Optical Polymer Composition for Blue-Light Blocking Without Haze

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Solution Overview

Problem

Existing optical materials face a trade-off between high ultraviolet absorption (cut rate) and design properties such as transparency and coloration, as increasing the amount of ultraviolet absorbers leads to cloudiness and reduced transparency.

Innovation Solution

A polymerizable composition comprising an isocyanate compound, an active hydrogen compound, and a specific ultraviolet absorber represented by General Formula (1) with an ester bond, which includes a polythiol compound and a compound with an episulfide group, allowing for a balanced high cut rate and design properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the amount of ultraviolet absorber is increased to achieve high blue light blocking, then the cut rate improves, but transparency deteriorates and cloudiness occurs

Engineering Contradiction:
Improveblue light blockingVSAvoidtransparency
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical structure parameters of the ultraviolet absorber by introducing ester bond-containing groups (such as carboxylate ester, sulfonate ester, or carbonate ester groups) at specific positions of the benzotriazole core structure. This structural modification enables the absorber to achieve high blue light blocking performance while maintaining transparency, resolving the trade-off between these two properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polymer system combining isocyanate compounds with active hydrogen compounds (polyols, polythiols, or amines) containing the ester-bonded ultraviolet absorber. This composite material approach integrates the UV absorption function within the polymer matrix itself, achieving both high cut rate and maintained transparency through synergistic material composition.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If the amount of ultraviolet absorber is increased to achieve high cut rate, then blue light blocking improves, but coloration deteriorates

Engineering Contradiction:
Improvecut rateVSAvoidcoloration
Core Design Contradiction:
Object-affected harmful factorsVSShape

Solution Approach 1:

The patent modifies the molecular structure parameters of the ultraviolet absorber by attaching ester bond-containing functional groups to the benzotriazole core. This structural change alters the electronic properties and light absorption characteristics of the molecule, enabling it to block blue light effectively while minimizing unwanted coloration in the visible spectrum.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If conventional ultraviolet absorbers are used to block blue light, then cut rate improves, but mechanical strength deteriorates

Engineering Contradiction:
Improveblue light blockingVSAvoidmechanical strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent merges the ultraviolet absorption function with the polymer matrix by incorporating ester bond-containing groups that can participate in or reinforce the polymer network. The ultraviolet absorber is not merely added as a separate additive but is chemically integrated into the polymer structure through ester bonds, ensuring both optical performance and mechanical strength are maintained.

Inventive Principle:
Principle #5Merging (Combining)

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 composition effectively blocks blue light of approximately 420 nm while maintaining transparency and design properties, preventing cloudiness and color deterioration.

Implementation Method 1

an ultraviolet absorber having an average light transmittance of 0.5% or less in a wavelength region of 300 nm to 400 nm

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

a polymerizable composition for an optical material including an isocyanate compound, an active hydrogen compound, and a predetermined ultraviolet absorber

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentEP3922656B1Polymerizable composition for optical materials, optical material and use of same
Publication Date: 2026.01.14 MITSUI CHEMICALS INC
  • EP3922656B1 patent drawingFigure 1
  • EP3922656B1 patent drawingFigure 2
  • EP3922656B1 patent drawing

AI summary

A polymerizable composition for an optical material of the present disclosure includes (A) an isocyanate compound, (B) at least one active hydrogen compound selected from the group consisting of a polythiol compound having two or more mercapto groups, a hydroxythiol compound having one or more mercapto groups and one or more hydroxyl groups, a polyol compound having two or more hydroxyl groups, and an amine compound, and (C) an ultraviolet absorber represented by General Formula (1).