UV Curable Coating Composition for Ophthalmic Lenses

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Solution Overview

Problem

Current UV curable coatings for ophthalmic lenses lack sufficient adhesion to both thermoplastic and thermoset substrates, requiring additional primer layers that increase manufacturing costs and complexity.

Innovation Solution

A UV curable coating composition comprising non-hydrolyzed (epoxy)(alkoxy)silane, high concentrations of polyfunctional acrylate monomer and/or polyfunctional epoxy compounds, and photoinitiators, cured without a hydrolysis step, which enhances adhesion and abrasion resistance on both thermoplastic and thermoset substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydrolyzed (epoxy)(alkoxy)silane is used in UV curable coating, then adhesion to substrates is improved, but viscosity of coating composition increases and stability decreases

Engineering Contradiction:
Improveadhesion to substratesVSAvoidviscosity and stability of coating
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical parameter of the silane from hydrolyzed to non-hydrolyzed state, and adjusts the concentration parameters of polyfunctional acrylate monomer (40-80 wt%) and polyfunctional epoxy compound (10-40 wt%) to achieve both low viscosity and high adhesion without hydrolysis step

Inventive Principle:
Principle #35Parameter changes

2Reliability

If separate primer layer is applied for adhesion, then adhesion to different substrates is improved, but manufacturing cost and process complexity increase

Engineering Contradiction:
Improveadhesion to substratesVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the primer function and topcoat function into a single integrated coating composition that provides both adhesion to diverse substrates and abrasion resistance, eliminating the need for separate primer and topcoat application steps

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The coating composition achieves universal adhesion to multiple substrate types (thermoplastics, thermosets, metals, glass, ceramics) through the synergistic combination of non-hydrolyzed (epoxy)(alkoxy)silane, polyfunctional acrylate monomer, and polyfunctional epoxy compound in a single formulation

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Stability of the object's composition

If non-hydrolyzed (epoxy)(alkoxy)silane is used, then viscosity and stability of coating are improved, but adhesion to substrates was traditionally considered to worsen

Engineering Contradiction:
Improveviscosity and stability of coatingVSAvoidadhesion to substrates
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent creates a composite coating system combining non-hydrolyzed (epoxy)(alkoxy)silane with polyfunctional acrylate monomer and polyfunctional epoxy compound, where the synergistic interaction between components provides both low viscosity and high adhesion without requiring hydrolysis

Inventive Principle:
Principle #40Composite 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 provides a single-layer coating with improved adhesion and scratch resistance on various substrates without the need for primers, reducing manufacturing costs and complexity while maintaining high abrasion resistance and tintability.

Implementation Method 1

c) at least one free radical photoinitiator and/or cationic photoinitiator

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

the adhesion of the final hard coatings is improved by using (epoxy)(alkoxy)silane monomers that are not subjected to hydrolysis before UV curing

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2800788B1Curable coating composition
Publication Date: 2018.05.02 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)

AI summary

UV curable coating composition comprising a non hydrolyzed epoxy- alkoxy-silane, polyfunctional acrylate and/or epoxy compounds and a cationic and/or free-radical photo-initiator; with polyfunctional acrylate and/or epoxy compounds representing more than 40 weight% of the total dry matter and the composition being without any hydrolysed epoxy-alkoxy-silane. This composition is coated and cureed on an optical substrate.