Polyurethane Optical Resin Impact Resistance via Polythiol Crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Polyurethane resins used in optical materials face limitations in impact resistance while maintaining transparency and refractive index, as described in Japanese Laid-open Patent Publication No. 2014-55229.
Innovation Solution
A polymerizable composition comprising a polyisocyanate component with 1,4-bis(isocyanatomethyl)cyclohexane, a polyol component with a diol compound of molecular weight 400 or more, and a polythiol component with a dithiol compound, specifically including polytetramethylene ether glycol and aromatic polyisocyanates, to enhance impact resistance and transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a polyurethane resin is used with specific polyisocyanate and polyol formulations to achieve transparency and heat resistance, then optical properties are improved, but impact resistance deteriorates
Solution Approach 1:
The patent uses a composite formulation combining polyisocyanate, polyol, and polythiol components to create a poly(thio)urethane resin that achieves both transparency and high impact resistance. The specific combination of compounds (1,4-bis(isocyanatomethyl)cyclohexane, polyether diol, and dithiol compound) creates a material that simultaneously satisfies optical and mechanical requirements.
Solution Approach 2:
The patent modifies the chemical composition parameters by introducing polythiol components and specific polyol molecular weight ranges (400-2000) to change the physical properties of the resin. This parameter adjustment enables the material to achieve both high transparency and improved impact resistance without compromising either property.
2Ease of manufacture
If polyol compounds with lower molecular weight are used to improve processing ease, then manufacturing precision is improved, but impact resistance deteriorates
Solution Approach 1:
The patent optimizes the molecular weight parameter of polyol compounds to a specific range (400-2000), which balances processing ease with impact resistance. This parameter selection ensures the resin remains workable during manufacturing while achieving the desired mechanical strength in the final product.
Solution Approach 2:
The patent combines polyol compounds within a specific molecular weight range with polythiol and polyisocyanate components to create a composite system that maintains both processability and mechanical performance. The synergistic interaction between components allows the material to be easily manufactured while achieving high impact resistance.
3Illumination intensity
If conventional polyurethane formulations are used to maintain refractive index, then optical properties are preserved, but impact resistance remains insufficient
Solution Approach 1:
The patent develops a composite poly(thio)urethane resin system that maintains the high refractive index characteristic of conventional polyurethane optical materials while dramatically improving impact resistance. The specific formulation with polythiol crosslinking provides both optical quality and mechanical strength.
Solution Approach 2:
The patent changes the chemical structure parameters by incorporating thiol groups that form disulfide crosslinks, which enhance the three-dimensional network structure. This structural modification improves impact resistance while maintaining the optical properties including refractive index required for optical applications.
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 composition achieves improved impact resistance and transparency in the cured product, maintaining high refractive index and heat resistance, suitable for optical materials like plastic lenses.
Implementation Method 1
a polymerizable composition for an optical material, including: a polyisocyanate component which includes 1,4-bis(isocyanatomethyl)cyclohexane; a polyol component which includes a diol compound having a molecular weight of 400 or more and having two hydroxyl groups; and a polythiol component which includes a dithiol compound having two mercapto groups
Data Source
AI summary
Provided is a polymerizable composition for an optical material including: a polyisocyanate component which includes 1,4-bis(isocyanatomethyl)cyclohexane; a polyol component which includes a diol compound having a molecular weight of 400 or more and having two or more hydroxyl groups; and a polythiol component which includes a polythiol compound having two or more mercapto groups.