Urethane Optical Material Moisture Control
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Solution Overview
Problem
The preparation of polyurethane-based optical materials often results in polymerization imbalance and the generation of white tape residues and foams due to the use of widely available isocyanate compounds, which deteriorate the optical properties of the material.
Innovation Solution
A method of preparing a urethane-based optical material by controlling the moisture content of the resin composition within a specific range (300 to 3,000 ppm) to inhibit polymerization imbalance and foam generation, using a mixture of polythiol and low-cost, widely available isocyanate compounds such as isophorone diisocyanate and hexamethylene diisocyanate, while minimizing the formation of white tape residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If widely available isocyanate compounds are used in the resin composition, then manufacturing cost is reduced, but polymerization imbalance and white tape residues are generated
Solution Approach 1:
The patent applies parameter changes by precisely controlling the moisture content of the resin composition within the range of 300 to 3,000 ppm. This parameter control modifies the polymerization rate to achieve a balanced reaction between polythiol and isocyanate compounds, preventing polymerization imbalance and white tape residue generation while using cost-effective isocyanate compounds
Solution Approach 2:
The patent introduces moisture as an intermediary element that mediates the polymerization reaction. By controlling moisture content within a specific range, the reaction rate is optimized to prevent excessive foaming and polymerization imbalance, enabling the use of widely available isocyanate compounds without compromising polymerization quality
2Productivity
If moisture content is increased to accelerate polymerization rate, then production efficiency is improved, but foaming increases and optical properties deteriorate
Solution Approach 1:
The patent applies parameter changes by establishing an optimal moisture content range (300 to 3,000 ppm) that balances polymerization rate with foam generation control. This parameter optimization ensures sufficient reaction speed for production efficiency while preventing excessive foaming that would compromise optical properties
3Productivity
If polymerization rate is increased to improve productivity, then manufacturing efficiency is improved, but white tape residues are generated
Solution Approach 1:
The patent resolves this contradiction by optimizing the moisture content parameter within 300 to 3,000 ppm, which controls the polymerization rate to an optimal level. This ensures sufficiently fast polymerization for productivity while maintaining reaction balance to prevent white tape residue formation
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 approach allows for the efficient production of high-quality, colorless, and transparent polyurethane-based optical materials with reduced white tape residues and foams, maintaining optical properties like transparency and thermal stability, and enabling the use of low-cost isocyanate compounds.
Implementation Method 1
preparing a resin for a urethane-based optical material by template-polymerizing a resin composition including a polythiol compound and a polyisocyanate compound
Implementation Method 2
When the reaction rate of the isocyanate compounds is low, moisture may accelerate the reaction rate. This is because an amine compound generated via reaction between moisture and isocyanate slightly accelerates the reaction rate
Implementation Method 3
Excessive moisture may generate a large amount of carbon dioxide, thereby generating foams during preparation of the optical lens
Data Source
AI summary
A method of preparing an optical material by polymerizing a resin composition including a thiol group-containing compound and an isocyanate group-containing compound, particularly, a method of preparing a high-quality urethane-based optical material using a universal polyisocyanate compound. According to one aspect, a resin composition including a polythiol compound and a widely available polyisocyanate compound, as main components, and having a moisture content of 300 to 3,000 ppm is template-polymerized to prepare the optical material. A colorless, transparent, and high-quality urethane-based optical material may be efficiently prepared in high yield using a low-cost and widely available isocyanate compound through template-polymerization using a tape while minimizing generation of white tape residues and foaming.