Multi-reactive mesogen system for polymer-stabilised vertical alignment liquid crystal displays

ABSTRACT

This study investigates a new binary reactive mesogen system, consisting of a photoinitiator and a UV-B reactive mesogen (RM), for polymer-stabilised vertical alignment (PS-VA) and compares it to an industry standard RM. Analysis of the achieved PS-VA by relevant parameters, such as tilt generation, showed that the new material combination shows the same high level of performance as the industry standard. Additionally, the new materials were tested on their reliability parameters such as voltage holding ratio and residual monomer content and completely fulfiled the high industry requirements. The advantages of this novel binary system lie in the fact that it adds an additional degree of freedom allowing for the system to be better adapted to new liquid crystal hosts and the design of the UV-B RM. It is designed to be inactive under irradiation conditions in production and in the finished display product, unless the photoinitiator is present. This opens up the possibility for a significant decrease in production time by making the need for complete removal of residual monomer during production obsolete.

Graphical abstract

KEYWORDS:

• Liquid crystal
• polymer-stabilised vertical alignment (PS-VA)
• liquid crystal displays (LCD)
• reactive mesogens

Acknowledgments

The authors thank Merck KGaA for its financial support. We are also grateful to Prof. Dr. Matthias Bremer and Dr. Dmitry Ushakov and their labs for preparing the materials tested in this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).