Phase Change Ink Composition for Conductive Patterns

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Solution Overview

Problem

Existing phase change inks with high melting temperatures require specialized inkjet heads and are not compatible with polar additives, leading to stability issues and environmental concerns due to the use of nonpolar solvents and complex processing steps in optical patterning methods.

Innovation Solution

A phase change ink composition with a melting temperature ranging from 60° C. to 90° C., comprising metal nanoparticles, a dispersing agent, and a solvent mixture of sulfur-containing compounds, allowing for the use of typical inkjet heads and incorporating polar additives, which maintains stability and reduces environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the melting temperature of phase change ink is increased to exceed 90°C, then the ink can be used with high-temperature inkjet heads, but the inkjet head temperature exceeds the 90°C allowance of most typical inkjet heads, limiting compatibility

Engineering Contradiction:
Improvemelting temperature of ink compositionVSAvoidcompatibility with inkjet head types
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent changes the melting temperature parameter of the phase change ink from exceeding 90°C to 60-90°C by modifying the wax component composition and ratio, enabling compatibility with typical inkjet heads while maintaining phase change functionality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates an ink composition that can be universally used with both typical inkjet heads (60-90°C) and specially designed high-temperature inkjet heads (>90°C), achieving multi-functionality across different inkjet head types

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If polar additives are added to phase change ink containing nonpolar wax components, then the ink can be used with typical inkjet heads, but the polar additive may not be well mixed, causing phase separation

Engineering Contradiction:
Improvecompatibility with polar additivesVSAvoidmixing stability of ink composition
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent introduces a polar solvent as an intermediary substance that bridges the nonpolar wax components and polar additives, enabling them to mix uniformly without phase separation while maintaining the ink's phase change properties

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite solvent system containing both polar and nonpolar components, allowing the ink to accommodate both polar additives and nonpolar wax while maintaining homogeneous mixing and stability

Inventive Principle:
Principle #40Composite materials

3Reliability

If metal nanoparticles are used as conductive material in ink, then conductive patterns can be formed, but the metal nanoparticles may be precipitated due to higher specific gravity than organic solvent, deteriorating storage stability

Engineering Contradiction:
Improveconductive pattern formation capabilityVSAvoidstorage stability of ink composition
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the physical state parameter of the ink from liquid to solid at room temperature using phase change materials, which eliminates metal nanoparticle precipitation by stopping their movement and settling

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition of the ink composition between solid state (at room temperature for stable storage) and liquid state (at jetting temperature for nanoparticle dispersion and printing), resolving the contradiction between nanoparticle stability and printability

Inventive Principle:
Principle #36Phase transitions

4Stability of the object's composition

If the viscosity of ink is increased to reduce settling speed of metal nanoparticles, then storage stability improves, but the inkjet head jetting capability may be affected

Engineering Contradiction:
Improvestorage stabilityVSAvoidjetting performance
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent makes the ink viscosity dynamic by utilizing phase change: the ink maintains high viscosity in solid state at room temperature for stability, and transitions to low viscosity in liquid state at jetting temperature for easy dispensing and jetting

Inventive Principle:
Principle #15Dynamics

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 phase change ink composition enables the formation of conductive patterns with improved stability, reduced settling of metal nanoparticles, and environmental friendliness, while allowing the use of standard inkjet heads and polar additives, thus enhancing storage stability and process efficiency.

Implementation Method 1

the phase change ink composition has a melting temperature ranging from 60° C. to 90° C.

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

an ink composition having a solid state at room temperature but a liquid state in a temperature rise range allowed by an inkjet device

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

the specific gravity of a metal is higher than an organic solvent, so that the metal nanoparticles may be precipitated

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 4

studies into an ink composition having a solid state at room temperature but a liquid state in a temperature rise range allowed by an inkjet device

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentUS8871014B2Phase change ink compositions and conductive patterns formed therefrom
Publication Date: 2014.10.28 LG CHEM LTD

AI summary

A phase change ink composition includes metal nanoparticles, a dispersing agent allowing the metal nanoparticles to be stably dispersed and arranged within the phase change ink composition, and a solvent in which the metal nanoparticles and the dispersing agent are mixed and which comprises at least two sulfur-containing compounds, wherein the phase change ink composition has a melting temperature ranging from 60° C. to 90° C.