TW202136369A - Organic electroluminescent element, organic el display device, and organic el lighting - Google Patents

Abstract

This organic electroluminescent element comprises, on a substrate, a positive electrode, a negative electrode, and an organic layer between the positive electrode and the negative electrode. The organic layer has a hole transport layer, and a light-emitting layer adjacent to the hole transport layer. At least one of materials contained in the hole transport layer and at least one of materials contained in the light-emitting layer both have the same partial structure A represented by formula (31). The ring HA is an aromatic heterocyclic ring, which may have a substituent, of a single ring or 2-6 fused rings. Ar0 is an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a monovalent group obtained by linking a plurality of at least two groups selected from an aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. n1 is 0 or an integer equal to or less than the number in which Ar0 can be substituted for the ring HA.

Description

Organic electroluminescence element, organic EL display device and organic EL lighting

The present invention relates to an organic electroluminescence element and an organic electroluminescence (EL) display device and organic EL illumination having the organic electroluminescence element.

As a method of forming an organic layer in an organic electroluminescent element, a vacuum vapor deposition method and a wet film formation method can be cited. The vacuum evaporation method is easy to achieve layering, and therefore has the following advantages: it is easy to improve the charge injection from the anode and/or the cathode, and it is easy to confine excitons in the light-emitting layer. On the other hand, the wet film-forming method has the following advantages: it does not require a vacuum process, and it is easy to achieve a large area, and by using a coating solution that mixes a variety of materials with various functions, it can be easily formed Layers of various materials with various functions, etc. However, the wet film formation method is difficult to build up in layers, and therefore, the driving stability is inferior compared with the element obtained by the vacuum vapor deposition method, and except for a part, it does not reach a practical level.

In order to achieve lamination by the wet film forming method, a charge-transporting polymer having a crosslinkable group is expected, and it is also being developed. For example, Patent Document 1 discloses an organic EL produced by laminating multiple layers by a wet film forming method. [Prior Art Literature] [Patent Literature]

Patent Document 1: International Publication No. 2013/080696

However, the conventional wet film forming method has problems in the hole transport efficiency between the layers of the build-up layer, for example, the light-emitting layer and the hole transport layer.

Patent Document 1 discloses that as the host compound of the light-emitting layer, from the viewpoint of charge transport, a host compound having a structure common to the compound constituting the hole transport layer is preferably used. However, the disclosed structure is a very small part, and it is not clear what other structure can exhibit this effect. In addition, there is still room for research regarding the effects of the entire organic electroluminescent element, such as brightness and driving life.

[The problem to be solved by the invention] The subject of the present invention is to provide an organic electroluminescent element with high brightness and long driving life.

[Means to solve the problem] The inventors discovered that in an organic electroluminescent device having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, the organic layer has a hole transport layer and a light emitting layer adjacent to the hole transport layer, and It includes materials that make the material contained in the hole transport layer and the material contained in the light-emitting layer have a specific structure as a material of the partial structure, wherein the specific structure is a structure with electron withdrawing property and includes a single ring or 2 The aromatic heterocyclic ring of ~6 condensed rings improves the performance of the organic electroluminescent device. The gist of the present invention is as follows [1] to [19].

[1] An organic electroluminescence element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, the organic layer having a hole transport layer and a luminescence adjacent to the hole transport layer At least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer both have the same partial structure A represented by the following formula (31).

[化1]

(In the formula (31), the ring HA represents a monocyclic or a 2-6 condensed ring of an optionally substituted aromatic heterocyclic ring. The benzene ring in the formula (31) may have a substituent. Ar ⁰ represents an optionally substituted aromatic heterocyclic ring An aromatic hydrocarbon group, an aromatic heterocyclic group that may have a substituent, or two or more groups selected from an aromatic hydrocarbon group that may have a substituent and an aromatic heterocyclic group that may have a substituent are connected in multiples N1 represents 0 or ^{an integer less than the number that Ar 0} can be substituted on the ring HA. When n1 is 2 or more, a plurality of Ar ⁰ may be the same or different)

[2] The organic electroluminescence element according to [1], wherein at least one of the material having the partial structure A contained in the hole transport layer and the material having the partial structure A contained in the light-emitting layer is at least One has more than two partial structures A.

[3] The organic electroluminescent element according to [1] or [2], wherein the partial structure A represented by the formula (31) is represented by any one of the following formulas (33) to (35) Representation of the structure.

[化2]

(In formula (33) to formula (35), Ar ⁰ and n1 have the same meaning as in formula (31). The benzene ring in formula (33) to formula (35) may have a substituent. X and Y are each independent地 means C atom or N atom. When X and Y are C atoms, Ar ⁰ can be bonded)

[4] The organic electroluminescence element according to [3], wherein in the partial structure represented by the formula (35), X and Y are N atoms.

[5] The organic electroluminescent element according to any one of [1] to [4], wherein the material having the partial structure A contained in the hole transport layer is represented by the following formula (1) The repeating unit of the polymer compound.

[化3]

(In formula (1), A represents the partial structure A. G represents an optionally substituted aromatic hydrocarbon group or N atom. Ar ² represents an optionally substituted divalent aromatic hydrocarbon group or an optionally substituted divalent aromatic group Heterocyclic group, or two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent, directly or through a linking group to form two or more groups A valent group. Ar ²⁰ represents a direct bond, a divalent aromatic hydrocarbon group that may have a substituent, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups that may have a substituent)

[6] The organic electroluminescent device according to [5], wherein the G is any one of a benzene ring which may have a substituent, a pyrene ring which may have a substituent, and a spiro fluorine ring which may have a substituent The basis of formation.

[7] The organic electroluminescent element according to [5], wherein the G is an N atom.

[8] The organic electroluminescence element according to [7], wherein the repeating unit represented by the formula (1) is represented by any one of the following formulas (2)-1 to (2)-3 The repeating unit.

[化4]

(In formula (2)-1 to formula (2)-3, A has the same meaning as A in formula (1). Q represents -C(R ⁵ )(R ⁶ )-, -N(R ⁷ )- or -C(R ¹¹ )(R ¹² )-C(R ¹³ )(R ¹⁴ )-. R ¹ to R ⁴ each independently represent an optionally substituted alkyl group or an optionally substituted alkoxy group Or an aralkyl group that may have a substituent. R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ each independently represent an alkyl group that may have a substituent, an alkoxy group that may have a substituent, and an aralkyl group that may have a substituent A group or an aromatic hydrocarbon group which may have a substituent. a and b are each independently an integer of 0 to 4. c1 to c5 are each independently an integer of 0 to 3. wherein at least one of c3 and c5 is 1. Above. d1 to d4 are each independently an integer of 1 to 4. When there are a plurality of R ¹ , R ² , R ³ , and R ⁴ in the repeating unit, R ¹ , R ² , R ³ , and R ⁴ may be Same or different)

[9] The organic electroluminescent element according to any one of [5] to [8], wherein -Ar ²⁰ -A in the formula (1) is represented by the following formula (15).

[化5]

(In formula (15), X and Y each independently represent a C atom or a N atom. The ring having X, Y, and N corresponds to the ring HA in formula (31). Ar ¹ represents an optionally substituted divalent aromatic A hydrocarbon group, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups ^{that may have a substituent. Ar 3} and Ar ⁴ each independently represent an aromatic hydrocarbon group that may have a substituent, and may have a substituent The aromatic heterocyclic group or a monovalent group formed by linking two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group. In ^{at least one of Ar 1} , Ar ³ , and Ar ⁴ , the structure bonded to the ring HA is a benzene ring. * indicates the bonding site with G)

[10] The organic electroluminescent element according to [9], wherein -Ar ²⁰ -A in the formula (1) is represented by the following formula (16).

[化6]

(In the formula (16), X, Y, * meaning and 15) (the same type having X, Y and N corresponds to the same manner as the ring of formula (15) ring HA. Ar ^{1 'represents} a direct bond or structure (15) wherein Ar ¹ and bonded to the ring of formula HA is a residue of a benzene ring. Ar ^{3 ',} Ar ^4' represents a hydrogen atom or, respectively, the formula (15) Ar ^3, Ar ⁴ , the structure bonded to the ring HA is the residue of the benzene ring)

[11] The organic electroluminescent element according to any one of [5] to [10], wherein the material having the partial structure A contained in the hole transport layer further has the following formula (3) The repeating unit.

[化7]

(In formula (3), Ar ¹³ represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group that does not include the partial structure A. Ar ¹⁴ represents an optionally substituted divalent aromatic hydrocarbon group, A divalent aromatic heterocyclic group which may have a substituent, or two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent directly or via A divalent group formed by connecting multiple connecting groups)

[12] The organic electroluminescent element according to [1] to [11], wherein the light-emitting layer contains a low-molecular compound having the partial structure A, and the low-molecular compound is the following formula (10) to (12) A compound having a molecular weight of 5,000 or less represented by any one of them.

[化8]

(In formula (10) ~ formula (12), A is the partial structure A. B represents a single bond or an arbitrary partial structure. na, nb, and nc represent an integer of 1-5. When na, nb, nc are 2 or more, multiple A, B, A-B may be the same or different)

[13] The organic electroluminescence element according to [12], wherein the low-molecular compound represented by the formula (10) is represented by the following formula (10A).

[化9]

(In formula (10A), HA represents any of the trivalent aromatic heterocyclic groups represented by the following structural formula (10A-a), structural formula (10A-b), and structural formula (10A-c). Xa ¹ , Ya ¹ and Za ¹ each independently represent an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbons, or an optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbons. Xa ^2. Ya ² and Za ² each independently represent a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted aromatic heterocyclic group having 3 to 30 carbon atoms. 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, h11, and j11 are 2 or more, Xa ¹ , Ya ¹ , and Za ¹ may be The same or different. R ³¹ represents a hydrogen atom or a substituent, four R ³¹ may be the same or different)

[化10]

(In formula (10A-a) ~ formula (10A-c), * represents the bonding position)

[14] The organic electroluminescence element according to [13], wherein the low-molecular compound represented by the formula (10) is represented by the following formulas (10A-1) to (10A-3).

[化11]

(In formulas (10A-1) to (10A-3), Xa ¹ , Ya ¹ , Za ¹ , Xa ² , Ya ² , and Za ² have the same meaning as in formula (10). R ³³ represents a hydrogen atom or substitution The base, a plurality of R ³³ may be the same or different. g11', h11', and j11' each independently represent an integer of 0 to 5. When g11', h11', and j11' are 2 or more, a plurality of Xa ¹ , Ya ¹ , Za ¹ can be the same or different)

[15] The organic electroluminescent element according to [12], wherein the low-molecular compound represented by the formula (10) is represented by the following formula (10B).

[化12]

(In the formula (10B), A has the same meaning as in the above formula (10). Xb ¹ , Yb ¹ and Zb ¹ each independently represent an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbons, or An optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms. p12, q12, and r12 each independently represent an integer of 0 to 6. When p12, q12, and r12 are 2 or more, a plurality of Xb ¹ , Yb ¹ and Zb ¹ may be the same or different. q13 and r13 each independently represent 0 or 1. Among them, q12 and q13 are not 0 at the same time, r12 and r13 are not 0 at the same time. Yb ² and when q13 is 0 ^{Zb 2} when r13 is 0 each independently represents a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted carbon number 3 to 30 aromatic heterocyclic group. q13 is 1 Yb ² when r13 is a direct bond. Zb ² when r13 is 1 is a direct bond)

[16] The organic electroluminescence element according to [15], wherein the low-molecular compound represented by the formula (10) is represented by the following formula (10B-1).

[化13]

(In formula (10B-1), A, Xb ¹ , Yb ¹ , Zb ¹ , Yb ² , Zb ² , q13, and r13 have the same meaning as in the formula (10B). p12', q12', and r12' each It independently represents an integer of 0 to 5. When p12', q12', and r12' are 2 or more, a plurality of Xb ¹ , Yb ¹ , and Zb ¹ may be the same or different. Each of q15 and r15 is independently 4 or 5. R ³³ is a hydrogen atom or a substituent. A plurality of R ³³ in the formula (10B-1) may be the same or different)

[17] The organic electroluminescence element according to [12], wherein the low-molecular compound represented by the formula (12) is represented by the following formula (12A).

[化14]

(In formula (12A), ring HA and Ar ⁰ have the same meaning as in formula (31). nc has the same meaning as in formula (12). Xc ¹ and Yc ¹ each independently represent that they may have a substituent A divalent aromatic hydrocarbon group with 6 to 30 carbons or an optionally substituted divalent aromatic heterocyclic group with 3 to 30 carbons. Xc ² and Yc ² each independently represent a hydrogen atom and optionally substituted An aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted aromatic heterocyclic group having 3 to 30 carbon atoms. s11 and t11 each independently represent an integer of 0 to 6. When s11 and t11 are 2 or more Below, a plurality of Xc ¹ and Yc ¹ may be the same or different. R ³¹ represents a hydrogen atom or a substituent. u11 is ^{the number that can be substituted by the substituent R 31.} u12 is the number that can be substituted by the substituent Ar ^0. Where u11 is 2 In the above case, multiple R ³¹ can be the same or different)

[18] An organic EL display device comprising the organic electroluminescent element according to any one of [1] to [17].

[19] An organic EL lighting comprising the organic electroluminescent element according to any one of [1] to [17].

[Effects of the invention] According to the present invention, an organic electroluminescent element with high brightness and long driving life can be provided.

The reason why the organic electroluminescence element as an embodiment of the present invention exerts the above-mentioned effects is not clear, but it is considered as follows. Regarding the organic electroluminescent element of the present invention, a material having a specific structure as a partial structure (in the present invention, referred to as "partial structure A") is included in both the hole transport layer and the light-emitting layer (hereinafter, sometimes referred to as Is a "material containing partial structure A"), wherein the specific structure is an electron withdrawing structure and includes a monocyclic or 2-6 condensed ring aromatic heterocyclic group. In the partial structure A, the Lowest Unoccupied Molecular Orbital (LUMO) tends to exist locally and has high electronic durability. Therefore, it is considered that the deterioration of the hole transport layer caused by electrons leaking from the light emitting layer to the hole transport layer is suppressed. Furthermore, it is considered that electrons locally present in the vicinity of the interface of the light-emitting layer of the hole transport layer contribute to rebonding in the light-emitting layer, and it is considered that the luminous efficiency is improved. Furthermore, it is thought that low voltage can be achieved by efficiently transferring electrons and holes.

Hereinafter, embodiments of an organic electroluminescence element as an embodiment of the present invention and an organic EL display device and organic EL illumination having the organic electroluminescence element will be described in detail. The following description is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents as long as it does not exceed the gist.

[Partial structure A] The organic electroluminescent element of the present invention is an organic electroluminescent element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, and is characterized in that the organic layer has a hole transport layer and is in contact with the electrical A light-emitting layer adjacent to the hole transport layer, at least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer have the same as represented by the following formula (31) Partial structure A.

[化15]

(In the formula (31), the ring HA represents a monocyclic or a 2-6 condensed ring of an optionally substituted aromatic heterocyclic ring. The benzene ring in the formula (31) may have a substituent. Ar ⁰ represents an optionally substituted aromatic heterocyclic ring An aromatic hydrocarbon group, an aromatic heterocyclic group that may have a substituent, or two or more groups selected from an aromatic hydrocarbon group that may have a substituent and an aromatic heterocyclic group that may have a substituent are connected in multiples N1 represents 0 or ^{an integer less than the number that Ar 0} can be substituted on the ring HA. When n1 is 2 or more, a plurality of Ar ⁰ may be the same or different)

The material containing the partial structure A contained in the hole transport layer and the material containing the partial structure A contained in the light-emitting layer have the partial structure A represented by the formula (31) and the same partial structure A is for the present An important constituent element for the invention. When the material contained in the hole transport layer and the material contained in the light-emitting layer have the common partial structure A represented by the formula (31), the effect of the present invention can be obtained.

In the present invention, either or both of the material containing the partial structure A contained in the hole transport layer and the material containing the partial structure A contained in the light-emitting layer more preferably have two or more partial structures A The material contains part of structure A. It is particularly preferable that the material containing the partial structure A contained in the hole transport layer and the material containing the partial structure A contained in the light-emitting layer are both the material containing the partial structure A having two or more identical partial structures A. With such a combination, it can be expected that the electronic durability of the organic electroluminescent element will be further improved, and the organic electroluminescent element will achieve high brightness and long life.

Here, the so-called partial structure A-containing material having two or more identical partial structures A, when the partial structure A-containing material having two or more identical partial structures A is a low-molecular compound, it means There are two or more identical partial structures A in one compound. When the partial structure A-containing material having two or more identical partial structures A is a polymer compound, it means that there are two or more identical partial structures A in one repeating unit.

In the present invention, either or both of the material containing the partial structure A contained in the hole transport layer and the material containing the partial structure A contained in the light-emitting layer are also preferably containing two or more types of materials having partial structures. A's material. With such a combination, it can be expected that the electronic durability of the organic electroluminescent element will be further improved, and the organic electroluminescent element will achieve high brightness and long life.

The material containing the partial structure A contained in the hole transport layer is not particularly limited, but is preferably a polymer compound. As the material containing the partial structure A of the polymer compound, a polymer compound having a repeating unit represented by the formula (1) described later is preferably used.

The material containing the partial structure A contained in the light-emitting layer is not particularly limited, but is preferably a low-molecular compound.

When the material containing the partial structure A is a polymer compound, the number of the partial structure A contained in the polymer compound is preferably more than the number of the partial structure A contained in the repeating unit of the polymer compound. When there are two partial structures A in all the repeating units of the polymer compound, the number of the partial structures A contained in the polymer compound is the repeating unit of the polymer compound×2. When the polymer compound has a plurality of repeating units, at least one repeating unit may have partial structure A.

The bonding method of the partial structure A in the material containing the partial structure A contained in the hole transport layer and the material containing the partial structure A contained in the light-emitting layer is not particularly limited.

From the viewpoint of charge transportability and electron durability, in the material containing the partial structure A in any one of the hole transport layer and the light-emitting layer, the partial structure A is also preferably as shown in the following formula (31)-2 As shown, the benzene ring in the partial structure A is bonded in the material containing the partial structure A.

[化16]

(In formula (31)-2, * represents the bonding site in the material containing partial structure A)

(HA) In the partial structure A represented by the formula (31), HA represents a monocyclic or 2-6 condensed ring optionally substituted aromatic heterocyclic ring. The ring-forming atom of the aromatic heterocyclic ring is preferably any one of a nitrogen atom, an oxygen atom, and a sulfur atom in addition to a carbon atom.

As described later, the ring HA is preferably a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring, a pyrimidine ring, a 1,3,5-triazine ring, and a 1,3,5-triazine ring is especially preferred. ring.

(Ar ⁰ ) In the partial structure A represented by the formula (31), Ar ⁰ represents an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or will be selected from optionally substituted A monovalent group formed by linking two or more groups in the aromatic hydrocarbon group and the optionally substituted aromatic heterocyclic group.

The aromatic hydrocarbon group is preferably one having 6 or more and 60 or less carbon atoms. Specifically, examples include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, fused tetraphenyl ring, pyrene ring, benzopyrene ring, pyrene ring, terphenylene ring, and acenaphthene (acenaphthene) A monovalent group consisting of a 6-membered ring such as a ring, a fluoranthene ring, and a fluorescein ring, or a 2 to 5 condensed ring, or a monovalent group formed by linking 2 to 10 rings selected from these. It is preferably a benzene ring, a naphthalene ring, a sulphur ring, or a monovalent group formed by linking two to ten rings selected from these.

The aromatic heterocyclic group is preferably one having 3 or more and 60 or less carbon atoms. Specifically, examples include 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, quinoline ring, quinoxaline ring, phenanthridine ring, perimidine Ring, quinazoline ring, quinazolinone ring, dibenzofuran ring, dibenzothiophene ring, indolocarbazole ring, phenanthroline ring, etc. 5-membered to 6-membered monocyclic ring or 2 to 4 The monovalent group of the condensed ring or the monovalent group formed by connecting two to ten of these. Preferably, thiophene ring, pyrrole ring, imidazole ring, pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, indolo A monovalent group such as a carbazole ring and a phenanthroline ring, or a monovalent group formed by connecting two to ten of these.

As a monovalent group formed by connecting two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group, it may be a group formed by connecting a plurality of the same groups, It may be a group formed by connecting a plurality of different groups. The total number of connections of the aromatic hydrocarbon group and/or the aromatic heterocyclic group is preferably 2-10.

Ar ^{0 is} preferably an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group substituted with an aromatic hydrocarbon group.

(Better part structure A) From the viewpoint of charge transport properties and electron durability, the partial structure A represented by the formula (31) is preferably a structure represented by the following formulas (33) to (35).

[化17]

(In formula (33) to formula (35), Ar ⁰ and n1 have the same meaning as in formula (31). The benzene ring in formula (33) to formula (35) may have a substituent. X and Y are each independent地 means C atom or N atom. When X and Y are C atoms, Ar ⁰ can be bonded)

From the viewpoint of charge transport properties and electron durability, the formula (35) is preferably represented by the following formula (36), and more preferably is represented by the following formula (37). In the structure represented by the formula (37), the biphenyl structure with high electron resistance is used to transfer electrons, and the electron durability of the compound is further improved. As a result, it is considered that the driving life of the organic electroluminescent element has been extended. In the following formula (36), three benzene rings may have substituents. In the following formula (37), the four benzene rings may have substituents.

[化18]

The structure represented by the above formula (37) is more preferably a structure represented by the following formula (37-2).

[化19]

The "*" and "*1" in the formula (37-2) represent the bonding position in the material containing the partial structure A contained in the hole transport layer or the material containing the partial structure A contained in the light-emitting layer or The bonding position of the substituent. In formula (37-2), regarding at least "*1", since the conjugation of the electronically durable biphenyl structure does not expand, the S1 energy level and T1 energy level are high, and the excitons in the light-emitting layer are not easily deactivated Therefore, in terms of higher luminous efficiency, it is preferable that the material containing the partial structure A contained in the hole transport layer or the bonding position or the substituent in the material containing the partial structure A contained in the light-emitting layer Bond position. From this viewpoint, it is further preferred that atoms other than hydrogen atoms are bonded to "*1" and at least one "*".

In the above formula (35), formula (36), and formula (37), X and Y are preferably N atoms. Therefore, from the viewpoint of electrochemical transmission and stability, it is preferable that the partial structures represented by the formula (36) and formula (37) are represented by the following formula (TzP) and formula (TzP-2), respectively The structure (hereinafter, sometimes referred to as "partial structure (TzP)" and "partial structure (TzP-2)"). Furthermore, the three benzene rings of the partial structure (TzP) and the four benzene rings of the partial structure (TzP-2) may also have substituents.

[化20]

The formula (TzP-2) is more preferably a structure represented by the following formula (TzP-3). The reason why the structure represented by the following formula (TzP-3) is preferable is the same as the reason why the structure represented by the above formula (37-2) is preferable.

[化21]

The "*" and "*1" in the formula (37-2) represent the bonding position in the material containing the partial structure A contained in the hole transport layer or the material containing the partial structure A contained in the light-emitting layer or The bonding position of the substituent.

In addition, in the organic electroluminescence element of the present invention, among the material containing the partial structure A contained in the hole transport layer and the material containing the partial structure A contained in the light-emitting layer, the partial structure A is preferable The skeleton of the common structure has a high degree of similarity. The high similarity of the skeleton as the common structure of the partial structure A means that the identical partial structure A has a large molecular weight.

When the partial structure A represented by the formula (31) is any one of the formulas (33) to (35), the material containing the partial structure A contained in the hole transport layer or Among the materials containing the partial structure A contained in the light-emitting layer, the benzene ring portion of the partial structure A is preferably a material containing the partial structure A contained in the hole transport layer or the partial structure A contained in the light-emitting layer The position of the bond in the material.

Ar ⁰ in formula (31), formula (33) to formula (35), benzene in formula (31), formula (33) to formula (37), formula (TzP) and formula (TzP-2) The substituent that the ring may have may be selected from the following substituent group Z.

[Substituent Group Z] Examples of the substituent group Z include the following substituents. For example, the carbon number of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, tertiary butyl, n-hexyl, cyclohexyl, dodecyl, etc. is usually 1 Above, preferably 4 or more and usually 24 or less, preferably 12 or less linear, branched or cyclic alkyl groups; For example, vinyl groups and other alkenyl groups having a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less; For example, an alkynyl group having a carbon number such as ethynyl group is usually 2 or more and usually 24 or less, preferably 12 or less; For example, an alkoxy group having a carbon number such as methoxy group and ethoxy group is usually 1 or more and usually 24 or less, preferably 12 or less; For example, aryloxy or heteroaryloxy having carbon numbers such as phenoxy, naphthyloxy, pyridyloxy, etc. are usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24; For example, alkoxycarbonyl groups with carbon numbers such as methoxycarbonyl and ethoxycarbonyl are usually 2 or more and usually 24 or less, preferably 12 or less; For example, dialkylamino groups with carbon numbers such as dimethylamino and diethylamino groups are usually 2 or more and usually 24 or less, preferably 12 or less; For example, diphenylamino groups, xylylamino groups, N-carbazolyl groups and other diarylamino groups with carbon numbers of usually 10 or more, preferably 12 or more, and usually 36 or less, preferably 24 or less; For example, an arylalkylamino group such as a phenylmethylamino group having a carbon number of usually 7 or more and usually 36 or less, preferably 24 or less; For example, an acetyl group, a benzyl group, and the like, which have a carbon number of 2 or more and usually 24 or less, preferably 12 or less; For example, halogen atoms such as fluorine atom and chlorine atom; For example, trifluoromethyl and other halogenated alkyl groups having a carbon number of usually 1 or more and usually 12 or less, preferably 6 or less; For example, an alkylthio group having a carbon number such as methylthio and ethylthio is usually 1 or more and usually 24 or less, preferably 12 or less; For example, phenylthio, naphthylthio, pyridinethio and other arylthio groups or heteroarylthio groups with carbon numbers of usually 4 or more, preferably 5 or more, and usually 36 or less, preferably 24 or less; For example, trimethylsilyl, triphenylsilyl and other silyl groups with carbon numbers of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less; For example, trimethylsilyloxy, triphenylsilyloxy and other silyloxy groups have carbon numbers of usually 2 or more, preferably 3 or more, and usually 36 or less, preferably 24 or less; Cyano For example, a phenyl group, a naphthyl group, etc., or a monovalent group formed by linking a plurality of the same or different monocyclic or condensed aromatic hydrocarbon rings have carbon numbers of usually 6 or more and usually 36 or less, preferably Aromatic hydrocarbon group below 24; For example, the number of carbon atoms of a monovalent group formed by linking a plurality of identical or different monocyclic or condensed aromatic heterocycles such as thienyl group or the like is usually 3 or more, preferably 5 or more, and usually 36 or less, Preferably it is an aromatic heterocyclic group of 24 or less; It is a monovalent aromatic group formed by connecting an aromatic hydrocarbon ring and an aromatic heterocyclic group, and when there are multiple aromatic hydrocarbon rings or aromatic heterocyclic groups, they may be the same or different. The carbon number is 8 or more and 36 Hereinafter, it is preferably a monovalent aromatic group of 24 or less.

In the substituent group Z, a monovalent aromatic group formed by connecting the alkyl group, alkoxy group, aromatic hydrocarbon group, aromatic heterocyclic group, aromatic hydrocarbon ring, and aromatic heterocyclic group is preferable. From the viewpoint of charge transport properties, it is more preferred to have no substituents or to have a monovalent aromatic group formed by connecting an aromatic hydrocarbon group, an aromatic heterocyclic group, an aromatic hydrocarbon ring, and an aromatic heterocyclic group.

Each substituent of the substituent group Z may further have a substituent. As these substituents, the same thing as the said substituent (substituent group Z) is mentioned. It is preferable to have no further substituents, or to have an alkyl group having 6 or less carbon atoms, an alkoxy group having 6 or less carbon atoms, a phenyl group, or a crosslinkable group described later as a further substituent. From the viewpoint of charge transportability, it is more preferable that it has no further substituents.

〔High molecular compound〕 Regarding the material containing the partial structure A contained in the hole transport layer of the present invention, that is, the polymer compound, a polymer compound containing a repeating unit represented by the following formula (1) (hereinafter, Sometimes referred to as "the polymer of this embodiment").

[化22]

(In formula (1), A represents the partial structure A. G represents an optionally substituted aromatic hydrocarbon group or N atom. Ar ² represents an optionally substituted divalent aromatic hydrocarbon group or an optionally substituted divalent aromatic group Heterocyclic group, or two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent, directly or through a linking group to connect a plurality of two A valent group. Ar ²⁰ represents a direct bond, a divalent aromatic hydrocarbon group that may have a substituent, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups that may have a substituent)

(G) In the repeating unit represented by the formula (1), G represents an aromatic hydrocarbon group which may have a substituent or an N atom. From the viewpoint of excellent charge transportability, the LUMO distributed in the periphery of the partial structure A is separated from the highest occupied molecular orbital (HOMO) distributed in the main chain and exists locally, G is preferably derived from A group composed of a substituted benzene ring, optionally substituted pyrene ring, or optionally substituted spiro fluorine ring is more preferably a structure shown in the following scheme 1. The following structure may have a substituent. In the figure, "-*" indicates the bonding site ^{with Ar 20.}

[化23]

When G is an aromatic hydrocarbon group that may have a substituent, it is preferable to use the substituent group Z, an aralkyl group having 7 to 40 carbons, or a heterocyclic group having 4 to 37 carbons as the optional substituent group. Any one or a combination of the aralkyl groups of the ring. Among these, in terms of durability, each occurrence is the same or different, and preferably is an alkyl group having 1 to 24 carbons, an aralkyl group having 7 to 40 carbons, and a heterocyclic ring having 3 to 37 carbons. Aralkyl group, arylamino group having 10 to 24 carbons, aromatic hydrocarbon group having 6 to 36 carbons, or aromatic heterocyclic group having 3 to 36 carbons, more preferably alkyl group having 1 to 12 carbons, carbon An aralkyl group having 7 to 30, a heterocyclic aralkyl group having 3 to 27 carbons, an aromatic hydrocarbon group having 6 to 24 carbons, or an aromatic heterocyclic group having 3 to 24 carbons, more preferably a carbon number of 6 to 24 aromatic hydrocarbon groups. From the viewpoint of charge transportability, each occurrence is the same or different, preferably an aromatic hydrocarbon group having 6 to 24 carbons or an aromatic heterocyclic group having 3 to 24 carbons, and more preferably a phenyl group or a naphthyl group , Stilbene, carbazolyl, indolocarbazolyl, indenocarbazolyl or indeno carbazolyl. In particular, if it is bonded to the 9-position of spirobifu or fu, the conjugation will be cut. Therefore, from the viewpoint that the LUMO distributed in the partial structure A and the HOMO distributed in the main chain are further localized, it is preferable to Base, indeno stilbene. In terms of ease of synthesis and charge transport stability, it is most preferable that G does not have a substituent.

In terms of excellent charge transportability, particularly excellent hole transportability, G is preferably a N atom (nitrogen atom).

(Ar ² , Ar ²⁰ ) In the repeating unit represented by the formula (1), Ar ² represents an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted divalent aromatic heterocyclic group, or A divalent group in which two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent are connected in plurality.

Ar ²⁰ represents a direct bond, a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups which may have a substituent.

The aromatic hydrocarbon group of Ar ² and Ar ²⁰ is preferably one having 6 or more and 60 or less carbon atoms. Specifically, examples include: benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, fused tetraphenyl ring, pyrene ring, benzopyrene ring, pyrene ring, terphenylene ring, ethane naphthalene ring, fluorescein A 6-membered monocyclic ring such as an anthracene ring and a sulphur ring or a divalent group of 2 to 5 condensed rings, or a divalent group formed by linking 2 to 10 rings selected from these.

The aromatic heterocyclic group of Ar ² is preferably one having 3 or more and 60 or less carbon atoms. Specifically, examples include 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, quinoline ring, quinoxaline ring, phenanthridine ring, pyridine ring, quinoline A 5-membered to 6-membered ring, such as an oxazoline ring and a quinazolinone ring, is a divalent group of a 5-membered to a 6-membered ring, or a 2- to 4-condensed ring, or a divalent group formed by linking 2 to 10 rings selected from these base.

Ar ^{2 is} a divalent group formed by connecting two or more groups selected from the group consisting of an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group, and the same group may be connected to each other. The group formed of a plurality of groups may also be a group formed by connecting a plurality of different groups. In the case of connecting a plurality of groups, it is preferably a group formed by connecting two to ten.

In terms of excellent charge transport properties and excellent durability, Ar ^{2 is} preferably one selected from the group consisting of a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent, or A divalent group formed by bonding multiple groups directly or via a linking group. When it has a linking group, it is preferably an oxygen atom or a carbonyl group. By forming a non-conjugated structure with an aromatic ring, the triplet level can be increased. Therefore, a structure in which the phenylene rings are connected to each other by an oxygen atom or a carbonyl group is preferred. From the viewpoint of improvement of charge transport properties and excellent stability due to the expansion of the π-conjugated system, a benzene ring or a sulphur ring is preferred. The main chain structure in which the expansion of the π-conjugated system is hindered is formed, the excited singlet energy level (S ₁ ) and excited triplet energy level (T ₁ ) become higher, and the extinction caused by the energy movement of the self-luminous excitons is suppressed From the viewpoint of excellent luminous efficiency, it is particularly preferable to have a twisted structure in which a sulphur ring and a phenylene extension having an alkyl group are bonded. Among them, in terms of the ease of synthesis or purification of the monomer intermediate, a structure including a phenylene group having a methyl group is particularly preferable.

From the viewpoint that the LUMO distributed in the partial structure A and the HOMO distributed in the main chain are respectively present locally, Ar ^{20 is} preferably a direct bond or a divalent aromatic hydrocarbon group that may have a substituent is connected to one to nine. The group of is more preferably a direct bond or a group formed by linking one to seven divalent aromatic hydrocarbon groups that may have a substituent. Among them, it is more preferably a group formed by connecting one to five benzene rings which may have a substituent, and particularly preferably a group formed by connecting three benzene rings which may have a substituent and together with the benzene ring contained in A Extension of quaterphenylene group. From the viewpoint of non-conjugation between the main chain and the partial structure A, and the LUMO distributed in the partial structure A and the HOMO distributed in the main chain are further locally present, it is preferable to include at least one benzene linked at the 1, 3 positions It is more preferable that the ring contains two or more. In the case of a group formed by connecting a plurality of divalent aromatic hydrocarbon groups that may have a substituent, from the viewpoint of charge transport properties or durability, it is preferable that all of them are directly bonded and connected.

When G is a nitrogen atom, in terms of improving hole transportability, ^{the partial structure of Ar 2} directly bonded to G is preferably an aromatic hydrocarbon group that may have a substituent, and more preferably may have The substituted phenylene group or the phenylene group which may have a substituent, and the phenylene group which may have a substituent is especially preferable. Preferably, a benzene ring or a sulphur ring is bonded to a benzene ring directly bonded to G as a nitrogen atom, and it is also preferable that one or more benzene rings and sulphur rings which are directly bonded to a nitrogen atom are further connected. Structure formed by phenyl extension.

When Ar ² and Ar ²⁰ are other than a direct bond, the substituent which may be possessed is the same as the substituent which may be possessed when G is an aromatic hydrocarbon group. In terms of ease of synthesis and charge transport stability, Ar ² and Ar ²⁰ preferably have no substituents.

^{From the viewpoint of excellent electronic durability, -Ar 20} -A in the repeating unit represented by the formula (1) is preferably represented by the following formula (15), more preferably represented by the following formula (16) ).

[化24]

(In formula (15), X and Y each independently represent a C atom or a N atom. The ring having X, Y, and N corresponds to the ring HA in formula (31). Ar ¹ represents an optionally substituted divalent aromatic A hydrocarbon group, or a divalent group formed by connecting two or more optionally substituted divalent aromatic hydrocarbon groups. Ar ³ and Ar ⁴ each independently represent an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic group A heterocyclic group, or a monovalent group formed by connecting two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group. Among them, in Ar ¹ In at least one of, Ar ³ , and Ar ⁴ , the structure bonded to the ring HA is a benzene ring. * indicates the bonding site with G)

(Ar ¹ ) Ar ¹ represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups which may have a substituent. The aromatic hydrocarbon preferably has 6 or more and 60 or less carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a fused tetrabenzene ring, a pyrene ring, a benzopyrene ring, a pyrene ring, a terphenylene ring, an ethane naphthalene ring, a fluorine A 6-membered monocyclic ring such as an anthracene ring and a sulphur ring or a divalent group of 2 to 5 condensed rings, or a divalent group formed by linking 2 to 10 rings selected from these. As ^{the substituent that Ar 1} may have, any one of the above-mentioned substituent group Z or a combination of these can be used. From the viewpoint of durability and charge transport properties, it is preferably selected from the same substituents as the substituents that ^{Ar 2 may have.}

(Ar ³ , Ar ⁴ ) Ar ³ and Ar ^{4 are} preferably each independently an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or may be selected from aromatic hydrocarbon groups which may have a substituent A monovalent group formed by connecting two or more groups in a hydrocarbon group and an optionally substituted aromatic heterocyclic group.

The aromatic hydrocarbon group is preferably one having 6 or more and 60 or less carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a fused tetrabenzene ring, a pyrene ring, a benzopyrene ring, a pyrene ring, a terphenylene ring, an ethane naphthalene ring, a fluorine A monovalent group of a 6-membered ring such as an anthracene ring and a sulphur ring, or a monovalent group of 2 to 5 condensed rings, or a monovalent group formed by linking 2 to 10 rings selected from these.

The aromatic heterocyclic group is preferably one having 3 or more and 60 or less carbon atoms. Specifically, examples include 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, quinoline ring, quinoxaline ring, phenanthridine ring, pyridine ring, quinoline A monovalent ring of 5-membered to 6-membered rings such as oxazoline ring and quinazolinone ring, or a monovalent group of 2 to 4 condensed rings, or a monovalent group formed by linking 2 to 10 rings selected from these base.

As a monovalent group formed by linking a plurality of two or more groups selected from aromatic hydrocarbon groups and aromatic heterocyclic groups, it is preferable to combine a group selected from the aromatic hydrocarbon and the aromatic heterocyclic ring. The structure connects 2 to 10 monovalent groups.

From the viewpoint of distributing LUMO, Ar ³ and Ar ^{4 are} preferably selected from a-1 to a-4, b-1 to b-9, and c-1 to shown in the following scheme 2 independently of each other. The structures of c-5, d-1 to d-17, and e-1 to e-4. From the viewpoint of promoting the expansion of the LUMO of the molecule by further having an electron withdrawing group, it is preferably selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d Structures of -1 to d-13 and e-1 to e-4. Furthermore, from the viewpoint of the effect of having a high triplet level and confining the formed excitons in the light-emitting layer, it is preferably selected from a-1 to a-4, d-1 to d-13, and e-1 ~ The structure of e-4. In order to prevent aggregation of molecules, a structure selected from d-1 to d-13 and e-1 to e-4 is more preferable. From the viewpoint of simple synthesis and excellent stability, the structure of a benzene ring with ^{Ar 3} =Ar ^{4 =d-3 is particularly preferred.} These structures may have substituents. In the figure, "-*" indicates the bonding site with the ring HA. When there are a plurality of "-*", any one of them represents the bonding site to the ring HA.

[化25]

^{R 3A} and R ^{3B in the above} scheme 2 are preferably each independently a linear, branched or cyclic alkyl group which may have a substituent. The carbon number of the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the carbon number is preferably 1 or more and 6 or less, more preferably 3 or less, and still more preferably methyl or ethyl.

R ^3A and R ^3B may be the same or different. ^{It is preferable that all R 3A} and R ^3B are the same group in terms of uniformly distributing the charge around the nitrogen atom and facilitating the synthesis.

As ^{the substituent that Ar 3} and Ar ⁴ may have, any one of the above-mentioned substituent group Z or a combination of these can be used. From the viewpoint of durability and charge transport properties, it is preferably selected from the same substituents as the substituents that ^{Ar 2 may have.}

[化26]

(In the formula (16), X, Y, * meaning and 15) (the same type having X, Y and N corresponds to the same manner as the ring of formula (15) ring HA. Ar ^{1 'represents} a direct bond or the formula (15) corresponds to the ring Ar ¹ and HA structure having X, Y and N of the ring is bonded residue of a benzene ring. Ar ^{3 ',} Ar ^4' represents a hydrogen atom or, respectively, In the formula (15), the structure of Ar ³ and Ar ⁴ bonded to the ring having X, Y, and N corresponding to the ring HA is the residue when a benzene ring is used)

[Preferable repeating unit structure] The repeating unit represented by the above formula (1) is preferably a repeating unit represented by any one of the following formula (2)-1 to formula (2)-3.

[化27]

(In formula (2)-1 to formula (2)-3, A has the same meaning as A in formula (1). Q represents -C(R ⁵ )(R ⁶ )-, -N(R ⁷ )- or -C(R ¹¹ )(R ¹² )-C(R ¹³ )(R ¹⁴ )-. R ¹ to R ⁴ each independently represent an optionally substituted alkyl group or an optionally substituted alkoxy group Or an aralkyl group that may have a substituent. R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ each independently represent an alkyl group that may have a substituent, an alkoxy group that may have a substituent, and an aralkyl group that may have a substituent A group or an aromatic hydrocarbon group which may have a substituent. a and b are each independently an integer of 0 to 4. c1 to c5 are each independently an integer of 0 to 3. wherein at least one of c3 and c5 is 1. Above. d1 to d4 are each independently an integer of 1 to 4. When there are a plurality of R ¹ , R ² , R ³ , and R ⁴ in the repeating unit, R ¹ , R ² , R ³ , and R ⁴ may be Same or different)

(R ¹ and R ²⁾ of the formula (2) -1 to (2) -3 a repeating unit represented by R ¹ and R ² are each independently an alkyl group may have a substituent group, may have a substituent group The alkoxy group or the aralkyl group which may have a substituent. It is ^{preferable that R 1} and R ² are each independently a linear, branched or cyclic alkyl group which may have a substituent. The carbon number of the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the carbon number is preferably 1 or more and 6 or less, more preferably 3 or less, and still more preferably methyl or ethyl.

When there are a plurality of R ¹ and R ² in the repeating unit, R ¹ and R ² may be the same or different. ^{It is preferable that all R 1} and R ² are the same group in terms of distributing the charge uniformly around the nitrogen atom and facilitating the synthesis.

(R ³ and R ⁴⁾ of the formula (2) -1 to the formula (2) -3 R ³ and R repeating unit represented by ⁴ each independently an optionally substituted alkyl group may have a substituent The alkoxy group or the aralkyl group which may have a substituent. It is ^{preferable that R 3} and R ⁴ are each independently a linear, branched or cyclic alkyl group which may have a substituent. The carbon number of the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, the carbon number is preferably 1 or more, more preferably 4 or more, and preferably 12 or less, and more preferably 8 or less. Especially good for hexyl.

(R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ ) R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ are each independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted group An aralkyl group or an aromatic hydrocarbon group which may have a substituent. R ⁵ to R ⁷ and R ¹¹ to R ^{14 are} preferably each independently an optionally substituted alkyl group, an optionally substituted aralkyl group, or an optionally substituted aromatic hydrocarbon group.

The alkyl group is not particularly limited, but in order to easily improve the solubility of the polymer, it is preferably long, and in order to increase the stability of the film and to increase the charge transport properties, it is preferably short. The carbon number of the alkyl group is preferably 1 or more and 24 or less, more preferably 12 or less, further preferably 8 or less, particularly preferably 6 or less, and more preferably 2 or more, further preferably 3 or more, and particularly preferably 4 above. In addition, the alkyl group may have any structure of linear, branched, or cyclic. Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, tertiary butyl, n-hexyl, and n-octyl. , Cyclohexyl, dodecyl, etc.

The alkoxy group is not particularly limited, but in order to easily improve the solubility of the polymer, the carbon number is preferably 1 or more and 24 or less, more preferably 12 or less, still more preferably 8 or less, and particularly preferably 6 or less. And it is more preferably 2 or more, still more preferably 3 or more, and particularly preferably 4 or more. Specific examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, and hexyloxy. Wait.

The aralkyl group is not particularly limited, but in order to easily improve the solubility of the polymer, the carbon number is preferably 7 or more and 60 or less, more preferably 40 or less, and more preferably 8 or more, and still more preferably 10 or more , Particularly preferably 12 or more. Specific examples of the aralkyl group include 1,1-dimethyl-1-phenylmethyl, 1,1-di(n-butyl)-1-phenylmethyl, 1,1- Bis(n-hexyl)-1-phenylmethyl, 1,1-bis(n-octyl)-1-phenylmethyl, phenylmethyl, phenylethyl, 3-phenyl-1-propyl , 4-phenyl-1-n-butyl, 1-methyl-1-phenylethyl, 5-phenyl-1-n-propyl, 6-phenyl-1-n-hexyl, 6-naphthyl- 1-n-hexyl, 7-phenyl-1-n-heptyl, 8-phenyl-1-n-octyl, 4-phenylcyclohexyl, etc.

The aromatic hydrocarbon group is not particularly limited, but in order to easily improve the solubility of the polymer, the carbon number is preferably 6 or more and 60 or less, more preferably 30 or less, still more preferably 24 or less, and particularly preferably 14 the following. Specific examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a fused tetrabenzene ring, a pyrene ring, a benzopyrene ring, a pyrene ring, a terphenylene ring, and ethyl A monovalent group consisting of a 6-membered ring such as a naphthalene ring, a fluoranthene ring, and a fluorine ring, or a 2 to 5 condensed ring, or a group formed by linking two to eight ring structures selected from these. Preferably, it is a monocyclic ring or a group formed by connecting 2 to 4 or less.

From the viewpoint of improvement in charge transportability and durability, R ⁵ to R ^{7 are} preferably alkyl groups or aromatic hydrocarbon groups, R ⁵ and R ^{6 are more} preferably alkyl groups, and R ^{7 is more} preferably an aromatic hydrocarbon group, and more preferably The carbon number of is as described above. In terms of improved solubility and excellent charge transportability, R ⁵ and R ^{6 are} preferably an alkyl group having 3 or more and 8 or less carbon atoms or an aralkyl group having 9 or more and 40 or less carbon atoms.

The alkyl group, alkoxy group, aralkyl group of R ¹ to R ⁴ , the alkyl group, alkoxy group, aralkyl group and aromatic hydrocarbon ^{group of R 5} to R ⁷ and R ¹¹ to R ^{14 may be further substituted} base. The substituents that may be further included include the groups exemplified as preferable groups of the alkyl group, alkoxy group, aralkyl group, and aromatic hydrocarbon group of ^{R 5} to R ⁷ and R ¹¹ to R ^{14, or the following groups} Cross-linking base. From the viewpoint of lowering the voltage, the ^{alkyl group, alkoxy group, aralkyl group of R 1} to R ⁴ , the alkyl group, alkoxy group, and aralkyl group of R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ And the aromatic hydrocarbon group preferably has no substituent.

When the polymer of the present embodiment is formed into a film and then applied to form another layer and laminated, from the viewpoint of improving the insolubility to the solvent, R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ may further have The substituent of is preferably a crosslinkable group described later. ^{Among them, it is preferable that any one of R 5} , R ^6, and R ¹¹ to R ¹⁴ has a crosslinkable group described later as a further substituent from the viewpoint that the charge transportability is not easily hindered, and it is more preferable that ^{R 5} and At least one of R ⁶ has a crosslinkable group described later as a further substituent.

(A, b, c1～c5, d1～d4) In the repeating unit represented by the formula (2)-1 to formula (2)-2, a and b are each independently an integer of 0-4. It is preferable that a and b are each 2 or less, and it is more preferable that both a and b are 0 or 1 at the same time.

In the repeating units represented by the above formula (2)-1 to formula (2)-3, c1 to c5 are each independently an integer of 0 to 3. However, at least one of c3 and c5 is 1 or more, and d1 to d4 are each independently an integer of 1-4. It is preferable that c1 to c5 and d1 to d4 are each independently 2 or less. More preferably, both c1 and c2 are 0 or 1 at the same time. c1 and c2 are more preferably 1 or more. It is preferable that at least one of c3 and c4 or both of c3 and c4 are 1 or more. Furthermore, it is preferable that both c3 and c4 are 1. c5 is preferably 1 or more. It is more preferable that c1 and c2, c3 and c4, and d1 to d4 are respectively equal to each other. More preferably, all of c1 to c5 and d1 to d4 are 1 or 2. It is particularly preferable that all of c1 to c5 and d1 to d4 are 1.

When both c1 and c2 in the repeating unit represented by the formula (2)-1 are 1 or 2 at the same time, and both a and b are 2 or 1, it is best that R ¹ and R ^{2 are} bonded In a symmetrical position to each other. In the case where both c3 and c4 in the repeating unit represented by the formula (2)-2 are both 1 or 2 and both a and b are 2 or 1, it is best that R ¹ and R ^{2 are} bonded In a symmetrical position to each other.

Here, regarding the ^{bonding of R 1} and R ² at positions symmetrical to each other, take an example of the case where Q=C, c1=c2=1, and a=b=2 in the formula (2)-1, and It will be explained by the following formula (1-1) and formula (1-2). The so-called R ¹ and R ² bonded to positions symmetrical to each other, means bonding position with respect to the main chain of the following formula (1-1), (1-2) a fluorene ring, R ¹ and R ² is relatively. At this time, the 180-degree rotation with the main chain as the axis is regarded as the same structure. For example, in the following formula (1-1), R ¹ 'is opposite to R ² ', R ¹ '' is opposite to R ² '', and formula (1-1) and formula (1-2) are regarded as the same structure .

[化28]

(Specific example) As a specific example of a preferable repeating unit structure, the following structures can be mentioned.

[化29]

[化30]

[化31]

[Terminal group] In the present embodiment, the term "terminal group" refers to the structure of the terminal portion of the polymer formed by the end-capping agent used at the end of the polymerization of the polymer. The terminal group of the polymer of this embodiment is usually a hydrocarbon group. As the hydrocarbon group, from the viewpoint of charge transportability, the carbon number is preferably 1 or more and 60 or less, more preferably 1 or more and 40 or less, and still more preferably 1 or more and 30 or less.

As said terminal group, the following are mentioned preferably. For example, the carbon number of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, tertiary butyl, n-hexyl, cyclohexyl, dodecyl, etc. is usually 1 Above, preferably 4 or more and usually 24 or less, preferably 12 or less linear, branched or cyclic alkyl groups; For example, vinyl groups and other alkenyl groups having a carbon number of usually 2 or more and usually 24 or less, preferably 12 or less; For example, an alkynyl group having a carbon number such as ethynyl group is usually 2 or more and usually 24 or less, preferably 12 or less; For example, an aromatic hydrocarbon ring group such as a phenyl group and a naphthyl group having a carbon number of usually 6 or more and usually 36 or less, preferably 24 or less.

These hydrocarbon groups may further have a substituent. The substituent which may be further possessed is preferably an alkyl group or an aromatic hydrocarbon group. When there are a plurality of substituents which may be further possessed, they may be bonded to each other to form a ring. The substituent which may be further possessed by the hydrocarbon group as the terminal group is preferably an alkyl group or an aromatic hydrocarbon group, and more preferably an aromatic hydrocarbon group, from the viewpoint of charge transport properties and durability.

[Soluble base] The polymer of this embodiment preferably has a soluble group in order to exhibit solubility in a solvent. The soluble group of the present embodiment is a group having a linear or branched alkyl group or alkylene group having a carbon number of 3 or more and 24 or less, preferably a carbon number of 12 or less. Among these, an alkyl group, an alkoxy group, or an aralkyl group is preferred, for example, n-propyl, 2-propyl, n-butyl, isobutyl, n-hexyl, n-octyl and the like. More preferably, it is n-hexyl or n-octyl. The soluble group may have a substituent.

(Number of soluble bases) Regarding the soluble groups possessed by the polymer of the present embodiment, it is preferable to have more soluble groups in terms of the ease of obtaining a polymer solution usable by the wet film forming method. On the other hand, when another layer is formed by a wet film forming method on a layer formed using the polymer of the present embodiment, the lower layer is dissolved in a solvent and the reduction in the film thickness is small, and it is better to be less.

The number of soluble groups possessed by the polymer of this embodiment can be represented by the number of moles per 1 g of the polymer. When the number of soluble groups in the polymer of the present embodiment is expressed as the number of moles per 1 g of the polymer, it is usually 4.0 millimoles or less per 1 g of the polymer, preferably It is 3.0 millimoles or less, more preferably 2.0 millimoles or less, and usually 0.1 millimoles or more, preferably 0.5 millimoles or more. If the number of soluble groups is within the above range, the polymer is easily dissolved in the solvent, and it is easy to obtain a composition containing a polymer suitable for a wet film forming method. In addition, the density of the soluble base is moderate, and the poor solubility in the organic solvent after heating the solvent to dry is sufficient, so it is possible to form a multi-layer laminated structure by a wet film formation method.

The number of soluble groups per 1 g of the polymer can be calculated based on the molar ratio of the charged monomer and the structural formula after the end group of the polymer is removed from the polymer. If the polymer 1 represented by the formula (HT-1) used in Example 1 described later is described, as described below, the average molecular weight of the repeating units other than the terminal groups in the polymer 1 is 748.4, and the hexyl group as a soluble group has an average of 1.3 per repeating unit. If it is calculated by a simple ratio, the number of soluble groups per 1 g of molecular weight is calculated to be 1.74 millimoles.

[化32]

[Crosslinkable group] The polymer of this embodiment may have a crosslinkable group. The crosslinkable group in the polymer of this embodiment may be present in the repeating unit represented by the formula (1), or may be present in another repeating unit different from the repeating unit represented by the formula (1) . In particular, it is preferable to have a crosslinkable group with an aromatic hydrocarbon group or an aromatic heterocyclic group bonded as a side chain because the crosslinking reaction easily proceeds. By having a crosslinkable group, it is possible to make a big difference in the solubility to an organic solvent before and after the reaction (insolubilization reaction) that occurs by the irradiation of heat and/or active energy rays.

The cross-linkable group refers to a group that reacts with a group constituting another molecule located in the vicinity of the cross-linkable group by irradiation of heat and/or active energy rays to form a new chemical bond. In this case, the group to be reacted may be the same group as the crosslinkable group or a different group.

The crosslinkable group is preferably a group containing a cyclobutene ring condensed to an aromatic ring and an alkenyl group bonded to an aromatic ring, and more preferably a group selected from the following crosslinkable group K. The crosslinkable group is preferably included in the polymer in a form further substituted with a substituent possessed by each of the above-mentioned structures.

(Crosslinkable group K) The crosslinkable group K has the structure shown below.

[化33]

In the crosslinkable group K, R ²¹ to R ²³ each independently represent a hydrogen atom or an alkyl group. R ²⁴ to R ²⁶ each independently represent an alkyl group or an alkoxy group. p represents an integer of 1-4, q represents an integer of 1-4, and r represents an integer of 1-4. When p is 2 or more, a plurality of R ²⁴ may be the same or different, and adjacent R ²⁴ may be bonded to each other to form a ring. When q is 2 or more, a plurality of R ²⁵ may be the same or different, and adjacent R ²⁵ may be bonded to each other to form a ring. When r is 2 or more, a plurality of R ²⁶ may be the same or different, and adjacent R ²⁶ may be bonded to each other to form a ring. Ar ²¹ and Ar ²² each independently represent an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group. "-*" is the bonding part.

Examples of the alkyl group of R ²¹ to R ²⁶ include linear or branched chain alkyl groups having 6 or less carbon atoms. For example, it is methyl, ethyl, n-propyl, 2-propyl, n-butyl, isobutyl and the like. More preferably, it is methyl or ethyl. It is considered that when ^{the carbon number of the alkyl group of R 21} to R ²⁶ is 6 or less, the crosslinking reaction is not hindered three-dimensionally, and the insolubilization of the film formed of the polymer of the present embodiment is likely to occur.

Examples of the alkoxy group represented by R ²⁴ to R ²⁶ include linear or branched chain alkoxy groups having 6 or less carbon atoms. For example, methoxy, ethoxy, n-propoxy, 2-propoxy, n-butoxy and the like. More preferred is methoxy or ethoxy. It is considered that if ^{the carbon number of R 24} to R ²⁶ is 6 or less, the crosslinking reaction will not be hindered three-dimensionally, and the insolubilization of the film formed of the polymer of the present embodiment is likely to occur.

Examples ^{of the optionally substituted aromatic hydrocarbon group of Ar 21} and Ar ²² include a 6-membered monocyclic ring or 2 to 5 condensed ring such as a benzene ring and a naphthalene ring having one free valence. In particular, a benzene ring having one free valence is preferable. Ar ²² may be a group in which two or more aromatic hydrocarbon groups that may have a substituent are bonded. Examples of such a group include biphenylene, triphenylene, etc., and 4,4'-biphenylene is preferred. Examples ^{of the optionally substituted aromatic heterocyclic group of Ar 21} and Ar ²² include a 6-membered monocyclic ring or 2 to 5 condensed ring such as a pyridine ring and a triazine ring having one free valence. In particular, a triazine ring having one free valence is preferred. The substituents that Ar ²¹ and Ar ²² may have are the same as the substituent group Z described above.

As the crosslinkable group, in terms of further improving the electrochemical stability of the device, an arylvinylcarbonyl group such as a cinnamyl group, a benzocyclobutene ring having a monovalent free atomic valence, and a The 1,2-dihydrocyclobutane [a] naphthalene ring with free valence, etc. is a group that undergoes cyclization addition reaction.

Among the crosslinkable groups, in terms of a particularly stable structure after crosslinking, it is preferable to include a cyclobutene ring condensed to an aromatic ring having a monovalent free valence, and a monovalent free valence 1 The group of the 2-dihydrocyclobutane[a] naphthalene ring is more preferably a benzocyclobutene ring or 1,2-dihydrocyclobutane[a]naphthalene ring having a univalent free valence. In terms of the low crosslinking reaction temperature, the crosslinkable group is particularly preferably a 1,2-dihydrocyclobutane[a]naphthalene ring having a monovalent free atomic valence.

(Number of cross-linkable groups) Regarding the crosslinkable group possessed by the polymer of the present embodiment, it is more preferable that it is sufficiently insolubilized by crosslinking, and other layers can be easily formed thereon by a wet film formation method. On the other hand, in terms of the fact that cracks are less likely to occur in the formed layer, unreacted crosslinkable groups are less likely to remain, and the organic electroluminescence element is likely to have a long life, it is preferable that the number of crosslinkable groups is small.

The number of crosslinkable groups present in one polymer chain in the polymer of this embodiment is preferably 1 or more, more preferably 2 or more, and more preferably 200 or less, and more preferably 100 or less.

The number of crosslinkable groups that the polymer of the present embodiment has can be expressed as the number per molecular weight of the polymer 1000. In the case where the number of crosslinkable groups possessed by the polymer of the present embodiment is expressed as the number per molecular weight of the polymer 1000, per molecular weight 1000, usually 3.0 or less, preferably 2.0 or less , More preferably 1.0 or less, and usually 0.01 or more, preferably 0.05 or more.

If the number of crosslinkable groups is within the above range, cracks and the like are less likely to occur, making it easy to obtain a flat film from the polymer of the present embodiment. In addition, since the cross-linking density is moderate, there are few unreacted cross-linkable groups remaining in the layer after the cross-linking reaction, and it is difficult to affect the life of the obtained device. Furthermore, since the poor solubility in the organic solvent after the crosslinking reaction is sufficient, it is easy to form a multilayer build-up structure by a wet film forming method.

The number of crosslinkable groups per molecular weight 1000 of the polymer can be calculated from the molar ratio of the charged monomer and the structural formula at the time of synthesis after removing the terminal groups from the polymer. If the polymer 1 represented by the formula (HT-1) used in Example 1 described later will be described, the average molecular weight of the repeating unit excluding the terminal group in the polymer 1 is 748.4, and the crosslinkability The base is 0.15 per repeat unit. If it is calculated by a simple ratio, the number of crosslinkable groups per molecular weight 1000 is calculated to be 0.20.

[化34]

[Content of Repeating Units] In the polymer of this embodiment, the content of the repeating unit represented by formula (1) is not particularly limited, and it is usually contained in the polymer at 5 mol% or more, preferably 10 mol% or more, and more preferably 15 mol% or more, more preferably 20 mol% or more. In the polymer of this embodiment, the repeating unit may include only the repeating unit represented by formula (1), but for the purpose of balancing various properties when making an organic electroluminescent device, it may have a different type from formula (1). Other repeating units. In this case, the content of the repeating unit represented by the formula (1) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[Other preferred repeating units that can be contained] The polymer of this embodiment also preferably further contains a repeating unit represented by the following formula (3). The repeating unit represented by the formula (3) is preferably a repeating unit represented by any one of the following formula (3)-1, formula (3)-2, or formula (3)-3.

[化35]

(In formula (3), Ar ¹³ represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group that does not include the partial structure A. Ar ¹⁴ represents an optionally substituted divalent aromatic hydrocarbon group, A divalent aromatic heterocyclic group which may have a substituent, or two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent directly or via A divalent group formed by connecting multiple connecting groups)

[化36]

(In formulas (3)-1 to (3)-3, Ar ⁷ represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group without partial structure A. Q represents -C( R ⁵ )(R ⁶ )-, -N(R ⁷ )- or -C(R ¹¹ )(R ¹² )-C(R ¹³ )(R ¹⁴ )-. R ¹ to R ⁴ each independently represent that they may have A substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ each independently represent an optionally substituted alkyl group, which may have Substituent alkoxy group, optionally substituted aralkyl group, or optionally substituted aromatic hydrocarbon group. a and b are each independently an integer of 0 to 4. c1 to c5 are each independently of 0 to 3 Integer. Wherein, at least one of c3 and c5 is 1 or more. d1 to d4 are each independently an integer of 1 to 4. There are a plurality of R ¹ , R ² , R ³ , and R ^{4 in the repeating unit} When, R ¹ , R ² , R ³ , and R ⁴ may be the same or different. Among them, Q, R ¹ to R ⁴ may be the same as those in the formula (2)-1 to the formula (2)-3 Q, R ¹ to R ^{4 have the} same structure, and the preferred range is also the same. Therefore, the same symbols are used, but they can also be different. The values of c1 to c5 and d1 to d4 in the formula (2)-3 are the same, and the preferred ranges are also the same. Therefore, the same symbols are used, but they may be different)

(Ar ⁷ ) In the repeating units represented by formulas (3)-1 to (3)-3, Ar ⁷ in each repeating unit independently represents an aromatic that may have a substituent that does not include the partial structure A A hydrocarbon group or an aromatic heterocyclic group which may have a substituent.

The aromatic hydrocarbon group is preferably one having 6 or more and 60 or less carbon atoms. Specifically, examples include: benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, fused tetraphenyl ring, pyrene ring, benzopyrene ring, pyrene ring, terphenylene ring, ethane naphthalene ring, fluorescein A 6-membered monocyclic ring, such as an anthracene ring and a stilbene ring, or a 2 to 5 condensed ring, or a monovalent group formed by linking a plurality of rings selected from these. In the case of connecting a plurality of units, it is preferably a monovalent group formed by connecting 2 to 10 units.

The aromatic heterocyclic group is preferably one having 3 or more and 60 or less carbon atoms. Specifically, examples include 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, pyrazine ring, pyridazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, phenanthridine ring, pyridine ring, quinazoline ring, quinazolinone ring, etc. A 5-membered to 6-membered monocyclic ring or a 2- to 4-condensed ring, or a monovalent group formed by connecting a plurality of rings selected from these. In the case of connecting a plurality of units, it is preferably a monovalent group formed by connecting 2 to 10 units.

In terms of excellent charge transport properties and excellent durability, Ar ^{7 is} preferably an aromatic hydrocarbon group that may have a substituent. Among them, the monovalent group of the benzene ring or the stilbene ring which may have a substituent, that is, the phenyl group or the stilbene group which may have a substituent is more preferable, the stilbene group which may have a substituent is more preferable, and the one which may have a substituent is particularly preferable. 2-茀基.

The substituent that the aromatic hydrocarbon group of Ar ⁷ may have is not particularly limited as long as it does not significantly reduce the characteristics of the polymer of the present embodiment. Preferably, a group selected from the substituent group Z or the crosslinkable group is mentioned. The substituent is preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, an aromatic heterocyclic group that does not correspond to the partial structure A, or the above-mentioned crosslinkable group, and more preferably an alkyl group.

In terms of solubility to the coating solvent, Ar ^{7 is} preferably a stilbene group substituted with an alkyl group having 1 to 24 carbons, and particularly preferably a 2-alkyl group substituted with an alkyl group having 4 to 12 carbons. Chi Ji. Furthermore, it is preferably a 9-alkyl-2-phosphonium group substituted with an alkyl group at the 9-position of the 2-phosphonium group, and particularly preferably a 9,9'-dialkyl-2 group substituted with two alkyl groups. Chi Ji. By being a stilbene group in which at least one of the 9-position and 9'-position is substituted with an alkyl group, the solubility to the solvent and the durability of the stilbene ring are easily improved. Furthermore, by being a stilbene group in which both the 9-position and the 9'-position are substituted with an alkyl group, the solubility to the solvent and the durability of the stilbene ring are likely to be further improved. Ar ⁷ includes the crosslinkable group, since the insolubility to the solvent is improved during the build-up coating after film formation, so it is preferable.

From the viewpoint of insolubilization, it is preferable to include a repeating unit represented by formula (3)-1 to formula (3)-3 containing at least one of the crosslinkable groups as a further substituent. It is preferable that this crosslinkable group is further substituted with the substituent which the aromatic hydrocarbon group represented by ^{Ar 7 may have.}

(Specific example) As a specific example of the repeating unit structure represented by the said formula (3)-1-the said formula (3)-3, the following structures are mentioned.

[化37]

[化38]

[化39]

[Other repeating units] In terms of charge transport properties and durability, the polymer of the present embodiment may further include a repeating unit represented by the following formula (4) or the following formula (5).

[化40]

In formula (4), R ⁸ and R ⁹ each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group.

In formula (5), Ar ¹⁰ represents an optionally substituted divalent aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or is selected from the optionally substituted divalent aromatic hydrocarbon group and an optionally substituted group Two or more groups in the divalent aromatic heterocyclic group of is a divalent group formed by connecting a plurality of groups directly or via a linking group.

(R ⁸ and R ⁹ ) ^{Examples of the alkyl group, aromatic hydrocarbon group, and aromatic heterocyclic group of R 8} and R ⁹ include the alkyl group, aromatic hydrocarbon group, and aromatic heterocyclic group exemplified as the substituent group Z. . The substituent that these groups may have is preferably the same group as the substituent group Z or the crosslinkable group.

(Ar ¹⁰ ) As ^{a specific structure of Ar 10} , the same divalent group as ^{Ar 2 in} the above formula (1) can be cited. The substituent that these groups may have is preferably the same group as the substituent group Z or the crosslinkable group.

[Molecular weight of polymer] The weight average molecular weight (Mw) of the polymer of this embodiment is usually 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, further preferably 200,000 or less, particularly preferably 100,000 or less, usually 10,000 or more, preferably 15,000 or more.

When the weight average molecular weight of the polymer is below the upper limit, solubility to a solvent can be obtained, and there is a tendency that the film-forming properties are excellent. When the weight average molecular weight of the polymer is greater than or equal to the lower limit, the decrease in the glass transition temperature, melting point, and vaporization temperature of the polymer may be suppressed, and the heat resistance may be improved. In addition, the coating film may have sufficient insolubility in the organic solvent after the crosslinking reaction.

The number average molecular weight (Mn) of the polymer of this embodiment is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, particularly preferably 100,000 or less, usually 2,000 or more, preferably 4,000 or more, and more preferably 8,000 or more, more preferably 20,000 or more.

The degree of dispersion (Mw/Mn) of the polymer of the present embodiment is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. The value of the degree of dispersion is as small as possible, so the lower limit is desirably 1. If the degree of dispersion of the polymer is below the upper limit, it is easy to purify, and the solubility to the solvent and the charge transport performance are good.

Generally, the weight average molecular weight and number average molecular weight of the polymer are determined by the determination of size exclusion chromatography (SEC). In SEC measurement, the higher the molecular weight component, the shorter the dissolution time, the lower the molecular weight component, the longer the dissolution time. By using a calibration curve calculated from the dissolution time of polystyrene (standard sample) with a known molecular weight Calculate the weight average molecular weight and number average molecular weight by converting the elution time of the sample into molecular weight.

[Preferred polymer] The polymer of this embodiment is most preferably represented by any one of the following formula (6a) to formula (6h).

[化41]

In each polymer of formula (6a) to formula (6h), A, Q, R ¹ , R ² , R ³ , and R ⁴ are the same as those in formula (2)-1 to formula (2)-3 . Ar ^{7 is the} same as in the above-mentioned formulas (3)-1 to (3)-3. At least one of A or Ar ^{7 in} each polymer preferably has the crosslinkable group. n and m represent the number of repetitions.

[Specific example] The following shows the polymer 1 represented by the formula (HT-1) and the polymers of the present embodiment other than the polymers represented by the formula (HT-2) and the formula (HT-4) used in the examples described later Specific examples. The polymer of this embodiment is not limited to these. The number in the following chemical formula represents the molar ratio of the repeating unit. These polymers may be any of random copolymers, alternating copolymers, block copolymers, graft copolymers, etc., and the sequence of repeating units is not limited.

[化42]

[化43]

[化44]

[化45]

[化46]

[Manufacturing method of polymer] The manufacturing method of the polymer of this embodiment is not specifically limited. For example, the polymerization method using Suzuki reaction, the polymerization method using Grignard reaction, the polymerization method using Yamamoto reaction, the polymerization method using Ullmann reaction, the polymerization method using Buchwald-Hartwig (Buchwald-Hartwig) reaction polymerization method.

In the case of a polymerization method using Ullmann reaction and a polymerization method using Buchwald-Hartwig reaction, for example, by making the following formula (1a) represented A dihalide aryl group (E represents a halogen atom such as I, Br, Cl, F) reacts with the primary amino aryl group represented by formula (1b), and then reacts with the dihalide aryl group represented by formula (2a), and The polymer of this embodiment is synthesized.

[化47]

In the above formula, A, R ¹ to R ² , Q, a, b, c1, and d1 have the same meaning as the above formula (2)-1 to (2)-3. n and m represent the number of repetitions.

In the polymerization method, generally, the reaction to form an N-aryl bond is carried out in the presence of a base such as potassium carbonate, sodium tert-butoxide, triethylamine, and the like. In addition, for example, it may be performed in the presence of a transition metal catalyst such as a copper or palladium complex compound.

〔Low molecular weight compounds〕 The material containing the partial structure A contained in the light-emitting layer as one aspect of the present invention is preferably a low-molecular compound. The material containing the partial structure A of the low-molecular compound is preferably a compound with a molecular weight of 5,000 or less represented by the following formula (10), the following formula (11) or the following formula (12) (hereinafter, sometimes these The compound is referred to as the "low-molecular compound of the present embodiment").

[化48]

(In formula (10) ~ formula (12), A is the partial structure A. B represents a single bond or an arbitrary partial structure. na, nb, and nc represent an integer of 1-5. When na, nb, nc are 2 or more, multiple A, B, A-B may be the same or different)

(B) The B in the formula (10) and the formula (11) is not particularly limited, but preferably includes a functional group that may have a substituent, an aromatic hydrocarbon group that may have a substituent, and an aromatic that may have a substituent. A heterocyclic group, or a group in which two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are connected to a plurality of groups directly or via a linking group.

The functional group is preferably a group including a structure having hole transport properties, a structure having electron transport properties, a structure inhibiting charge transport, a structure imparted to an organic solvent, and a structure that inhibits crystallization. A structure that improves amorphousness or a structure that has light-emitting properties. It is preferable to include an aromatic amine structure, that is, a structure in which at least one aromatic hydrocarbon group is bonded to the nitrogen atom of the amine, as the group having a hole-transporting structure.

As an aromatic hydrocarbon group, an aromatic heterocyclic group, two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are connected directly or through a linking group. The base of is preferably based on the same structure as ^{Ar 0 in the above formula (31).}

As the position of A to which B is bonded, it is preferable that at least one B is bonded to the ring HA in the partial structure A.

The low-molecular compound of this embodiment is preferably a charge transport material in the light-emitting layer. The low-molecular compound of the present embodiment is preferably a compound represented by the formula (10) or the formula (12).

The compound represented by the formula (10) is preferably a compound represented by the following formula (10A) or the following formula (10B). The compound represented by the formula (12) is preferably a compound represented by the following formula (12A).

[化49]

(In formula (10A), HA represents any of the trivalent aromatic heterocyclic groups represented by the following structural formula (10A-a), structural formula (10A-b), and structural formula (10A-c). Xa ¹ , Ya ¹ and Za ¹ each independently represent an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbons, or an optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbons. Xa ^2. Ya ² and Za ² each independently represent a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted aromatic heterocyclic group having 3 to 30 carbon atoms. 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, h11, and j11 are 2 or more, Xa ¹ , Ya ¹ , and Za ¹ may be The same or different. R ³¹ represents a hydrogen atom or a substituent. Four R ^31s may be the same or different)

[化50]

(In formula (10A-a) ~ formula (10A-c), * represents the bonding position)

[化51]

(In the formula (10B), A has the same meaning as in the above formula (10). Xb ¹ , Yb ¹ and Zb ¹ each independently represent an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbons, or An optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms. p12, q12, and r12 each independently represent an integer of 0 to 6. When p12, q12, and r12 are 2 or more, a plurality of Xb ¹ , Yb ¹ and Zb ¹ may be the same or different. q13 and r13 each independently represent 0 or 1. Among them, q12 and q13 are not 0 at the same time, r12 and r13 are not 0 at the same time. Yb ² and when q13 is 0 ^{Zb 2} when r13 is 0 each independently represents a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted carbon number 3 to 30 aromatic heterocyclic group. q13 is 1 Yb ² when r13 is a direct bond. Zb ² when r13 is 1 is a direct bond)

[化52]

(In formula (12A), ring HA and Ar ⁰ have the same meaning as in formula (31). nc has the same meaning as in formula (12). Xc ¹ and Yc ¹ each independently represent that they may have a substituent A divalent aromatic hydrocarbon group with 6 to 30 carbons or an optionally substituted divalent aromatic heterocyclic group with 3 to 30 carbons. Xc ² and Yc ² each independently represent a hydrogen atom and optionally substituted An aromatic hydrocarbon group having 6 to 30 carbons, or an optionally substituted aromatic heterocyclic group having 3 to 30 carbons. s11 and t11 each independently represent an integer of 0 to 6. When s11 and t11 are 2 or more Below, a plurality of Xc ¹ and Yc ¹ may be the same or different. R ³¹ represents a hydrogen atom or a substituent. u11 is ^{the number that can be substituted by the substituent R 31.} u12 is the number that can be substituted by the substituent Ar ^0. Where u11 is 2 In the above case, multiple R ³¹ can be the same or different)

In the formula (10A), formula (10B), and formula (12A), the aromatic hydrocarbon ring as the aromatic hydrocarbon group having 6 to 30 carbon atoms is preferably a 6-membered monocyclic ring or a 2 to 5 condensed ring . Specifically, examples include: benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, perylene ring, fused tetraphenyl ring, pyrene ring, benzopyrene ring, pyrene ring, terphenylene ring, fluoranthene ring, etc. . More preferably, it is a monocyclic ring or a 2 to 3 condensed ring, and specific examples include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, and a sulphur ring. Among them, a benzene ring, a naphthalene ring, a phenanthrene ring, and a sulphur ring are preferred, and a benzene ring or a sulphur ring is more preferred.

In the formula (10A), formula (10B), and formula (12A), the aromatic heterocyclic ring of the aromatic heterocyclic group having 3 to 30 carbon atoms is preferably a 5-membered ring or a 6-membered monocyclic ring, Or these 2 to 5 condensed rings. Specifically, examples include furan ring, benzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, Indole ring, carbazole ring, indolocarbazole 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, piperidine ring, quinazoline ring, quinazolinone ring, etc. Among them, preferred are thiophene ring, pyrrole ring, imidazole ring, pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, indole Dolocarbazole ring, phenanthroline ring or indolocarbazole ring, more preferably pyridine ring, pyrimidine ring, triazine ring, quinoline ring, quinazoline ring, carbazole ring, dibenzofuran ring, two The benzothiophene ring or indolocarbazole ring is more preferably a carbazole ring, dibenzofuran ring, dibenzothiophene ring or indolocarbazole ring.

Xa ² , Ya ² , Za ^{2 in the formula (10A), Yb 2} when q13=0 in the formula (10B) ^{, and Zb 2} when r13=0, in the formula (12A) Among Xc ² , Yc ² , particularly preferred aromatic hydrocarbon rings are benzene ring, naphthalene ring or phenanthrene ring, and particularly preferred aromatic heterocyclic rings are carbazole ring, dibenzofuran ring, dibenzothiophene ring or indolo The carbazole ring is more preferably an aromatic hydrocarbon ring.

As R ³¹ when it is a substituent, it is preferable that it is a C6-C30 aromatic hydrocarbon group which may have a substituent, or a C3-C30 aromatic heterocyclic group which may have a substituent. From the viewpoint of improving durability and charge transportability, an aromatic hydrocarbon group that may have a substituent is more preferable. ^{When there are a plurality of R 31} in the case of a substituent, they may be different from each other.

The substituents that the hydrocarbon aromatic ring with 6 to 30 carbons may have, the substituents that the heteroaromatic ring with 3 to 30 carbons may have, and the substituents that R ³¹ which is a substituent may have are the same as those of the present embodiment The substituents listed in the substituent group Z in the polymer or the crosslinkable groups are the same, and the preferred substituents are also the same. The substituents that these substituents may further have are also the same.

The compound represented by the formula (10A) is more preferably a compound represented by the following general formula (10A-1) to (10A-3).

[化53]

(In formula (10A-1) to formula (10A-3), Xa ¹ , Ya ¹ , Za ¹ , Xa ² , Ya ² , Za ² have the same meaning as in formula (10). R ³³ represents a hydrogen atom or substitution The group. A plurality of R ³³ may be the same or different. g11', h11', and j11' each independently represent an integer of 0 to 5. When g11', h11', and j11' are 2 or more, a plurality of Xa ¹ , Ya ¹ , Za ¹ can be the same or different)

In each of the formulas (10A-1) to (10A-3), the part formed by bonding one of the three benzene rings to the central pyridine ring, pyrimidine ring or triazine ring structure considered partial structure a, and the benzene ring a constitutes a partial structure of the junction of R ³³ corresponds to formula (10A) R ^31.

The compound represented by the formula (10B) is preferably a compound represented by the following formula (10B-1).

[化54]

(In formula (10B-1), A, Xb ¹ , Yb ¹ , Zb ¹ , Yb ² , Zb ² , q13, and r13 have the same meaning as in the formula (10B). p12', q12', and r12' each It independently represents an integer of 0 to 5. When p12', q12', and r12' are 2 or more, a plurality of Xb ¹ , Yb ¹ , and Zb ¹ may be the same or different. Each of q15 and r15 is independently 4 or 5. R ³³ is a hydrogen atom or a substituent. A plurality of R ³³ in the formula (10B-1) may be the same or different)

^{When R 33 in} the formula (10A-1) to formula (10A-3) and formula (10B-1) is a substituent, and when R ³³ is a substituent, the substituent that may be further possessed is the same as that of the R The situation is the same for ^31.

[Molecular Weight] The molecular weight of the low-molecular compound of this embodiment is usually 5,000 or less, preferably 4,000 or less, particularly preferably 3,000 or less, most preferably 2,000 or less, usually 300 or more, preferably 350 or more, more preferably 400 or more. Since the molecular weight of the low-molecular-weight compound of the present embodiment contains the desired partial structure A, the molecular weight thereof is usually not less than the above-mentioned lower limit.

[Specific example] Specific examples of the low-molecular compound of the present embodiment are shown below. The low-molecular compound of the present embodiment is not limited to these.

[化55]

[化56]

[化57]

[Light-emitting dopant] The low-molecular compound contained in the light-emitting layer according to one aspect of the present invention, that is, the material containing the partial structure A, is preferably a case where a light-emitting dopant is also used. As the light-emitting dopant, a compound represented by the following formula (40) is preferred. In the following formula (40), the ring HA in the partial structure A represented by the formula (31) corresponds to a triazine ring, and Ar ⁰ corresponds to a pyridine ring. ^{R 44} in formula (40) is an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or is selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic group In the case of a monovalent group formed by connecting a plurality of two or more groups in the heterocyclic group, n1 is 2, and the other Ar ⁰ is R ⁴⁴ .

[化58]

In the formula (40), R ⁴¹ , R ⁴² and R ⁴³ are each independently an alkyl group having 1 to 20 carbons, a (hetero)aralkyl group having 7 to 40 carbons, and an alkoxy group having 1 to 20 carbons. Group, (hetero)aryloxy group with 3-20 carbons, alkylsilyl group with 1-20 carbons, arylsilyl group with 6-20 carbons, alkylcarbonyl group with 2-20 carbons, carbon number A 7-20 arylcarbonyl group, a C 1-20 alkylamino group, a C 6-20 arylamino group, or a C 3-30 (hetero)aryl group. These groups may further have a substituent. When there are a plurality of R ⁴¹ , R ⁴² , and R ⁴³ , these may be the same or different. When there are a plurality of R ¹ , adjacent R ¹ may be bonded to each other to form a ring. a40 is an integer of 0-4, b40 is an integer of 0-3, and c40 is an integer of 0-5.

R ^{44 is} each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 20 carbons, a (hetero)aralkyl group having 7 to 40 carbons, an alkoxy group having 1 to 20 carbons, (Hetero)aryloxy group with 3 to 20 carbons, alkylsilyl group with 1 to 20 carbons, arylsilyl group with 6 to 20 carbons, alkylcarbonyl group with 2 to 20 carbons, 7 to carbon atoms 20 aryl carbonyl group, C 2-20 alkylamino group, C 6-20 arylamino group or C 3-20 (hetero)aryl group. These groups may further have a substituent. When there are a plurality of R ⁴⁴ , these may be the same or different. L ¹ represents an organic ligand, and m40 is an integer of 1-3.

In terms of durability, R ⁴¹ to R ^{44 are more} preferably each independently an alkyl group having 1 to 20 carbons, a (hetero)aralkyl group having 7 to 40 carbons, and an aryl group having 6 to 20 carbons. Amino group, or (hetero)aryl group having 3-30 carbons or (hetero)aryl group having 3-20 carbons, more preferably alkyl having 1-20 carbons, (hetero)aryl having 7-40 carbons The alkyl group or the (hetero)aryl group having 3 to 20 carbons is more preferably an alkyl group having 1 to 20 carbons, an aralkyl group having 7 to 40 carbons, or an aryl group having 6 to 20 carbons. The substituent that R ⁴¹ to R ⁴⁴ may further have is preferably a substituent selected from the substituent group Z. When a40 is 2 or more, two adjacent R ⁴¹ may be bonded to each other to form a ring.

Examples of those in which a plurality of R ⁴¹ are present and adjacent R ⁴¹ are bonded to each other to form a ring include pyrene, naphthalene, dibenzothiophene, and dibenzofuran. From the viewpoint of stability, tea is particularly preferred. From the viewpoint of increasing the emission wavelength, it is preferable that adjacent R ⁴¹ are bonded to each other to form a ring.

In addition, from the viewpoint of not making the emission wavelength longer, it is preferable that adjacent R ^{41 are} not bonded to each other and do not form a ring. That is, it is preferable that a40 in the formula (40) is 1, or a40 is 2 or more and does not have ^{a ring in which adjacent R 41} are bonded to each other.

In terms of ease of manufacture, a40 is preferably 0, and in terms of improving durability and solubility, it is preferably 1 or 2, and more preferably 1. In terms of ease of manufacture, b40 is preferably 0, and in terms of improving solubility, it is preferably 1. In terms of having many electron-accepting structures including triazine rings and more stable LUMO, m40 is preferably 2 or 3, and more preferably 3.

L ¹ is an organic ligand and is not particularly limited. It is preferably a monovalent bidentate ligand, and more preferably selected from the following chemical formulas. In addition, the dotted line in the following chemical formula represents a coordinate bond. In the case where there are two organic ligands L ¹ , the organic ligands L ¹ may have different structures from each other. In addition, when m40 is 3, L ¹ does not exist. When m40 in the formula (40) is less than 3, L ¹ preferably has at least one structure selected from the group consisting of the following formula (3), formula (4), and formula (5).

[化59]

In the formula (3), formula (4), and formula (5), R ⁴⁹ and R ⁵⁰ have the same meaning ^{as R 41} in the formula (40). That is, it is selected from the ^{same group as the substituent selected as R 41} , and preferable examples are also the same, and furthermore, it may have a substituent. When there are a plurality of R ⁴⁹ and R ⁵⁰ , these may be the same or different.

R ⁵¹ to R ⁵³ are each independently a hydrogen atom, a C 1-20 alkyl group which may be substituted with a fluorine atom, a phenyl group which may be substituted with a C 1-20 alkyl group, or a halogen atom.

g is an integer of 0-4. h is an integer of 0-4.

Ring B ⁴⁰ is a pyridine ring, a pyrimidine ring, an imidazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, an azatriphenylene ring, a carboline ring, a benzothiazole ring or a benzo Oxazole ring. Ring B ⁴⁰ may further have a substituent.

The substituent that R ⁴⁹ , R ⁵⁰ , and ring B ⁴⁰ may further have is preferably a substituent selected from the substituent group Z. ^More preferably, R ⁴⁹ and R 50 are each independently an alkyl group having 1 to 20 carbons, or an aryl group having 6 to 30 carbons which may be substituted with an alkyl group having 1 to 20 carbons. Here, the aryl group having 6 to 30 carbon atoms means a monocyclic ring, a bicyclic condensed ring, a tricyclic condensed ring, or a group formed by connecting a plurality of monocyclic, bicyclic condensed rings, or tricyclic condensed rings.

In terms of ease of manufacture, g and h are preferably 0, and in terms of improving solubility, they are preferably 1 or 2, and more preferably 1.

R ⁵¹ to R ⁵³ each independently represent a hydrogen atom, a C 1-20 alkyl group which may be substituted with a fluorine atom, a phenyl group which may be substituted with a C 1-20 alkyl group, or a halogen atom, preferably R ⁵¹ and R ⁵³ are a methyl group or a tertiary butyl group, and R ⁵² is a hydrogen atom, a C 1-20 alkyl group, or a phenyl group.

In terms of durability, the ring B ^{40 is} preferably a pyridine ring, a pyrimidine ring, or an imidazole ring, and more preferably a pyridine ring. In terms of durability and improved solubility ^{, the hydrogen atom on ring B 40} is preferably an alkyl group having 1 to 20 carbons, a (hetero)aralkyl group having 7 to 40 carbons, or carbon Number of 3-20 (hetero) aryl substitution. In terms of ease of manufacture, the hydrogen atom on the ^{ring B 40 is preferably unsubstituted.} The hydrogen atom on the ring B ⁴⁰ is likely to generate excitons when used as an organic electroluminescent device. Therefore, in terms of improving the luminous efficiency, it is preferably substituted with a phenyl group or a naphthyl group which may have a substituent. The substituent that the phenyl or naphthyl group may have is preferably a substituent selected from the substituent group Z.

Ring B ⁴⁰ easily generates excitons on the auxiliary dopant. Therefore, in terms of improving luminous efficiency, it is preferably a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, and a azatrile ring. Benzene ring, carboline ring. Among them, the quinoline ring, the isoquinoline ring, and the quinazoline ring are more preferable in terms of durability and the point of exhibiting red light emission. A more preferable substituent of the ring B ^{40 is} an alkyl group having 1 to 20 carbons, or an aryl group having 6 to 20 carbons which may be substituted with an alkyl group having 1 to 20 carbons. Here, the aryl group having 6 to 20 carbon atoms means a monocyclic ring, a bicyclic condensed ring, a tricyclic condensed ring, or a group formed by connecting a plurality of monocyclic, bicyclic condensed rings, or tricyclic condensed rings.

Regarding the light-emitting dopant contained in the light-emitting layer as one aspect of the present invention, that is, the compound represented by formula (40), a compound in which R ⁴⁴ is an optionally substituted phenyl group, that is, the following formula ( 40-1) The compound represented.

[化60]

In the formula, R ^41, R ^42, of ^{R 43, a40, b40, c40} , L 1, m40 and the formula ^{(40) R 41, R 42} , R 43, a40, b40, c40, L 1, m40 They have the same meaning respectively. R ⁴⁵ and R ^{43 have} the same meaning, and R ⁴³ and R ⁴⁵ may be the same or different. When there are a plurality of R ⁴³ and R ⁴⁵ , these may be the same or different. d40 is an integer of 0-5.

In terms of durability, R ⁴³ and R ^{45 are} preferably an alkyl group having 1 to 20 carbons, a (hetero)aralkyl group having 7 to 40 carbons, an arylamino group having 6 to 20 carbons, or The (hetero)aryl group having 3 to 30 carbons is more preferably an alkyl group having 1 to 20 carbons, a (hetero)aralkyl group having 7 to 40 carbons, or a (hetero)aryl group having 3 to 20 carbons, and further More preferably, it is an alkyl group having 1 to 20 carbons or an aralkyl group having 7 to 40 carbons. The substituent that R ⁴³ and R ⁴⁵ may further have is preferably a substituent selected from the substituent group Z.

In terms of ease of manufacture, c40 and d40 are preferably 0, and in terms of improving durability and solubility, they are preferably 1 or 2, and more preferably 1. In terms of ease of manufacture, b40 is preferably 0, and in terms of improving solubility, it is preferably 1.

The light-emitting dopant represented by formula (40) contained in the light-emitting layer as one aspect of the present invention preferably has a structure in which a40 is 2 or more and adjacent R ⁴¹ are bonded to each other to form a chrysanthemum ring. Among them, a compound represented by the following formula (40-2) is preferred.

[化61]

In the formula, R ⁴² ~ R ^44, in b40, c40, L ^1, m40 and the formula ^{(40) R 42 ~ R 44} , b40, c40, L 1, m40 are the same meanings. R ⁵⁴ to R ⁵⁶ are substituents. When there are a plurality of R ⁵⁴ to R ⁵⁶ , these may be the same or different. i40 is an integer of 0-4.

R ⁵⁴ is a substituent substituted on R ⁵¹ when R ⁵¹ is a phenyl group, and is preferably a substituent selected from the substituent group Z. R ^{54 is more} preferably an alkyl group having 1 to 20 carbons, or an aromatic hydrocarbon group having 6 to 30 carbons which may be substituted with an alkyl group having 1 to 20 carbons. Here, the aromatic hydrocarbon group having 6 to 30 carbon atoms refers to a monocyclic ring, a condensed ring of 2 to 4 rings, or a group formed by connecting a plurality of monocyclic rings or condensed rings of 2 to 4 rings. R ⁵⁴ is more preferably an alkyl group having 1 to 20 carbons, and still more preferably an alkyl group having 1 to 8 carbons.

R ^55, R ⁵⁶ is substituted to a part of R or R ⁴¹ R ⁴¹ is a methyl substituent at the ^41, preferably are each independently an alkyl group having 1 to 20 carbon atoms, and may be from 1 to 20 carbon atoms The alkyl substituted aromatic hydrocarbon group with 6 to 30 carbons, the alkoxy group with 1 to 20 carbons, or the aromatic hydrocarbon group with 6 to 30 carbons which may be substituted by the alkoxy group with 1 to 20 carbons. Here, the aromatic hydrocarbon group having 6 to 30 carbon atoms refers to a monocyclic ring, a condensed ring of 2 to 4 rings, or a group formed by connecting a plurality of monocyclic rings or condensed rings of 2 to 4 rings. R ⁵⁵ and R ^{56 are more} preferably an alkyl group having 1 to 20 carbons or an aromatic hydrocarbon group having 6 or 12 carbons which may be substituted with an alkyl group having 1 to 20 carbons, and more preferably an alkyl group having 1 to 8 carbons Or an aromatic hydrocarbon group having 6 carbons which may be substituted with an alkyl group having 1 to 8 carbons. Here, the aromatic hydrocarbon structure with carbon number 6 is a benzene structure, and the aromatic hydrocarbon structure with carbon number 12 is a biphenyl structure.

Specific examples of preferred alkyl groups in R ⁵⁴ to R ⁵⁶ include: methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, isopropyl, isopropyl Butyl, isopentyl, tertiary butyl, cyclohexyl, 2-ethylhexyl, etc.

Specific examples of preferable aromatic hydrocarbon groups in R ⁵⁴ to R ⁵⁶ include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, fused tetraphenyl ring, pyrene ring, benzopyrene ring, and Monovalent groups such as ring, terphenylene ring, fluoranthene ring, biphenyl group, and terphenyl group.

Specific examples of preferable alkoxy groups in R ⁵⁴ to R ⁵⁶ include: methoxy, ethoxy, propoxy, isopropoxy, hexyloxy, cyclohexyloxy, and octadecane基oxy etc.

The compound used as a light-emitting dopant represented by formula (40-1) contained in the light-emitting layer as one aspect of the present invention is more preferably a compound represented by the following formula (40-3).

[化62]

In the formula, R ^42, R ^43, of ^{R 45, b40, c40, d40} , L 1, m40 and the formula ^{(40-1) R 42, R 43} , R 45, b40, c40, d40, L 1 , M40 have the same meaning respectively. R ⁵⁴ ~ R ⁵⁶ is R ⁵⁴ ~ R ^56, i40 and Formula (40-2), i40 respectively, the same meanings.

The following shows preferred specific examples of the compound represented by formula (40) as a light-emitting dopant contained in the light-emitting layer as one aspect of the present invention other than the compounds shown in the examples. However, the present invention It is not limited to these.

[化63]

[化64]

[化65]

〔Hole transport layer〕 The hole transport layer of the organic electroluminescence element of the present invention (hereinafter, sometimes referred to as the “hole transport layer of this embodiment”) preferably contains the polymer of this embodiment described above as the material containing the partial structure A. The hole transport layer of this embodiment may contain one type of the polymer of this embodiment, or may contain two or more types in any combination and arbitrary ratio.

The content of the polymer of the present embodiment in the hole transport layer of the present embodiment is usually 1% by weight to 100% by weight, preferably 5% by weight to 100% by weight, and more preferably 10% by weight to 100% by weight. If it is in the above range, the charge transportability of the hole transport layer of the present embodiment is improved, the driving voltage is lowered, and the driving stability is improved, which is preferable.

In the case where the polymer of this embodiment is not 100% by weight in the hole transport layer of this embodiment, as a component constituting the hole transport layer of this embodiment, a hole transporting compound described later can be cited.

Since the organic electroluminescent element can be easily manufactured, the polymer of this embodiment is preferably used for the hole transport layer of this embodiment formed by a wet film formation method. The method of forming the hole transport layer by the wet film formation method, etc. will be described later.

[Composition for forming hole transport layer] The composition for forming a hole transport layer for forming the hole transport layer of the present embodiment by a wet film formation method contains the polymer of the present embodiment described above. The composition for forming a hole transport layer of the present embodiment may contain one kind of the above-mentioned polymer, or may contain two or more kinds in any combination and any ratio.

[Content of polymer] The content of the polymer in the composition for forming a hole transport layer of the present embodiment is usually 0.01% by weight to 70% by weight, preferably 0.1% by weight to 60% by weight, and more preferably 0.5% by weight to 50% by weight %. If it is within the above range, defects are less likely to occur in the formed hole transport layer, and unevenness in film thickness is less likely to occur, which is preferable. The composition for forming a hole transport layer of the present embodiment may contain a solvent and the like in addition to the above-mentioned polymer.

[Solvent] The composition for forming a hole transport layer of the present embodiment usually contains a solvent. The solvent is preferably one that dissolves the polymer. Specifically, it is preferably a solvent that dissolves the polymer in an amount of usually 0.05% by weight or more, preferably 0.5% by weight or more, and more preferably 1% by weight or more at room temperature.

Specific examples of the solvent include: aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene; ethylene dichloride Aliphatic ethers such as Glycol Dimethyl Ether, Glycol Diethyl Ether, Propylene Glycol Monomethyl Ether Acetate (PGMEA), 1,2-Dimethoxybenzene, 1,3-Di Methoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethyl Ether solvents such as aromatic ethers such as methyl anisole; aliphatic ester solvents such as ethyl acetate, n-butyl acetate, ethyl lactate, n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate Organic solvents such as ester solvents such as aromatic esters such as ethyl benzoate, isopropyl benzoate, propyl benzoate, n-butyl benzoate, etc., and other composition for forming a hole injection layer or a hole transport layer described later The organic solvent used in the formation composition.

One type of solvent may be used, or two or more types may be used in any combination and any ratio.

Among them, as the solvent contained in the composition for forming a hole transport layer of the present embodiment, the surface tension at 20°C is preferably less than 40 dyn/cm, preferably 36 dyn/cm or less, more preferably Solvent below 33 dyn/cm.

In the case of using the composition for forming a hole transport layer of this embodiment and forming a coating film by a wet film forming method to crosslink the polymer to form a hole transport layer, it is preferably a combination of a solvent and a base High affinity. The reason is that the uniformity of the film quality has a large influence on the uniformity and stability of the light emission of the organic electroluminescent element. Therefore, the composition for forming a hole transport layer used in the wet film forming method is required to have a low surface tension so that a uniform coating film with higher leveling properties can be formed. Therefore, by using the solvent with low surface tension, a uniform layer containing the polymer can be formed, and a uniform crosslinked layer can be formed, which is preferable.

Specific examples of low surface tension solvents include aromatic solvents such as toluene, xylene, mesitylene, cyclohexylbenzene, aromatic ester solvents such as ethyl benzoate, and aromatic ethers such as anisole. System solvents, trifluoromethoxy anisole, pentafluoromethoxy benzene, 3-(trifluoromethyl) anisole, ethyl (pentafluorobenzoate), etc.

On the other hand, as the solvent contained in the composition for forming the hole transport layer of the present embodiment, the vapor pressure at 25°C is preferably 10 mmHg or less, preferably 5 mmHg or less, and usually 0.1 mmHg. The above solvent. By using such a solvent, it is possible to prepare a composition for forming a hole transport layer that is suitable for the process of producing a hole transport layer by a wet film formation method and conforms to the properties of the polymer of the present embodiment.

In order to obtain a more uniform film, it is preferable that the solvent evaporate from the liquid film immediately after film formation at an appropriate speed. Therefore, the boiling point of the solvent used is as described above, usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 300°C or lower, more preferably the boiling point Below 280°C. Specific examples of such solvents include aromatic solvents such as mesitylene and cyclohexylbenzene, aromatic ether solvents, and aromatic ester solvents.

Moisture may cause deterioration of the performance of the organic electroluminescence element, and among them, it may promote the decrease in brightness during continuous driving. Therefore, in order to reduce the residual moisture in the wet film formation as much as possible, among the solvents, a solvent having a solubility of water at 25° C. of 1% by weight or less is preferable, and a solvent having a solubility of 0.1% by weight or less is more preferable.

The content of the solvent contained in the composition for forming a hole transport layer of the present embodiment is usually 10% by weight or more, preferably 30% by weight or more, and particularly preferably 50% by weight or more. When the content of the solvent is more than the above lower limit, the flatness and uniformity of the formed layer can be improved.

[Electron-accepting compound] From the viewpoint of low resistance, the composition for forming a hole transport layer of the present embodiment may further contain an electron-accepting compound. As the electron-accepting compound, a compound having an oxidizing power and the ability to accept one electron from the polymer is preferred. Specifically, a compound having an electron affinity of 4 eV or more is preferable, and a compound having an electron affinity of 5 eV or more is more preferable.

Examples of such electron-accepting compounds include triaryl boron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids. One or two or more compounds in the group.

Specifically, include: 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, triphenyl sulfonium tetrafluoroborate, etc. oniums substituted with organic groups Salt (International Publication No. 2005/089024), (International Publication No. 2017/164268); Iron(III) chloride (Japanese Patent Laid-Open No. 11-251067), ammonium peroxodisulfate and other high-valent inorganic Compounds; cyano compounds such as tetracyanoethylene; aromatic boron compounds such as tris(pentafluorophenyl)borane (Japanese Patent Laid-Open No. 2003-31365); fullerene derivatives, iodine, etc.

The composition for forming a hole transport layer of the present embodiment may contain one kind of the above-mentioned electron-accepting compound alone, or may contain two or more kinds in any combination and ratio.

When the composition for forming a hole transport layer of the present embodiment contains an electron-accepting compound, the content of the electron-accepting compound is usually 0.0005% by weight or more, preferably 0.001% by weight or more, and usually 20% by weight or less , Preferably 10% by weight or less. The ratio of the electron-accepting compound to the polymer in the composition for forming a hole transport layer is usually 0.5% by weight or more, preferably 1% by weight or more, more preferably 3% by weight or more, and usually 80% by weight Hereinafter, it is preferably 60% by weight or less, and more preferably 40% by weight or less.

When the content of the electron-accepting compound in the composition for forming a hole transport layer is more than the above-mentioned lower limit, the electron acceptor accepts electrons from the polymer, and the formed hole transport layer has a low resistance, which is preferable. If the content of the electron-accepting compound in the composition for forming a hole transport layer is less than the above upper limit, the formed hole transport layer is less likely to cause defects, and the film thickness is less likely to be uneven, which is preferable.

[Cation radical compound] The composition for forming a hole transport layer of this embodiment may further contain a cationic radical compound. The cationic radical compound is preferably an ionic compound containing a cationic radical, which is a chemical species from which one electron is removed from the hole transporting compound, and a counter anion. Among them, when the cationic radical is derived from a hole-transporting polymer compound, the cationic radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

The cationic radical is preferably a chemical species in which one electron is removed from the hole transporting compound described later. In terms of amorphous properties, visible light transmittance, heat resistance, solubility, and the like, a chemical species that removes one electron from a compound that is preferable as a hole-transporting compound is preferable.

Here, the cationic radical compound can be produced by mixing the hole-transporting compound and the electron-accepting compound described later. That is, by mixing the hole-transporting compound and the electron-accepting compound, electrons move from the hole-transporting compound to the electron-accepting compound, and cation radicals including the hole-transporting compound and the counter anion are generated. Compound.

When the composition for forming a hole transport layer of the present embodiment contains a cationic radical compound, the content of the cationic radical compound in the composition for forming a hole transport layer is usually 0.0005% by weight or more, preferably 0.001% by weight % Or more, and usually 40% by weight or less, preferably 20% by weight or less. If the content of the cationic radical compound is more than the lower limit, the hole transport layer formed will have a low resistance, which is preferable. If the content of the cationic radical compound is equal to or less than the upper limit, the hole transport layer formed is less likely to cause defects, and the film thickness is less likely to be uneven, which is preferable.

In the composition for forming a hole transport layer of the present embodiment, in addition to the above-mentioned components, components contained in the composition for forming a hole injection layer or the composition for forming a hole transport layer described later may be contained in the content described later. .

[Light-emitting layer] The light-emitting layer of the organic electroluminescent element of the present invention (hereinafter, sometimes referred to as “light-emitting layer of this embodiment”) preferably contains the low-molecular compound of this embodiment as the material containing the partial structure A. The light-emitting layer of this embodiment may contain one kind of the low-molecular compound of this embodiment, or may contain two or more of them in any combination and arbitrary ratio.

The light-emitting layer of this embodiment contains at least the low-molecular compound of this embodiment and a light-emitting material, and the low-molecular compound of this embodiment functions as a host material of the light-emitting material. As the light-emitting material, a phosphorescent light-emitting material or a fluorescent light-emitting material can be used.

The content of the light-emitting material contained in the light-emitting layer of the present invention is usually 0.1% by weight to 50% by weight, preferably 0.2% by weight to 40% by weight, more preferably 0.5% by weight to 35% by weight. If the content of the luminescent material is within the above range, high luminous efficiency can be obtained.

The content of the low-molecular compound of this embodiment in the light-emitting layer of this embodiment is usually 5 wt% or more, preferably 10 wt% or more, and more preferably 20 wt% or more, based on the content in materials other than the light-emitting material. It is particularly preferably 30% by weight or more, usually 100% by weight or less, preferably 90% by weight or less, more preferably 80% by weight or less, and particularly preferably 70% by weight or less. If it is in the above range, it is considered that the charge transportability of the light-emitting layer of this embodiment is improved, the driving voltage is lowered, and the driving stability is improved, which is preferable.

In the case where the light-emitting layer of this embodiment contains other components than the light-emitting material and the low-molecular compound of this embodiment, the other components include charge transport materials described later. The content of other components such as the charge transport material described later in the light-emitting layer of this embodiment is generally 0% by weight or more, preferably 10% by weight or more, and more preferably 20% by weight or more, based on the content in materials other than the light-emitting material , Particularly preferably 30% by weight, and usually 95% by weight or less, preferably 90% by weight or less, further preferably 80% by weight or less, and particularly preferably 70% by weight or less. It is considered that if it is within the above range, the carrier balance of electrons and holes in the light-emitting layer is good, the luminous efficiency is improved, the charge transportability is improved, the voltage is reduced, and the driving stability is improved, which is preferable.

Since the organic electroluminescent element can be easily manufactured, the low-molecular compound of this embodiment is preferably used for the light-emitting layer of this embodiment formed by a wet film formation method. The method of forming the light-emitting layer by the wet film formation method, etc. will be described later.

[Composition for forming luminescent layer] The composition for forming a light-emitting layer for forming the light-emitting layer of this embodiment by a wet film formation method contains the low-molecular compound of the above-mentioned embodiment. The composition for forming a light-emitting layer of the present embodiment may contain one kind of the low-molecular compound, or two or more kinds in any combination and any ratio.

[Content of low molecular compound] The total content of the low-molecular compound, luminescent material, charge transport material and other solid components in the composition for forming a light-emitting layer of this embodiment is usually 0.01% by weight to 70% by weight, preferably 0.1% by weight to 60% by weight , More preferably 0.5% by weight to 50% by weight. If it is within the above range, the formed light-emitting layer is less likely to cause defects and less likely to cause unevenness in film thickness, which is preferable. The composition for forming a light-emitting layer of the present embodiment may contain a solvent and the like in addition to the components such as the low-molecular compound, light-emitting material, and charge-transporting material.

[Solvent] The composition for forming a light-emitting layer of this embodiment usually contains a solvent.

As the solvent, it can be selected and used from the same solvents as those contained in the composition for forming a hole transport layer. The required characteristics of the solvent are also the same, and the preferred solvents are also the same.

As long as the effect of the present invention is not significantly impaired, the amount of solvent used is arbitrary, but it is preferably 1% by mass or more, more preferably 10% by mass or more, and particularly preferably 50% by mass based on the content in the composition for forming the light-emitting layer % Or more, and preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and particularly preferably 99% by mass or less.

[Phosphorescent layer] When the light-emitting layer of the present embodiment is a phosphorescent light-emitting layer containing a phosphorescent light-emitting material as the light-emitting material, the following materials are preferable as the phosphorescent light-emitting material.

＜Phosphorescent materials＞ The so-called phosphorescent light-emitting material refers to a material that exhibits light emission in a self-excited triplet state. For example, metal complex compounds having Ir, Pt, Eu, etc. are representative examples, and the structure of the material is preferably one containing a metal complex.

Among the metal complexes, as phosphorescent light-emitting organometallic complexes that emit light through a triplet state, examples include those selected from the long-period periodic table (hereinafter, unless otherwise agreed, the term "periodic table" In the case of, it refers to a Werner-type complex or organometallic complex compound in which metals in Groups 7 to 11 of the long-period periodic table are used as the central metal. As such a phosphorescent material, the compound represented by formula (201) or the compound represented by the following formula (205) is preferred, and the compound represented by the following formula (201) is more preferred.

[Compound represented by formula (201)] [Chemical Formula 66]

In formula (201), ring A1 represents an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic structure. Ring A2 represents an aromatic heterocyclic structure which may have a substituent. R ²⁰¹ and R ²⁰² are each independently a structure represented by formula (202). "*" indicates the bonding site with ring A1 or ring A2. R ²⁰¹ and R ²⁰² may be the same or different. In ^{the case where there are a plurality of R 201} and R ²⁰² respectively, these may be the same or different. Ar ²⁰¹ and Ar ²⁰³ each independently represent an optionally substituted aromatic hydrocarbon structure or an optionally substituted aromatic heterocyclic structure. Ar ²⁰² represents an optionally substituted aromatic hydrocarbon structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure. The substituents bonded to ring A1, the substituents bonded to ring A2, or the substituents bonded to ring A1 and the substituents bonded to ring A2 may be bonded to each other to form a ring. B ²⁰¹ -L ²⁰⁰ -B ²⁰² represents an anionic bidentate ligand. B ²⁰¹ and B ²⁰² each independently represent a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may also be atoms constituting a ring. L ²⁰⁰ represents a single bond or an atomic group that forms a bidentate ligand together ^{with B 201} and B ^202. When ^{there are multiple B 201} -L ²⁰⁰ -B ²⁰² , these may be the same or different. i1 and i2 each independently represent an integer of 0 or more and 12 or less. i3 is an integer of 0 or more whose upper limit is the number that can be substituted with Ar ^202. j1 is an integer of 0 or more whose upper limit is the number that can be substituted with Ar ^201. k1 and k2 are each independently an integer of 0 or more whose upper limit is the number of ring A1 and ring A2 that can be substituted. m1 is an integer of 1-3.

Unless otherwise specified, the substituent is preferably a group selected from the following substituent group Z'.

<Substituent group Z'> ·Alkyl group: preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 8 carbon atoms, particularly preferably Alkyl and alkoxy having 1 to 6 carbons: preferably alkoxy having 1 to 20 carbons, more preferably alkoxy having 1 to 12 carbons, and still more preferably alkoxy having 1 to 6 carbons Group and aryloxy group: preferably an aryloxy group having 6 to 20 carbons, more preferably an aryloxy group having 6 to 14 carbons, more preferably an aryloxy group having 6 to 12 carbons, especially Preferably a C6 aryloxy·heteroaryloxy group: preferably a C3-20 heteroaryloxy group, more preferably a C3-12 heteroaryloxy·alkylamine Group: preferably alkylamino group having 1 to 20 carbons, more preferably alkylamino group having 1 to 12 carbons. Arylamino group: preferably arylamino group having 6 to 36 carbons, more preferably It is preferably an arylamino group and aralkyl group having 6 to 24 carbon atoms: preferably an aralkyl group having 7 to 40 carbon atoms, more preferably an aralkyl group having 7 to 18 carbon atoms, and still more preferably an aralkyl group having 7 to 18 carbon atoms. Aralkyl and heteroaralkyl of 12: preferably heteroaralkyl having 4 to 40 carbons, more preferably heteroaralkyl and alkenyl having 4 to 18 carbons: preferably 2 to 20 carbons The alkenyl group is more preferably an alkenyl group having 2 to 12 carbons, more preferably an alkenyl group having 2 to 8 carbons, and particularly preferably an alkenyl group having 2 to 6 carbons. Alkynyl group: preferably a carbon number of 2 to 20 alkynyl group, more preferably alkynyl group having 2 to 12 carbons. Aryl group: preferably an aryl group having 6 to 30 carbons, more preferably an aryl group having 6 to 24 carbons, and more preferably a carbon number of 6 The aryl group of ～18, especially the aryl group and heteroaryl group having 6 to 14 carbons: preferably a heteroaryl group having 3 to 30 carbons, more preferably a heteroaryl group having 3 to 24 carbons, and more preferably Heteroaryl groups having 3 to 18 carbons, particularly heteroaryl and alkylsilyl groups having 3 to 14 carbons: preferably alkylsilyl groups having 1 to 20 carbons, more preferably Alkylsilyl group and arylsilyl group having 1 to 12 carbon atoms in the alkyl group: preferably an arylsilyl group having 6 to 20 carbon atoms in the aryl group, and more preferably an aryl group having 6 to 14 carbon atoms in the aryl group The arylsilyl group and alkylcarbonyl group: preferably an alkylcarbonyl group having 2 to 20 carbon atoms. Arylcarbonyl group: preferably an arylcarbonyl group having 7 to 20 carbon atoms. Regarding the above substituents, one or more hydrogen atoms Substitution by fluorine atoms, or more than one hydrogen atom may be substituted by deuterium atoms. Unless otherwise specified, the aryl group is an aromatic hydrocarbon group, and the heteroaryl group is an aromatic heterocyclic group. ·Hydrogen atom, deuterium atom, fluorine atom, cyano group, or -SF ₅

(Preferable group in the substituent group Z') In the substituent group Z', an alkyl group, an alkoxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, and an aryl group are preferred. Groups, heteroaryl groups, alkylsilyl groups, arylsilyl groups, and groups in which one or more hydrogen atoms of these groups are substituted with fluorine atoms, fluorine atoms, cyano groups, -SF ₅ , more preferably alkyl groups, and alkyl groups An oxy group, an aryloxy group, an arylamino group, an aralkyl group, an alkenyl group, an aryl group, a heteroaryl group, and groups in which one or more hydrogen atoms of these groups are substituted with a fluorine atom, a fluorine atom, a cyano group, -SF ₅ , more preferably alkyl, alkoxy, aryloxy, arylamino, aralkyl, alkenyl, aryl, heteroaryl, particularly preferably alkyl, arylamino, aryl Alkyl, alkenyl, aryl, heteroaryl, most preferably alkyl, arylamino, aralkyl, aryl, and heteroaryl.

(Substituent substituted with Z') These substituent group Z'may further have a substituent selected from the substituent group Z'as a substituent. The preferable group, the more preferable group, the more preferable group, the most preferable group, and the most preferable group of the substituent which may be possessed are the same as the preferable group in the substituent group Z'.

＜Ring A1＞ Ring A1 represents an aromatic hydrocarbon ring structure which may have a substituent or an aromatic heterocyclic structure which may have a substituent.

The aromatic hydrocarbon ring of ring A1 is preferably an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenylyl ring, an ethane naphthalene ring, a fluoranthene ring, and a sulphur ring are preferable. The aromatic heterocyclic ring of ring A1 is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a hetero atom, and more preferably a furan ring or a benzofuran Ring, thiophene ring, benzothiophene ring. The ring A1 is more preferably a benzene ring, a naphthalene ring, and a sulphur ring, particularly preferably a benzene ring or a sulphur ring, and most preferably a benzene ring.

＜Ring A2＞ Ring A2 represents an aromatic heterocyclic structure which may have a substituent.

The aromatic heterocyclic ring of ring A2 is preferably an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a hetero atom. Specifically, examples include pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring, benzoxazole ring, benzimidazole ring, and quinoline ring , Isoquinoline ring, quinoxaline ring, quinazoline ring, naphthyridine ring, phenanthridine ring, more preferably pyridine ring, pyrazine ring, pyrimidine ring, imidazole ring, benzothiazole ring, benzoxazole ring , Quinoline ring, isoquinoline ring, quinoxaline ring, quinazoline ring, more preferably pyridine ring, imidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, quinoxaline ring, quinazole The phylloline ring is preferably a pyridine ring, an imidazole ring, a benzothiazole ring, a quinoline ring, a quinoxaline ring, and a quinazoline ring.

(Combination of ring A1 and ring A2) As a preferable combination of ring A1 and ring A2, if expressed as (ring A1-ring A2), it is (benzene ring-pyridine ring), (benzene ring-quinoline ring), (benzene ring-quinoxaline ring) , (Benzene ring-quinazoline ring), (benzene ring-imidazole ring), (benzene ring-benzothiazole ring).

(Substituents of ring A1 and ring A2) The substituents that the ring A1 and the ring A2 may have can be arbitrarily selected, but one or more substituents selected from the substituent group Z′ are preferred.

<Ar ²⁰¹ , Ar ²⁰² , Ar ²⁰³ > Ar ²⁰¹ and Ar ²⁰³ each independently represent an optionally substituted aromatic hydrocarbon ring structure or an optionally substituted aromatic heterocyclic structure. Ar ²⁰² represents an optionally substituted aromatic hydrocarbon ring structure, an optionally substituted aromatic heterocyclic structure, or an optionally substituted aliphatic hydrocarbon structure.

(Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ aromatic hydrocarbon ring) When ^{any one of Ar 201} , Ar ²⁰² , and Ar ²⁰³ is an aromatic hydrocarbon structure that may have a substituent, the aromatic hydrocarbon structure is more Preferably, it is an aromatic hydrocarbon ring having 6 to 30 carbon atoms. Specifically, a benzene ring, a naphthalene ring, an anthracene ring, a triphenyl ring, an ethane naphthalene ring, a fluoranthene ring, a sulphur ring, a benzene ring, a naphthalene ring, a sulphur ring are more preferred, and a benzene ring is most preferred. .

(9 and 9'positions of 茀) When ^{any one of Ar 201} , Ar ²⁰² , and Ar ²⁰³ is a 茀 ring which may have a substituent, the 9 and 9'positions of the 茀 ring preferably have a substituent Or bonding with adjacent structures.

(Ortho-phenylene, meta-phenylene) In ^{the case where any of Ar 201} and Ar ²⁰² is a benzene ring which may have a substituent, it is preferable that at least one benzene ring is adjacent to the ortho or meta position. The structural bonding is more preferably that at least one benzene ring is bonded to the adjacent structure at the meta position.

(Ar ²⁰¹ , Ar ²⁰² , and Ar ²⁰³ aromatic heterocyclic ring) When ^{any one of Ar 201} , Ar ²⁰² , and Ar ²⁰³ is an aromatic heterocyclic structure that may have a substituent, it is an aromatic heterocyclic structure Preferably, it is an aromatic heterocyclic ring having 3 to 30 carbon atoms containing any one of a nitrogen atom, an oxygen atom, or a sulfur atom as a hetero atom. Specifically, examples include pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, oxazole ring, thiazole ring, benzothiazole ring, benzoxazole ring, benzimidazole ring, and quinoline ring , Isoquinoline ring, quinoxaline ring, quinazoline ring, naphthyridine ring, phenanthridine ring, carbazole ring, dibenzofuran ring, dibenzothiophene ring, more preferably pyridine ring, pyrimidine ring, tri The oxazine ring, the carbazole ring, the dibenzofuran ring, the dibenzothiophene ring.

(N-position of carbazole) When ^{any one of Ar 201} , Ar ²⁰² , and Ar ²⁰³ is a carbazole ring that may have a substituent, the N-position of the carbazole ring is preferably substituted or adjacent to Structural bonding.

(Aliphatic hydrocarbon Ar ²⁰²⁾ Ar ²⁰² which may have in the case where an aliphatic hydrocarbon structure substituted group, straight chain, branched, or cyclic aliphatic hydrocarbon structures having a structure, preferably a carbon number of 1 Above and 24 or less, more preferably the carbon number is 1 or more and 12 or less, and more preferably the carbon number is 1 or more and 8 or less.

<i1, i2, i3, j1, k1, k2> (Preferable range of i1, i2) i1 represents the integer of 0-12, Preferably it is 1-12, More preferably, it is an integer of 1-8, More preferably, it is an integer of 1-6. The improvement of solubility and charge transportability is expected by being in the said range.

(Preferable range of i3) i3 preferably represents an integer of 0-5, more preferably 0-2, and more preferably 0 or 1.

(The preferred range of j1) j1 preferably represents an integer of 0-2, and more preferably 0 or 1.

(The preferred range of k1, k2) k1 and k2 preferably represent an integer of 0 to 3, more preferably 1 to 3, more preferably 1 or 2, and particularly preferably 1.

^{<Ar 201, Ar 202, Ar} 203 preferred substituent ^{group> Ar 201, Ar 202, Ar} 203 may have a substituent group may be arbitrarily selected, preferably selected from the substituent group Z 'is one or Multiple substituents. Preferable groups are also the same as the substituent group Z′, and more preferably are a hydrogen atom, an alkyl group, and an aryl group, particularly preferably a hydrogen atom and an alkyl group, and most preferably are unsubstituted (hydrogen atom).

<Preferable structure of formula (201)> Among the compounds represented by the formula (201), compounds having the following structures are preferred.

(Phenyl extension linking formula) A structure having a group formed by linking benzene rings. That is, Ar ²⁰¹ is a benzene ring structure, i1 is 1 to 6, and at least one of the benzene rings is bonded to the adjacent structure at the ortho position or the meta position. Due to this structure, it is expected that the solubility will be improved and the charge transport properties will be improved.

((Phenylene)-(aralkyl)-(alkyl)) A structure having an aromatic hydrocarbon group or an aromatic heterocyclic group in which an alkyl group or an aralkyl group is bonded to ring A1 or ring A2. That is, Ar ²⁰¹ is an aromatic hydrocarbon structure or an aromatic heterocyclic structure, i1 is 1 to 6, Ar ²⁰² is an aliphatic hydrocarbon structure, i2 is 1 to 12, preferably 3 to 8, and Ar ²⁰³ is a benzene ring structure. i3 is 0 or 1. Preferably, Ar ²⁰¹ is the aromatic hydrocarbon structure, further preferably a structure formed by connecting 1 to 5 benzene rings, and more preferably one benzene ring. Due to this structure, it is expected that the solubility will be improved and the charge transport properties will be improved.

(Dendron) A structure in which dendrites are bonded to ring A1 or ring A2. For example, Ar and Ar ²⁰² are benzene ring structures, Ar ²⁰³ is biphenyl or terphenyl structure, i1 and i2 are 1 to 6, i3 is 2, and j is 2. Due to this structure, it is expected that the solubility will be improved and the charge transport properties will be improved.

<B ²⁰¹ -L ²⁰⁰ -B ²⁰² > B ²⁰¹ -L ²⁰⁰ -B ²⁰² represents an anionic bidentate ligand. B ²⁰¹ and B ²⁰² each independently represent a carbon atom, an oxygen atom, or a nitrogen atom, and these atoms may also be atoms constituting a ring. L ²⁰⁰ represents a single bond or an atomic group that forms a bidentate ligand together ^{with B 201} and B ^202. When ^{there are multiple B 201} -L ²⁰⁰ -B ²⁰² , these may be the same or different.

The structure represented by B ²⁰¹ -L ²⁰⁰ -B ²⁰² is preferably a structure represented by the following formula (203) or formula (204).

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(In formula (203), R ²¹¹ , R ²¹² , and R ²¹³ represent substituents)

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(In formula (204), ring B3 represents an aromatic heterocyclic structure containing a nitrogen atom which may have a substituent. Ring B3 is preferably a pyridine ring)

<Preferable phosphorescent luminescent material represented by formula (201)> The phosphorescent material represented by the formula (201) is not particularly limited, and specifically, the following structures can be cited. Hereinafter, "Ph" means "phenyl" and "Me" means "methyl".

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[化70]

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[Compound represented by formula (205)] [化74]

In the formula (205), M ² represents a metal. T represents a carbon atom or a nitrogen atom. R ⁹² to R ⁹⁵ each independently represent a substituent. However, when T is a nitrogen atom, R ⁹⁴ and R ⁹⁵ do not exist.

In the formula (205), M ² represents a metal. As specific examples, metals described as metals selected from Group 7 to Group 11 of the periodic table can be cited. Among them, preferable examples include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, or gold, and particularly preferable examples include divalent metals such as platinum and palladium.

In formula (205), R ⁹² and R ⁹³ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, a carboxyl group, and an alkoxy group. , Alkylamino, aralkylamino, haloalkyl, hydroxyl, aryloxy, aromatic hydrocarbon or aromatic heterocyclic group.

When T is a carbon atom, R ⁹⁴ and R ⁹⁵ each independently represent a substituent represented by the same exemplified substance as ^{R 92} and R ^93. When T is a nitrogen atom, there is no R ⁹⁴ or R ^{95 directly bonded to the T.} R ⁹² to R ⁹⁵ may further have a substituent. As a substituent, it can be set as the said substituent. Any two or more groups of R ⁹² to R ⁹⁵ may be connected to each other to form a ring.

＜Molecular weight of phosphorescent material＞ The molecular weight of the phosphorescent light-emitting material is preferably 5000 or less, more preferably 4000 or less, particularly preferably 3000 or less, usually 800 or more, preferably 1000 or more, and more preferably 1200 or more. It is considered that by being in the above molecular weight range, it is possible to obtain a light-emitting layer in which phosphorescent light-emitting materials do not aggregate with each other but are uniformly mixed with the charge-transporting material, and have high luminous efficiency.

In terms of high Tg, melting point, decomposition temperature, etc., the phosphorescent light-emitting material and the formed light-emitting layer have excellent heat resistance, and the reduction in film quality caused by gas generation, recrystallization, and molecular migration or the accompanying material is unlikely to occur. In terms of an increase in impurity concentration resulting from thermal decomposition, etc., the molecular weight of the phosphorescent material is preferably large. On the other hand, in terms of easy purification of the organic compound, the molecular weight of the phosphorescent light-emitting material is preferably small.

[Host material for phosphorescent light-emitting layer] The light-emitting layer of this embodiment includes the low-molecular compound of this embodiment as a host material. When the light-emitting layer is a phosphorescent light-emitting layer, it is preferable to include the following materials as other host materials.

The host material of the light-emitting layer is a material having a skeleton having excellent charge transport properties, and is preferably selected from electron transport materials, hole transport materials, and bipolar materials capable of transporting both electrons and holes.

(Framework with excellent charge transport properties) Specific examples of the skeleton having excellent charge transport properties include: aromatic structure, aromatic amine structure, triarylamine structure, dibenzofuran structure, naphthalene structure, phenanthrene structure, phthalocyanine structure, porphyrin structure, and thiophene Structure, benzyl phenyl structure, pyridine structure, quinacridone structure, terphenyl structure, carbazole structure, pyrene structure, anthracene structure, phenanthroline structure, quinoline structure, pyridine structure, pyrimidine structure, triazine structure, Oxadiazole structure or imidazole structure, etc.

(Electronic transmission material) As the electron-transporting material, from the viewpoint of a material having excellent electron-transporting properties and a relatively stable structure, a compound having a pyridine structure, a pyrimidine structure, or a triazine structure is more preferable, and a compound having a pyrimidine structure or a triazine structure is more preferable Compound.

(Hole-transmitting material) The hole-transporting material is a compound having a structure having excellent hole-transporting properties, and in the central skeleton having excellent charge-transporting properties, as a structure having excellent hole-transporting properties, a carbazole structure and a dibenzofuran structure are preferable , Triarylamine structure, naphthalene structure, phenanthrene structure or pyrene structure, more preferably carbazole structure, dibenzofuran structure or triarylamine structure.

(Condensed ring structure with more than three rings) The host material of the light-emitting layer is preferably a compound having a condensed ring structure of three or more rings, and more preferably a compound having two or more condensed ring structures of three or more rings, or a compound having at least one condensed ring of five or more rings. By using these compounds, it is easy to obtain the following effects: the rigidity of the molecules is increased, and the degree of molecular motion in response to heat is suppressed. Furthermore, in terms of charge transport properties and durability of the material, it is preferable that the condensed ring of three or more rings and the condensed ring of five or more rings have an aromatic hydrocarbon ring or an aromatic heterocyclic ring.

Specific examples of condensed ring structures having three or more rings include: anthracene structure, phenanthrene structure, pyrene structure, pyrene structure, condensed tetrabenzene structure, terphenylene structure, pyrene structure, benzopyrene structure, indenopyrene structure , Indolopyridine structure, carbazole structure, indenocarbazole structure, indolocarbazole structure, dibenzofuran structure, dibenzothiophene structure, etc. From the viewpoint of charge transportability and solubility, it is preferably selected from the group consisting of a phenanthrene structure, a stilbene structure, an indenopyridine structure, a carbazole structure, an indenocarbazole structure, an indolocarbazole structure, and a dibenzofuran structure. And at least one of the group consisting of a dibenzothiophene structure. From the viewpoint of durability with respect to charge, a carbazole structure or an indolocarbazole structure is more preferable.

From the viewpoint of the durability of the organic electroluminescence element against charges, it is preferable that at least one of the host materials of the light-emitting layer is a material having a pyrimidine skeleton or a triazine skeleton.

(Molecular weight range) From the viewpoint of excellent flexibility, the host material of the light-emitting layer is preferably a polymer material. A light-emitting layer formed using a material having excellent flexibility is preferable as a light-emitting layer of an organic electroluminescence element formed on a flexible substrate. When the host material contained in the light-emitting layer is a polymer material, the molecular weight is preferably 5,000 or more and 1,000,000 or less, more preferably 10,000 or more and 500,000 or less, and more preferably 10,000 or more and 100,000 or less.

From the viewpoints of ease of synthesis and purification, ease of design of electron transport performance and hole transport performance, and ease of viscosity adjustment when dissolved in a solvent, the host material of the light-emitting layer is preferably a low molecular weight. When the host material contained in the light-emitting layer is a low-molecular material, the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, most preferably 2,000 or less, and usually 300 or more, preferably It is 350 or more, more preferably 400 or more.

[Fluorescent light-emitting layer] When the light-emitting layer of this embodiment is a fluorescent light-emitting layer, it is preferable to use the following blue fluorescent light-emitting material as the blue fluorescent light-emitting layer of the fluorescent light-emitting material.

＜Blue fluorescent material＞ The light-emitting material for the blue fluorescent light-emitting layer is not particularly limited, but is preferably a compound represented by the following formula (211).

[化75]

In the formula (211), Ar ²⁴¹ represents an aromatic hydrocarbon condensed ring structure which may have a substituent. Ar ²⁴² and Ar ²⁴³ each independently represent an optionally substituted alkyl group, an aromatic hydrocarbon group, or a group to which these groups are bonded. n41 is an integer of 1-4.

Ar ²⁴¹ preferably represents an aromatic hydrocarbon condensed ring structure having 10 to 30 carbon atoms. As a specific structure, a naphthalene ring, an ethane naphthalene ring, a pyrene ring, an anthracene ring, a phenanthrene ring, a fluoranthene ring, a pyrene ring, a fused tetraphenyl ring, a chrysene ring, a perylene ring, etc. are mentioned. More preferably, it is a C12-20 aromatic hydrocarbon condensed ring structure. As a specific structure, an ethane naphthalene ring, a pyrene ring, an anthracene ring, a phenanthrene ring, a fluoranthene ring, a pyrene ring, a fused tetraphenyl ring, a chrysene ring, and a perylene ring are mentioned. Furthermore, it is preferable that it is a C16-18 aromatic hydrocarbon condensed ring structure. As a specific structure, a fluoranthene ring, a pyrene ring, and a ring are mentioned.

n41 is an integer of 1-4, preferably 1-3, more preferably 1-2, most preferably 2.

^{(Ar 241, Ar 242, Ar} 243 is a substituted ^{group) Ar 241, Ar 242, Ar} 243 may have a substituent group selected from the substituent is preferably the group Z 'in the base, more preferably a substituent group Z' The hydrocarbyl group contained in is further preferably a hydrocarbyl group among the groups preferable as the substituent group Z'.

[Host material for blue fluorescent light-emitting layer] In the light-emitting layer of this embodiment, as the host material of the light-emitting material, the low-molecular compound of this embodiment is used. When a blue fluorescent light-emitting material is used, the following materials are preferable as other host materials.

The host material for the blue fluorescent light-emitting layer is not particularly limited, but is preferably a compound represented by the following formula (212).

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In the above-mentioned formula (212), R ²⁴¹ and R ²⁴² are each independently a structure represented by the following formula (213). R ²⁴³ represents a substituent. When ^{there are a plurality of R 243} , they may be the same or different. n43 is an integer of 0-8.

[化77]

In the formula (213), Ar ²⁴⁴ and Ar ²⁴⁵ each independently represent an optionally substituted aromatic hydrocarbon structure or an optionally substituted heteroaromatic ring structure. When ^{there are a plurality of Ar 244} and Ar ²⁴⁵ respectively, they may be the same or different. n44 is an integer of 1-5. n45 is an integer of 0-5.

Ar ^{244 is} preferably a monocyclic or condensed aromatic hydrocarbon structure having 6 to 30 carbon atoms which may have a substituent, and more preferably a monocyclic or condensed aromatic hydrocarbon structure having 6 to 12 carbon atoms which may have a substituent structure.

Ar ^{245 is} preferably a monocyclic or condensed aromatic hydrocarbon structure having a carbon number of 6 to 30 which may have a substituent, or an aromatic heterocyclic structure having a condensed ring of 6 to 30 carbon which may have a substituent, more preferably It is a monocyclic or condensed aromatic hydrocarbon structure having a carbon number of 6 to 12 which may have a substituent, or an aromatic heterocyclic structure of a condensed ring having a carbon number of 12 which may have a substituent.

n44 is preferably an integer of 1-3, more preferably 1 or 2. n45 is preferably 0-3, more preferably 0-2.

( ^{Substituents of R 243} , Ar ²⁴⁴ , and Ar ²⁴⁵ ) The substituents that R ²⁴³ , Ar ²⁴⁴ and Ar ²⁴⁵ may have as substituents are preferably selected from the group of substituents Z', and more preferably The hydrocarbon group contained in the substituent group Z'is more preferably a hydrocarbon group among the groups preferred as the substituent group Z'.

(Molecular weight) The molecular weight of the light-emitting material for the blue fluorescent light-emitting layer and its host material is preferably 5,000 or less, more preferably 4,000 or less, particularly preferably 3,000 or less, most preferably 2,000 or less, and usually 300 or more, preferably 350 or more , More preferably 400 or more.

〔Organic electroluminescence element〕 The organic electroluminescence element of the present embodiment is an organic electroluminescence element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, and is characterized in that the organic layer has a hole transport layer and is connected to the hole. For the light-emitting layer adjacent to the transport layer, at least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer is a material containing the partial structure A having the same partial structure A.

The preferred forms of the hole transport layer of the present embodiment including the material containing the partial structure A and the light-emitting layer of the present embodiment including the material containing the partial structure A are as described above.

As an example of the structure of the organic electroluminescence element of this embodiment, a schematic diagram (cross section) of a structure example of the organic electroluminescence element 10 is shown in FIG. 1. In Fig. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light-emitting layer, 6 is a hole blocking layer, 7 is an electron transport layer, 8 is an electron injection layer, 9 represents the cathode.

Hereinafter, referring to FIG. 1, an example of embodiments such as the layer structure of the organic electroluminescent element and the general forming method thereof will be described.

In this embodiment, the so-called wet film forming method refers to, for example, the use of spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, spray coating, etc. Ink method, nozzle printing method, screen printing method, gravure printing method, flexographic printing method, and other wet film forming methods are used as the film forming method, that is, the coating method, and the coating film is dried to form the film method. Among these film forming methods, a spin coating method, a spraying method, an inkjet method, a nozzle printing method, etc. are preferred.

[Substrate] The substrate 1 is a support for an organic electroluminescence element, and generally a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, etc. can be used. Among these, a glass plate or a plate made of transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, and polycure is preferred. In terms of less prone to deterioration of the organic electroluminescent element caused by external air, the substrate is preferably made of a material with high gas barrier properties. Therefore, especially when a material with low gas barrier properties such as a synthetic resin substrate is used, 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.

[anode] The anode 2 has a function of injecting holes into the layer on the light-emitting layer 5 side. Anode 2 usually contains: metals such as aluminum, gold, silver, nickel, palladium, platinum; metal oxides such as indium and/or tin oxides; halogenated metals such as copper iodide; carbon black and poly(3-methylthiophene) , Polypyrrole, polyaniline and other conductive polymers.

The formation of the anode 2 is usually usually performed by a dry method such as a sputtering method or a vacuum vapor deposition method. In the case of using silver and other metal particles, copper iodide and other particles, carbon black, conductive metal oxide particles, conductive polymer fine powder, etc. to form the anode, it can also be dispersed in a suitable binder resin solution And coated on the substrate to form. In the case of conductive polymer, it is also possible to directly form a thin film on the substrate by electrolytic polymerization, or coat a conductive polymer on the substrate to form an anode (Appl. Phys. Lett.), 60 rolls , Page 2711, 1992).

The anode 2 usually has a single-layer structure, but a layered structure may be appropriately adopted. When the anode 2 has a laminated structure, different conductive materials may be laminated on the anode of the first layer.

The thickness of the anode 2 may be determined according to the required transparency, material, and the like. In particular, when high transparency is required, it is preferable that the transmittance of visible light be a thickness of 60% or more, and more preferably a thickness of 80% or more. The thickness of the anode 2 is preferably set to be usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. In the case where transparency is not required, the thickness of the anode 2 may be any thickness according to the required strength and the like. In this case, the anode 2 may be the same thickness as the substrate.

In the case of forming a film on other layers on the surface of the anode 2, it is preferable to perform treatments such as ultraviolet/ozone, oxygen plasma, argon plasma, etc. before film formation to remove impurities on the anode 2 and adjust its ions. Change the potential to improve hole injection.

[Hole injection layer] The layer that performs the function of transporting holes from the anode 2 side to the light emitting layer 5 side is generally called a hole injection transport layer or a hole transport layer. When there are two or more layers that perform the function of transporting holes from the anode 2 side to the light emitting layer 5 side, the layer closer to the anode side may be referred to as the hole injection layer 3. In terms of enhancing the function of transporting holes from the anode 2 side to the light emitting layer 5 side, it is preferable to form the hole injection layer 3. In the case of forming the hole injection layer 3, the hole injection layer 3 is usually formed on the anode 2.

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.

The formation method of the hole injection layer may be a vacuum evaporation method or a wet film formation method. In terms of excellent film-forming properties, it is preferably formed by a wet film-forming method.

The hole injection layer 3 preferably includes a hole-transporting compound, and more preferably includes a hole-transporting compound and an electron-accepting compound. Furthermore, it is preferable to include a cationic radical compound in the hole injection layer, and it is particularly preferable to include a cationic radical compound and a hole transporting compound.

Hereinafter, a general method of forming the hole injection layer will be described. In the organic electroluminescence device of this embodiment, the hole injection layer is preferably formed by a wet film forming method using the composition for organic electroluminescence device.

＜Hole transporting compound＞ The composition for forming a hole injection layer usually contains a hole transporting compound that becomes the hole injection layer 3. In the case of the wet film forming method, the composition for forming a hole injection layer usually further contains a solvent. The composition for forming the hole injection layer preferably has high hole transport properties and can efficiently transport the injected holes. Therefore, it is preferable that the hole mobility is large, and impurities that become traps are not easily generated during manufacturing or use. In addition, it is preferably excellent in stability, low in ionization potential, and high in transparency to visible light. Especially when the hole injection layer 3 and the light emitting layer 5 are in contact with each other, it is preferable that the light emitted from the light emitting layer 5 is not extinguished or an exciplex is formed with the light emitting layer 5 so as not to reduce the luminous efficiency. By.

As the hole-transporting compound, from the viewpoint of the charge injection barrier from the anode 2 to the hole injection layer 3, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferred. Examples of hole-transporting compounds include aromatic amine-based compounds, phthalocyanine-based compounds, porphyrin-based compounds, oligothiophene-based compounds, polythiophene-based compounds, benzylphenyl-based compounds, and triphenylene-based compounds. Compounds formed by linking grade amines, hydrazone-based compounds, silazane-based compounds, quinacridone-based compounds, etc.

Among the exemplified compounds, in terms of amorphous properties and visible light transmittance, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred. The aromatic tertiary amine compound also includes a compound having an aromatic tertiary amine structure and having a group derived from an aromatic tertiary amine.

The type of aromatic tertiary amine compound is not particularly limited. In terms of easily obtaining uniform light emission due to the surface smoothing effect, it is preferable to use a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less (repeat Polymeric compounds with connected units).

The hole injection layer 3 preferably contains the electron-accepting compound or the cationic radical compound, so that the conductivity of the hole injection layer can be improved by oxidation of the hole-transporting compound.

PEDOT/PSS (Adv. Mater., 2000, vol. 12, page 481) or emeraldine hydrochloride (J. Phys. Chem., 1990, vol. 94, 7716) and other cationic radical compounds derived from polymer compounds can also be produced by oxidative polymerization (dehydrogenation polymerization).

The oxidative polymerization mentioned here is to chemically or electrochemically oxidize the monomer in an acid solution using peroxodisulfate or the like. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomer is polymerized by oxidation, and an anion derived from an acidic solution is used as a counter anion, and a cation is generated from the repeating unit of the polymer with one electron removed. base.

＜Formation of hole injection layer by wet film forming method＞ In the case of forming the hole injection layer 3 by a wet film formation method, the material for the hole injection layer 3 is usually mixed with a soluble solvent (a solvent for the hole injection layer) to prepare a composition for film formation (A composition for forming a hole injection layer), the composition for forming an electron injection layer is applied to a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2) to form a film, and then dried , To form.

As long as the effect of the present invention is not significantly impaired, the concentration of the hole-transporting compound in the composition for forming a hole injection layer is arbitrary. In terms of uniformity of the film thickness, it is preferably low. It is preferable that it is high from the point that defects are less likely to occur in the injection layer. Specifically, it is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, particularly preferably 0.5% by weight or more, and preferably 70% by weight or less, further preferably 60% by weight or less, and particularly preferably 50% by weight %the following.

Examples of the solvent include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

As ether solvents, for example, aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA) and 1,2-dimethoxybenzene, 1,3-Dimethoxybenzene, anisole, phenethyl ether, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2 , 4-dimethyl anisole and other aromatic ethers.

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

Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, and 1,4-diisopropylbenzene. , Cyclohexylbenzene, methyl naphthalene, etc.

Examples of amide-based solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and the like. In addition to these, dimethyl sulfoxide and the like can also be used.

The formation of the hole injection layer 3 by the wet film formation method is usually performed by preparing the composition for forming the hole injection layer, and then coating it to form a film to a layer corresponding to the lower layer of the hole injection layer 3 (usually 2) on the anode and dried to proceed. In the hole injection layer 3, the coating film is usually dried by heating or drying under reduced pressure after film formation.

<Formation of the hole injection layer by the vacuum evaporation method> When forming the hole injection layer 3 by the vacuum evaporation method, the constituent material of the hole injection layer 3 (the hole transport compound , Electron-accepting compounds, etc.) are placed in a crucible set in a vacuum container (when two or more materials are used, they are usually placed in different crucibles), and the vacuum container After exhausting the internal gas to about 10 ^-4 Pa, heat the crucible (when two or more materials are used, the crucible is usually heated separately), while controlling the evaporation of the material in the crucible, make it evaporate (in When two or more kinds of materials are used, it is usually evaporated while controlling the amount of evaporation independently, and a hole injection layer 3 is formed on the anode 2 on the substrate 1 placed facing the crucible. In the case of using two or more materials, the mixture of these can also be put into a crucible and heated to evaporate to form a hole injection layer.

That does not significantly impair the effects of the present invention, the degree of vacuum during the deposition is not limited, but is usually ^{0.1 × 10 -6 Torr (0.13 ×} 10 -4 Pa) or more and ^{9.0 × 10 -6 Torr (12.0 ×} 10 - ⁴ Pa) or less. As long as the effect of the present invention is not significantly impaired, the vapor deposition rate is not limited, and it is usually 0.1 Å/sec or more and 5.0 Å/sec or less. As long as the effect of the present invention is not significantly impaired, the film formation temperature during vapor deposition is not limited, and it is preferably performed at 10°C or higher and 50°C or lower. The hole injection layer 3 may be crosslinked in the same manner as the hole transport layer 4 described later.

[Hole transport layer] The hole transport layer 4 is a layer that performs the function of transporting holes from the anode 2 side to the light emitting layer 5 side. The hole transport layer 4 of this embodiment preferably contains the polymer of this embodiment as a material containing the partial structure A. The hole transport layer 4 is usually formed between the anode 2 and the light-emitting layer 5. When the 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.

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.

The method of forming the hole transport layer 4 may be a vacuum evaporation method or a wet film forming method. In terms of excellent film-forming properties, it is preferably formed by a wet film-forming method.

Hereinafter, a general method of forming a hole transport layer will be described. The hole transport layer of the present embodiment is preferably formed by a wet film forming method using the composition for forming the hole transport layer.

The hole transport layer 4 usually contains a hole transport compound. The hole-transporting compound contained in the hole-transporting layer 4 is preferably the polymer of the present embodiment described above, or one obtained by cross-linking the polymer when the polymer has a cross-linkable group polymer. Furthermore, in addition to the polymer, the hole-transporting compound may preferably include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl represented by Aromatic diamine containing two or more tertiary amines and two or more condensed aromatic rings substituted with nitrogen atoms (Japanese Patent Laid-Open No. 5-234681), 4,4',4''-tri(1 -Naphthylphenylamino) triphenylamine and other aromatic amine compounds with a Starburst structure (J. Lumin., Volume 72-74, Page 985, 1997), containing triphenyl Aromatic amine compound of tetramer of base amine (Chem. Commun., 2175 page, 1996), 2,2',7,7'-tetra-(diphenylamino)-9, Spiro compounds such as 9'-spirobifen (Synth. Metals, Volume 91, page 209, 1997), 4,4'-N,N'-dicarbazole biphenyl and other carbazole derivatives, etc. In addition, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Laid-Open No. 7-53953), and poly(arylene ether) containing tetraphenylbenzidine (polymer for advanced technology ( Polym. Adv. Tech.), Volume 7, 33 pages, 1996) and so on.

＜Formation of hole transport layer by wet film forming method＞ In the case of forming the hole transport layer 4 by a wet film formation method, the hole transport layer formation composition is generally used in the same manner as when the hole injection layer 3 is formed by the wet film formation method. The hole injection layer forming composition is formed.

In the case of forming the hole transport layer 4 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 solvent as the solvent used in the composition for forming the hole injection layer. 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. The formation of the hole transport layer 4 by the wet film formation method can be performed in the same manner as the film formation method of the hole injection layer 3 described above.

＜Formation of hole transport layer by vacuum evaporation method＞ In the case of forming the hole transport layer 4 by a vacuum evaporation method, it is usually the same way as when the hole injection layer 3 is formed by the vacuum evaporation method, and the constituent material of the hole transport layer 4 can be used instead The hole injection layer 3 is formed by the constituent material. Regarding the film forming conditions such as the degree of vacuum during the vapor deposition, the vapor deposition rate, and the temperature, the film can be formed under the same conditions as those during the vacuum vapor deposition of the hole injection layer 3.

[Light-emitting layer] The light-emitting layer 5 is a layer that performs the function of being excited by recombination of holes injected from the anode 2 and electrons injected from the cathode 9 to emit light when an electric field is applied between a pair of electrodes. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 9. The light-emitting layer 5 is formed between the hole transport layer 4 and the cathode 9.

The film thickness of the light-emitting layer 5 is arbitrary as long as the effect of the present invention is not significantly impaired, but it is preferably thick in terms of the film's resistance to defects. On the other hand, in terms of easy formation of a low driving voltage, it is preferably thin. Therefore, the film thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and generally preferably 200 nm or less, and more preferably 100 nm or less.

The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material), and preferably contains a material having charge-transporting properties (charge-transporting material). The light-emitting layer of this embodiment preferably contains at least the low-molecular compound of this embodiment as a light-emitting material and a material containing partial structure A.

Hereinafter, a general method of forming a light-emitting material and a light-emitting layer will be described. In the organic electroluminescence element of this embodiment, the light-emitting layer is preferably formed by a wet film forming method using the composition for forming the light-emitting layer.

＜Luminescent material＞ The luminescent material is not particularly limited as long as it emits light at a desired emission wavelength without impairing the effect of the present invention, and a known luminescent material can be applied. The luminescent material may be a fluorescent luminescent material or a phosphorescent luminescent material, but it is preferably a material with good luminous efficiency, and from the viewpoint of internal quantum efficiency, it is preferably a phosphorescent luminescent material.

As a fluorescent material, the following materials can be mentioned, for example.

As the fluorescent material (blue fluorescent material) that provides blue light emission, for example, naphthalene, perylene, pyrene, anthracene, coumarin, ch, p-bis(2-phenylvinyl)benzene and the Some derivatives, etc.

Examples of fluorescent materials that provide green light emission (green fluorescent light-emitting materials) include quinacridone derivatives, coumarin derivatives, aluminum complexes such as _{Al(C 9} H ₆ NO) _{3 and the like.}

As a fluorescent light emitting material (yellow fluorescent light emitting material) that provides yellow light emission, for example, fluorescein, perimidone derivatives, and the like can be cited.

As a fluorescent light emitting material (red fluorescent light emitting material) that provides red light emission, for example, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl) -4H-pyran (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran, DCM) series compounds, benzopyran derivatives, rose bengal derivatives, benzothioxanthene derivatives Sulfide, azabenzothioxanthone and so on.

As the phosphorescent light-emitting material, for example, an organometallic complex containing a metal selected from Group 7 to Group 11 of the long-period periodic table, and the like can be cited. Preferred examples of metals selected from Group 7 to Group 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, gold, and the like.

As the ligands of the organometallic complexes, (hetero)arylpyridine ligands, (hetero)arylpyrazole ligands and other (hetero)aryl groups are preferably linked to pyridine, pyrazole, phenanthroline, etc. The ligands formed are particularly preferably phenylpyridine ligands and phenylpyrazole ligands. Here, the (hetero)aryl group means an aryl group or a heteroaryl group.

As a preferred phosphorescent light-emitting material, specifically, it can include: tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-benzene) Phenylpyridine complexes such as platinum, tris(2-phenylpyridine)osmium, tris(2-phenylpyridine)rhenium, octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium Porphyrin complexes such as porphyrin and octaphenylpalladium porphyrin.

Examples of polymer-based luminescent materials include: poly(9,9-dioctyl -2,7-diyl), poly[(9,9-dioctyl -2,7-diyl)-co -(4,4'-(N-(4-Second-butylphenyl))diphenylamine)], poly[(9,9-dioctyl -2,7-diyl)-co- (1,4-Benzo-2{2,1'-3}-triazole)] and other polytetrafluoroethylene materials, poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-styrene ethylene] and other polystyrene ethylene-based materials.

＜Charge transport material＞ The charge-transporting material is a material having positive charge (hole) or negative charge (electron) transport properties. As long as the effect of the present invention is not impaired, the charge-transporting material is not particularly limited, and known charge-transporting materials can be applied.

The charge-transporting material can be a compound used in the light-emitting layer of an organic electroluminescent element, etc., and a compound used as a host material of the light-emitting layer is particularly preferable.

Specific examples of charge-transporting materials other than the low-molecular compound of this embodiment include aromatic amine-based compounds, phthalocyanine-based compounds, porphyrin-based compounds, and oligothiophene-based compounds containing the polymer of this embodiment. Compounds, polythiophene-based compounds, benzylphenyl-based compounds, compounds formed by linking tertiary amines with stilbene groups, hydrazone-based compounds, silazane-based compounds, silanamine-based compounds, phosphoramine-based compounds, quinacridines A ketone-based compound or the like is a compound exemplified as a hole-transporting compound of the hole injection layer. In addition, electron-transporting compounds such as anthracene-based compounds, pyrene-based compounds, carbazole-based compounds, pyridine-based compounds, phenanthroline-based compounds, oxadiazole-based compounds, and silole-based compounds, and the like can be cited.

In addition, for example, it can also be preferably used: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl containing two or more tertiary amines and two or more Aromatic diamines in which the condensed aromatic ring is substituted with a nitrogen atom (Japanese Patent Laid-Open No. 5-234681), 4,4',4''-tris(1-naphthylphenylamino)triphenylamine And other aromatic amine compounds with starburst structure (J. Lumin.), Volume 72-74, page 985, 1997), aromatic amine compounds containing tetramers of triphenylamine (Chemical Communication (Chem. Commun.), 2175 pages, 1996), 2,2',7,7'-tetra-(diphenylamino)-9,9'-spirobifen and other stilbene compounds (synthetic metal (Synth. Metals), Volume 91, page 209, 1997), 4,4'-N,N'-dicarbazole biphenyl and other carbazole-based compounds are exemplified as hole-transporting compounds in the hole-transporting layer The compound and so on.

In addition, in addition, you can also cite: 2-(4-biphenyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), 2,5-bis (1-Naphthyl)-1,3,4-oxadiazole (BND) and other oxadiazole compounds; 2,5-bis(6'-(2',2''-bipyridyl))-1 ,1-Dimethyl-3,4-diphenylsilole (PyPySPyPy) and other silole compounds; bathophenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl -1,10-phenanthroline (bathocuproin, BCP) and other phenanthroline compounds, etc.

＜Formation of light-emitting layer by wet film forming method＞ The method of forming the light-emitting layer 5 may be a vacuum evaporation method or a wet film formation method. In terms of excellent film forming properties, a wet film forming method is preferred, and a spin coating method and an inkjet method are more preferred. In particular, if the hole transport layer forming composition is used to form the hole transport layer 4 that is the lower layer of the light emitting layer 5, it is easy to be laminated by a wet film formation method, and therefore, wet film formation is preferred. Law. In the case of forming the light-emitting layer 5 by a wet film formation method, generally, as in the case of forming the hole injection layer by a wet film formation method, the composition for forming the light-emitting layer is used instead of the hole injection layer The formation is formed with a composition.

As a solvent removal method after wet film formation, heating or reduced pressure can be used. As the heating mechanism used in the heating method, in terms of uniformly supplying heat to the entire film, it is preferable to clean an oven or a hot plate.

As long as the effect of the present invention is not significantly impaired, the heating temperature in the heating step is arbitrary. In terms of shortening the drying time, the temperature is preferably high, and in terms of less damage to the material, it is preferably low. The upper limit of the heating temperature is usually 250°C or lower, preferably 200°C or lower, and more preferably 150°C or lower. The lower limit of the heating temperature is usually 30°C or higher, preferably 50°C or higher, and more preferably 80°C or higher. At a temperature at which the heating temperature exceeds the upper limit, the heat resistance of the charge transport material or phosphorescent light-emitting material generally used is higher, and may be decomposed or crystallized to be poor. If the heating temperature is less than the lower limit, it takes a long time to remove the solvent, which is not preferable. The heating time in the heating step can be appropriately determined according to the boiling point of the solvent in the composition for forming the light-emitting layer, the vapor pressure, the heat resistance of the material, and the heating conditions.

<Formation of the light-emitting layer by the vacuum vapor deposition method> When the light-emitting layer 5 is formed by the vacuum vapor deposition method, the constituent materials of the light-emitting layer 5 (the light-emitting material, the low-molecular compound of the present embodiment, the charge One or two or more types of transportable compounds, etc.) are placed in a crucible set in a vacuum container (when two or more materials are used, they are usually placed in different crucibles), and the vacuum container is drained by a vacuum pump After the gas ^{reaches about 10 -4} Pa, heat the crucible (in the case of using two or more materials, the crucible is usually heated separately), while controlling the evaporation of the material in the crucible, make it evaporate (when using two materials) In the case of more than two kinds of materials, generally, the luminescent layer 5 is formed on the hole transport layer 4 placed facing the crucible while evaporating while controlling the amount of evaporation independently. When two or more kinds of materials are used, the mixture of these may be put into a crucible and heated to evaporate to form the light-emitting layer 5.

That does not significantly impair the effects of the present invention, the degree of vacuum during the deposition is not limited, but is usually ^{0.1 × 10 -6 Torr (0.13 ×} 10 -4 Pa) or more and ^{9.0 × 10 -6 Torr (12.0 ×} 10 - ⁴ Pa) or less. As long as the effect of the present invention is not significantly impaired, the vapor deposition rate is not limited, and it is usually 0.1 Å/sec or more and 5.0 Å/sec or less. As long as the effect of the present invention is not significantly impaired, the film formation temperature during vapor deposition is not limited, and it is preferably performed at 10°C or higher and 50°C or lower.

[Hole blocking layer] A hole blocking layer 6 may also be provided between the light-emitting layer 5 and the electron injection layer 8 described later. The hole blocking layer 6 is a layer laminated on the light-emitting layer 5 so as to be in contact with the interface on the cathode 9 side of the light-emitting layer 5.

The hole blocking layer 6 has a function of blocking holes moved from the anode 2 from reaching the cathode 9 and a function of efficiently transporting electrons injected from the cathode 9 to the direction of the light-emitting layer 5. The physical properties required for the material constituting the hole blocking layer 6 include high electron mobility, low hole mobility, large energy gap (difference between HOMO and LUMO), and high excited triplet energy level (T ₁ ).

As a material of the hole blocking layer 6 that satisfies such conditions, for example, bis(2-methyl-8-hydroxyquinoline) (phenol)aluminum, bis(2-methyl-8-hydroxyquinoline) ( Triphenylsilanol) aluminum (bis(2-methyl-8-quinolinolato)(triphenyl silanolato)aluminum) and other mixed ligand complexes, bis(2-methyl-8-quinolinolato)aluminum-μ- Oxo-bis-(2-methyl-8-quinolato) aluminum dinuclear metal complexes and other metal complexes, stilbene biphenyl derivatives and other styryl compounds (Japanese Patent Laid-open Hei 11-242996), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole and other triazole derivatives (Japan Japanese Patent Laid-Open No. 7-41759), bathocuproin and other phenanthroline derivatives (Japanese Patent Laid-Open No. 10-79297), etc. Furthermore, the compound having at least one substituted pyridine ring at the 2, 4, and 6 positions described in International Publication No. 2005/022962 is also suitable as the material of the hole blocking layer 6.

The method of forming the hole blocking layer 6 is not limited. Therefore, it can be formed by a wet film formation method, an evaporation method, or other methods. The film thickness of the hole blocking layer 6 is arbitrary as long as the effect of the present invention is not significantly impaired, but it is usually 0.3 nm or more, preferably 0.5 nm or more, usually 100 nm or less, and preferably 50 nm or less.

[Electron Transport Layer] The electron transport layer 7 is provided between the light emitting layer 5 and the electron injection layer 8 for the purpose of further improving the current efficiency of the device.

The electron transport layer 7 is formed of a compound capable of efficiently transporting electrons injected from the cathode 9 to the direction of the light emitting layer 5 between electrodes to which an electric field is applied. The electron-transporting compound used in the electron-transporting layer 7 needs to be a compound that has high electron injection efficiency from the cathode 9 or the electron injection layer 8 and high electron mobility, and can efficiently transport the injected electrons.

Specific examples of the electron-transporting compound used in the electron-transporting layer include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), 10 -Hydroxybenzo[h]quinoline metal complexes, oxadiazole derivatives, stilbene biphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes Compound, benzoxazole metal complex, benzothiazole metal complex, tribenzimidazolylbenzene (U.S. Patent No. 5645948), Quinoxaline compound (Japanese Patent Laid-Open No. 6-207169) , Phenanthroline derivatives (Japanese Patent Laid-open No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimide, n-type hydrogenated amorphous silicon carbide , N-type zinc sulfide, n-type zinc selenide, etc.

The thickness of the electron transport layer 7 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

The electron transport layer 7 is formed by laminating the hole blocking layer 6 by a wet film formation method or a vacuum evaporation method in the same manner as described above. Generally, a vacuum evaporation method is used.

[Electron injection layer] The electron injection layer 8 plays a role of efficiently injecting electrons injected from the cathode 9 into the electron transport layer 7 or the light-emitting layer 5.

In order to perform electron injection efficiently, the material forming the electron injection layer 8 is preferably a metal with a low work function. As an example, alkali metals such as sodium or cesium, alkaline earth metals such as barium or calcium, etc. can be used. In this case, the film thickness of the electron injection layer 8 is generally preferably 0.1 nm or more and 5 nm or less.

As a material for forming the electron injection layer 8, an organic electron transport material represented by a nitrogen-containing heterocyclic compound such as bathophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline is doped with sodium and potassium. Alkali metals such as cesium, cesium, lithium, rubidium (described in Japanese Patent Laid-Open No. 10-270171, Japanese Patent Laid-Open No. 2002-100478, Japanese Patent Laid-Open No. 2002-100482, etc.) can also take into account electron injection and transmission Excellent film quality with improved properties, and therefore preferred. In this case, the thickness of the electron injection layer 8 is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer 8 is formed by laminating the light-emitting layer 5 or the hole blocking layer 6 or the electron transport layer 7 thereon by a wet film formation method or a vacuum evaporation method. The details of the wet film formation method are the same as those of the light-emitting layer.

[cathode] The cathode 9 plays a role of injecting electrons into the layer on the light-emitting layer 5 side (the electron injection layer 8 or the light-emitting layer 5, etc.).

As the material of the cathode 9, the material used in the anode 2 can be used. In terms of efficiently performing electron injection, it is preferable to use a metal with a low work function. For example, metals such as tin, magnesium, indium, calcium, aluminum, silver, or alloys thereof can be used. Specific examples include, for example, alloy electrodes with low work functions such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

In terms of device stability, it is preferable to laminate a metal layer with a high work function and stable with respect to the atmosphere on the cathode 9 to protect the cathode containing a metal with a low work function. Examples of the metal to be laminated include metals such as aluminum, silver, copper, nickel, chromium, gold, and platinum. The film thickness of the cathode 9 is usually the same as that of the anode 2.

[Other layers] As long as the effect of the present invention is not significantly impaired, the organic electroluminescent element of this embodiment may further have other layers. In other words, any other layer described above may be provided between the anode 2 and the cathode 9.

[Other component structure] The organic electroluminescent element of this embodiment may also have a structure opposite to the above description, that is, a cathode 9, an electron injection layer 8, an electron transport layer 7, a hole blocking layer 6, a light emitting layer 5, and a hole are formed on the substrate 1. The transport layer 4, the hole injection layer 3, and the anode 2 are laminated in this order. It is also possible to provide the organic electroluminescent element of the present invention between at least one of two highly transparent substrates.

When the organic electroluminescence element of this embodiment is applied to an organic electroluminescence device, it can be used as a single organic electroluminescence element, and it can be used as a structure in which a plurality of organic electroluminescence elements are arranged in an array. It can also be used as a structure in which the anode and the cathode are arranged in an XY matrix.

[Organic EL display device] The organic EL display device (organic electroluminescence element display device) of this embodiment uses the organic electroluminescence element. Regarding the model or structure of the organic EL display device of this embodiment, there is no particular limitation, and the organic electroluminescent element can be used and assembled according to a common method. For example, the organic EL display of the present invention can be formed by a method as described in "Organic EL Display" (Ohmsha, published on August 20, 2004, by Shishiji at the time, Chinami Adachi, Hideyuki Murata). Display device.

〔Organic EL lighting〕 The organic EL lighting (organic electroluminescence element lighting) of this embodiment uses the organic electroluminescence element. Regarding the model or structure of the organic EL lighting of this embodiment, there is no particular limitation, and the organic electroluminescent element can be used and assembled according to a common method. [Example]

Hereinafter, examples are shown to explain the present invention more specifically. The present invention is not limited to the following examples, and can be arbitrarily modified and implemented as long as it does not deviate from the gist of the present invention.

[Synthesis example 1: Synthesis of polymer compound having partial structure A] <Synthesis of raw material monomer> [Chemical 78]

Under nitrogen flow, put 3-bromo-3'-nitro-biphenyl (14.1 g, 50.5 mmol), bis(pinacolato)diboron (17.1 g) in a 1000 ml flask , 60.6 mmol), potassium acetate (24.8 g, 253.0 mmol), and nitrogen replacement at room temperature. After that, put in 200 ml of 1,4-dioxane, add 1,1'-bis(diphenylphosphino)ferrocene-dichloropalladium(II)-dichloromethane [PdCl ₂ (dppf)CH ₂ Cl ₂ ] (1.24 g, 1.52 mmol), the reaction was carried out at 100°C for 8.5 hours. The reaction liquid was filtered under reduced pressure, diluted with toluene, and crudely refined with activated clay. Furthermore, the crude product was purified by column chromatography (developing solution: hexane/ethyl acetate=80/20) to obtain compound 1 (16.3 g, yield 99.5%).

[化79]

Then, compound 1 (8.7 g, 26.76 mmol), 1-bromo-3-iodobenzene (7.95 g, 28.1 mmol), potassium phosphate aqueous solution (2 M, 40.1 ml), toluene (80 ml), ethanol (40 ml ) Put it into a flask, fully replace the system with nitrogen, and heat to 65°C. Bis(triphenylphosphine)dichloropalladium(II) (0.094 g, 0.134 mmol) was added thereto, and the mixture was stirred at 65°C for 3 hours. Water was added to the reaction liquid, and extraction was performed with toluene. The organic layer was dried with anhydrous magnesium sulfate and coarsely refined with activated clay. The crude refined product was purified by column chromatography (developing solution: hexane/dichloromethane=80/20) to obtain compound 2 (8.6 g, yield 90.5%).

[化80]

Under nitrogen flow, put 100 ml of dimethyl sulfide, compound 2 (8.55 g, 24.14 mmol), bis(pinacol) diboron (7.36 g, 28.97 mmol), potassium acetate ( 7.1 g, 72.42 mmol), stirred at 60°C for 30 minutes. Afterwards, 1,1'-bis(diphenylphosphino)ferrocene-dichloropalladium(II)-dichloromethane [PdCl ₂ (dppf)CH ₂ Cl ₂ ] (0.99 g, 1.21 mmol) was added to The reaction was carried out at 85°C for 4.0 hours. The reaction solution was filtered under reduced pressure, and the filtrate was extracted with toluene, dried with anhydrous magnesium sulfate, and refined with activated clay. Furthermore, the crude product was purified by column chromatography (developing solution: hexane/ethyl acetate=90/10) to obtain compound 3 (9.3 g, yield 96.0%).

[化81]

Then, compound 3 (9.3 g, 23.18 mmol), 1-bromo-4-iodobenzene (6.88 g, 24.33 mmol), potassium phosphate aqueous solution (2 M, 34.8 ml), toluene (80 ml), ethanol (40 ml ) Put it into a flask, fully replace the system with nitrogen, and heat to 65°C. Bis(triphenylphosphine)dichloropalladium(II) (0.081 g, 0.116 mmol) was added thereto, and the mixture was stirred at 65°C for 3.5 hours. Water was added to the reaction liquid, and extraction was performed with toluene. The organic layer was dried with anhydrous magnesium sulfate and coarsely refined with activated clay. The crude product was purified by column chromatography (developing solution: hexane/dichloromethane=75/25) to obtain compound 4 (8.7 g, yield 87.2%).

[化82]

Under nitrogen flow, put 100 ml of dimethyl sulfide, compound 4 (8.7 g, 20.22 mmol), bis(pinacol) diboron (6.2 g, 24.26 mmol), potassium acetate ( 5.95 g, 60.66 mmol), stirred at 60°C for 30 minutes. After that, 1,1'-bis(diphenylphosphino)ferrocene-dichloropalladium(II)-dichloromethane [PdCl ₂ (dppf)CH ₂ Cl ₂ ] (0.83 g, 1.01 mmol) was added to The reaction was carried out at 85°C for 3.0 hours. The reaction solution was filtered under reduced pressure, and the filtrate was extracted with toluene, dried with anhydrous magnesium sulfate, and refined with activated clay. Furthermore, the crude product was purified by column chromatography (developing solution: hexane/dichloromethane=50/50) to obtain compound 5 (7.2 g, yield 75.0%).

[化83]

Then, compound 5 (7.1 g, 14.87 mmol), commercially available 2-chloro-4,6-diphenyl-1,3,5-triazine (3.98 g, 14.87 mmol), potassium phosphate aqueous solution (2 M , 23.0 ml), toluene (50 ml), ethanol (25 ml) are put into the flask, the system is fully replaced with nitrogen, and the temperature is raised to 65°C. Tetrakis(triphenylphosphine)palladium(0) (0.52 g, 0.45 mmol) was added thereto, and the mixture was stirred at 85°C for 4.0 hours. The precipitated insoluble matter was filtered under reduced pressure, and the filtrate was suspended and washed with 50 ml of dichloromethane and added dropwise to 200 ml of ethanol. The precipitate was filtered under reduced pressure and dried to obtain compound 6 (5.3 g, yield 61.2%).

[化84]

Under nitrogen flow, put 500 ml of tetrahydrofuran, 50 ml of ethanol, compound 6 (5.3 g, 9.10 mmol), palladium/carbon (10%, about 55% wet product, 0.72 g) in a 1000 ml flask, Stir at 50°C for 15 minutes. After that, hydrazine monohydrate (3.1 g) was added dropwise, and the reaction was carried out at this temperature for 3 hours. The reaction solution was filtered under reduced pressure using wet diatomaceous earth, and the filtrate was concentrated to obtain compound 7 (4.8 g, yield 95.1%).

[化85]

Put compound 8 (8.0 g, 49 mmol), 1-bromo-1'-iodine-3,3'-biphenyl (17.7 g, 49 mmol), 120 ml of toluene, 60 ml of ethanol, 2 M potassium phosphate aqueous solution (62 ml), nitrogen bubbling for 30 minutes. After adding tetrakis(triphenylphosphine)palladium(0) (1.43 g, 1.24 mmol), it was heated and stirred at 90°C for 3 hours. After cooling to room temperature, water and toluene were added for liquid separation and washing, and then the organic layer was dried with anhydrous magnesium sulfate. After that, the solvent was removed under reduced pressure. The residue obtained was purified by silica gel column chromatography (dichloromethane/hexane=1/9) to obtain 15.5 g of compound 9 as a colorless oil.

[化86]

Put compound 9 (15.5 g, 44 mmol), 3-aminophenylboronic acid monohydrate (6.4 g, 41 mmol), toluene 100 ml, ethanol 50 ml, 2 M potassium phosphate aqueous solution ( 55 ml), nitrogen bubbling for 30 minutes. After adding tetrakis(triphenylphosphine)palladium (0) (1.3 g, 1.15 mmol), it was heated and stirred at 90°C for 3.5 hours. After cooling to room temperature, water and toluene were added for liquid separation and washing, and then the organic layer was dried with anhydrous magnesium sulfate. After that, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate/hexane=2/8) to obtain 7.8 g of compound 10 in the form of pale yellow syrup.

[化87]

In a 1 L flask, 270 ml of toluene, 135 ml of ethanol, 20.0 g (44.8 mmol) of compound 11, 50.72 g (179.3 mmol) of 1-bromo-4-iodotoluene, 2 M potassium phosphate aqueous solution (191 ml) The resulting solution is vacuum degassed and then replaced with nitrogen. Heat under nitrogen flow and stir for 30 minutes. After that, 0.63 g (0.90 mmol) of bis(triphenylphosphine)dichloropalladium(II) was added, and the mixture was refluxed for 6 hours. Put water in the reaction solution, extract with toluene, and treat with anhydrous magnesium sulfate and activated clay. After the toluene solution was heated to reflux, the insoluble matter was filtered and recrystallized to obtain compound 12 as a colorless solid (yield 14.2 g, yield 60.2%).

[化88]

The compound 14 was synthesized using the same method as the synthesis of compound 12 except that 1-bromo-4-iodobenzene was used instead of 5-bromo-2-iodotoluene.

<Synthesis of polymer compound with partial structure A (polymer 1)> [Chemical 89]

Load compound 12 (2.5 g, 4.7 mmol), compound 13 (2.134 g, 6.1 mmol), compound 10 (0.51 g, 1.4 mmol), compound 7 (1.04 g, 1.9 mmol), sodium tert-butoxide (3.48 g) , 36.2 mmol) and toluene (71 ml), fully replace the system with nitrogen, and heat to 60°C (solution A1). In addition, [4-(N,N-dimethylamino)phenyl]bis-th Tributylphosphine (Amphos) (199.4 mg, 0.8 mmol), heated to 60°C (solution B1).

In a nitrogen stream, the solution B1 was added to the solution A1, and the reaction was heated and refluxed for 1.0 hour. It was confirmed that compound 7, compound 10, and compound 13 had disappeared, and compound 14 (1.78 g, 3.5 mmol) was added. After heating and refluxing for 2 hours, bromobenzene (1.84 g, 11.7 mmol) was added, and the heating and refluxing reaction was performed for 1 hour. The reaction solution was left to cool, and was added dropwise to the ethanol/water (370 ml/70 ml) solution to obtain the end-capped crude polymer. The blocked crude polymer was dissolved in toluene and re-precipitated in acetone, and the precipitated polymer was separated by filtration. The obtained polymer was dissolved in toluene, washed with dilute hydrochloric acid, and re-precipitated with ethanol containing ammonia. The filtered polymer was purified by column chromatography to obtain the target polymer 1 (2.5 g). The molecular weight and the like of the obtained polymer 1 are as follows.

Weight average molecular weight (Mw)=20,600 Number average molecular weight (Mn)=15,260 Dispersion (Mw/Mn)=1.35

[Example 1] The organic electroluminescent element was produced by the following method. For those made by depositing Indium Tin Oxide (ITO) transparent conductive film on a glass substrate to a thickness of 70 nm (manufactured by Sanyong Vacuum Co., Ltd., sputtered film product), the usual photolithography technology and It was etched with hydrochloric acid and patterned into 2 mm wide stripes, thereby forming an anode. The substrate patterned with ITO in the manner described above is cleaned in the order of ultrasonic cleaning with a surfactant aqueous solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water. , Use compressed air to make it dry, and finally perform ultraviolet ozone cleaning.

As a composition for forming a hole injection layer, 100 parts by weight of a hole-transporting polymer compound having a repeating structure represented by the following formula (P-1) and a compound 20 represented by the following formula (HI-1) were weighed Parts by weight, these were dissolved in ethyl benzoate to prepare a composition having a solid content concentration of 3.0% by weight.

[化90]

The composition for forming the hole injection layer was spin-coated on the substrate in the atmosphere, and dried on a heating plate at 240°C for 30 minutes in the atmosphere to form a uniform thin film with a thickness of 40 nm. Hole injection layer.

Next, 100 parts by weight of the charge-transporting polymer compound represented by the following formula (HT-1), which is the polymer 1 synthesized in Synthesis Example 1, was dissolved in cyclohexylbenzene to prepare a solution containing 3.0% by weight. A composition for forming a hole transport layer. The composition for forming the hole transport layer was spin-coated in a nitrogen glove box onto the substrate coated with the hole injection layer, and dried at 230° C. on a hot plate in a nitrogen glove box. Minutes, a uniform thin film with a thickness of 40 nm is formed to form a hole transport layer.

[化91]

Next, weigh 15 parts by weight of the compound represented by the following formula (H-1), 15 parts by weight of the compound represented by the following formula (H-2), and 70 parts by weight of the compound represented by the following formula (H-3) And 20 parts by weight of the compound represented by the following formula (D-1) as a material of the light-emitting layer, was dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 7.8% by weight as a composition for forming a light-emitting layer.

[化92]

[化93]

The composition for forming a light-emitting layer was spin-coated in a nitrogen glove box onto the substrate coated with the hole transport layer, and dried using a hot plate in a nitrogen glove box at 120°C for 20 minutes, A uniform thin film with a thickness of 70 nm was formed to form a light-emitting layer.

The substrate formed into the light-emitting layer was set in a vacuum vapor deposition apparatus, and the inside of the apparatus was evacuated to 2×10 ^-4 Pa or less.

Next, the compound represented by the following formula (HB-1) and lithium 8-quinolinolate were co-evaporated on the light-emitting layer at a rate of 1 Å/sec at a film thickness ratio of 2:3 by a vacuum evaporation method. A hole blocking layer with a thickness of 30 nm is formed.

[化94]

Next, a 2 mm-wide striped shadow mask as a mask for cathode vapor deposition was closely attached to the substrate so as to be orthogonal to the ITO stripes of the anode, and set in another vacuum vapor deposition apparatus. Furthermore, as a cathode, aluminum was heated by a molybdenum boat to form an aluminum layer with a film thickness of 80 nm at a deposition rate of 1 Å/sec to 8.6 Å/sec to form the cathode. Operated in the manner described, an organic electroluminescent element having a light-emitting area portion having a size of 2 mm×2 mm was obtained.

[Comparative Example 1] Except that the material composition of the light-emitting layer was changed to (H-4): (H-5): (H-3): (D-1) = 15: 15: 70: 20 in terms of weight ratio, the same as the examples 1 In the same manner, an organic electroluminescent element was produced. (H-4) and (H-5) are represented by the following formulas.

[化95]

^{[Evaluation of the device] The voltage when a current of 10 mA/cm 2 was} applied to the organic electroluminescent device obtained in Example 1 and Comparative Example 1 was measured, and the voltage of Comparative Example 1 was subtracted from the voltage of Example 1 As a relative voltage. In addition, the current luminous efficiency (cd/A) at this time was measured, and the relative current luminous efficiency of Example 1 when the current luminous efficiency of Comparative Example 1 was 1 was taken as the relative luminous efficiency. In addition, these organic electroluminescent elements were driven at 40 mA/cm ² and the 15% brightness decay life (LT85) was measured, and the ratio when the 15% decay life of Comparative Example 1 was 1 (hereinafter referred to as "relative decay life "). These are shown in Table 1.

According to Table 1, it can be seen that in the organic electroluminescent element of the present invention that contains a compound having the same partial structure A, that is, the structure represented by the formula (TzP), in the hole transport layer and the light-emitting layer, lower voltage, Longer life. Here, the charge-transporting polymer compound represented by formula (HT-1) and the compound represented by formula (H-1) used in Example 1 both have a structure in which four benzene rings are connected to triazine, and Therefore, the commonality is high, and it is believed that this aspect also contributes to a longer life.

[Table 1] Partial structure TzP Relative voltage (V) Relative luminous efficiency Relative attenuation life Hole transport layer Luminescent layer Example 1 Have Have -0.2 1.13 2.55 Comparative example 1 Have without 0.0 1.00 1.00

[Example 2] The organic electroluminescent element was produced by the following method. For those made by depositing indium tin oxide (ITO) transparent conductive film on a glass substrate to a thickness of 50 nm (manufactured by Geomatec, sputtered film product), the usual photolithography technology and hydrochloric acid etching are used The patterning is 2 mm wide stripes to form an anode. The substrate patterned with ITO in the manner described above is cleaned in the order of ultrasonic cleaning with a surfactant aqueous solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water. , Use compressed air to make it dry, and finally perform ultraviolet ozone cleaning.

As a composition for forming a hole injection layer, a hole-transporting polymer compound having a repeating structure represented by formula (P-1) used in Example 1 was prepared so that 3.0% by weight and represented by formula (HI-1) 0.6% by weight of the compound is dissolved in ethyl benzoate.

The composition for forming the hole injection layer was spin-coated on the substrate in the atmosphere, and dried on a heating plate at 240°C for 30 minutes in the atmosphere to form a uniform thin film with a thickness of 40 nm. Hole injection layer.

Next, 100 parts by weight of a charge-transporting polymer compound represented by the following formula (HT-2) as a material for the hole transport layer was dissolved in cyclohexylbenzene to prepare a hole transport layer containing a 3.0% by weight solution. Use the composition. The composition for forming the hole transport layer was spin-coated in a nitrogen glove box onto the substrate coated with the hole injection layer, and dried at 230° C. on a hot plate in a nitrogen glove box. Minutes, a uniform thin film with a thickness of 40 nm is formed to form a hole transport layer.

[化96]

Next, 50 parts by weight of the compound represented by the formula (H-1) used in Example 1, 50 parts by weight of the compound represented by the following formula (H-6) and the formula (D-1) As a material of the light-emitting layer, 15 parts by weight of the compound shown was dissolved in cyclohexylbenzene to prepare a solution with a solid content of 5.0% by weight as a composition for forming a light-emitting layer.

[化97]

The composition for forming a light-emitting layer was spin-coated in a nitrogen glove box onto the substrate coated with the hole transport layer, and dried using a hot plate in a nitrogen glove box at 120°C for 20 minutes, A uniform thin film with a thickness of 80 nm was formed to form a light-emitting layer.

The substrate formed into the light-emitting layer was set in a vacuum vapor deposition apparatus, and the inside of the apparatus was evacuated to 2×10 ^-4 Pa or less.

Next, the compound represented by the following formula (ET-1) and lithium 8-quinolinolate were co-evaporated on the light-emitting layer at a rate of 1 Å/sec at a film thickness ratio of 2:3 by a vacuum evaporation method. A hole blocking layer with a thickness of 30 nm is formed.

[化98]

Next, a 2 mm wide striped shadow mask as a mask for cathode vapor deposition was closely attached to the substrate so as to be orthogonal to the ITO stripes of the anode, and set in another vacuum vapor deposition apparatus. Furthermore, as a cathode, aluminum was heated by a molybdenum boat to form an aluminum layer with a film thickness of 80 nm at a deposition rate of 1 Å/sec to 8.6 Å/sec to form the cathode. Operated in the manner described, an organic electroluminescent element having a light-emitting area portion having a size of 2 mm×2 mm was obtained.

[Comparative Example 2] Except that the material composition of the light-emitting layer was changed to (H-4): (H-6): (D-1)=50:50:15 in terms of weight ratio, an organic electroluminescent element was produced in the same manner as in Example 1. . (H-4) is the one shown in the comparative example 1.

[Evaluation Device] The organic electroluminescent element is energized to Example 2 and Comparative Example 2 is obtained, and when determined at 1000 cd / m ² of luminance of light emission voltage and external quantum efficiency (EQE (External Quantum Efficiency) ( % )). The value obtained by subtracting the voltage of Comparative Example 2 from the voltage of Example 2 is described in Table 2 as the relative voltage. The EQE of Example 2 when the EQE of Comparative Example 2 is set to 1 is described in Table 2 as the relative EQE. In addition, as an evaluation of the drive life of the ^{device, the device was continuously energized at a current density of 60 mA/cm 2} and the time until the brightness of the device decreased to 90% of the initial brightness (LT90 (hr)) was measured. The life of the LT90 of Example 2 when the LT90 is set to 1 is described in Table 2 as the relative life.

According to Table 2, it can be seen that in the organic electroluminescent element of the present invention that contains a compound having the same partial structure A, that is, the structure represented by the formula (TzP), in the hole transport layer and the light-emitting layer, lower voltage, Longer life.

[Table 2] Partial structure TzP Relative voltage (V) Relative EQE Relative life Hole transport layer Luminescent layer Example 2 Have Have -0.83 1.03 1.42 Comparative example 2 Have without 0.00 1.00 1.00

[Example 3] Weigh 50 parts by weight of the compound represented by the following formula (H-7), 50 parts by weight of the compound represented by the following formula (H-8), and 15 parts by weight of the compound represented by the formula (D-1) as luminescence The material of the layer was dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer, and an element was produced in the same manner as in Example 2, except that a solution was prepared.

[化99]

[Example 4] Weigh 50 parts by weight of the compound represented by the formula (H-1), 50 parts by weight of the compound represented by the formula (H-8), and 15 parts by weight of the compound represented by the formula (D-1) as luminescence The material of the layer was dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer, and an element was produced in the same manner as in Example 2, except that a solution was prepared.

[Comparative Example 3] Weigh 50 parts by weight of the compound represented by the formula (H-4), 50 parts by weight of the compound represented by the formula (H-8), and 15 parts by weight of the compound represented by the formula (D-1) as luminescence The material of the layer was dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming a light-emitting layer, and an element was produced in the same manner as in Example 2, except that a solution was prepared.

[Comparative Example 4] Except that the charge-transporting polymer compound represented by the following formula (HT-3) was used instead of the charge-transporting polymer compound represented by the formula (HT-2) as the hole transport layer material, compared with Comparative Example 3 Make the components in the same way.

[化100]

[Evaluation element] to Example 3, Example 4 and Comparative Example 3, the organic electroluminescent element is energized obtained in Comparative Example 4, and obtains the voltage and external quantum efficiency at 1000 cd / m ² of luminance of light emission ( EQE (%)). The value obtained by subtracting the voltage of Comparative Example 4 from the voltages of Example 3, Example 4, and Comparative Example 3 is described in Table 3 as the relative voltage. The EQEs of Example 3, Example 4, and Comparative Example 3 when the EQE of Comparative Example 4 is set to 1, are described in Table 3 as relative EQE. In addition, as an evaluation of the drive life of the ^{device, the device was continuously energized at a current density of 60 mA/cm 2} and the time until the brightness of the device decreased to 95% of the initial brightness (LT95 (hr)) was measured. The life of LT95 of Example 3, Example 4, and Comparative Example 3 when LT95 is set to 1 is described in Table 3 as a relative life.

According to Table 3, it can be seen that in the organic electroluminescent element of the present invention that includes a compound having the same partial structure A, that is, the structure represented by the formula (TzP), in the hole transport layer and the light-emitting layer, low voltage, Longer life.

[table 3] Partial structure TzP Relative voltage (V) Relative EQE Relative life Hole transport layer Luminescent layer Example 3 Have Have -1.00 1.09 76.6 Example 4 Have Have -0.98 1.04 84.8 Comparative example 3 Have without 0.27 1.01 1.8 Comparative example 4 without without 0.00 1.00 1.0

[Example 5] Weigh 50 parts by weight of the compound represented by the following formula (H-9), 50 parts by weight of the compound represented by the formula (H-6), and 15 parts by weight of the compound represented by the following formula (D-2) as luminescence The material of the layer was dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as the composition for forming a light-emitting layer.

[化101]

[Comparative Example 5] Use the charge-transporting polymer compound represented by the formula (HT-3) instead of the charge-transporting polymer compound represented by the formula (HT-2) as the hole transport layer material; and weigh the formula ( 50 parts by weight of the compound represented by H-9), 50 parts by weight of the compound represented by the formula (H-6), and 15 parts by weight of the compound represented by the following formula (D-3) are used as the material of the light-emitting layer, This was dissolved in cyclohexylbenzene, and a solution with a solid content concentration of 5.0% by weight was prepared as a composition for forming a light-emitting layer, and an element was produced in the same manner as in Example 4, except that the solution was prepared.

[化102]

[Evaluation of the element] The organic electroluminescence element obtained in Example 5 and Comparative Example 5 was energized, and the voltage and external quantum efficiency (EQE (%)) when emitting light with a luminance of ^{1000 cd/m 2 were determined.} The value obtained by subtracting the voltage of Comparative Example 5 from the voltage of Example 5 is described in Table 4 as the relative voltage. The EQE of Example 5 when the EQE of Comparative Example 5 is set to 1 is described in Table 4 as the relative EQE. In addition, as an evaluation of the drive life of the ^{device, the device was continuously energized at a current density of 60 mA/cm 2} and the time until the brightness of the device decreased to 95% of the initial brightness (LT95 (hr)) was measured. The life of the LT95 of Example 5 when the LT95 is set to 1 is described in Table 4 as the relative life.

From Table 4, it can be seen that in the organic electroluminescent device of the present invention that contains a compound having the same partial structure A, that is, the structure represented by the formula (TzP), in the hole transport layer and the light-emitting layer, lower voltage, Longer life.

[Table 4] Partial structure TzP Relative voltage (V) Relative EQE Relative life Hole transport layer Luminescent layer Example 5 Have Have -2.03 1.13 1.26 Comparative example 5 without without 0.00 1.00 1.00

[Example 6] Use the charge-transporting polymer compound represented by the following formula (HT-4) instead of the charge-transporting polymer compound represented by the formula (HT-2) as the hole transport layer material; and weigh the following formula ( 50 parts by weight of the compound represented by H-10), 25 parts by weight of the compound represented by the following formula (H-11), 25 parts by weight of the compound represented by the following formula (H-12), and the following formula (D- 4) 30 parts by weight of the compound shown as a material for the light-emitting layer was dissolved in cyclohexylbenzene to prepare a solution with a solid content concentration of 5.0% by weight as a composition for forming the light-emitting layer, except that it was the same as Example 2 To make components.

[化103]

[Comparative Example 6] Except that the charge-transporting polymer compound represented by the formula (HT-3) was used instead of the charge-transporting polymer compound represented by the formula (HT-4) as the hole transport layer material, the same as in Example 6 Make the components in the same way.

[Evaluation of the element] The organic electroluminescent elements obtained in Example 6 and Comparative Example 6 were energized, and the external quantum efficiency (EQE (%)) when emitting light with a luminance of ^{1000 cd/m 2 was determined.} The EQE of Example 6 when the EQE of Comparative Example 6 is set to 1 is described in Table 5 as the relative EQE. In addition, as an evaluation of the drive life of the ^{device, the device was continuously energized at a current density of 15 mA/cm 2} and the time until the brightness of the device decreased to 90% of the initial brightness (LT90 (hr)) was measured. The life of the LT90 of Example 6 when the LT90 is set to 1 is described in Table 5 as the relative life.

From Table 5, it can be seen that in the organic electroluminescent element of the present invention including the compound having the same partial structure A in the hole transport layer and the light emitting layer, low voltage and long life are achieved.

[table 5] Partial structure A Relative EQE Relative life Hole transport layer Luminescent layer Example 6 Have Have 1.19 1.07 Comparative example 6 without Have 1.00 1.00

The present invention has been described in detail using a specific form, but it is clear to those skilled in the art that various changes can be made without departing from the intent and scope of the present invention. This application is based on Japanese Patent Application 2020-027324 filed on February 20, 2020, and the entire content is incorporated by reference.

1: substrate 2: anode 3: hole injection layer 4: hole transport layer 5: Light-emitting layer 6: Hole barrier layer 7: Electron transport layer 8: Electron injection layer 9: Cathode 10: Organic electroluminescent element

FIG. 1 is a schematic diagram showing a cross-section of a structural example of the organic electroluminescence element of the present invention.

1: substrate

2: anode

3: hole injection layer

4: hole transport layer

5: Light-emitting layer

6: Hole barrier layer

7: Electron transport layer

8: Electron injection layer

9: Cathode

10: Organic electroluminescent element

Claims (19)

An organic electroluminescence element having an anode, a cathode, and an organic layer between the anode and the cathode on a substrate, the organic layer having a hole transport layer and a light emitting layer adjacent to the hole transport layer, and At least one of the materials contained in the hole transport layer and at least one of the materials contained in the light-emitting layer both have the same partial structure A represented by the following formula (31);

In formula (31), ring HA represents a monocyclic or 2-6 condensed ring of an optionally substituted aromatic heterocyclic ring; in formula (31) the benzene ring may have a substituent; Ar ⁰ represents an optionally substituted aromatic A hydrocarbon group, an aromatic heterocyclic group which may have a substituent, or a combination of two or more groups selected from the aromatic hydrocarbon group which may have a substituent and an aromatic heterocyclic group which may have a substituent. A monovalent group; n1 represents 0 or ^{an integer less than the number that Ar 0} can be substituted on the ring HA; when n1 is 2 or more, a plurality of Ar ⁰ may be the same or different. The organic electroluminescent element according to claim 1, wherein at least one of the material having the partial structure A contained in the hole transport layer and the material having the partial structure A contained in the light-emitting layer has Two or more partial structures A. The organic electroluminescent element according to claim 1 or 2, wherein the partial structure A represented by the formula (31) is a structure represented by any one of the following formulas (33) to (35) ；

In formula (33) to formula (35), Ar ⁰ and n1 have the same meaning as in formula (31); the benzene ring in formula (33) to formula (35) may have a substituent; X and Y are each independently It represents a C atom or a N atom; when X and Y are C atoms, Ar ⁰ can be bonded. The organic electroluminescence element according to claim 3, wherein in the partial structure represented by the formula (35), X and Y are N atoms. The organic electroluminescent element according to any one of claims 1 to 4, wherein the material having the partial structure A contained in the hole transport layer is a repeating unit represented by the following formula (1) Of polymer compounds;

In formula (1), A represents a partial structure A; G represents an aromatic hydrocarbon group or N atom ^{that may have a substituent; Ar 2} represents a divalent aromatic hydrocarbon group that may have a substituent, a divalent aromatic heterocyclic group that may have a substituent A cyclic group, or a divalent group formed by connecting two or more groups selected from a divalent aromatic hydrocarbon group that may have a substituent and a divalent aromatic heterocyclic group that may have a substituent, directly or through a linking group. Group; Ar ²⁰ represents a direct bond, a divalent aromatic hydrocarbon group that may have a substituent, or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups that may have a substituent. The organic electroluminescent element according to claim 5, wherein the G is a group composed of any one of a benzene ring which may have a substituent, a pyrene ring which may have a substituent, and a spiro fluorine ring which may have a substituent . The organic electroluminescent element according to claim 5, wherein the G is an N atom. The organic electroluminescent element according to claim 7, wherein the repeating unit represented by the formula (1) is a repeating unit represented by any of the following formulas (2)-1 to (2)-3 ；

In formulas (2)-1 to (2)-3, A has the same meaning as A in the formula (1); Q represents -C(R ⁵ )(R ⁶ )-, -N(R ⁷ ) -Or-C(R ¹¹ )(R ¹² )-C(R ¹³ )(R ¹⁴ )-; R ¹ to R ⁴ each independently represent an optionally substituted alkyl group, an optionally substituted alkoxy group, Or an aralkyl group that may have a substituent; R ⁵ to R ⁷ and R ¹¹ to R ¹⁴ each independently represent an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or an aralkyl group that may have a substituent , Or an aromatic hydrocarbon group that may have a substituent; a and b are each independently an integer of 0 to 4; c1 to c5 are each independently an integer of 0 to 3; wherein at least one of c3 and c5 is 1 or more ; D1 to d4 are each independently an integer of 1 to 4; when there are multiple R ¹ , R ² , R ³ , and R ⁴ in the repeating unit, R ¹ , R ² , R ³ , and R ⁴ may be the same Can be different. The organic electroluminescent element according to any one of claims 5 to 8, wherein -Ar ²⁰ -A in the formula (1) is represented by the following formula (15);

In the formula (15), X and Y each independently represent a C atom or a N atom; the ring having X, Y, and N corresponds to the ring HA in the formula (31); Ar ¹ represents a divalent aromatic which may have a substituent A hydrocarbon group or a divalent group formed by connecting two or more divalent aromatic hydrocarbon groups ^{that may have a substituent; Ar 3} and Ar ⁴ each independently represent an aromatic hydrocarbon group that may have a substituent, or a substituent that may have a substituent An aromatic heterocyclic group, or a monovalent group formed by connecting two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group; wherein, in Ar ^{1. In} at least one of Ar ³ and Ar ⁴ , the structure bonded to the ring HA is a benzene ring; * indicates the bonding site with G. The organic electroluminescent element according to claim 9, wherein -Ar ²⁰ -A in the formula (1) is represented by the following formula (16);

In the formula (16), X, Y, * and sense (15) of the same formula; with X, Y and N ring and formula (15) corresponds to the ring in the same manner HA; Ar ^{1 'represents} a direct bond or structure (15) wherein Ar ¹ and bonded to the ring of formula HA is a residue of a benzene ring; Ar ^{3 ',} Ar ^4' represents a hydrogen atom or, respectively, the formula (15) Ar ^3, Ar ⁴ The structure bonded to the ring HA is the residue of the benzene ring. The organic electroluminescent element according to any one of claim 5 to claim 10, wherein the material having a partial structure A contained in the hole transport layer further has a repeating unit represented by the following formula (3) ；

In formula (3), Ar ¹³ represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group that does not contain the partial structure A; Ar ¹⁴ represents a substituted or unsubstituted divalent aromatic hydrocarbon group, A substituted divalent aromatic heterocyclic group, or two or more groups selected from a divalent aromatic hydrocarbon group which may have a substituent and a divalent aromatic heterocyclic group which may have a substituent, directly or via a connection A divalent group formed by connecting multiple groups. The organic electroluminescent element according to claim 1 to claim 11, wherein the light-emitting layer contains a low-molecular compound having the partial structure A, and the low-molecular compound is the following formula (10) to formula (12) A compound with a molecular weight of 5,000 or less represented by any one of them;

In formulas (10) to (12), A is the partial structure A; B represents a single bond or an arbitrary partial structure; na, nb, and nc represent an integer of 1 to 5; where na, nb, and nc are 2 or more In the case of, multiple A, B, AB may be the same or different. The organic electroluminescent element according to claim 12, wherein the low-molecular compound represented by the formula (10) is represented by the following formula (10A);

In formula (10A), HA represents any one of the trivalent aromatic heterocyclic groups represented by the following structural formulas (10A-a), structural formulas (10A-b), and structural formulas (10A-c); Xa ^1. Ya ¹ and Za ¹ each independently represent an optionally substituted divalent aromatic hydrocarbon group having 6 to 30 carbons, or an optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbons; Xa ² , Ya ² and Za ² each independently represent a hydrogen atom, an optionally substituted aromatic hydrocarbon group with 6 to 30 carbons, or an optionally substituted aromatic heterocyclic group with 3 to 30 carbons; g11, h11, and j11 each independently represents an integer of 0-6; at least one of g11, h11, and j11 is an integer of 1 or more; when g11, h11, and j11 are 2 or more, Xa ¹ , Ya ¹ , and Za ¹ may be the same May be different; R ³¹ represents a hydrogen atom or a substituent; four R ³¹ may be the same or different;

In formulas (10A-a) to (10A-c), * represents the bonding position. The organic electroluminescent element according to claim 13, wherein the low-molecular compound represented by the formula (10) is represented by the following formulas (10A-1) to (10A-3);

In formula (10A-1) to formula (10A-3), Xa ¹ , Ya ¹ , Za ¹ , Xa ² , Ya ² , Za ² have the same meaning as in formula (10); R ³³ represents a hydrogen atom or a substituent ; A plurality of R ³³ may be the same or different; g11', h11', and j11' each independently represent an integer from 0 to 5; when g11', h11', and j11' are 2 or more, a plurality of Xa ¹ , Ya ¹ and Za ¹ may be the same or different. The organic electroluminescent element according to claim 12, wherein the low-molecular compound represented by the formula (10) is represented by the following formula (10B);

In formula (10B), A has the same meaning as in formula (10); Xb ¹ , Yb ¹ and Zb ¹ each independently represent a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms that may have a substituent, or A substituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; p12, q12, and r12 each independently represent an integer of 0 to 6; when p12, q12, and r12 are 2 or more, a plurality of Xb ¹ , Yb ¹ , Zb ¹ may be the same or different; q13 and r13 each independently represent 0 or 1; wherein, q12 and q13 are not 0 at the same time, r12 and r13 are not 0 at the same time; Yb ² and r13 when q13 is 0 ^{When Zb 2} is 0, each independently represents a hydrogen atom, an optionally substituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or an optionally substituted carbon number 3 to 30 aromatic heterocyclic group; when q13 is 1 Yb ^{2 of} is a direct bond; Zb ² when r13 is 1 is a direct bond. The organic electroluminescent element according to claim 15, wherein the low-molecular compound represented by the formula (10) is represented by the following formula (10B-1);

In the formula (10B-1), A, Xb ¹ , Yb ¹ , Zb ¹ , Yb ² , Zb ² , q13, and r13 have the same meaning as in the formula (10B); p12', q12' and r12' are each independent Ground represents an integer from 0 to 5; when p12', q12', and r12' are 2 or more, a plurality of Xb ¹ , Yb ¹ , and Zb ¹ may be the same or different; q15 and r15 are each independently 4 or 5 ; R ³³ is a hydrogen atom or a substituent; a plurality of R ³³ in the formula (10B-1) may be the same or different. The organic electroluminescent element according to claim 12, wherein the low-molecular compound represented by the formula (12) is represented by the following formula (12A);

In formula (12A), ring HA and Ar ⁰ have the same meanings as in formula (31); nc has the same meaning as in formula (12); Xc ¹ and Yc ¹ each independently represent optionally substituted A divalent aromatic hydrocarbon group having 6 to 30 carbons, or an optionally substituted divalent aromatic heterocyclic group having 3 to 30 carbons; Xc ² and Yc ² each independently represent a hydrogen atom and an optionally substituted carbon An aromatic hydrocarbon group having 6 to 30, or an optionally substituted aromatic heterocyclic group having 3 to 30 carbons; s11 and t11 each independently represent an integer of 0 to 6; when s11 and t11 are 2 or more , A plurality of Xc ¹ and Yc ¹ may be the same or different; R ³¹ represents a hydrogen atom or a substituent; u11 is the substitutable ^{number of the substituent R 31} ; u12 is the substitutable number of the substituent Ar ⁰ ; in u11, it is 2 or more In the case of, multiple R ³¹ may be the same or different. An organic electroluminescence display device comprising the organic electroluminescence element according to any one of claim 1 to claim 17. An organic electroluminescence lighting, comprising the organic electroluminescence element according to any one of claim 1 to claim 17.

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