Episulfide Optical Composition for Lens Mold Release and Dyeability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical materials based on episulfide compounds face challenges with mold release failure and inadequate dyeability, leading to reduced yield and insufficient surface accuracy in plastic lenses.

Innovation Solution

A composition for optical materials containing a specific episulfide compound, represented by formula (1) and (2), with controlled ratios and combined with polythiol, polyisocyanate, and sulfur, along with a polymerization catalyst, to enhance mold release characteristics and dyeability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If episulfide compound is used for high refractive index, then optical properties are improved, but mold release characteristics deteriorate causing breakage

Engineering Contradiction:

Improverefractive indexVSAvoidmold release characteristics

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent uses a composite material system combining episulfide compound (for high refractive index) with silicone oil (for mold release characteristics) and polythiol (for crosslinking). This composite approach allows simultaneous achievement of optical performance and manufacturing reliability by distributing functions across different components.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

Silicone oil acts as an intermediary substance that mediates between the episulfide compound and the mold surface. It provides the mold release function without interfering with the optical properties of the lens, allowing the episulfide compound to maintain high refractive index while enabling successful demolding.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Length of moving object

If episulfide compound is used for high refractive index, then lens thickness is reduced, but dyeability deteriorates

Engineering Contradiction:

Improvelens thicknessVSAvoiddyeability

Core Design Contradiction:

Length of moving objectVSEase of manufacture

Solution Approach 1:

Polythiol serves as an intermediary that enhances dyeability without affecting the thin lens structure. It introduces functional groups that facilitate dye absorption and bonding, enabling effective coloring of thin high-refractive-index lenses that would otherwise resist dyeing.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If mold release characteristics are increased to prevent breakage, then surface accuracy deteriorates due to lens release during polymerization

Engineering Contradiction:

Improvemold release characteristicsVSAvoidsurface accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent creates a dynamic, staged release mechanism where the lens remains firmly attached during polymerization (maintaining surface accuracy) and releases automatically after curing (preventing breakage). The silicone oil-polythiol system provides conditional adhesion that changes from strong to weak based on the polymerization state.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10065940B2Episulfide compound and optical material composition containing same

Publication Date: 2018.09.04 MITSUBISHI GAS CHEM CO INC

AI summary

According to the present invention, it is possible to provide an optical material composition that contains an episulfide compound represented by formula (1) and an episulfide compound represented by formula (2). According to this optical material composition, it is possible to suppress a reduction in the yield rate caused by molding defects, and possible to obtain an optical material having excellent dyeability.(In formula (1), m and p are each an integer between 0 and 4, and n and q are each an integer between 0 and 2.)(In formula (2), m is an integer between 0 and 4 and n is an integer between 0 and 2).