The present invention relates to the technical field of liquid crystal displays, and particularly relates to a liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound and use thereof, wherein the liquid crystal composition of the present invention comprises, in percentages by weight, 1-50% of one or more compounds represented by general formula I and 10-70% of one or more compounds represented by general formula II, and may further comprise 0-30% of compounds represented by general formula III and/or 6-45% of one or more compounds represented by general formulas IV to XIII The liquid crystal composition provided by the present invention has a low rotational viscosity and a large elastic constant, is presented as having a shorter response time, and can significantly improve the display effect of a liquid crystal display when applied to TN, IPS and FFS mode displays.

A liquid-crystalline medium having a nematic phase, a dielectric anisotropy of 0.5 or more and a ratio of the dielectric constant perpendicular to the director (∈.sub.⊥) to the dielectric anisotropy (Δ∈), i.e. (∈.sub.⊥/Δ∈), of 2.0 or less and comprises one or more compounds of formula I

##STR00001##

wherein the parameters have the meaning given in the text.

An electro-optical display containing such a medium, particularly in an active-matrix display based on the IPS or FFS effect. Methods for using of the compounds of formula I for improvement of the transmission and/or response times of a liquid-crystalline medium which comprises one or more additional mesogenic compounds.

The invention relates to a liquid-crystalline medium, in particular based on a mixture of polar compounds, and to the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PA-VA, PALC, FFS, PS-FFS, IPS or PS-IPS effect.

Provided is a liquid crystal compound that can obtain a high-speed response and a sufficient contrast ratio in switching of a display device. A compound represented by formula (1) described below is utilized.

##STR00001##

In formula (1), ring A is naphthylene, phenantolylene or anthracenylene, and in the groups, at least one piece of hydrogen may be replaced by halogen, —CH.sub.3, —C.sub.2H.sub.5, —CF.sub.3, —CHF.sub.2, —CH.sub.2F, —OCF.sub.3, —OCHF.sub.2 or —OCH.sub.2F; and X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4 and Y.sup.5 are independently hydrogen or fluorine, but at least two or more of X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4 and Y.sup.5 is fluorine.

Provided is a liquid crystal compound that can obtain a high-speed response and a sufficient contrast ratio in switching of a display device. A compound represented by formula (1) described below is utilized.

##STR00001##

In formula (1), ring A is naphthylene, phenantolylene or anthracenylene, and in the groups, at least one piece of hydrogen may be replaced by halogen, —CH.sub.3, —C.sub.2H.sub.5, —CF.sub.3, —CHF.sub.2, —CH.sub.2F, —OCF.sub.3, —OCHF.sub.2 or —OCH.sub.2F; and X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4 and Y.sup.5 are independently hydrogen or fluorine, but at least two or more of X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, Y.sup.1, Y.sup.2, Y.sup.3, Y.sup.4 and Y.sup.5 is fluorine.

It is an object of the present invention to provide a liquid crystal composition having positive Δ∈, having a liquid crystal phase in a wide temperature range, having high solubility at low temperatures, having high ODF process compatibility, having a high specific resistance and voltage holding ratio, and being insensitive to heat and light. In order to achieve this object, there is provided a liquid crystal composition containing at least one compound represented by the following general formula (i) and at least one compound represented by the following general formula (ii). ##STR00001## (wherein R.sup.i1 denotes an alkyl group having 2 to 5 carbon atoms) ##STR00002## (wherein R.sup.ii1 and R.sup.ii2 independently denote an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and X.sup.ii1 and X.sup.ii2 independently denote a hydrogen atom or a fluorine atom)

It is an object of the present invention to provide a liquid crystal composition having positive Δ∈, having a liquid crystal phase in a wide temperature range, having high solubility at low temperatures, having high ODF process compatibility, having a high specific resistance and voltage holding ratio, and being insensitive to heat and light. In order to achieve this object, there is provided a liquid crystal composition containing at least one compound represented by the following general formula (i) and at least one compound represented by the following general formula (ii). ##STR00001## (wherein R.sup.i1 denotes an alkyl group having 2 to 5 carbon atoms) ##STR00002## (wherein R.sup.ii1 and R.sup.ii2 independently denote an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and X.sup.ii1 and X.sup.ii2 independently denote a hydrogen atom or a fluorine atom)

The present invention provides a novel liquid crystal material composition comprising one or more compound, in order to achieve the properties of low viscosity, high resistivity, good low-temperature mutual solubility, fast response, excellent transmission, and which can be used for a variety of fast response display modes. Since the working temperature of a LCD material is subjected to the temperature range of individual LC molecules, information can only be displayed in a specific temperature range of the specific liquid crystal macro-alignment phase. At low temperature, the viscosity of liquid crystal increases exponentially, which in turn substantially reduces the response speed and overall performances of the display system. The liquid crystal composition according to the present invention overcomes these problems with balanced chemical composition by achieving low viscosity, good low-temperature performance and excellent transmission in a wide range of LCD applications including TN, IPS or FFS displays, thus improving display performance.

The present invention provides a polymerizable liquid crystal composition containing at least one polymerizable liquid crystal compound (I) having one polymerizable functional group in its molecule, at least one polymerizable liquid crystal compound (II) having two polymerizable functional groups in its molecule, and at least one compound (III) having tree or more aromatic rings at least one of which is substituted by an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. Also, the present invention provides an optically anisotropic body using the polymerizable liquid crystal composition of the present invention.

The present invention provides a polymerizable liquid crystal composition containing at least one polymerizable liquid crystal compound (I) having one polymerizable functional group in its molecule, at least one polymerizable liquid crystal compound (II) having two polymerizable functional groups in its molecule, and at least one compound (III) having tree or more aromatic rings at least one of which is substituted by an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. Also, the present invention provides an optically anisotropic body using the polymerizable liquid crystal composition of the present invention.