Polymerizable Composition Haze Control for Impact Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Polythiourethane-based resin molded products lack sufficient impact resistance, and achieving stable impact resistance in large-scale production of plastic spectacle lenses is challenging due to variations in polymerizable composition preparation.

Innovation Solution

A process involving the mixing of specific thiol compounds, tin compounds, and isocyanate compounds to achieve a polymerizable composition with a haze value of 0.05 or less, ensuring improved impact resistance and manufacturing stability by controlling the physical properties of the monomer components and catalysts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If polythiourethane-based resin is used to manufacture plastic spectacle lenses, then the lenses achieve high refractive index and good processability, but the impact resistance of the molded products is insufficient

Engineering Contradiction:
Improveimpact resistanceVSAvoidstability of impact resistance in large-scale production
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the haze value parameter of the polymerizable composition to 0.05 or less. This parameter control directly impacts the impact resistance of the molded products. The invention changes the physical-chemical parameters of the monomer components and catalysts to achieve stable impact resistance in large-scale production while maintaining high refractive index and good processability of polythiourethane-based resins.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the haze value of the polymerizable composition is not controlled, then the production process is simpler, but the impact resistance and manufacturing stability of the molded products deteriorate

Engineering Contradiction:
Improvehaze value controlVSAvoidcomplexity of production process
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by controlling the haze value of the polymerizable composition before the molding process. By pre-establishing the haze value at 0.05 or less in the composition stage, the invention ensures subsequent impact resistance and manufacturing stability without adding complex post-processing steps. This preliminary control of physical-chemical parameters simplifies the overall production process while achieving high manufacturing precision.

Inventive Principle:
Principle #10Preliminary action

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 process stabilizes the impact resistance of molded products and enhances the yield of optical materials by controlling the haze value of the mixed solution, allowing for consistent production of high-quality plastic spectacle lenses.

Implementation Method 1

mixing (A) at least one kind of thiol compound having at least two mercapto groups, (B) a tin compound represented by general formula (1), and (C) at least one kind of isocyanate compound having at least two isocyanato groups, to obtain a polymerizable composition for an optical material

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentEP3333207B1Method for manufacturing polymerizable composition for optical material, and polymerizable composition for optical material
Publication Date: 2020.01.15 MITSUI CHEMICALS INC

AI summary

A process for producing a polymerizable composition for an optical material of the present invention includes a step of mixing (A) at least one kind of thiol compound having at least two mercapto groups, (B) a tin compound represented by general formula (1), and (C) at least one kind of isocyanate compound having at least two isocyanato groups, in which the polymerizable composition for an optical material obtained in the above step has a haze value of 0.05 or less.         (R4)c- Sn - X4-c     (1)