Photochromic Lens Surface Casting Adhesion via Primer Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods fail to produce uniformly photochromic segmented polycarbonate optical lenses efficiently and cost-effectively, with challenges in achieving successful adhesion of surface casting layers onto lenses with photochromic coatings and ensuring durability and scratch resistance.
Innovation Solution
A composite optical lens is created using a photochromic base lens with a primer composition and a cured casting composition, including a segment region, where a polyurethane latex-based primer is applied to the lens, followed by a UV-curable surface casting monomer solution, allowing for successful adhesion and multifocal capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a photochromic coating is applied onto a polycarbonate lens, then uniform color density is achieved regardless of lens prescription or thickness, but the lens becomes vulnerable to scratches and surface damage
Solution Approach 1:
The patent applies a scratch-resistant coating over the photochromic coating to create a composite structure. This composite material approach combines the photochromic properties with enhanced durability and scratch resistance, resolving the contradiction between achieving uniform color density and maintaining reliability against surface damage.
2Adaptability or versatility
If a surface casting layer is applied onto a photochromic lens, then multifocal capabilities are achieved, but adhesion of the casting surface is difficult to accomplish
Solution Approach 1:
The patent applies a primer layer to the photochromic lens surface before applying the surface casting layer. This preliminary action prepares the surface by enhancing its adhesion properties, making it more receptive to the casting material and enabling successful bonding of the multifocal segment.
Solution Approach 2:
The primer acts as an intermediary layer between the photochromic lens and the surface casting material. This intermediate layer facilitates adhesion by creating a compatible interface, allowing the casting layer to bond effectively to the photochromic surface.
3Manufacturing precision
If injection molding is used to produce photochromic polycarbonate lenses, then uniform photochromic properties are achieved, but significant investment in costly machinery is required
Solution Approach 1:
The patent uses a mold-based casting process that replicates the lens shape and multifocal segment geometry without requiring complex injection molding machinery. The surface casting layer is poured into a mold and cured to form the desired multifocal pattern, achieving uniform photochromic properties through a more cost-effective process.
4Adaptability or versatility
If segmented lenses with raised areas are produced, then multifocal functionality is achieved, but the surface profile becomes non-uniform
Solution Approach 1:
The patent applies the surface casting layer selectively to create localized multifocal segments while maintaining the overall uniformity of the lens surface. The raised segment areas provide the necessary focal variation while the rest of the lens surface remains smooth and uniform, balancing multifocal functionality with surface profile consistency.
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
This method enables the production of cost-effective, durable, and scratch-resistant photochromic segmented optical lenses with successful adhesion of the casting composition to the photochromic lens, achieving uniform photochromic and multifocal properties in a single structure.
Implementation Method 1
Photochromic lenses change from light to dark when exposed to ultraviolet (UV) radiation
Implementation Method 2
UV-curable surface casting monomer solution
Data Source
AI summary
A system and method for providing photochromic segmented multifocal optical lenses. A latex primer formulation is provided for effectuating adhesion of a surface casting composition onto a lens having a photochromic coating. The method provides efficient, cost effective production of durable photochromic segmented lenses, via secure adhesion of a surface casting layer onto a photochromic substrate while maintaining desirable optical characteristics. A composite optical lens is advantageously formed having a photochromic base lens, a primer composition bonded to a convex surface of said base lens, and a cured casting composition bonded to said primer composition layer. The cured casting formulation includes a segment region to impart multifocal qualities onto the resultant composite optical lens.