Polymerizable Composition for Liquid Crystal Devices

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The manufacturing process of liquid crystal displays (LCDs) is costly and complex, requiring large-scale production lines and equipment, and existing polymer-dispersed liquid crystal (PDLC) technologies face challenges in achieving high contrast ratios and low energy consumption while maintaining thermal stability.

Innovation Solution

A liquid crystal device is developed using an alignable polymer network that can orient and reorder liquid crystals with external actions, such as voltage application, incorporating a polymerizable composition with bifunctional and multifunctional acrylate compounds to form a polymer network, which includes a liquid crystal compound, and is manufactured using a squeeze coating method to achieve high contrast ratios and low driving voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional LCD manufacturing process is used, then high image quality can be achieved, but the manufacturing cost and process complexity increase significantly

Engineering Contradiction:
Improveimage qualityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the liquid crystal layer formation step from the complex conventional LCD manufacturing process by using a polymer-dispersed liquid crystal (PDLC) structure. This allows the liquid crystal to be dispersed in a polymer matrix that can be applied as a coating, eliminating the need for precise alignment layers and complex electrode structures while maintaining display functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a composite material system consisting of liquid crystal droplets dispersed in a polymer matrix. This composite structure combines the optical properties of liquid crystals with the mechanical stability of polymers, achieving both high image quality and simplified manufacturing through coating processes.

Inventive Principle:
Principle #40Composite materials

2Device complexity

If PDLC technology is used to simplify manufacturing, then process complexity decreases, but achieving high contrast ratios and low energy consumption becomes difficult

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidcontrast ratio and energy efficiency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent optimizes the PDLC performance by carefully controlling parameters including the size and distribution of liquid crystal droplets, the polymer matrix composition, and the coating process conditions. These parameter adjustments enable the simplified PDLC structure to achieve high contrast ratios and low energy consumption comparable to conventional LCDs.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality optimization by controlling the spatial distribution and size of liquid crystal droplets within the polymer matrix. By creating uniform droplet distributions and optimizing local droplet concentrations, the device achieves high contrast ratios and efficient voltage switching despite the simplified manufacturing process.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If PDLC structure is used, then manufacturing cost decreases, but thermal stability becomes challenging to maintain

Engineering Contradiction:
Improvemanufacturing costVSAvoidthermal stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent uses the polymer-liquid crystal composite structure where the polymer matrix provides thermal stability while the dispersed liquid crystal droplets maintain optical functionality. The polymer network structure resists thermal degradation and maintains the structural integrity of the device under varying temperature conditions, addressing the thermal stability challenge of cost-reduced PDLC manufacturing.

Inventive Principle:
Principle #40Composite materials

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 device exhibits excellent transparency, high contrast ratios, and thermal stability, enabling efficient manufacturing and operation with low energy consumption, suitable for various optical applications like smart windows and flexible displays.

Implementation Method 1

a liquid crystal compound and a precursor of an alignable polymer network... The polymer network capable of aligning the liquid crystal compound... The liquid crystal compound which can be dispersed in the alignable polymer network may be orientationally ordered by an action of the alignable polymer network

Methodology Applied
Scientific EffectLiquid crystal alignment: Liquid Crystals

Implementation Method 2

a polymerizable composition comprising a liquid crystal compound and a precursor of an alignable polymer network... polymerizing a layer formed by coating a polymerizable composition

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP2933273B1Polymerizable composition
Publication Date: 2020.09.16 LG CHEM LTD
  • EP2933273B1 patent drawingFigure 1~2
  • EP2933273B1 patent drawingFigure 3
  • EP2933273B1 patent drawingFigure 4~5

AI summary

Provided are a liquid crystal device, a composition capable of forming a liquid crystal layer, a method of manufacturing the liquid crystal device, a system for manufacturing the liquid crystal device, and a use of the liquid crystal device. The liquid crystal device is a device capable of exhibiting, for example, a normally white or black mode, which may exhibit a high contrast ratio and be driven with a low driving voltage, and exhibit excellent durability such as thermal stability. Such a liquid crystal device may be applied to various optical modulators such as a smart window, a window protective film, a flexible display device, an active retarder for displaying 3D images, or a viewing angle control film.