Photochromic Curable Composition Scratch Resistance
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Solution Overview
Problem
Current photochromic spectacle lenses face challenges with low scratch resistance and inadequate photochromic properties, particularly when using thin coatings, which compromise color density and fading rates.
Innovation Solution
A photochromic curable composition combining a silsesquioxane component with radically polymerizable groups and a bifunctional radically polymerizable monomer, along with a photochromic compound, is used to create a coating that achieves high hardness and excellent photochromic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a thin photochromic coating is used, then the scratch resistance is improved, but the photochromic properties (color density and fading rate) deteriorate
Solution Approach 1:
The patent uses a composite curable composition containing silsesquioxane particles (inorganic component) and polymerizable monomer/oligomer (organic component) to form a coating that combines the hardness and scratch resistance of inorganic materials with the photochromic properties enabled by the organic matrix. This composite structure allows thin coatings to achieve both high scratch resistance and adequate photochromic performance.
Solution Approach 2:
The patent modifies the chemical composition parameters of the coating by incorporating silsesquioxane with specific particle sizes (0.1-10 μm) and using specific ratios of polymerizable monomers and oligomers. These parameter changes enable the coating to achieve high scratch resistance while maintaining sufficient photochromic properties through optimized material composition rather than increasing coating thickness.
2Reliability
If the lens material is made soft to allow easy dispersion of photochromic compound, then the photochromic properties are improved, but the scratch resistance deteriorates
Solution Approach 1:
The patent applies composite materials by incorporating silsesquioxane particles into the polymer matrix, creating a coating that is inherently hard and scratch-resistant while the polymerizable monomer/oligomer component provides the photochromic functionality. This eliminates the need to make the base material soft for compound dispersion.
Solution Approach 2:
The patent implements local quality by having the photochromic compound distributed within the polymerizable monomer/oligomer phase of the composite, while the silsesquioxane particles provide the hard, scratch-resistant structure. Different regions of the coating material serve different functions: the polymer phase enables photochromism while the inorganic silsesquioxane phase provides mechanical durability.
3Adaptability or versatility
If photochromic coating is applied on plastic lenses, then the adaptability to different lens materials is improved, but the scratch resistance deteriorates
Solution Approach 1:
The patent uses a composite formulation where silsesquioxane particles provide universal hard coating properties that work on various lens materials (plastic, glass, etc.), while the polymerizable monomer/oligomer component ensures adequate adhesion and photochromic functionality. This composite approach maintains scratch resistance across different substrate materials.
Solution Approach 2:
The patent achieves universality by formulating a curable composition that can be applied to various lens materials (plastic, glass, polycarbonate, etc.) while maintaining both scratch resistance and photochromic properties. The silsesquioxane-polymer composite system provides multi-functional performance that is not limited to specific substrate types.
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 forms a cured product with high scratch resistance and superior photochromic performance, including high color density and fast fading rates, while maintaining durability.
Implementation Method 1
as radically polymerizable component (A), a silsesquioxane component (A1) having radically polymerizable groups and a bifunctional radically polymerizable monomer (A2)
Implementation Method 2
a photochromic compound (B)
Data Source
AI summary
A photochromic curable composition comprising, as radically polymerizable component (A), a silsesquioxane component (A1) having a radically polymerizable group and a bifunctional radically polymerizable monomer (A2) represented by the following general formula (1), wherein a is a number of 0 to 30, and b is a number of 0 to 30 on condition that an average value of a + b is 2 to 30, R1, R2, R3 and R4 are each a hydrogen atom or a methyl group, and A is a divalent organic group on condition that the number of carbon atoms is 1 to 20, and a photochromic compound (B). The photochromic curable composition is useful specifically as a photochromic coating agent, and from which photochromic lenses can be produced by the coating method having a hardness large enough not to be get scratched even in the step of machining the lenses, and featuring excellent photochromic properties such as color density, fading rate and repeat durability.