Light-Curing Thermoplastic Epoxy Adhesive for Optical Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adhesives for securing optical components like lenses and semifinished eyeglass blanks face challenges such as high stress, long curing times, and inadequate solubility, which can lead to reduced adhesion and residue issues, especially when exposed to humidity or processing media, and are not environmentally friendly.
Innovation Solution
A polymerizable composition comprising cycloaliphatic epoxide, monovalent alcohol, and photopolymerization initiator, with a specific molar ratio of epoxide to hydroxyl groups, which forms a thermoplastic oligomer or low-molecular weight polymer for low-stress fixation and easy release, maintaining adhesion and solubility in polar solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If cold cements based on peroxide-cured acrylates are used, then adhesive power is achieved, but highly exothermic temperature peaks and high volume shrinkage cause stresses
Solution Approach 1:
The patent changes the chemical composition parameters by using epoxy resin with secondary diamines as hardeners instead of peroxide-cured acrylates, fundamentally altering the curing mechanism to eliminate exothermic peaks and volume shrinkage while maintaining adhesive strength
Solution Approach 2:
The patent creates a composite adhesive system combining epoxy resin, secondary diamines, and specific additives to achieve both low stress during curing and high adhesive power, resolving the contradiction between strength and stress
2Stress or pressure
If epoxy resin with secondary diamines as hardeners is used, then low stress and good stability are achieved, but curing time is long (at least 24 hours at room temperature)
Solution Approach 1:
The patent applies preliminary heating to accelerate the curing reaction of epoxy resin with secondary diamines, allowing the long-curing adhesive system to achieve full cure in a shortened time frame while maintaining its low-stress characteristics
Solution Approach 2:
The patent uses periodic or controlled heating cycles to optimize the curing process, applying heat at specific stages to accelerate reaction without causing thermal stress, thereby reducing overall curing time while preserving the low-stress benefit
3Loss of time
If UV-reactive acrylate adhesives are used, then fast curing is achieved, but adhesion is reduced by swelling in polar solvents and surface remains tacky
Solution Approach 1:
The patent changes the adhesive chemistry from UV-reactive acrylates to epoxy resin systems, fundamentally altering the polymer structure to resist swelling in polar solvents while maintaining fast curing through thermal acceleration, thereby preserving adhesion reliability
Solution Approach 2:
The patent uses a disposable-like approach with the adhesive formulation designed to cure completely without residual tackiness, eliminating the need for additional protective measures against solvent swelling that would be required with acrylate systems
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 fast, low-stress fixation method for optical components with adequate adhesion and solubility, allowing for easy release and processing without residue, while being environmentally friendly and minimizing stress on the components.
Implementation Method 1
a photopolymerization initiator, wherein the molar ratio of the epoxide groups of the cycloaliphatic epoxide compound to the hydroxyl groups of the monovalent alcohol is 0.9:1.0 to 4.0:1.0
Data Source
AI summary
The present invention relates to a polymerizable composition comprising a cycloaliphatic epoxide compound, a monovalent alcohol, a photopolymerization initiator, wherein the molar ratio of the epoxide groups of the cycloaliphatic epoxide to the hydroxyl groups of the monovalent alcohol is 0.9:1.0 to 4.0:1.0 and the hydroxyl functionality of all organic compounds of the polymerizable composition having OH group(s) is in the range of 1.0 to 1.25.