Liquid Crystal Composition for Wide Temperature and Low Viscosity

The patent employs a composite liquid crystal composition comprising four distinct types of compounds (formulas I, II, III, and IV) with specific structural characteristics. Each compound type contributes different properties: Formula I compounds provide thermal stability with their bicyclic structures, Formula II compounds contribute to optical anisotropy, Formula III compounds adjust viscosity through their specific ring structures, and Formula IV compounds enhance dielectric properties. The synergistic combination of these diverse compounds creates a composition that simultaneously achieves wide temperature range and low viscosity, resolving the technical contradiction between these two parameters.

The patent systematically varies key structural parameters of the liquid crystal compounds including alkyl chain lengths (R1-R7), alkenyl group configurations (Z1-Z5), and ring structures to optimize performance. By adjusting these molecular parameters within specific ranges, the composition achieves optimal balance between temperature range and viscosity. For instance, varying the carbon atom numbers in alkyl and alkenyl groups allows fine-tuning of intermolecular forces, thereby controlling both phase transition temperatures and viscosity simultaneously.

The patent optimizes molecular parameters to achieve low viscosity (reducing response time) while maintaining appropriate dielectric anisotropy (reducing threshold voltage and power consumption). The specific structural parameters of compounds I-IV, including alkyl chain lengths and ring structures, are adjusted to balance these competing requirements, enabling fast response with low power consumption.

The composite composition combines compounds with complementary properties: some compounds contribute to low viscosity for fast response, while others provide high dielectric anisotropy for low threshold voltage. This synergistic combination resolves the contradiction between response time and power consumption by distributing functional requirements across multiple compound types.