Optical Member Polymerization Striae Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to produce a thick optical member, such as a spectacle lens, that is free from optical distortion and striae, while optimizing the polymerization conditions to minimize the occurrence of striae, which requires setting appropriate temperature and catalyst levels, but this process can be time-consuming and prone to errors.
Innovation Solution
Incorporating a urethaneurea compound with a structural unit derived from tolylene diisocyanate into the polymerizable composition, which is injected into a molding die and polymerized, effectively suppressing the occurrence of striae by adjusting the content and molecular weight of the urethaneurea compound within specific ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the polymerization time is shortened to suppress striae occurrence, then productivity is improved, but manufacturing precision deteriorates due to frequent striae occurrence
Solution Approach 1:
The patent changes the chemical composition parameter by introducing a urethaneurea compound with specific structural units (cyclic carbonate structural unit, cyclic carboxylate structural unit, and/or cyclic sulfate structural unit) into the polymerizable composition. This compositional parameter change enables the polymerization process to achieve both short duration and high optical quality by modifying the fundamental chemistry of the system rather than merely adjusting process parameters like temperature or time
Solution Approach 2:
The patent creates a composite polymerizable composition by combining multiple components: polymerizable monomers, urethaneurea compounds with specific cyclic structural units, and crosslinking agents. This composite material approach allows the system to achieve rapid curing while maintaining optical quality, as the different components work synergistically to provide both speed and precision
2Manufacturing precision
If the amount of catalyst and polymerization temperature are optimized to reduce striae, then manufacturing precision is improved, but loss of time increases due to extensive condition setting
Solution Approach 1:
The urethaneurea compound with cyclic structural units acts as a self-regulating component that inherently controls polymerization uniformity. The specific cyclic structures (carbonate, carboxylate, sulfate) provide built-in molecular architecture that promotes even polymerization without requiring extensive external optimization of catalyst amounts or temperature profiles, thereby reducing the time needed for condition setting
3Productivity
If the polymerization temperature is increased to reduce polymerization time, then productivity is improved, but manufacturing precision deteriorates due to increased striae occurrence
Solution Approach 1:
The patent fundamentally changes the chemical composition by incorporating urethaneurea compounds with cyclic structural units, which modify the polymerization kinetics and thermodynamics. This compositional parameter change allows the system to achieve rapid polymerization at elevated temperatures while maintaining optical quality, breaking the conventional trade-off between speed and precision that plagues standard polymerization 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 use of the urethaneurea compound in the polymerizable composition significantly reduces the occurrence of striae and white turbidity, enabling the production of high-quality optical members with improved polymerization efficiency and reduced man-hours for setting polymerization conditions.
Implementation Method 1
a polymerizable composition for optical member containing a polymerizable component and a urethaneurea compound
Data Source
AI summary
The present invention relates to [1] a polymerizable composition for optical member containing a polymerizable component and a urethaneurea compound having a structural unit derived from tolylene diisocyanate in an amount of 0.1 to 10 parts by mass based on 100 parts by mass of a total amount of the polymerizable component; [2] a production method of an optical member, including a step of injecting the polymerizable composition of [1] into a molding die, and a step of polymerizing the polymerizable composition; and [3] a spectacle lens including a spectacle lens substrate obtained by the production method of [2].