TN liquid crystals generally have short molecular chains, and it is difficult to adjust the characteristic parameters, so the characteristic differences are more obvious. STN liquid crystal is to calculate the required liquid crystal molecular length and its optical and electrical performance parameters through the STN display data model, and then chemically synthesize a variety of monomers with similar molecular chain structures with different polar molecular groups, which are mixed with each other to form a A series of liquid crystals with similar properties. Different series of STN liquid crystals often have completely different molecular chains. Therefore, different series of STN liquid crystals cannot be mixed with each other unless the manufacturer indicates that they can be mixed with each other.

There are polar groups and non-polar groups in liquid crystal molecules. Liquid crystal monomers with polar group molecules mainly determine the threshold voltage parameters of mixed liquid crystals. Liquid crystal monomers without polar group molecules It mainly determines the refractive index and clearing point of the mixed liquid crystal. Monomers with polar groups and monomers without polar groups in liquid crystals will appear isomeric chromatographic phenomenon under standing conditions.

In order to increase the standby time of the machine itself and enhance the driving ability of the liquid crystal display, liquid crystal manufacturers have developed low-threshold voltage liquid crystals that can meet the conditions of low voltage and low frequency. It has the following properties:

The monomers with polar groups and the monomers without polar groups in low-threshold voltage liquid crystals have a shorter time for isomeric chromatographic phenomenon under static conditions.

More monomer components with polar groups also mean that the liquid crystal is more likely to bind water molecules and other polar free ions, thereby reducing the capacitive resistance of the liquid crystal, resulting in an increase in leakage current and power consumption. big.

When the molecular chain of the polar liquid crystal monomer is excited by ultraviolet rays, the polar molecular groups are easily entangled with each other to form neutral molecular groups, which become non-smectic dislocation state, thus causing the threshold voltage to increase, and the anchorage of the guiding layer It is not sensitive to the fixed action and loses the low voltage driving ability.