Transparent Conductive Laminate Phase Separation Durability

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Solution Overview

Problem

Touch panels with transparent conductive laminates containing fine particles suffer from issues like Newton rings, reduced visibility, and degradation of electric properties due to particle projections, which affect sliding and edge-writing durability and lead to flicker and haze problems.

Innovation Solution

A transparent conductive laminate with concavoconvex shapes formed by phase separation of two components in a cured resin layer without fine particles, ensuring improved durability and reduced flicker, using a polymer film, a cured resin layer with specific roughness, and a crystalline transparent conductive layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a coating layer containing fine particles (1-15 μm) is formed to reduce Newton rings, then Newton ring visibility is improved, but display visibility is degraded due to lens effects and color separation

Engineering Contradiction:
ImproveNewton ring visibilityVSAvoiddisplay visibility
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The invention extracts and removes the fine particles (1-15 μm) from the coating layer that cause lens effects and color separation, while retaining the concavoconvex shape structure that prevents Newton rings. This is achieved by forming the concavoconvex shapes through phase separation of two resin components instead of using particle-based structures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the fundamental parameter of how concavoconvex shapes are formed - from particle-based structures to phase-separated resin structures. By controlling the phase separation of two resin components with different solubility parameters, the invention creates the desired surface topology without the harmful optical effects of fine particles.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If fine particles are added to form concavoconvex shapes for preventing Newton rings, then Newton ring development is reduced, but sliding durability and edge-writing durability deteriorate due to transparent conductive layer peeling

Engineering Contradiction:
ImproveNewton ring developmentVSAvoidsliding durability and edge-writing durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention extracts and eliminates the fine particles from the coating layer, replacing them with a particle-free phase-separated resin structure. This removes the projection points that cause transparent conductive layer peeling during sliding and edge-writing operations, thereby improving durability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses a composite resin system with two components having different solubility parameters that phase separate to form the concavoconvex structure. This composite approach creates a unified particle-free matrix that maintains structural integrity and prevents conductive layer degradation.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If fine particles are incorporated into the resin to create matting effect, then flicker is controlled, but display visibility is degraded due to increased haze

Engineering Contradiction:
ImproveflickerVSAvoiddisplay visibility
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The invention removes fine particles from the system entirely, replacing the particle-based matting mechanism with a phase-separated resin structure. This eliminates the haze caused by light scattering from particles while maintaining the concavoconvex surface topology that controls flicker.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention fundamentally changes the mechanism for creating surface topology from particle incorporation to phase separation of resin components. By controlling the phase separation parameters (solubility differences, concentration ratios, curing conditions), the invention achieves matting and flicker control without the optical degradation caused by fine particles.

Inventive Principle:
Principle #35Parameter changes

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 solution enhances sliding and edge-writing durability, reduces flicker and haze, and maintains the visibility of displays by eliminating particle-related issues, while maintaining the electric properties of the touch panel.

Implementation Method 1

cured resin layer having concavoconvex shapes formed by phase separation of two components

Methodology Applied
Scientific EffectPhase separation:

Data Source

PatentEP2211355B1Transparent conductive laminate and touch panel
Publication Date: 2017.04.26 TEIJIN LTD
  • EP2211355B1 patent drawingFigure 1~2
  • EP2211355B1 patent drawingFigure 3~4
  • EP2211355B1 patent drawing

AI summary

This invention aims to provide a transparent conductive laminate excellent in sliding durability, edge-writing durability, finger writing durability and light resistance and suitable as a movable electrode substrate for a touch panel. Further, it aims to provide a touch panel using the above transparent conductive laminate. This invention is a transparent conductive laminate that is a laminate formed by laminating a polymer film, a cured resin layer-1 and a transparent conductive layer in this order, the cured resin layer-1 having concavoconvex shapes formed by phase separation of two components and containing no fine particles that impart concavoconvex shapes, and the cured resin layer-1 having an arithmetic average roughness (Ra), measured according to JIS B0601-1994, of 0.05 µm or more but less than 0.5 µm and a ten-point average roughness (Rz), measured according to JIS B0601-1982, of 0.5 µm or more but less than 2.0 µm, and a touch panel using the transparent conductive laminate.