Low Refractive Index Coating for Display Sharpness

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current antireflection coatings for display devices face challenges in achieving high alkali resistance and scratch resistance while maintaining low reflectance and high light transmittance, often compromising on mechanical properties and surface sharpness.

Innovation Solution

A photocurable coating composition comprising a photopolymerizable compound, inorganic hollow silica particles, polysilsesquioxane with reactive functional groups, and a fluorine-based compound with photoreactive functional groups, which forms a low refractive index layer that enhances alkali resistance, scratch resistance, and mechanical properties when cured.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a multi-layer structure with hard coating layer and low reflection coating layer is formed, then light reflection is reduced, but interlayer adhesion becomes weak and scratch resistance lowers

Engineering Contradiction:

Improvelight reflectionVSAvoidscratch resistance

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent combines the hard coating layer and low reflection coating layer into a single integrated layer that simultaneously provides both hardness/scratch resistance and low light reflection properties, eliminating the interlayer adhesion problem of multi-layer structures

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a composite material containing inorganic fine particles (for hardness and scratch resistance) and fluorine-containing polymer (for low light reflection) dispersed in a photocurable resin, achieving both functions in a single layer

Inventive Principle:

Principle #40Composite materials

2Strength

If inorganic filler is added to enhance scratch resistance, then scratch resistance improves, but alkali resistance is greatly lowered

Engineering Contradiction:

Improvescratch resistanceVSAvoidalkali resistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent changes the type and surface treatment of inorganic fillers, using specifically treated particles that maintain scratch resistance while improving alkali resistance through surface modification and optimal particle selection

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies different surface treatments to different regions or aspects of the inorganic filler particles, creating local variations in properties that simultaneously provide scratch resistance and alkali resistance in different locations within the coating

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If AG coating with inorganic fine particles is applied, then light scattering is achieved, but surface sharpness deteriorates due to surface irregularities

Engineering Contradiction:

Improvelight reflectionVSAvoidsurface sharpness

Core Design Contradiction:

Object-affected harmful factorsVSShape

Solution Approach 1:

The patent creates local irregularities only at the microscopic level for light scattering, while maintaining overall surface smoothness and sharpness through controlled particle distribution and size selection

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses inorganic fine particles with controlled porosity and surface structure that provide light scattering effects while maintaining surface smoothness, creating a hierarchical structure with pores at the nanoscale but smooth appearance at the macroscale

Inventive Principle:

Principle #31Porous 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 solution provides a low refractive index layer with improved alkali resistance, scratch resistance, and mechanical properties, allowing for enhanced screen sharpness and simplified production processes, reducing the need for additional protective films and lowering production costs.

Implementation Method 1

a photopolymerizable compound, wherein the photopolymerizable compound is a monomer containing one or more (meth)acrylate or vinyl groups

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a fluorine-based compound containing a photoreactive functional group

Methodology Applied

Scientific EffectPhotoreactive functional group absorption: Absorption (EM radiation)

Data Source

PatentEP3243884B1Radiation curable coating composition, low-refractive-index layer, and antireflective film

Publication Date: 2020.10.28 LG CHEM LTD

AI summary

The present invention relates to a photocurable coating composition for forming a low refractive index layer, including: a photopolymerizable compound; inorganic fine particles; a polysilsesquioxane substituted with one or more reactive functional groups; a fluorine-based compound containing a photoreactive functional group; and a photopolymerization initiator, wherein the polysilsesquioxane substituted with one or more reactive functional groups is contained in an amount of 0.5 to 25 parts by weight based on 100 parts by weight of the photopolymerizable compound, a low refractive index layer including a photo-cured product of the photocurable coating composition, and an antireflection film including the low refractive index layer.