JP-7856970-B2 - compound

Inventors

• 長谷川 司
• 飯田 宏一朗
• 岡部 一毅
• 五郎丸 英貴
• 中村 正治
• 松田 博
• アベナ ラモン フランシスコ ベルナルディノ
• ソン ウンチョル
• 松浦 良介

Assignees

• 三菱ケミカル株式会社
• 国立大学法人京都大学
• 株式会社TSK

Dates

Publication Date

20260512

Application Date

20220329

Claims (1)

1. An aromatic compound represented by the following formula (A) . (In the above formula (A) , A1 to A5 are each independently represented by a hydrogen atom or by the following formula (2). However, at least four of A1 to A5 are represented by the following formula (2). (In equation (2), the asterisk (*) indicates a combination with equation (A) above , R 11 represents a hydrogen atom or an alkyl group.

Description

This invention relates to compounds that can be used in organic electroluminescent devices (hereinafter sometimes referred to as "OLEDs" or "devices"). In recent years, the development of organic electroluminescent devices using organic thin films has shifted from inorganic materials to organic electroluminescent devices. Organic electroluminescent devices (OLEDs) typically have a charge injection layer, charge transport layer, organic light-emitting layer, and electron transport layer between the anode and cathode. Materials suitable for each of these layers are being developed, and progress is also being made in developing red, green, and blue emission colors. While the common method for manufacturing organic electroluminescent devices involves depositing organic materials using vacuum deposition and then stacking them, research into wet deposition methods—where organic materials in solution are deposited using inkjet technology and then stacked—has become increasingly popular in recent years as a more material-efficient manufacturing method. To form an organic electroluminescent element by laminating multiple layers using wet deposition, the coated thin film must be insoluble in the composition applied to the upper layer. Generally, the most stable method involves incorporating crosslinking groups or polymerizable functional groups into the composition applied to the lower layer, and then creating bonds and making it insoluble through post-coating processing. Patent Document 1 discloses specific asymmetric bis(1,2-diarylamino)benzenes having suitable HOMO-LUMO levels and particularly favorable Eg (energy gap) values for use as organic electroluminescent material, such as hole transport materials. When the diamine derivative disclosed in Patent Document 1 is used in the hole injection layer or hole transport layer, its solvent resistance is insufficient. International Publication No. 2021/201287 Figure 1 is a schematic cross-sectional view showing an example of the structure of the organic electroluminescent element of the present invention. The embodiments of the present invention will be described in detail below, but the present invention is not limited to the embodiments described below and can be implemented in various ways within the scope of its gist. In this invention, "may have substituents" means that it may have one or more substituents. <Aromatic compounds represented by formula (1)> The compound of the present invention is represented by the following formula (1). (In formula (1), R1 to R5 are each independently a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, which may have substituents. n1 to n4 are each independent integers from 0 to 5. n5 is an integer between 0 and 4. a1 to a5 are each independently either 0 or 1. A1 to A5 are each independently represented by a hydrogen atom or by the following formula (2). However, at least one of A1 to A5 is represented by formula (2). (In equation (2), the asterisk (*) indicates a combination with equation (1), R 11 represents a hydrogen atom or an alkyl group. Furthermore, the statement "In formula (2), the asterisk (*) represents a bond with formula (1)" means, in more detail, that when A1 is represented by formula (2), if a1 is 0, the asterisk (*) represents a bond with the benzene ring connected to R1 in formula (1), and if a1 is not 0, the asterisk (*) represents a bond with R1 . When A2 to A5 are represented by formula (2), a1 and R1 for A1 can be replaced with a2 to a5 and R2 to R5 , respectively, and interpreted similarly. The compounds of the present invention function as charge transport materials. That is, because the compounds of the present invention have a diamine structure, they can be made to function as hole transport materials. Therefore, the compound of the present invention is preferably a charge transport compound and is preferably used as a hole injection layer material or hole transport layer material in an organic field light-emitting device. In formula (1) above, the substituents that may be present in the divalent aromatic hydrocarbon groups having 6 to 60 carbon atoms in R1 to R5 are preferably selected from the substituent group Z described below. The above formula (1) is preferably represented by one of the following formulas (2) to (5). <R 1 to R 5 > In formula (1) above, R1 to R5 each independently represent a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms, which may have substituents. Examples of divalent aromatic hydrocarbon groups with 6 to 60 carbon atoms include the divalent groups of benzene, naphthalene, anthracene, phenanthrene, tetraphenylene, chrysene, pyrene, benzoanthracene, perylene, biphenyl, or terphenyl rings. From the viewpoint of the solubility and durability of the compound, R1 to R5 are each preferably independently a divalent group of a benzene ring and a divalent group of a naphthalene ring, more preferably a divalent group of a benzene ring, and even more prefera