Photoreactive Polymer with Multi-Cyclic Main Chain for LCD Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photoreactive polymers used in liquid crystal display (LCD) alignment layers suffer from low thermal stability and slow photoreaction rates, leading to inefficient liquid crystal alignment and reduced contrast in large-size displays.
Innovation Solution
A multi-cyclicmulticyclic compound with a photoactive group is used as the main chain in a polymer, allowing for high glass transition temperatures and rapid photoreaction rates, overcoming the limitations of conventional polymers by forming a polymer with a catalyst mixture containing a Group 10 transition metal and a cocatalyst for improved alignment layer performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polycinnamate-based polymer is used for alignment layer, then photoalignment characteristics are excellent, but thermal stability is low
Solution Approach 1:
The invention uses a copolymer composed of a first monomer unit (providing thermal stability through rigid aromatic structures) and a second monomer unit (providing photoalignment functionality through cinnamate groups). This composite structure combines the advantages of both components, achieving high thermal stability (glass transition temperature of 100°C or higher) while maintaining excellent photoalignment characteristics.
2Stability of the object's composition
If photoreactive group is bound to main chain of polymer, then polymer structure is stable, but photoreaction rate is slow
Solution Approach 1:
The invention places the photoreactive cinnamate groups at the side chains rather than the main chain, creating local photoactive regions that can respond quickly to light irradiation. The main chain maintains structural stability through rigid aromatic monomer units, while the side chains provide rapid photoreaction capability, achieving both stability and speed requirements.
3Productivity
If alignment treatment is performed for insufficient time, then production efficiency is high, but liquid crystal alignment is insufficient and contrast deteriorates
Solution Approach 1:
The invention changes the photoreaction rate parameter by optimizing the molecular structure of the monomers and the arrangement of photoreactive groups. This structural modification accelerates the photoreaction kinetics, allowing sufficient liquid crystal alignment to be achieved in shorter irradiation times, thereby improving production efficiency without sacrificing alignment quality.
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 resulting polymer exhibits excellent thermal stability and enhanced photoreaction rates, enabling efficient liquid crystal alignment and improved contrast in liquid crystal display devices, particularly suitable for large-size displays.
Implementation Method 1
Photoalignment refers to a mechanism for aligning of liquid crystals in which a photoreactive group bound to a polymer reacts when exposed to prepolarized ultraviolet rays such that a main chain of the polymer is aligned in a predetermined direction.
Implementation Method 2
liquid crystals are aligned by photopolymerisation resulting from optical irradiation
Data Source
AI summary
Provided are a photoreactive polymer that includes a multi-cyclicmulticyclic compound at as its main chain and a method of preparing the same. The photoreactive polymer exhibits excellent thermal stability since it includes a multi-cyclicmulticyclic compound having a high glass transition temperature at as its main chain. In addition, the photoreactive polymer has a relatively large vacancy so that a photoreactive group can move relatively freely in the main chain therein. As a result, a slow photoreaction rate, which is a disadvantage of a conventional polymer material used to form an alignment layer for a liquid crystal display device, can be overcome.