Antireflection Coating Adhesion via Ionic Bombardment
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Solution Overview
Problem
Existing antireflection coatings on ophthalmic lenses face challenges in achieving both improved abrasion resistance and adhesion to the substrate without compromising transparency or introducing optical defects, particularly due to the insertion of a sub-layer which can weaken the coating stack and affect adhesion.
Innovation Solution
A method involving the deposition of a multilayered antireflection stack onto a substrate with a SiO2-based sub-layer, where the sub-layer's surface undergoes ionic bombardment treatment before the stack deposition, and gas supply during sub-layer deposition to regulate pressure, enhancing adhesion and abrasion resistance while maintaining transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a sub-layer is inserted between the substrate and the antireflection coating stack, then abrasion resistance is improved, but adhesion to the substrate deteriorates
Solution Approach 1:
The patent applies ionic bombardment treatment to the sub-layer surface, changing the physical and chemical parameters of the surface to improve adhesion. This treatment modifies the surface energy and roughness, enabling better bonding between the sub-layer and the subsequent antireflection coating stack without compromising the abrasion resistance provided by the sub-layer's presence.
2Strength
If a sub-layer is inserted to improve abrasion resistance, then scratch resistance is improved, but the coating stack adhesion weakens
Solution Approach 1:
The ionic bombardment treatment is performed in advance, before depositing the antireflection coating stack. This preliminary action prepares the sub-layer surface by cleaning it and activating it for better adhesion, ensuring that when the coating stack is deposited, it will bond strongly to the sub-layer while the sub-layer continues to provide scratch resistance.
3Ease of manufacture
If conventional coating methods are used, then manufacturing is simple, but adhesion and abrasion resistance cannot be simultaneously optimized
Solution Approach 1:
The patent replaces conventional mechanical or chemical surface treatment methods with ionic bombardment treatment. This substitution allows for better control of surface properties and improved adhesion while maintaining a relatively simple manufacturing process, as the ionic treatment can be integrated into existing vacuum deposition systems used for coating application.
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 method results in optical articles with improved abrasion resistance and adhesion properties, maintaining excellent transparency and resistance to hot water dip treatments without optical defects, and optionally providing antistatic properties.
Implementation Method 1
wherein the exposed surface of the sub-layer has been submitted to an ionic bombardment treatment prior to depositing the multilayered stack
Implementation Method 2
depositing onto said exposed surface of the sub-layer a multilayered antireflection stack comprising at least one high refractive index layer and at least one low refractive index layer
Data Source
AI summary
The invention relates to a method for producing an optical article having antireflection or reflective properties and comprising a substrate having at least one main surface, comprising the step of depositing an sub-layer onto a substrate's main surface, the step of treating the sub-layer by ionic bombardment and the step of depositing onto said sub-layer a multilayered stack comprising at least one high refractive index layer and at least one low refractive index layer. According to a preferred embodiment, the deposition of the sub-layer is conducted in a vacuum chamber in which a gas is supplied during the deposition step.