Antireflective Coating Structure for Low Reflectance and Scratch Resistance
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Solution Overview
Problem
Antireflective members with resin layers lack sufficient scratch resistance, making them less versatile for applications like touch panels where they are frequently touched by hands, despite achieving low reflectance through the use of hollow particles.
Innovation Solution
An antireflective member with a low refractive index layer containing a binder resin and hollow particles, where the spatial frequency analysis of the surface elevation meets specific power spectrum intensity criteria, promoting aggregation of hollow particles to enhance scratch resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If hollow particles are used in the low refractive index layer to achieve low reflectance, then reflectance is reduced, but scratch resistance deteriorates
Solution Approach 1:
The patent applies local quality by creating distinct regions within the low refractive index layer: hollow particles are concentrated at both the top surface and bottom interface to maximize light scattering and reduce reflectance, while the middle region contains primarily binder resin to provide mechanical strength and scratch resistance. This spatial differentiation of particle distribution resolves the contradiction between optical performance and mechanical durability.
Solution Approach 2:
The patent uses composite materials by combining hollow particles, binder resin, and optionally solid particles in a multi-phase low refractive index layer. The hollow particles provide low refractive index for antireflection, the binder resin provides mechanical cohesion and scratch resistance, and solid particles can enhance surface hardness. This composite structure allows simultaneous achievement of low reflectance and high scratch resistance.
2Ease of manufacture
If resin layer is used instead of inorganic thin film, then cost is reduced and chemical stability is improved, but mechanical properties such as scratch resistance deteriorate
Solution Approach 1:
The patent creates a composite resin layer containing hollow particles, binder resin, and solid particles. The hollow particles provide the low refractive index needed for antireflection while keeping the layer thin and cost-effective. The solid particles (such as silica) dispersed in the resin matrix enhance surface hardness and scratch resistance. This composite approach maintains the cost and chemical stability advantages of resin layers while overcoming their inherent mechanical weakness.
Solution Approach 2:
The patent changes the physical and chemical parameters of the resin layer by controlling the refractive index, particle size distribution, particle concentration, and curing characteristics. By optimizing these parameters, the resin layer achieves both low reflectance (through appropriate refractive index and thickness) and high scratch resistance (through crosslinked network structure and dispersed hard particles), making it a viable alternative to expensive inorganic thin films.
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 method improves scratch resistance by ensuring a significant proportion of hollow particles are covered by the binder resin, reducing exposure and enhancing mechanical durability.
Implementation Method 1
an antireflective member having a resin layer... has a low refractive index layer containing hollow inorganic nanoparticles such as silica and solid inorganic nanoparticles
Implementation Method 2
the low refractive index layer comprises a binder resin and hollow particles... ensuring the hollow particles are effectively covered by the binder resin
Data Source
AI summary
Provided is an antireflective member capable of improving scratch resistance. An antireflective member having a low refractive index layer on an optically transmissive substrate, the low refractive index layer containing a binder resin and hollow particles, wherein the antireflective member satisfies the following condition 1. <condition 1> In a region of 5 μm×5 μm on a surface of the antireflective member on a side having the low refractive index layer with respect to the optically transmissive substrate, spatial frequency analysis of elevation is performed to calculate power spectrum intensity of elevation for each wavelength; when a sum of power spectrum intensity of elevation for each wavelength is calculated and the sum is normalized to 1, the power spectrum intensity P1 of elevation at a wavelength of 1.25 μm is 0.015 or more.