Room-Temperature Lamination of Plastic Substrates Using Reactive Polyurethane Resin
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Solution Overview
Problem
Current methods for preparing functional laminates for optical devices and lenses face challenges such as the need for high-temperature thermal curing, UV curing that can cause aesthetic issues, and the use of environmentally impactful film treatments, which can lead to adhesion problems and delamination during processing.
Innovation Solution
A method involving the application of a polyurethane resin, specifically polyester, polyether, or polycaprolactone resin, combined with isopropyl alcohol or methanol and water, to the surfaces of plastic substrates, allowing for lamination at room temperature under pressure to achieve strong adhesion without the need for heating or UV radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermal curing at high temperatures is used to achieve adhesion between functional film and thermoplastic film, then adhesion strength is improved, but the functional film may generate bubbles and create cosmetic issues due to sensitivity to moisture and heating
Solution Approach 1:
The patent changes the temperature parameter from high-temperature thermal curing (80-100°C) to room temperature lamination, eliminating the thermal stress that causes bubbles in moisture-sensitive functional films while maintaining adhesion through the reactive polyurethane resin chemistry
Solution Approach 2:
The patent replaces the thermal curing mechanism with a chemical reaction mechanism using reactive polyurethane resin that cures at room temperature, substituting thermal energy with chemical bonding to achieve adhesion without heating the sensitive functional film
2Strength
If UV curing is used to achieve adhesion between functional film and thermoplastic film, then adhesion strength is improved, but the functional film may yellow and present aesthetic issues due to sensitivity to UV light
Solution Approach 1:
The patent replaces UV curing with room temperature lamination using reactive polyurethane resin, substituting optical energy (UV radiation) with chemical bonding at ambient conditions, thereby preventing UV-induced yellowing of light-sensitive functional films while maintaining strong adhesion
Solution Approach 2:
The patent introduces reactive polyurethane resin as an intermediary bonding agent between the functional film and thermoplastic substrate, enabling adhesion through chemical reaction at room temperature without requiring direct UV exposure of the functional film
3Strength
If film treatments such as caustic treatment, plasma treatment, or corona treatment are implemented to improve adhesion, then adhesion strength is improved, but the process complexity and equipment cost increase
Solution Approach 1:
The patent extracts and eliminates the need for complex pre-treatment processes (caustic, plasma, or corona treatment) by using reactive polyurethane resin that provides adequate adhesion through its chemical reactivity with the thermoplastic substrate at room temperature, simplifying the overall lamination process
Solution Approach 2:
The patent uses a simple, consumable polyurethane resin coating that provides sufficient adhesion without requiring expensive, complex treatment equipment, replacing capital-intensive plasma or corona treatment systems with a low-cost chemical bonding approach
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
This method results in a strongly bonded functional laminate with improved photochromic performance and adhesion, suitable for integration with optical lenses, without additional energy costs or environmental impact, and is applicable in various settings including small-scale laboratories.
Implementation Method 1
the treating includes applying a polyurethane resin to the front surface of the first plastic substrate or the back surface of the first plastic substrate
Implementation Method 2
the treating includes applying isopropyl alcohol or methanol, in combination with water, to the applied polyurethane resin
Data Source
AI summary
The present disclosure relates to a method of preparing a laminate or a laminated lens, comprising obtaining a first plastic substrate having a front surface and a back surface, treating the front surface of the first plastic substrate or the back surface of the first plastic substrate, and laminating a second plastic substrate on the treated front surface of the first plastic substrate or the treated back surface of the first plastic substrate. The treating may include applying a polyurethane resin to a surface of the first plastic substrate. The method may further comprise treating a surface of the second plastic substrate. The method may further comprise applying activator to the treated surfaces of the first plastic substrate and the second plastic substrate and laminating by apposing the treated surfaces of the first plastic substrate and the second plastic substrate.