Organic EL Ink Composition Stabilizing Surface Tension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing organic electroluminescent element production methods face challenges with the stability of liquid physical properties, particularly surface tension stability, which affects the emission efficiency and driving lifetime, especially when using solvents like alkylated naphthalene or diphenyl alkane and phenol derivatives in wet-process film formation.
Innovation Solution
A composition combining alkylated naphthalene or diphenyl alkane as a solvent with an aromatic ether and/or aromatic ester, along with a phenol derivative, is used to stabilize the ink's liquid physical properties, preventing deterioration and maintaining uniformity over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If alkylated naphthalene or diphenyl alkane is used as an organic solvent to dissolve functional material, then solubility and emission efficiency are improved, but stability of liquid physical properties (surface tension) deteriorates over time
Solution Approach 1:
The patent combines alkylated naphthalene or diphenyl alkane with aromatic ether or aromatic ester to create a composite solvent system. This composite approach allows the first solvent to provide high solubility and emission efficiency while the second solvent stabilizes the liquid physical properties and surface tension over time, resolving the contradiction between reliability and compositional stability.
Solution Approach 2:
The patent modifies the solvent system by introducing a second solvent component that specifically addresses the instability of surface tension. This parameter change in the solvent composition enables the maintenance of stable liquid physical properties while preserving the high emission efficiency provided by the first solvent.
2Reliability
If phenol derivative is added to prevent deterioration, then emission efficiency and driving lifetime are maintained, but complexity of ink composition increases
Solution Approach 1:
The second solvent (aromatic ether or aromatic ester) serves multiple functions: it stabilizes the surface tension, maintains the uniform state of the ink, and contributes to preventing material deterioration. This multi-functionality reduces the need for additional components like phenol derivatives, thereby maintaining reliability while limiting complexity increase.
3Productivity
If wet-process film formation method is used, then productivity is improved, but uniformity of film formation deteriorates due to precipitation
Solution Approach 1:
The composite solvent system maintains the functional material in a stable, uniform dissolved state over extended periods. This prevents precipitation during storage and application, enabling consistent film formation through wet-process methods while maintaining high productivity. The stable uniformity allows for reliable inkjet printing and other wet-forming techniques.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition ensures stable surface tension and reduced changes in liquid physical properties, enabling efficient large-area coating and prolonged storage without significant decreases in emission efficiency or driving lifetime.
Implementation Method 1
the composition for an organic electroluminescent element has favorable stability of liquid physical properties, in particular, favorable surface tension stability of the ink
Implementation Method 2
an attempt to contain a phenol derivative in the ink has been made for the purpose of preventing a decrease in emission efficiency and driving lifetime
Implementation Method 3
The organic solvent used in the ink is required to have solubility in two ways of rapidly dissolving the functional material, and maintaining a uniform state without precipitating the functional material after the dissolution
Data Source
AI summary
An object of the present invention is to provide a composition for an organic electroluminescent element, which is used for forming an emission layer in an organic electroluminescent element by wet-process film formation, and which has favorable stability of liquid physical properties, in particular, favorable surface tension stability of ink. The present invention relates to a composition for an organic electroluminescent element including a functional material, a specific compound, alkylated naphthalene or diphenyl alkane as a first solvent, and at least one of an aromatic ether and an aromatic ester as a second solvent.