Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, a large elastic constant and large negative dielectric anisotropy, or having a suitable balance regarding at least two of the characteristics; and an AM device including the composition. The liquid crystal composition contains a specific compound having small viscosity and negative dielectric anisotropy as a first component, and a specific compound having negative dielectric anisotropy as a second component, and may contain a specific compound having high maximum temperature or small viscosity as a third component, or a specific compound having a polymerizable group as a first additive.

Provided are a liquid crystal composition that contains a polar compound having a polymerizable group, in which vertical alignment of liquid crystal molecules can be achieved by action of the compound (or polymer), and a liquid crystal display device including the composition. The composition satisfies at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and heat. The composition is a nematic liquid crystal composition that has negative dielectric anisotropy and contains the polar compound as a first additive, and may contain a specific liquid crystal compound having large negative dielectric anisotropy as a first component, a specific liquid crystal compound having high maximum temperature or small viscosity as a second component and a polymerizable compound as a second additive, and the liquid crystal display device includes the composition.

Provide is a polar compound having high chemical stability, high capability of aligning liquid crystal molecules, high solubility in a liquid crystal composition, and a large voltage holding ratio when the compound is used in a liquid crystal display device. A compound represented by formula (1) is applied.

##STR00001##

For example, in formula (1), P.sup.1 is any one of formulas (1b) to (1i), Sp is a single bond, Z is COO, and A is 1,4-phenylene.

##STR00002##

As a material to be used in a device used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz, a liquid crystal composition having a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, large optical anisotropy, small dielectric loss, and thermal stability in a frequency range used for phase control and having good balance between characteristics is required. A liquid crystal composition used for phase control of an electromagnetic wave signal with any frequency of 1 MHz to 400 THz containing at least one compound selected from a group consisting of compounds represented by formula (1) and at least one compound selected from a group consisting of compounds represented by formula (2).

##STR00001##

Provided is a reverse mode light scattering type liquid crystal device that is capable of withstanding practical use, has a low driving voltage, and shows a high haze when voltage is applied and a low haze when no voltage is applied. A reverse mode liquid crystal device includes a light control layer and at least a pair of electrodes, wherein the light control layer includes a polymerization product of a polymerizable material including: (A) a liquid crystal composition, (B) a perpendicular alignment agent, and (C) at least one polymerizable compound selected from polymer forming monomers and polymer forming oligomers.

Liquid-crystalline (LC) media having positive dielectric anisotropy and liquid-crystal displays (LCDs) containing these media, especially displays addressed by an active matrix and in particular LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS PS-FFS, SA-HB-FFS, polymer stabilised SA-HB-FFS, positive VA or positive PS-VA type.

Shown is a compound represented by formula (1). For example, R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons; M.sup.1 is methyl; and R.sup.2, M.sup.2 and M.sup.3 are hydrogen. ##STR00001##

A liquid crystal composite that contains a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, large optical anisotropy and large positive dielectric anisotropy, and that is suitable for dimming, or having a suitable balance regarding at least two of the characteristics; and a liquid crystal dimming device having the liquid crystal composite. The liquid crystal composite contains a polymer and a liquid crystal composition containing a specific compound having large positive dielectric anisotropy. The liquid crystal composite may further contain a specific compound having high maximum temperature or low minimum temperature; or a specific compound having large negative dielectric anisotropy.

The present invention relates to a liquid crystal display device. The liquid crystal display device of the present invention comprises a first substrate, a second substrate, and a liquid crystal composition disposed between said first substrate and said second substrate, wherein said first substrate and said second substrate are disposed in parallel and opposite to each other, with the distance between said first substrate and said second substrate being 2.5 m to 3.2 m; alignment layers are disposed on the sides of said first and second substrates that are close to said liquid crystal composition; and said alignment layers are provided with vertical alignment films that allow liquid crystal molecules in said liquid crystal composition to be arranged roughly perpendicular to said first or second substrate.

The present invention relates to a liquid crystal display device. The liquid crystal display device of the present invention comprises a first substrate, a second substrate, and a liquid crystal composition disposed between said first substrate and said second substrate, wherein said first substrate and said second substrate are disposed in parallel and opposite to each other; alignment layers are disposed on the sides of said first and second substrates that are close to said liquid crystal composition; and said alignment layers are provided with vertical alignment films that allow liquid crystal molecules in said liquid crystal composition to be arranged roughly perpendicular to said first and second substrates, with said liquid crystal molecules having a pretilt angle of 88.5 to 89.5.