Antifouling Layer Stabilization via Accelerated Grafting
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Solution Overview
Problem
The rapid deposition of a temporary top coat on antifouling layers of ophthalmic lenses for edging purposes leads to significant degradation of the antifouling layer's properties, particularly the receding angle of liquids, especially when stored for extended periods before removal of the top coat.
Innovation Solution
A process involving the deposition of an organic antifouling layer with fluoropolymer compounds and a mineral top coat, preceded by an accelerated grafting step in a wet atmosphere or catalytic treatment to stabilize the antifouling layer, reducing degradation and maintaining the receding angle's value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a temporary top coat is deposited rapidly after the antifouling layer for edging purposes, then the adhesion for edging is improved, but the antifouling layer degrades significantly after top coat removal
Solution Approach 1:
The patent applies a preliminary grafting treatment to the antifouling layer before depositing the top coat. This preliminary action modifies the antifouling layer's structure in advance, creating a more stable configuration that can withstand the subsequent top coat deposition and removal processes without significant degradation of the receding angle
Solution Approach 2:
The grafting treatment serves as a preliminary counter-action that prevents the harmful effect of top coat-induced degradation. By modifying the antifouling layer through grafting before top coat application, the patent creates resistance against the degradation mechanism that would otherwise occur during top coat deposition and removal
2Loss of time
If the top coat is deposited immediately after antifouling layer formation, then manufacturing time is reduced, but antifouling layer degradation increases
Solution Approach 1:
The grafting treatment is applied as a preliminary step that enables immediate top coat deposition without compromising antifouling layer quality. This preliminary modification allows the process to proceed rapidly while maintaining the structural integrity and surface properties of the antifouling layer
Solution Approach 2:
The grafting treatment changes the physical-chemical parameters of the antifouling layer, specifically modifying its molecular structure and surface properties. This parameter change enables the layer to tolerate rapid processing and extended storage with the top coat without significant degradation of its receding angle and other antifouling properties
3Ease of manufacture
If lenses are stored for extended periods with the top coat before removal, then edging preparation is improved, but antifouling layer properties deteriorate
Solution Approach 1:
The grafting treatment creates a stable antifouling layer configuration in advance that can withstand prolonged storage with the top coat. This preliminary structural modification prevents the degradation mechanisms that would otherwise occur during extended storage periods, maintaining the receding angle and other critical properties
Solution Approach 2:
The grafting treatment provides beforehand cushioning against the harmful effects of prolonged top coat presence. By modifying the antifouling layer structure in advance, the patent creates a buffer that protects against the degradation that would occur during extended storage, allowing longer preparation periods without quality loss
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 accelerated grafting step effectively retains the antifouling layer's properties, ensuring the receding angle remains high even after durability tests and prolonged storage, preventing the degradation caused by the temporary top coat.
Implementation Method 1
an organic antifouling layer comprising at least one fluoropolymer compound comprising hydrolysable functions
Implementation Method 2
a treatment of the antifouling layer deposited in a wet atmosphere, preferably in an air atmosphere at atmospheric pressure, having a degree of relative humidity (RH) of from 45% to 95% and a temperature of from 15° C. to 75° C.
Implementation Method 3
the deposition, on the antifouling layer, of a top coat that facilitates edging, of mineral nature, comprising one or more metal fluorides and/or one or more metal oxides or hydroxides
Data Source
AI summary
The invention concerns a method for producing an optical article suitable for edging comprising an antifouling layer on which there is deposited a temporary overlayer for assisting with edging, comprising:depositing, on an optical substrate, an organic antifouling layer comprising at least a fluorinated polymer compound comprising hydrolysable functions; anddepositing, on the antifouling layer, an overlayer for assisting with edging, of mineral nature, comprising one or more metal fluorides and/or one or more metal oxides or hydroxides;method characterised in that it further comprises a step of accelerated grafting of the antifouling layer chosen from:(a) a treatment of the deposited antifouling layer in a humid atmosphere of the deposited antifouling layer and(b) a catalytic treatment in the acidic or basic vapour phase of the deposited antifouling layer.