Soluble Pyrimidine Charge Transport Material for Wet-Processed OLEDs

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Solution Overview

Problem

Conventional organic electroluminescent materials have low solubility in organic solvents and poor storage stability, making it difficult to produce high-performance organic electroluminescent elements using a wet film formation method.

Innovation Solution

Introducing specific substituents into the pyrimidine and 1,3,5-triazine frameworks to enhance solubility and stability, resulting in an organic compound with improved solubility in solvents and a composition that forms thin films with high luminescent efficiency and long life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional organic electroluminescent materials are used, then the materials have good electron-accepting properties and high electron mobility, but the materials have low solubility in organic solvents and poor storage stability

Engineering Contradiction:
Improveelectron-accepting properties and electron mobilityVSAvoidsolubility and storage stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent modifies the molecular structure of pyrimidine and 1,3,5-triazine derivatives by changing parameters such as substituent types (introducing bulky groups like adamantyl, tert-butyl, or silyl groups), molecular weight (750-2000), and structural configuration to achieve optimal balance between solubility and charge transport properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates composite molecular structures combining rigid aromatic heterocyclic cores (pyrimidine or 1,3,5-triazine) with flexible aromatic hydrocarbon substituents and bulky groups, resulting in materials that exhibit both high solubility and excellent charge transport characteristics

Inventive Principle:
Principle #40Composite materials

2Productivity

If a wet film formation method is used to produce organic electroluminescent elements, then large-area production is enabled and space saving is achieved, but the method requires materials with high solubility and composition stability which conventional materials lack

Engineering Contradiction:
Improvelarge-area production capabilityVSAvoidmaterial solubility and composition stability requirements
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent optimizes molecular parameters including molecular weight (750-2000), substituent types (adamantyl, tert-butyl, silyl groups), and structural configuration to achieve solubility sufficient for wet film formation while maintaining composition stability for efficient production

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces specific substituent groups (aromatic hydrocarbon groups, bulky groups) as intermediaries that mediate between the solubility requirement for wet processing and the stability requirement for efficient manufacturing, enabling both large-area production and material stability

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If pyrimidine derivatives or 1,3,5-triazine derivatives are used as charge-transporting materials, then high electron-accepting properties and high electron mobility are achieved, but the materials have low solubility making wet film formation difficult

Engineering Contradiction:
Improveelectron mobilityVSAvoidsolubility for wet film formation
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality modification by introducing specific functional groups (aromatic hydrocarbon groups, bulky groups) at specific positions (A, B, C) on the pyrimidine or 1,3,5-triazine core, creating local regions that enhance solubility without compromising the overall electron mobility of the charge transport material

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes molecular parameters by introducing substituents with specific properties (aromatic hydrocarbon groups, bulky groups like adamantyl and silyl groups) to enhance solubility while maintaining the electron mobility characteristics of the parent pyrimidine or 1,3,5-triazine structure

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2695882B1Organic compound, charge transport material, composition containing said compound, organic electroluminescent element, display device, and lighting device
Publication Date: 2017.03.01 MITSUBISHI CHEM CORP
  • EP2695882B1 patent drawingFigure 1

AI summary

The invention provides an organic compound incorporating a specific structure into a pyridine skeleton or a 1,3,5-triazine skeleton and adapting the molecular weight to a specific range, a composition comprising the organic compound and a solvent, organic electroluminescent element comprising a layer that is formed by using the composition, and the uses thereof.