Single-Step Polysiloxane Polyurethane Coating for Ophthalmic Lenses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polymeric ophthalmic lenses are susceptible to scratching and require multiple coatings for abrasion resistance and easy cleaning, which are costly and inefficient in high-volume production, with existing coatings offering poor abrasion resistance and being prone to dirt collection and smudging.
Innovation Solution
A thermally-curable coating composition comprising polysiloxane, polyurethane, and fluorinated materials applied in a single step, providing superior abrasion resistance and hydrophobic properties without altering the optical or mechanical performance of the lens, and allowing easy cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple coating layers are applied to polymeric lenses to provide abrasion resistance and easy cleaning, then the lenses gain improved durability and cleaning properties, but the manufacturing process becomes more complex and costly
Solution Approach 1:
The patent combines multiple coating functions (abrasion resistance, easy cleaning, hydrophobicity) into a single integrated coating layer. This single-layer coating contains both hard coat resins for scratch resistance and fluorinated compounds for water repellency, eliminating the need for separate primer and top coat applications while achieving all desired properties simultaneously.
Solution Approach 2:
The coating composition serves multiple functions within a single layer: it provides mechanical durability through abrasion-resistant polymers, water repellency through fluorinated compounds, and adhesion to the lens substrate. This multi-functional coating replaces what would traditionally require multiple specialized coating layers applied in sequence.
2Productivity
If conventional UV curable coatings are applied to provide easy cleaning features, then the coating cures quickly with high throughput, but the abrasion resistance is poor compared to thermal curable coatings
Solution Approach 1:
The patent modifies the chemical composition of the coating to include both UV-curable groups (acrylate or epoxy functionalities) and thermally-curable polysiloxane components. This allows the coating to be cured by UV light for rapid processing while the polysiloxane network provides the superior abrasion resistance typically associated with thermal curing, effectively combining the advantages of both curing methods.
3Weight of moving object
If polymeric lenses are used instead of glass lenses, then the lenses become lighter with better impact resistance, but they become more susceptible to scratching
Solution Approach 1:
The patent creates a composite coating system combining multiple material types: hard coat resins (polyurethane, polyester, acrylic) provide the scratch-resistant matrix, while fluorinated compounds (perfluorocarboxylic acids, perfluorosulfonic acids) provide the hydrophobic surface properties. This composite structure delivers both mechanical durability and water repellency, compensating for the inherent softness of polymeric lens materials.
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 significantly reduces manufacturing time and cost, enhances abrasion resistance, and imparts hydrophobic properties to the lenses, making them resistant to scratches, stains, and smudging, while enabling easy cleaning with minimal maintenance.
Implementation Method 1
The coating exhibits a water contact angle of greater than 90° as measured by a goniometer
Implementation Method 2
The coating composition is applied to the polymeric lens and the solvent is evaporated
Data Source
AI summary
Ophthalmic lenses, coatings for ophthalmic lenses, and methods for manufacturing ophthalmic lenses are provided herein. In one exemplary embodiment, an ophthalmic lens comprising a polymeric lens has a first surface and second surface. A coating overlies the first surface. The coating comprises a polysiloxane, a polyurethane, an oligomer derived from a polysiloxane or a polyurethane, a polymer derived from a polysiloxane or a polyurethane, or a combination thereof, and a fluorinated material. The coating exhibits a water contact angle of greater than 90° as measured by a goniometer.