| 摘要 |
PROBLEM TO BE SOLVED: To obtain an ester compound capable of raising a nematic isotropic phase transition temperature (hereafter referred to as N-I point) of a liquid crystal composition and lowering a threshold voltage Vth. SOLUTION: This ester compound is shown by formula I (R is an alkyl) such as a compound of formula II. The compound of formula I can be obtained, for example, by treating a carboxylic acid of formula III with a halogenating agent such as thionyl chloride, phosphorus pentoxide, etc., to give an acid chloride, then reacting the acid chloride with a substituted phenol of formula IV in an inert organic solvent such as pyridine, etc., washing the reaction mixture with water, drying and recrystallizing the mixture. At least one kind of the compound of formula I is mixed with a liquid crystal composition to raise the N-I point of the liquid crystal composition and to lower a threshold voltage Vth. Consequently a liquid crystal display apparatus having excellent characteristics as a liquid crystal material, a wide temperature range and a wide angle of visibility can be provided.
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