Optical Material Composition Preventing White Turbidity

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Solution Overview

Problem

The challenge is to predict and prevent white turbidity in optical materials after polymerization and curing, as it renders defective products and results in significant losses, especially in resin compositions containing polythiol compounds.

Innovation Solution

A composition for optical materials is developed using a polythiol compound with specific ranges of ammonium cation and thiocyanate anion concentrations, along with a polyepoxy or polyepisulfide compound, where the ammonium cation concentration is between 0.1 to 150 µmol/kg, thiocyanate anion concentration is between 0.1 to 300 µmol/kg, and their ion concentration product is between 0.01 to 15000 (µmol/kg)², to ensure the prevention of white turbidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a polythiol compound is used for optical materials, then high refractive index and impact resistance are achieved, but white turbidity occurs after polymerization

Engineering Contradiction:
Improveimpact resistanceVSAvoidtransparency
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the concentration parameters of ammonium cations and thiocyanate anions in the polythiol compound to specific ranges (ammonium cation: 0.01-10 µmol/kg, thiocyanate anion: 0.01-5 µmol/kg). This parameter optimization prevents white turbidity while maintaining the high impact resistance and refractive index properties of polysulfide resins.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If polythiol compound concentrations are increased for better optical properties, then refractive index improves, but white turbidity occurrence increases

Engineering Contradiction:
Improverefractive indexVSAvoidwhite turbidity
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The invention optimizes the concentration parameters of ammonium cations and thiocyanate anions to specific ranges, allowing the polythiol compound to achieve high refractive index without causing white turbidity. The controlled ion concentrations prevent adverse reactions that lead to turbidity while maintaining optimal optical properties.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional polythiol compounds are used, then manufacturing is simple, but product quality cannot be predicted before curing

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidquality prediction
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention replaces empirical quality assessment with a scientific measurement system based on ion concentration analysis. By measuring ammonium cation and thiocyanate anion concentrations with instruments like ion chromatographs, manufacturers can predict and ensure product quality before polymerization, transitioning from trial-and-error to precision control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 prediction and prevention of white turbidity in optical materials before polymerization, ensuring the quality of the final product and reducing defects, thereby minimizing losses.

Implementation Method 1

a composition for optical materials containing a polythiol compound and a polyepoxy compound and/or a polyepisulfide compound

Methodology Applied
Scientific EffectPolymerization:

Data Source

PatentEP3059272B1Optical material composition and optical material using same
Publication Date: 2018.02.21 MITSUBISHI GAS CHEM CO INC

AI summary

The present invention is able to provide an optical material composition containing: a polythiol compound satisfying one of the belowmentioned i) through iii); and a polyepoxy compound and/or a polyepisulfide compound of which i) the ammonium cation concentration is 0.1-150 µmol/kg, ii) the thiocyanate anion concentration is 0.1-300 µmol/kg, or iii) the ammonium cation concentration is 0.1-150 µmol/kg, the thiocyanate anion concentration is 0.1-300 µmol/kg, and furthermore the ion concentration product of the ammonium cations and the thiocyanate anions is 0.01-15000 (µmol/kg)2.