more preferably 3 or more, and particularly preferably 5 or more.

[0681] Furthermore, from the viewpoint of containing an electron-transporting host material and a hole-transporting host material, it is also preferable to contain the compound II and also contain the compound III or the compound IV, and it is more preferable to contain the compound II and the compound IV. When the compound II and also the compound III or the compound IV are contained, the blending ratio (mass ratio) of the amount of the compound II to the total amount of the compound II and the amount of the compound III or the compound IV is preferably 10 or more, more preferably 30 or more, particularly preferably 50 or more, most preferably 70 or more, and is preferably 95 or less, more preferably 90 or less, and particularly preferably 85 or less.

[0682] The thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention, but a thicker layer is preferable in terms of preventing defects from occurring in the film, and a thinner layer is preferable in terms of facilitating a low driving voltage. The thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and is preferably 200 nm or less, and more preferably 100 nm or less.

[0683] The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material), and preferably contains one or more host materials. The host material is usually a charge-transporting material, but a material with low charge-transporting properties may be blended to adjust the charge-transporting properties.

[0684] (Formation of light-emitting layer by wet film formation method) The method for forming the light-emitting layer may be a vacuum deposition method or a wet film-forming method, but a wet film-forming method is preferred due to its excellent film-forming properties, and a spin coating method and an ink-jet method are more preferred. In particular, when the light-emitting layer is formed using the light-emitting layer-forming composition of the present invention, lamination by the wet film-forming method is easy, so that a wet film-forming method is preferably employed. When the light-emitting layer is formed by the wet film-forming method, it is usually formed using a light-emitting layer-forming composition prepared by mixing the material to be the light-emitting layer with a soluble solvent (light-emitting layer solvent) instead of the hole-injection layer-forming composition, in the same manner as when the hole-injection layer is formed by the wet film-forming method.

[0685] Examples of the solvent include the ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents mentioned for forming the hole injection layer, as well as alkane solvents, halogenated aromatic hydrocarbon solvents, aliphatic alcohol solvents, alicyclic alcohol solvents, aliphatic ketone solvents, and alicyclic ketone solvents. Specific examples of the solvent are listed below, but are not limited to these as long as the effects of the present invention are not impaired.

[0686] For example, aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ether solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; aromatic ester solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; toluene, xylene, mesitylene, cyclohexylbenzene, tetralin, 3-isopropylbiphenyl, 1, Examples of suitable solvents include aromatic hydrocarbon solvents such as 2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; alkane solvents such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; aliphatic alcohol solvents such as butanol and hexanol; alicyclic alcohol solvents such as cyclohexanol and cyclooctanol; aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone; and alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fenchone. Among these, alkane solvents and aromatic hydrocarbon solvents are particularly preferred.

[0687] <Hole-blocking layer> A hole-blocking layer may be provided between the light-emitting layer 5 and the electron-transporting layer 6 described below. The hole-blocking layer is a layer laminated on the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 7 side.

[0688] This hole-blocking layer has the roles of preventing holes migrating from the anode 2 from reaching the cathode 7 and efficiently transporting electrons injected from the cathode 7 toward the light-emitting layer 5. Required physical properties of the material constituting the hole-blocking layer include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1).

[0689] Examples of materials for hole-blocking layers that satisfy these conditions include mixed ligand complexes such as bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum; metal complexes such as bis(2-methyl-8-quinolinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolinolato)aluminum binuclear metal complex; styryl compounds such as distyrylbiphenyl derivatives (JP 11-242996 A); triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (JP 7-41759 A); and phenanthroline derivatives such as bathocuproine (JP 10-79297 A). Compounds having at least one pyridine ring substituted at the 2-, 4-, and 6-positions, as described in WO 2005 / 022962, are also preferred as materials for the hole-blocking layer.

[0690] There is no limitation on the method for forming the hole blocking layer, and it can be formed by a wet film forming method, a vapor deposition method, or other methods.

[0691] The thickness of the hole blocking layer is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

[0692] <Electron transport layer> The electron transport layer 6 is provided between the light emitting layer 5 and the cathode 7 for the purpose of further improving the current efficiency of the device.

[0693] The electron transport layer 6 is formed from a compound capable of efficiently transporting electrons injected from the cathode 7 between electrodes to which an electric field is applied, toward the light-emitting layer 5. The electron transporting compound used in the electron transport layer 6 is required to have a high efficiency of electron injection from the cathode 7, a high electron mobility, and the ability to efficiently transport the injected electrons.

[0694] Examples of electron transporting compounds used in the electron transport layer include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (U.S. Pat. No. 5,645,948), quinoxaline compounds (Japanese Patent Laid-Open No. 6-207169), phenanthroline derivatives (Japanese Patent Laid-Open No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

[0695] The film thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0696] The electron transport layer 6 is formed by laminating it on the light-emitting layer or the hole-blocking layer by a wet film-forming method or a vacuum deposition method in the same manner as described above. Usually, the vacuum deposition method is used.

[0697] <Electron injection layer> In order to efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light emitting layer 5, an electron injection layer may be provided between the electron transport layer 6 and the cathode 7.

[0698] To efficiently inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. Examples of materials that can be used to form the electron injection layer include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is usually preferably 0.1 nm or more and 5 nm or less.

[0699] Furthermore, doping an organic electron transport material, typically a nitrogen-containing heterocyclic compound such as bathophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline, with an alkali metal such as sodium, potassium, cesium, lithium, or rubidium (as described in JP-A Nos. 10-270171, 2002-100478, and 2002-100482, for example) is also preferred, as it improves both the electron injection and transport properties and enables excellent film quality to be achieved.

[0700] The thickness of the electron injection layer is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

[0701] The electron injection layer is formed by laminating it on the light-emitting layer 5 or the hole blocking layer or electron transport layer 6 thereon by a wet film-forming method or a vacuum deposition method. The details of the wet film formation method are the same as those of the light-emitting layer described above.

[0702] In some cases, the hole blocking layer, the electron transporting layer, and the electron injecting layer are formed into one layer by co-doping the electron transporting material with a lithium complex.

[0703] <Cathode> The cathode 7 serves to inject electrons into the layer on the light-emitting layer 5 side (such as the electron injection layer or the light-emitting layer).

[0704] The cathode 7 can be made of the same material as that used for the anode 2. For efficient electron injection, it is preferable to use a metal with a low work function as the material for the cathode 7, such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof. Specific examples include low-work-function alloy electrodes such as a magnesium-silver alloy, a magnesium-indium alloy, or an aluminum-lithium alloy.

[0705] In terms of the stability of the organic electroluminescent device, it is preferable to protect the cathode made of a metal having a low work function by laminating a metal layer having a high work function and stability against the atmosphere on the cathode. Examples of the metal to be laminated include aluminum, silver, copper, nickel, chromium, gold, and platinum.

[0706] The thickness of the cathode is usually the same as that of the anode.

[0707] <Other layers> The organic electroluminescent device of the present invention may further include other layers as long as the effects of the present invention are not significantly impaired. Any other layer may be provided between the anode and the cathode.

[0708] <Other element configurations> The organic electroluminescent device of the present invention may have a structure opposite to that described above, i.e., for example, a cathode, an electron injection layer, an electron transport layer, a hole blocking layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode stacked in this order on a substrate.

[0709] When the organic electroluminescent element of the present invention is applied to an organic electroluminescent device, it may be used as a single organic electroluminescent element, or may be used in a configuration in which a plurality of organic electroluminescent elements are arranged in an array, or may be used in a configuration in which anodes and cathodes are arranged in an XY matrix.

[0710] [Organic EL display device] The organic EL display device (organic electroluminescent element display device) of the present invention includes the organic electroluminescent element of the present invention. The type and structure of the organic EL display device of the present invention are not particularly limited, and it can be assembled using the organic electroluminescent element of the present invention according to a conventional method.

[0711] For example, the organic EL display device of the present invention can be formed by the method described in "Organic EL Display" (Ohmsha, published August 20, 2004, by Tokito Shizuo, Adachi Chinaya, and Murata Hideyuki).

[0712] [Organic EL lighting] The organic EL lighting (organic electroluminescent element lighting) of the present invention comprises the organic electroluminescent element of the present invention. There are no particular limitations on the type or structure of the organic EL lighting of the present invention, and it can be assembled using the organic electroluminescent element of the present invention according to a conventional method. [Example]

[0713] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples, and the present invention can be practiced with any modifications without departing from the gist of the present invention.

[0714] Unless otherwise specified, the organic electroluminescent device produced using the light-emitting material represented by formula (D-1) described below emitted blue light with an emission spectrum having a peak wavelength of about 464 nm and a half-value width of about 30 nm.

[0715] [Example I-1] An organic electroluminescent device was fabricated in the following manner. A 50-nm-thick indium tin oxide (ITO) transparent conductive film (Geomatec, sputter-deposited) was deposited on a glass substrate and patterned into 2-mm-wide stripes using standard photolithography and hydrochloric acid etching to form the anode. The substrate with the ITO pattern formed was then ultrasonically cleaned with a surfactant solution, rinsed with ultrapure water, ultrasonically cleaned with ultrapure water, and rinsed with ultrapure water again, followed by drying with compressed air and finally cleaning with ultraviolet ozone.

[0716] A composition for forming a hole injection layer was prepared by dissolving 3.0% by mass of a hole transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6% by mass of an oxidizing agent (HI-1) in ethyl benzoate.

[0717] [ka]

[0718] This composition for forming a hole injection layer was spin-coated onto the substrate in the atmosphere and dried on a hot plate in the atmosphere at 240° C. for 30 minutes to form a uniform thin film with a thickness of 40 nm, which was used as a hole injection layer.

[0719] Next, a charge transporting polymer compound having the following structural formula (HT-1) was dissolved in cyclohexylbenzene at a concentration of 3.0% by mass to prepare a composition for forming a hole transporting layer.

[0720] [ka]

[0721] This composition for forming a hole transport layer was spin-coated in a nitrogen glove box onto the substrate on which the hole injection layer had been coated, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 40 nm, which served as the hole transport layer.

[0722] Next, as materials for the light-emitting layer, 72 parts by mass of the following structural formula (H-1), 25 parts by mass of (H-2), and 3 parts by mass of (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solids concentration of 4.2% by mass, which was used as a composition for forming the light-emitting layer.

[0723] [ka]

[0724] This composition for forming an emissive layer was spin-coated in a nitrogen glove box onto the substrate on which the hole transport layer had been coated, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm, which served as the emissive layer.

[0725] The substrate on which the light-emitting layer had been formed was placed in a vacuum deposition device, and the inside of the device was heated to 2 × 10 -4 The pressure was evacuated until it reached a pressure of 0.1 Pa or less.

[0726] Next, the following structural formula (ET-1) and 8-hydroxyquinolinolatolithium were co-deposited on the light-emitting layer in a thickness ratio of 2:3 by vacuum deposition to form a hole-blocking layer with a thickness of 30 nm.

[0727] [ka]

[0728] Next, a 2 mm wide striped shadow mask was attached to the substrate as a mask for cathode deposition so that it was perpendicular to the ITO stripes of the anode, and aluminum was heated using a molybdenum boat to form an 80 nm thick aluminum layer, forming the cathode. In this manner, an organic electroluminescent device having a light-emitting area measuring 2 mm×2 mm was obtained.

[0729] [Comparative Example 1] A device was prepared in the same manner as in Example I-1, except that the composition for forming the light-emitting layer contained 97 parts by mass of (H-1) and 3 parts by mass of (D-1), and did not contain (H-2).

[0730] [Element evaluation] The organic electroluminescent devices obtained in Example I-1 and Comparative Example 1 were subjected to a current of 20 mA / cm 2 The time (LT75 (hr)) until the luminance of the element decreased to 75% of the initial luminance when a current was continuously applied at a current density of 1000 kJ / s was measured. In Table 1, the relative value of the LT75 of Example I-1 when the LT75 of Comparative Example 1 was set to 1 is shown as the relative lifespan.

[0731] [Table 1]

[0732] The results in Table 1 show that the organic electroluminescent device of the present invention using Compound I as the first host material has improved performance (driving life).

[0733] [Example II-1] As materials for the light-emitting layer, 92 parts by mass of the following structural formula (H-1), 5 parts by mass of (H-3), and 3 parts by mass of (D-1) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solid concentration of 4.2% by mass, which was used as a composition for forming the light-emitting layer.

[0734] [ka]

[0735] A device was produced in the same manner as in Example I-1, except that the above composition for forming a light-emitting layer was used as the composition for forming a light-emitting layer.

[0736] [Element evaluation] The organic electroluminescent devices obtained in Example II-1 and Comparative Example 1 were subjected to a current of 10 mA / cm 2 The voltage (V) and the luminous efficiency (current luminous efficiency (cd / A) and external quantum efficiency (EQE) (%) were measured when a current was applied at a current density of 20 mA / cm. 2 The time required for the luminance of the organic electroluminescent device to decrease to 75% of the initial luminance when the current was continuously applied at a current density of 1000 kJ / s was measured as the lifetime (hr).

[0737] Table 2 shows the voltage difference (V) obtained by subtracting the voltage of Comparative Example 1 from that of Example II-1, the relative current luminous efficiency of Example II-1 when the current luminous efficiency of Comparative Example 1 is set to 1, the relative external quantum efficiency (EQE) of Example II-1 when the EQE of Comparative Example 1 is set to 1, and the relative lifetime of Example II-1 when the lifetime of Comparative Example 1 is set to 1.

[0738] [Table 2]

[0739] [Example II-2] An element was prepared in the same manner as in Example II-1, except that the materials for the light-emitting layer were 92 parts by mass of the above-mentioned structural formula (H-1), 5 parts by mass of the following structural formula (H-6), and 3 parts by mass of the above-mentioned structural formula (D-1).

[0740] [ka]

[0741] [Example II-3] An element was prepared in the same manner as in Example II-1, except that the materials for the light-emitting layer were 92 parts by mass of the above-mentioned structural formula (H-1), 5 parts by mass of the following structural formula (H-7), and 3 parts by mass of the above-mentioned structural formula (D-1).

[0742] [ka]

[0743] [Element evaluation] The organic electroluminescent devices obtained in Example II-2 and Comparative Example 1 were subjected to a current of 10 mA / cm 2 The current luminous efficiency (cd / A) and external quantum efficiency (EQE) (%) were measured as the luminous efficiency when a current was applied at a current density of 20 mA / cm. 2 The time required for the luminance of the organic electroluminescent device to decrease to 75% of the initial luminance when the current was continuously applied at a current density of 1000 kJ / s was measured as the lifetime (hr).

[0744] Table 3 shows the relative current luminous efficiency of Example II-2 when the current luminous efficiency of Comparative Example 1 is set to 1, the relative external quantum efficiency (EQE) of Example II-2 when the EQE of Comparative Example 1 is set to 1, and the relative lifetime of Example II-2 when the lifetime of Comparative Example 1 is set to 1.

[0745] [Table 3]

[0746] The organic electroluminescent devices obtained in Example II-3 and Comparative Example 1 were subjected to a current of 10 mA / cm 2 The voltage (V) when a current was applied at a current density of 1000 kJ / s, and the luminous efficiency (current luminous efficiency) (cd / A) and external quantum efficiency (EQE) (%) were measured.

[0747] Table 4 shows the voltage difference (V) obtained by subtracting the voltage of Comparative Example 1 from that of Example II-3, the relative current luminous efficiency of Example II-3 when the current luminous efficiency of Comparative Example 1 is set to 1, the relative external quantum efficiency (EQE) of Example II-3 when the EQE of Comparative Example 1 is set to 1, and the relative lifetime of Example II-3 when the lifetime of Comparative Example 1 is set to 1.

[0748] [Table 4]

[0749] The results in Tables 2 to 4 show that the organic electroluminescent device of the present invention using compound II as the first host material has high luminous efficiency, and is expected to achieve lower voltage and longer life, thereby improving device performance.

[0750] [Example III-1] An element was prepared in the same manner as in Example I-1, except that the materials for the light-emitting layer were 92 parts by mass of the following structural formula (H-1), 5 parts by mass of (H-4), and 3 parts by mass of (D-1).

[0751] [ka]

[0752] [Example III-2] A device was fabricated in the same manner as in Example III-1, except that (H-5) having the following structure was used instead of (H-4) as the material for the light-emitting layer.

[0753] [ka]

[0754] [Element evaluation] The organic electroluminescent devices obtained in Examples III-1 and III-2 and the above-mentioned Comparative Example 1 were subjected to a current of 10 mA / cm 2 The voltage (V) when a current was applied at a current density of 1000 kJ / s, and the luminous efficiency (current luminous efficiency) (cd / A) and external quantum efficiency (EQE) (%) were measured.

[0755] Table 5 shows the voltage difference (V) obtained by subtracting the voltage of Comparative Example 1 from that of Examples III-1 and III-2, the relative current luminous efficiency of Examples III-1 and III-2 when the current luminous efficiency of Comparative Example 1 is set to 1, and the relative external quantum efficiency (EQE) of Examples III-1 and III-2 when the EQE of Comparative Example 1 is set to 1.

[0756] [Table 5]

[0757] As shown in Table 5, it was found that the organic electroluminescent device of the present invention using Compound III as the first host material exhibited high luminous efficiency when driven at a low voltage, and exhibited improved device performance. In addition, the elements obtained in Example III-1 and Comparative Example 1 were subjected to a current of 20 mA / cm 2 The device life was measured as the time (hr) until the luminance of the device decreased to 90% of the initial luminance when a current was continuously applied at a current density of 1. The relative life of Example III-1 was 1.39 when the life of Comparative Example 1 was taken as 1, indicating that the device life was longer.

[0758] [Advantages over conventional technology] Next, the superiority of the effect over the case where the light-emitting material of the light-emitting layer is a conventionally used light-emitting material was confirmed.

[0759] [Comparative Example III-1] An element was prepared in the same manner as in Example III-2, except that the materials for the light-emitting layer were 92 parts by mass of the formula (H-1), 5 parts by mass of the formula (H-5), and 3 parts by mass of the following formula (D-2).

[0760] [ka]

[0761] [Comparative Example III-2] A device was produced in the same manner as in Comparative Example III-1, except that the materials for the light-emitting layer were 97 parts by mass of the compound represented by formula (H-1) and 3 parts by mass of the compound represented by formula (D-2).

[0762] [Element evaluation] The organic electroluminescent devices obtained in Comparative Examples III-1 and III-2 were supplied with a current of 10 mA / cm 2 The voltage (V) was measured when a current was passed through at a current density of 100 kJ / cm2, and the voltage difference obtained by subtracting the voltage of Comparative Example III-2 from the voltage of Comparative Example III-1 was −0.03 V. As shown in Example III-2 in Table 5, when the above formula (D-1) was used as the emitting material of the emitting layer and compound III was used as the first host material, the voltage difference was −0.13 V, which shows that the organic electroluminescent device of the present invention has a greater effect of reducing voltage than conventional organic electroluminescent devices.

[0763] [Example IV-1] An element was prepared in the same manner as in Example I-1, except that the materials for the light-emitting layer were 92 parts by mass of the formula (H-1), 5 parts by mass of the following formula (H-8), and 3 parts by mass of the formula (D-1).

[0764] [ka]

[0765] [Element evaluation] The organic electroluminescent devices obtained in Example IV-1 and Comparative Example 1 were subjected to a luminance measurement at 1000 cd / m 2 The voltage (V) and the luminous efficiency (current luminous efficiency (cd / A) and external quantum efficiency (EQE) (%) were measured when the organic electroluminescent device was lit at a current of 20 mA / cm. 2 The time required for the luminance of the organic electroluminescent device to decrease to 75% of the initial luminance when the current was continuously applied at a current density of 1000 kJ / s was measured as the lifetime (hr).

[0766] Table 6 shows the voltage difference (V) obtained by subtracting the voltage of Comparative Example 1 from that of Example IV-1, the relative current luminous efficiency of Example IV-1 when the current luminous efficiency of Comparative Example 1 is set to 1, the relative external quantum efficiency (EQE) of Example IV-1 when the EQE of Comparative Example 1 is set to 1, and the relative lifetime of Example IV-1 when the lifetime of Comparative Example 1 is set to 1.

[0767] [Table 6]

[0768] The results in Table 6 show that the organic electroluminescent device of the present invention using compound IV as the first host material has a low driving voltage, high luminous efficiency, and long driving life, and thus has improved device performance.

[0769] [Example 1] Next, a polymer having no crosslinking group is used as a second polymer for forming a hole transport layer, An organic electroluminescent device was fabricated containing Compound II and Compound IV as the host material of the light-emitting layer. As a material for the hole transport layer, the following formula (HT-2) is used instead of the formula (HT-1): As materials for the light-emitting layer, 22.5 parts by mass of the following formula (H-9), 22.5 parts by mass of the following formula (H-10), 15 parts by mass of the formula (H-8), and 3 parts by mass of the following formula (D-3) were weighed out and dissolved in cyclohexylbenzene to prepare a solution with a solids concentration of 4.2% by mass, which was used as a composition for forming a light-emitting layer. An element was produced in the same manner as in Example I-1, except that this was used as a composition for forming a light-emitting layer.

[0770] [ka]

[0771] [Example 2] An organic electroluminescent device was produced in the same manner as in Example 1, except that the compound represented by structural formula (HT-3) was used as the material for the hole transport layer instead of the compound represented by structural formula (HT-2).

[0772] [ka]

[0773] [Example 3] An organic electroluminescent device was produced in the same manner as in Example 1, except that the compound represented by structural formula (HT-1) was used as the material for the hole transport layer instead of the compound represented by structural formula (HT-2).

[0774] [Evaluation of organic electroluminescent devices] The emission spectra of the organic electroluminescent devices obtained in Examples 1 to 3 all showed green light emission with a peak wavelength of 528 nm and a half-value width of 30 nm. 2 The voltage (V) and current efficiency (cd / A) were measured when the device was lit.

[0775] The organic electroluminescent devices obtained in Examples 1 to 3 were subjected to a luminance measurement of 1000 cd / m 2 The voltage (V) and luminous efficiency (current luminous efficiency (cd / A) and external quantum efficiency (EQE) (%) were measured when the organic electroluminescent device was lit at 20 mA / cm. 2 The time required for the luminance of the organic electroluminescent device to decrease to 90% of the initial luminance when the current was continuously applied at a current density of 1000 kJ / s was measured as the lifetime (hr).

[0776] Table 7 shows the voltage difference (V) obtained by subtracting the voltage of Example 3 from that of Example 1 and Example 2, the relative current luminous efficiency of Example 1 and Example 2 when the current luminous efficiency of Example 3 is set to 1, the relative external quantum efficiency (EQE) of Example 1 and Example 2 when the EQE of Example 3 is set to 1, and the relative EQE of Example 1 and Example 2 when the EQE of Example 3 is set to 1. 3 The relative lifetimes of Example 1 and Example 2 are shown, assuming that the lifetime of Example 1 is 1.

[0777] [Table 7]

[0778] All of these organic electroluminescent devices exhibited good device characteristics, but in particular, by using a polymer having no crosslinking group in the hole transport layer, the device exhibited even better device characteristics, such as low voltage, high luminous efficiency, and long life.

[0779] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application Nos. 2020-214856, 2020-214857, and 2020-214858, filed on December 24, 2020, and is incorporated by reference in its entirety. [Industrial Applicability]

[0780] The present invention can be suitably used in various fields in which organic electrol...

Claims

1. The present invention relates to a method for manufacturing a photosensitive layer comprising: a polycyclic heterocyclic compound represented by the following formula (1); at least one of the following compounds I, II, III, and IV as a first host material; an anthracene derivative as a second host material; and an organic solvent. A composition comprising the following compound I as a first host material: 【Chemistry 1】 (In formula (1), ring a, ring b, and ring c each independently represent an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent; Y's are independently O, N-R, or S; R represents an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is a ring selected from the group consisting of the ring a, the ring b, and the ring c, and a carbon atom adjacent to the atom bonded to the Y, and -O-, -S-, -C(-R ａ ) ２ - or may be linked by a single bond, The R ａ is a hydrogen atom or an alkyl group, the adjacent carbon atom is not a carbon atom constituting the central fused two-ring structure of formula (1) containing B and the Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Compound I: a compound represented by the following formula (20): Compound II: a compound represented by the following formula (200): Compound III: one or more compounds selected from the group consisting of a compound represented by the following formula (210), a compound represented by the following formula (220), and a compound represented by the following formula (230): Compound IV: A compound represented by the following formula (240): 【Chemistry 2】 (In formula (20), Ar ２１ ~Ar ３５ each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner. 【Transformation 3】 (In formula (200), Each W independently represents CH or N, and at least one W is N; Xa １ , Ya １ , and Za １ each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, Xa ２ , Ya ２ and Za ２ each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, g11, h11, and j11 each independently represent an integer of 0 to 6; At least one of g11, h11, and j11 is an integer of 1 or more, When g11 is 2 or more, a plurality of Xa １ may be the same or different, When h11 is 2 or more, multiple Ya １ may be the same or different, If j11 is 2 or more, multiple Za １ may be the same or different, R ３１ represents a hydrogen atom or a substituent, and four R ３１ may be the same or different Ku, However, when g11, h11, or j11 is 0, the corresponding Xa ２ , Ya ２ , Za ２ is not a hydrogen atom.) 【Chemistry 4】 (In formula (210), formula (220) and formula (230), Ar ４１ , Ar ４２ , Ar ４３ each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, R ２１ , R ２２ , R ２３ each independently represents a hydrogen atom or a substituent, X ２１ , X ２２ are each independently O, S, or N—Ar ４４ represents Ar ４４ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, n21, n22, and n23 each independently represent 1 or 2; n24 represents an integer of 1 to 4, When n24 is 2 or more, multiple R ２１ may be the same or different.) 【Transformation 5】 (In formula (240), Ar ６１１ , Ar ６１２ each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R ６１１ , R ６１２ each independently represents a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent; n ６１１ , n ６１２ are each independently an integer of 0 to 4.

2. The composition according to claim 1, wherein Y in formula (1) is N—R.

3. In the formula (20), Ar ２２ , Ar ２３ , Ar ２４ , Ar ２７ , Ar ２８ , Ar ２９ , Ar ３２ , Ar ３３ and Ar ３４ The composition according to claim 1 or 2, wherein at least one of the following is a structure represented by the following formula (21) or the following formula (22): 【Transformation 6】 (In formulas (21) and (22), Ar ３６ ~Ar ３９ each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 8 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

4. In the formula (20), Ar ２２ , Ar ２３ and Ar ２４ and Ar ２７ , Ar ２８ and Ar ２９ and Ar ３２ , Ar ３３ and Ar ３４ Any one of the above is a structure represented by the formula (21) or the formula (22). The composition of claim 3.

5. In the formula (20), Ar ２２ , Ar ２７ and Ar ３２ The composition according to claim 4, wherein: is a structure represented by the formula (21) or the formula (22).

6. The composition according to any one of claims 3 to 5, wherein the structure represented by formula (21) is a structure represented by the following formula (21-1), (21-2), (21-3), (21-4), or (21-5), and the structure represented by formula (22) is a structure represented by the following formula (22-1), (22-2), (22-3), or (22-4). 【Transformation 7】

7. The composition according to claim 1 or 2, wherein at least two of the three Ws in formula (200) are N.

8. The composition according to claim 7, wherein all W in formula (200) are N.

9. Ar in the formula (210), the formula (220), and the formula (230) ４１ , Ar ４２ and Ar ４３ The composition according to claim 1 or 2, wherein is a group represented by any one of the following formulas (20-1) to (20-13): 【Transformation 8】 (In the above formula, * represents a bonding position, Ar ４５ is an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group in which 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent are linked together.

10. A method for producing an organic electroluminescent device, comprising the step of applying and drying the composition for forming a light-emitting layer of an organic electroluminescent device according to any one of claims 1 to 9 to form a light-emitting layer.

11. A method for manufacturing an organic EL display device, comprising the method for manufacturing the organic electroluminescent device according to claim 10.

12. A method for manufacturing an organic EL lighting device, comprising the method for manufacturing the organic electroluminescent device according to claim 10.

13. an anode, a cathode, and a light-emitting layer provided between the anode and the cathode; the light-emitting layer comprises a polycyclic heterocyclic compound represented by the following formula (1), at least one of the following compounds I, II, III, and IV as a first host material, and an anthracene derivative as a second host material; An organic electroluminescent device comprising the following compound I as a first host material: 【Chemistry 9】 (In formula (1), ring a, ring b, and ring c each independently represent an aromatic hydrocarbon ring which may have a substituent or an aromatic heterocycle which may have a substituent; Y's are independently O, N-R, or S; R represents an aromatic hydrocarbon ring group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or an alkyl group, The R is a ring selected from the group consisting of the ring a, the ring b, and the ring c, and a carbon atom adjacent to the atom bonded to the Y, and -O-, -S-, -C(-R ａ ) ２ - or may be linked by a single bond, The R ａ is a hydrogen atom or an alkyl group, the adjacent carbon atom is not a carbon atom constituting the central fused two-ring structure of formula (1) containing B and the Y, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium. Compound I: a compound represented by the following formula (20): Compound II: a compound represented by the following formula (200): Compound III: one or more compounds selected from the group consisting of a compound represented by the following formula (210), a compound represented by the following formula (220), and a compound represented by the following formula (230): Compound IV: A compound represented by the following formula (240): 【Chemistry 10】 (In formula (20), Ar ２１ ~Ar ３５ each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 10 benzene ring structures which may have a substituent are linked in an unbranched or branched manner. 【Chemistry 11】 (In formula (200), Each W independently represents CH or N, and at least one W is N; Xa １ , Ya １ , and Za １ each independently represents a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, Xa ２ , Ya ２ and Za ２ each independently represents a hydrogen atom, an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, g11, h11, and j11 each independently represent an integer of 0 to 6; At least one of g11, h11, and j11 is an integer of 1 or more, When g11 is 2 or more, a plurality of Xa １ may be the same or different, When h11 is 2 or more, multiple Ya １ may be the same or different, If j11 is 2 or more, multiple Za １ may be the same or different, R ３１ represents a hydrogen atom or a substituent, and four R ３１ may be the same or different Ku, However, when g11, h11, or j11 is 0, the corresponding Xa ２ , Ya ２ , Za ２ is not a hydrogen atom.) 【Chemistry 12】 (In formula (210), formula (220) and formula (230), Ar ４１ , Ar ４２ , Ar ４３ each independently represent an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, R ２１ , R ２２ , R ２３ each independently represents a hydrogen atom or a substituent, X ２１ , X ２２ are each independently O, S, or N—Ar ４４ represents Ar ４４ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group formed by linking 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, n21, n22, and n23 each independently represent 1 or 2; n24 represents an integer of 1 to 4, When n24 is 2 or more, multiple R ２１ may be the same or different.) 【Chemistry 13】 (In formula (240), Ar ６１１ , Ar ６１２ each independently represents a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent, R ６１１ , R ６１２ each independently represents a deuterium atom, a halogen atom, or an optionally substituted monovalent aromatic hydrocarbon group having 6 to 50 carbon atoms, G represents a single bond or a divalent aromatic hydrocarbon group having 6 to 50 carbon atoms which may have a substituent; n ６１１ , n ６１２ are each independently an integer of 0 to 4.

14. 14. The organic electroluminescent device according to claim 13, wherein Y in the formula (1) is N—R.

15. In the formula (20), Ar ２２ , Ar ２３ , Ar ２４ , Ar ２７ , Ar ２８ , Ar ２９ , Ar ３２ , Ar ３３ and Ar ３４ The organic electroluminescent device according to claim 13 or 14, wherein at least one of the above is a structure represented by the following formula (21) or the following formula (22): 【Chemistry 14】 (In formulas (21) and (22), Ar ３６ ~Ar ３９ each independently represents a hydrogen atom, a benzene ring structure which may have a substituent, or a structure in which 2 to 8 benzene ring structures which may have a substituent are linked in an unbranched or branched manner.

16. In the formula (20), Ar ２２ , Ar ２３ and Ar ２４ and Ar ２７ , Ar ２８ and Ar ２９ and Ar ３２ , Ar ３３ and Ar ３４ The organic electroluminescent device according to claim 15, wherein any one of the following is a structure represented by formula (21) or formula (22):

17. In the formula (20), Ar ２２ , Ar ２７ and Ar ３２ The organic electroluminescent device according to claim 16 , wherein

18. The structure represented by the formula (21) is a structure represented by the following formula (21-1), (21-2), (21-3), (21-4) or (21-5), and the structure represented by the formula (22) is a structure represented by the following formula (22-1), (22-2), (22-3) or (22-4). The organic electroluminescent element according to any one of claims 15 to 17. 【Chemistry 15】

19. The organic electroluminescent device according to claim 13 or 14, wherein at least two of the three Ws in the formula (200) are N.

20. The organic electroluminescent device according to claim 19, wherein all W in the formula (200) are N.

21. Ar in the formula (210), the formula (220), and the formula (230) ４１ , Ar ４２ and Ar ４３ The organic electroluminescent device according to claim 13 or 14, wherein is a group represented by any one of the following formulas (20-1) to (20-13): 【Chemistry 16】 (In the above formula, * represents a bonding position, Ar ４５ is an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent, or a monovalent group in which 2 to 5 structures selected from an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent and an aromatic heterocyclic group having 3 to 30 carbon atoms which may have a substituent are linked together.

22. An organic EL display device comprising the organic electroluminescent device according to any one of claims 13 to 21.

23. An organic EL lighting device comprising the organic electroluminescent device according to any one of claims 13 to 21.

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