Coating Composition for Optical Member Scratch Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional coating compositions for high-refractive index plastic lenses suffer from issues such as interference fringes, poor adhesion, stability, water resistance, and discoloration due to ultraviolet light, leading to scratches, peeling, and color irregularities in anti-reflective coatings.
Innovation Solution
A coating composition comprising silicon-containing substances and hydrolyzed organic silicon compounds bonded to modified metal oxide colloidal particles, with an organic silicon compound having a ureido group, which forms a cured film with excellent adhesion, scratch resistance, and resistance to ultraviolet discoloration, and an anti-reflective coating applied on the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a coating composition including silicon dioxide sol is added to improve scratch resistance, then scratch resistance is improved, but interference fringes are generated on the coating film causing poor appearance
Solution Approach 1:
The patent changes the particle size parameters of the colloidal particles to 0.1 µm to 1.0 µm, which is larger than conventional silicon dioxide sol particles. This parameter change prevents interference fringes while maintaining scratch resistance, as the larger particles do not create the optical interference effects that cause appearance defects.
Solution Approach 2:
The patent uses a composite coating composition containing both the specific colloidal particles (0.1-1.0 µm) and silane coupling agents. This composite approach allows the coating to achieve both good appearance (no interference fringes) and excellent scratch resistance through the synergistic effect of the particle size control and chemical bonding from the silane coupling agent.
2Ease of manufacture
If conventional coating compositions are applied to high-refractive index plastic lenses, then the lenses can be produced, but adhesion is poor causing film peeling
Solution Approach 1:
The patent introduces silane coupling agents as intermediary substances that chemically bond to both the colloidal particles and the plastic lens substrate. This intermediary mechanism creates strong adhesion between the coating film and the high-refractive index plastic lens, preventing film peeling while maintaining coating applicability.
3Strength
If titanium oxide sol is used as coating material, then scratch resistance is improved, but discoloration in blue occurs due to light excitation of titanium oxide
Solution Approach 1:
The patent extracts or removes titanium oxide from the coating composition to eliminate the harmful blue discoloration effect caused by light excitation. Instead, it uses colloidal particles of specific size ranges combined with silane coupling agents to achieve scratch resistance without the discoloration problem inherent to titanium oxide.
Solution Approach 2:
The patent replaces the problematic titanium oxide with alternative colloidal particle systems that provide the necessary mechanical properties (scratch resistance) without the optical defects (blue discoloration). This substitution uses different materials that achieve the same functional goal without the harmful side effects.
4Reliability
If anti-reflective coating is applied on the coating film, then optical performance is improved, but color irregularities occur due to reflection color variation
Solution Approach 1:
The patent changes the base coating film parameters (particle size to 0.1-1.0 µm, use of silane coupling agents) to create a more uniform and stable substrate. This parameter change in the underlying coating film provides a consistent base that prevents color irregularities when anti-reflective coating is applied, while maintaining good optical performance.
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 coating composition achieves high transparency, excellent adhesion, and resistance to scratches, heat, and weathering, preventing interference fringes and discoloration, suitable for high-refractive index lenses and various optical applications.
Implementation Method 1
a hydrolyzed compound of the organic silicon compound of General Formula (I)
Implementation Method 2
an (S) component and a (T) component, wherein the (S) component is at least one silicon-containing substance... forms a cured film having excellent adhesion
Data Source
AI summary
There is provided a coating composition which a coating formed therefrom is excellent in transparency and weather resistance, particularly in adhesion to a substrate after weatherability test, and an optical member. A coating composition comprising: an (S) component and a (T) component, wherein the (S) component is a silicon-containing substance, and the (T) component is colloidal particles (D) formed by bonding an organic silicon compound having a ureido group to surfaces of modified metal oxide colloidal particles (C) having a primary particle diameter of 3 nm to 100 nm formed by providing metal oxide colloidal particles (A) having a primary particle diameter of 2 nm to 60 nm as nucleuses and partially or fully coating the surfaces of the colloidal particles (A) with a coating material (B) made of acidic oxide colloidal particles.