Properties of Voltage Holding Ratios of Liquid Crystal Cells Using Organic-Solvent-Soluble Polyimide Alignment Films

We have synthesized organic-solvent-soluble polyimides containing various diamine moieties. The voltage holding ratios of liquid crystal (LC) cells using these polyimides as alignment films have been investigated. The results show that the structures of polyimides considerably affect the characteristics of the voltage holding ratios of LC cells. It is shown that the large polarization in polyimides, which is evaluated from the calculation of partial atomic charges of diamines and the capacitance-voltage measurement of LC cells, gives rise to lower voltage holding ratios of LC cells.