Triarylmethane Monomers for High-Refractive Optical Resins

Solution Overview

Problem

Existing optical resins, particularly polycarbonate resins, lack high refractive index, low Abbe number, good thermoplastic processability, and sufficient moisture and heat resistance, making them unsuitable for mass production of optical devices.

Innovation Solution

The use of triarylmethane compounds as monomers in the preparation of optical resins, specifically polycarbonate resins, which provide higher refractive indices, maintain transparency, and do not impair other optical properties, with the ability to be easily prepared in high yields and purity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If optical glass is used for optical lenses, then heat resistance, transparency, size stability, and chemical resistance are improved, but material costs increase and moldability decreases

Engineering Contradiction:

Improveheat resistanceVSAvoidmoldability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent modifies the chemical structure of polycarbonate monomers by introducing specific aromatic groups and substituents (R1-R6, Ar, X1-X4) to change the material parameters. This achieves high refractive index (1.55-1.65) and low Abbe number (20-30) while maintaining thermoplastic processability and moldability, resolving the contradiction between optical performance and ease of manufacture

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates copolycarbonate resins by combining different monomer units (formula I monomers with other polycarbonate monomers) to achieve composite material properties. The resulting copolymers exhibit both the desired optical properties (high refractive index, low Abbe number) and good thermoplastic processability, resolving the contradiction between optical performance and manufacturability

Inventive Principle:

Principle #40Composite materials

2Weight of moving object

If polycarbonate resins with higher refractive index are used, then lens size and weight are reduced, but thermoplastic processability and moldability deteriorate

Engineering Contradiction:

Improvelens weightVSAvoidthermoplastic processability

Core Design Contradiction:

Weight of moving objectVSEase of manufacture

Solution Approach 1:

The patent carefully balances the chemical structure parameters of monomer formula (I) to achieve high refractive index (1.55-1.65) while maintaining appropriate glass transition temperature (80-150°C) and melt flow characteristics. The specific structural parameters (R1-R6, Ar, X1-X4) are optimized to ensure both high optical performance and good thermoplastic processability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs copolycarbonate resins combining monomer (I) units with other polycarbonate monomer units in specific ratios (5-50 mol%). This composite approach allows the high refractive index component to provide optical performance while the other monomer components maintain thermoplastic processability and moldability

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If copolycarbonate resins with high refractive index are synthesized, then optical properties are improved, but moisture resistance and heat resistance are insufficient

Engineering Contradiction:

Improverefractive indexVSAvoidmoisture resistance

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent modifies the chemical structure of polycarbonate monomers by introducing specific aromatic groups and substituents (R1-R6, Ar, X1-X4) to change the material parameters. This achieves high refractive index (1.55-1.65) and low Abbe number (20-30) while maintaining thermoplastic processability and moldability, resolving the contradiction between optical performance and ease of manufacture

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates copolycarbonate resins by combining different monomer units (formula I monomers with other polycarbonate monomers) to achieve composite material properties. The resulting copolymers exhibit both the desired optical properties (high refractive index, low Abbe number) and good thermoplastic processability, resolving the contradiction between optical performance and manufacturability

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS12570593B2Triarylmethane compounds

Publication Date: 2026.03.10 MITSUBISHI GAS CHEM CO INC

AI summary

The present invention relates to triarylmethane compounds of the formula (I), which suitable as monomers for preparing thermoplastic resins having beneficial optical properties and which can be used for producing optical devices. R1 , R2 are e.g. hydrogen; Y is an alkylene group having 2, 3 or 4 carbon atoms, Ar is selected from mono- or polycyclic aryl and mono- or polycyclic hetaryl; X1, X2, X3, X4 are CH, C—Rx or N, provided that in each ring at most two of X1, X2, X3, X4 are N; Rx is e.g. halogen, CN or CH═CH2. The invention also relates to thermoplastic resins comprising a polymerized unit of the compound of formula (I).