| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composition having a very high resistivity and a low threshold voltage by forming it from a mixture containing at least one polar compound having a specified structure and positive dielectric anisotropy. SOLUTION: There is provided a liquid crystal medium being a mixture of a polar compound having positive dielectric anisotropy and comprising a mixture containing 10-50 wt.% compound represented by formula I and 30-70 wt.% compounds represented by formulae II to IV. This medium has a low viscosity at a low temperature (<=600 Pa.s at -30 deg.C, and <=1,800 Pa.s at -40 deg.C), a dielectric anisotropy >=3.5, a transparentizing point >=65 deg., a high resistivity, and a threshold voltage <=1.6V. In the formulae, X is F, Cl, CF3, OCF3, or the like; Y is H or F; ring A is trans-1,4-cyclohexylene or 1,4- phenylene; R is a 1-7C alkyl, an oxaalkyl, an alkenyl, or the like; Q is -C2H4-, -C4H8-, or -CO-O; and r is 0 or 1.
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