Colored Spectacle Lens Intermediate Layer Prevents Colorant Migration
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Solution Overview
Problem
Spectacle lenses with antifogging layers containing surfactants face durability issues and colorant migration when used on colored substrates, leading to decolorization, while water-absorbent antifogging layers excel in durability but suffer from colorant migration and decolorization when applied to colored substrates.
Innovation Solution
A colored spectacle lens design featuring a substrate with a colorant, a water-absorbent antifogging layer, and an intermediate layer between the substrate and the antifogging layer, where the intermediate layer has a higher indentation hardness than the antifogging layer, preventing colorant migration and decolorization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a water-absorbent antifogging layer is formed on a colored substrate, then antifogging durability is improved, but colorant migration occurs leading to decolorization
Solution Approach 1:
The patent introduces an intermediate layer between the colored substrate and the water-absorbent antifogging layer. This intermediate layer acts as a barrier that prevents colorant migration from the substrate to the antifogging layer, while still allowing the antifogging layer to maintain its water-absorbent properties and durability. The intermediate layer mediates the interaction between the substrate and antifogging layer, solving the contradiction between durability and colorant migration.
Solution Approach 2:
The patent divides the coating structure into multiple segments: the colored substrate, the intermediate layer, and the water-absorbent antifogging layer. This segmentation allows each layer to perform its specific function independently - the substrate provides color, the intermediate layer prevents migration, and the antifogging layer provides durability - thereby resolving the contradiction between antifogging durability and colorant migration.
2Reliability
If a surfactant-containing antifogging layer is formed on the lens surface, then antifogging performance is achieved, but the surfactant is easily peeled off reducing durability
Solution Approach 1:
The patent changes the fundamental parameter of the antifogging layer from surfactant-based to water-absorbent resin-based. This parameter change transforms the mechanism of antifogging action while significantly improving durability. The water-absorbent resin layer maintains antifogging performance through its ability to absorb and retain water, replacing the surfactant mechanism that suffered from poor adhesion and easy peeling.
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 configuration effectively suppresses colorant migration and decolorization, ensuring the antifogging layer maintains its performance while preserving the color of the spectacle lens.
Implementation Method 1
a water-absorbent antifogging layer (Z) present on at least one surface side of the substrate (X)
Implementation Method 2
an intermediate layer (Y) between the substrate (X) and the water-absorbent antifogging layer (Z)... wherein a difference (IY−IZ) between an indentation hardness IY of the intermediate layer (Y) at a load of 100 mgf and an indentation hardness IZ of the water-absorbent antifogging layer (Z) at a load of 100 mgf is more than 0 mgf/μm2
Data Source
AI summary
A colored spectacle lens comprising: a substrate containing a colorant; a water-absorbent antifogging layer present on at least one surface side of the substrate; and an intermediate layer between the substrate and the water-absorbent antifogging layer.