Conductive Composite Composition Phase Separation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electrically conductive composites for stretchable electronic devices have insufficient electrical properties, such as low conductivity and high contact resistance, when using a small amount of electrically conductive filler, which compromises mechanical properties like stretchability.

Innovation Solution

A composition comprising 37-84% epoxy, 0.001-22% electrically conductive filler, and 15-45% thermoplastic resin, where the thermoplastic resin is miscible with epoxy and forms a phase-separated domain upon heat curing, enhancing electrical conductivity without compromising mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a small amount of electrically conductive filler is used, then mechanical properties (stretchability) are maintained, but electrical properties (conductivity, contact resistance) are insufficient

Engineering Contradiction:

Improvemechanical propertiesVSAvoidelectrical properties

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent uses a composite system comprising epoxy resin, thermoplastic resin, and electrically conductive filler. The thermoplastic resin forms a continuous phase that connects conductive filler particles, creating effective electrical pathways even at low filler concentrations (0.001-22 wt%). This composite structure allows maintaining mechanical stretchability while achieving sufficient electrical conductivity through the synergistic interaction of components.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the physical state parameter of the thermoplastic resin (liquid at 25°C) and its phase behavior upon curing. The thermoplastic resin transitions from a liquid state during mixing to a phase-separated domain structure upon heat curing, which reorganizes the conductive filler distribution and creates conductive networks. This parameter change enables effective electrical pathways without increasing filler content.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the amount of electrically conductive filler is increased to improve electrical conductivity, then electrical properties improve, but mechanical properties (stretchability) deteriorate

Engineering Contradiction:

Improveelectrical conductivityVSAvoidstretchability

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The thermoplastic resin acts as an intermediary substance between the epoxy matrix and the electrically conductive filler. It mediates the interaction by forming a continuous phase that envelops and connects conductive filler particles, enabling electrical conductivity without requiring high filler concentrations that would compromise the mechanical flexibility and stretchability of the composite.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If thermoplastic resin forms phase-separated domains, then electrical conductivity is enhanced, but manufacturing precision may be affected

Engineering Contradiction:

Improveelectrical conductivityVSAvoidphase separation control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent utilizes the phase transition behavior of the thermoplastic resin upon heat curing. The resin transitions from a liquid state (miscible with epoxy) to a phase-separated domain structure during curing, which automatically organizes the conductive filler into effective networks. This self-organizing phase transition reduces the need for precise manufacturing control while enhancing electrical conductivity.

Inventive Principle:

Principle #36Phase transitions

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 achieves improved electrical conductivity and mechanical properties, allowing for the creation of stretchable, deformable, and foldable electrically conductive composites suitable for complex electronic device shapes with reduced filler content.

Implementation Method 1

the thermoplastic resin is miscible with the epoxy and forms a domain upon heat curing that is phase-separated from the epoxy and the electrically conductive inorganic filler

Methodology Applied

Scientific EffectPhase separation: Phase Change

Data Source

PatentUS10115496B2Compositions for preparing electrically conductive composites, composites prepared therefrom, and electronic devices including the same

Publication Date: 2018.10.30 SAMSUNG ELECTRONICS CO LTD

AI summary

A composition for preparing an electrically conductive composite includes, based on the total weight of the composition:about 37 weight percent to about 84 weight percent of an epoxy;about 0.001 weight percent to about 22 weight percent of an electrically conductive filler; andabout 15 weight percent to about 45 weight percent of a thermoplastic resin, wherein the thermoplastic resin is a liquid at about 25° C., is miscible with the epoxy, and forms a domain upon heat curing that is phase-separated from the epoxy and the electrically conductive inorganic filler. Also composites prepared therefrom and an electronic device including the same.