Liquid Crystal Composition for Optically Anisotropic Layers

Solution Overview

Problem

Existing liquid crystal compositions used for forming optically anisotropic layers require stringent aging conditions for alignment, limiting their application in image display devices with relaxed time and temperature constraints.

Innovation Solution

A liquid crystal composition is developed by blending a polymer obtained from polymerizing a monomer with two or more radically polymerizable double bonds and one or more hydroxyl groups with a liquid crystal compound and a photo-alignment compound, enhancing alignment and phase separation properties even under relaxed aging conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional liquid crystal compositions are used to form optically anisotropic layers, then alignment properties can be maintained, but stringent aging conditions (time and temperature) are required

Engineering Contradiction:

Improvealigning propertiesVSAvoidaging time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The invention changes the chemical composition parameters of the liquid crystal system by introducing a polymerizable liquid crystal compound with specific molecular structure (Formula 1) and a photopolymerization initiator. This allows the system to transition from requiring thermal aging to requiring photopolymerization, fundamentally changing the activation mechanism from thermal to photochemical.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces the thermal aging mechanism with a photopolymerization mechanism. Instead of relying on heat and time for alignment, the system uses light irradiation to trigger polymerization that locks in the aligned state, substituting a photochemical process for a thermal process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If conventional liquid crystal compositions are used, then optically anisotropic layers can be formed, but high temperature aging conditions are required

Engineering Contradiction:

Improveplane stateVSAvoidaging temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The invention replaces the thermal aging mechanism with a photopolymerization mechanism. Instead of relying on heat and time for alignment, the system uses light irradiation to trigger polymerization that locks in the aligned state, substituting a photochemical process for a thermal process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the chemical composition parameters of the liquid crystal system by introducing a polymerizable liquid crystal compound with specific molecular structure (Formula 1) and a photopolymerization initiator. This allows the system to transition from requiring thermal aging to requiring photopolymerization, fundamentally changing the activation mechanism from thermal to photochemical.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If polymerization is used to form optically anisotropic layers, then alignment can be fixed, but control over polymerization timing and uniformity becomes difficult

Engineering Contradiction:

Improvealignment fixationVSAvoidpolymerization control

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The invention introduces a photopolymerization initiator that responds to light irradiation, creating a controllable feedback mechanism. The polymerization process is activated only when exposed to light of specific wavelength and intensity, allowing precise control over when and how polymerization occurs, ensuring uniform alignment fixation throughout the layer.

Inventive Principle:

Principle #23Feedback

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 maintains excellent plane state and aligning properties of optically anisotropic layers, enabling their formation under less stringent temperature and time conditions, thus improving the efficiency and flexibility in producing optical laminates and image display devices.

Implementation Method 1

a polymer obtained by polymerizing a monomer having two or more radically polymerizable double bonds

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

a photo-alignment compound

Methodology Applied

Scientific EffectPhoto-alignment: Photochromism

Data Source

PatentUS11111437B2Liquid crystal composition, optically anisotropic layer, optical laminate, and image display device

Publication Date: 2021.09.07 FUJIFILM CORP

AI summary

A liquid crystal composition contains a liquid crystal compound; a photo-alignment compound; and a polymer obtained by polymerizing a monomer having two or more radically polymerizable double bonds and one or more hydroxyl groups.