Anti-soiling Coating Adhesion via Methacrylate Mediator
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Solution Overview
Problem
Existing ophthalmic lens coatings face adhesion issues when an anti-soiling coating is deposited on organic abrasion-resistant coatings, leading to poor interfacial adhesion and hydrophobicity.
Innovation Solution
A (meth)acrylate based coating composition is used, comprising (meth)acrylate compounds, ethylenically unsaturated alkoxysilanes, and silica or metal oxide colloids, which improves adhesion by forming a hydrophobic layer that enhances cleaning ease and anti-soiling properties when combined with an anti-soiling coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an anti-soiling coating is deposited on an organic abrasion-resistant coating, then anti-soiling properties are achieved, but adhesion at the interface deteriorates
Solution Approach 1:
The patent introduces a specific (meth)acrylate based coating composition as an intermediary layer between the substrate and the anti-soiling coating. This intermediate coating contains reactive groups that can hydrolyze and react with pendant reactive groups at the surface of the abrasion resistant coating, thereby mediating the adhesion between the two layers and preventing delamination.
Solution Approach 2:
The patent employs a composite coating system consisting of multiple layers with different functionalities: an organic abrasion-resistant coating for mechanical durability, a (meth)acrylate based intermediate coating for adhesion promotion, and a fluorinated anti-soiling top coating for hydrophobicity. The synergistic combination of these composite materials resolves the contradiction between adhesion and anti-soiling properties.
2Ease of operation
If a fluorinated hydrophobic coating is applied to improve cleaning ease, then hydrophobicity increases, but adhesion to organic coatings worsens
Solution Approach 1:
The (meth)acrylate based coating acts as a mediator between the hydrophobic fluorinated coating and the substrate. It contains reactive groups that ensure strong adhesion to both the underlying abrasion-resistant coating and the overlying anti-soiling coating, thereby maintaining coating integrity while enabling hydrophobic functionality.
Solution Approach 2:
The patent applies different functional properties to different layers: the intermediate (meth)acrylate coating is designed specifically for adhesion promotion with reactive groups, while the top fluorinated coating is optimized for hydrophobicity and cleaning ease. This local differentiation of material properties allows each layer to excel at its specific function without compromising overall 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 solution provides improved adhesion and hydrophobicity, ensuring effective cleaning and durability of the anti-soiling coating on ophthalmic lenses, reducing contact angles and enhancing resistance to solvent and caustic washes.
Implementation Method 1
the first coating being a (meth)acrylate based coating and being obtained by polymerizing a polymerizable composition comprising i) at least one (meth)acrylate compound
Implementation Method 2
ii) at least one compound I having at least one —M-Z′ bond with M representing Si or a Metal atom, Z′ representing OH or a hydrolysable group
Implementation Method 3
the second coating, having anti-soiling properties, being obtained by depositing on said first coating an anti-soiling coating composition comprising at least one compound II
Data Source
AI summary
A substrate having at least one main surface comprising a first coating deposited on said main surface and a second coating having anti-soiling properties deposited and adhering on the surface of said first coating,the first coating being a (meth)acrylate based coating and being obtained by polymerizing a polymerizable composition comprising:i) at least one (meth)acrylate compound andii) at least one compound I having at least one —M—Z′ bond with M representing Si or a Metal atom, Z′ representing OH or a hydrolysable group, and at least one ethylenic unsaturated group or epoxy group, and/oriii) at least one silica or metal oxide colloid having free ethylenically unsaturated groups; andthe second coating, having anti-soiling properties, being obtained by depositing on said first coating an anti-soiling coating composition comprising at least one compound II, or a hydrolyzate thereof, having at least one —Si—Z″ group with Z″ representing OH or a hydrolysable group.