Interlayer Composition for Non-Polar Metal Nanoparticle Ink Adhesion

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Solution Overview

Problem

Existing metal nanoparticle inks, particularly non-polar silver nanoparticle inks, face issues with adhesion and mechanical robustness on substrates like glass and flexible plastics, leading to reduced print quality and conductivity, while current solutions compromise electrical conductivity for improved adhesion.

Innovation Solution

An interlayer composition comprising epoxy, polyvinyl phenol, a cross-linking agent, and epoxy silane, which provides film forming capability, adhesion to various substrates, and non-polar solvent-based ink wettability, enhancing print quality and conductivity without affecting the electrical properties of the nanoparticle inks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If non-polar metal nanoparticle inks are used, then ease of manufacture and cost are improved, but adhesion and print quality deteriorate

Engineering Contradiction:
Improveease of manufactureVSAvoidprint quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces a surfactant as an intermediary substance between the non-polar metal nanoparticle ink and the substrate. The surfactant contains both polar and non-polar regions, allowing it to interact with both the non-polar ink and polar substrates, thereby improving adhesion without requiring changes to the ink formulation or substrate surface treatment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses composite material structures, specifically combining surfactant molecules with amphiphilic properties (having both hydrophilic and hydrophobic regions) with the non-polar ink and substrate system. This composite approach allows the surfactant to bridge the interface between incompatible materials, improving adhesion while maintaining the benefits of non-polar inks.

Inventive Principle:
Principle #40Composite materials

2Strength

If adhesion promoters are added to improve adhesion, then adhesion strength is improved, but electrical conductivity deteriorates

Engineering Contradiction:
ImproveadhesionVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies local quality by using surfactants that concentrate at the interface between the ink and substrate, providing adhesion promotion only where needed (at the interface) while leaving the bulk ink properties unchanged. This localized action allows adhesion improvement without affecting the electrical conductivity of the conductive features.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The surfactant acts as an intermediary that provides adhesion at the interface without becoming part of the conductive path. By positioning the surfactant at the ink-substrate interface rather than mixing it throughout the ink, the patent achieves adhesion improvement while maintaining the electrical conductivity of the metal nanoparticle network.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 interlayer composition significantly improves adhesion and print quality of non-polar metal nanoparticle inks on diverse substrates, maintaining high conductivity and flexibility, suitable for electronic device applications without requiring additional surface treatments.

Implementation Method 1

an epoxy silane

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

a cross-linking agent

Methodology Applied
Scientific EffectCross-linking: Chemical Bonding

Data Source

PatentEP3231607B1Interlayer composition and devices made therefrom
Publication Date: 2021.08.11 XEROX CORP
  • EP3231607B1 patent drawingFigure 1
  • EP3231607B1 patent drawingFigure 2A~2B
  • EP3231607B1 patent drawingFigure 3A~3B

AI summary

A composition formed from ingredients comprising: an epoxy; a polyvinyl phenol; a cross-linking agent; an epoxy silane; and a solvent is disclosed. A printable medium and other devices made from the composition are also disclosed.