Encapsulated Nanoparticle Ink for Abrasion-Resistant Printing

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Solution Overview

Problem

Existing inks containing luminescent nanoparticles for display devices face issues with abrasion of printing elements due to the hardness and chemical aggressiveness of the particles, leading to premature wear and reduced lifetime of printing components, and existing encapsulation methods fail to provide long-term stability and preserve photoluminescence properties.

Innovation Solution

Development of an ink with nanoparticles encapsulated in a protective material that prevents mechanical and chemical abrasion, using a dual encapsulation method to maintain the properties of luminescent nanoparticles while ensuring compatibility with the liquid vehicle, thereby enhancing stability and photoluminescence quantum yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If luminescent nanoparticles are used in inkjet printing, then display device performance is improved, but printing elements suffer from mechanical and chemical abrasion leading to premature wear

Engineering Contradiction:
Improvedisplay device performanceVSAvoidprinting elements lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent introduces an encapsulation shell as an intermediary layer between the luminescent nanoparticles and the printing elements. This shell acts as a protective mediator that prevents direct contact and interaction between the abrasive nanoparticles and the printhead nozzles, thereby reducing mechanical and chemical abrasion while allowing the inkjet printing process to continue using the luminescent particles for display device fabrication

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs thin film encapsulation structures around the luminescent nanoparticles. These flexible thin films provide a protective barrier that is sufficiently thin to maintain particle functionality and inkjet printability while thick enough to prevent direct abrasion of printing elements, resolving the contradiction between maintaining particle performance and protecting printing components

Inventive Principle:
Principle #30Flexible shells and thin films

2Duration of action of stationary object

If particles are encapsulated in protective material, then abrasion of printing elements is reduced, but particle properties may be compromised

Engineering Contradiction:
Improveprinting elements lifetimeVSAvoidparticle properties
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The encapsulation structure is designed with local quality variations - the shell material and thickness are optimized specifically for the interface with printing elements to minimize abrasion, while the core luminescent nanoparticle maintains its original properties. The encapsulation provides localized protection without uniformly compromising particle functionality throughout

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies physical parameters of the encapsulation system, such as shell thickness, material composition, and surface properties, to achieve optimal balance. By carefully controlling these parameters, the encapsulation provides sufficient protection against abrasion while maintaining the luminescent properties and size characteristics necessary for display device application

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If existing encapsulation methods are used, then some protection is provided, but long-term stability and photoluminescence properties are not maintained

Engineering Contradiction:
Improveprotection from environmentVSAvoidphotoluminescence stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent employs composite material structures combining the luminescent nanoparticle core with a specifically designed encapsulation shell material. This composite structure provides both environmental protection and maintains photoluminescence stability by selecting materials that are chemically compatible and physically protective, preventing degradation while preserving optical properties

Inventive Principle:
Principle #40Composite materials

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 encapsulated nanoparticles exhibit improved resistance to environmental factors and photobleaching, maintaining photoluminescence properties and extending the lifetime of printing elements, while being compatible with ROHS requirements.

Implementation Method 1

the first material limits or prevents the diffusion of outer molecular species or fluids (liquid or gas) into said first material

Methodology Applied
Scientific EffectDiffusion barrier: Diffusion Barrier

Implementation Method 2

luminescent inorganic particles, especially semiconductor nanoparticles known as emissive material, are currently used in display devices as phosphors

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentEP3630920B1Ink comprising encapsulated nanoparticles
Publication Date: 2022.12.07 NEXDOT
  • EP3630920B1 patent drawingFigure 1~2
  • EP3630920B1 patent drawingFigure 3~4
  • EP3630920B1 patent drawingFigure 5

AI summary

The present invention relates to an ink comprising at least one particle (1) comprising a first material (11); and at least one liquid vehicle; wherein the particle (1) comprises at least one particle (2) comprising a second material (21) and at least one nanoparticle (3) dispersed in said second material (21); wherein the first material (11) and the second material (21) have an extinction coefficient less or equal to 15x10-5 at 460 nm. The invention also relates to inks, light emitting materials comprising at least one ink, patterns comprising at least one ink, particles deposited on a support, optoelectronic devices comprising at least one ink and method for depositing an ink on a support.