The present invention provides a compound represented by general formula (1) as well as a liquid crystal composition containing this compound and a liquid crystal display using this liquid crystal composition. Using the compound represented by general formula (1) as a component of a liquid crystal composition makes it possible to obtain a liquid crystal composition having a low viscosity (η), a high Δn, suitable T.sub.-i, high miscibility with other liquid crystal compounds, and presenting a liquid crystal phase over a wide temperature range. This is therefore extremely useful as a structural component of a liquid crystal composition for a liquid crystal display requiring a high speed response.

A liquid crystal (LC) medium comprising a polymerizable compound, a process for its preparation, its use for optical, electro-optical and electronic purposes, such as LC displays, including LC displays of the polymer sustained alignment (PSA) type, and LC displays, including PSA displays, comprising the LC medium.

Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, low viscosity, suitable optical anisotropy 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 large negative dielectric anisotropy as a first component, and a specific compound having high maximum temperature or low viscosity as a second component, and may contain a specific compound having negative dielectric anisotropy as a third component, or a specific compound having a polymerizable group as an additive.

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 and large dielectric anisotropy, or the liquid crystal composition 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 optical anisotropy as a first component, and a specific compound having positive dielectric anisotropy as a second component, and may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having positive dielectric anisotropy as a fourth component, or a specific compound having negative dielectric anisotropy as a fifth component.

A liquid crystal composition containing a polymerizable compound of the present invention has excellent characteristics of being able to prepare a PSA type liquid crystal display element with no problem of depositing in a wide temperature range, having high polymerization speed, high liquid crystal alignment regulation force after polymerization, excellent display qualities with no display unevenness, and excellent display characteristics with no defects in display characteristics such as image sticking and is appropriate as a liquid crystal composition in a practical use. Further, the liquid crystal display element with the above-described liquid crystal composition can be appropriately used for a PSA type liquid crystal display element.

A liquid crystal composition containing a polymerizable compound of the present invention has excellent characteristics of being able to prepare a PSA type liquid crystal display element with no problem of depositing in a wide temperature range, having high polymerization speed, high liquid crystal alignment regulation force after polymerization, excellent display qualities with no display unevenness, and excellent display characteristics with no defects in display characteristics such as image sticking and is appropriate as a liquid crystal composition in a practical use. Further, the liquid crystal display element with the above-described liquid crystal composition can be appropriately used for a PSA type liquid crystal display element.

Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, low viscosity, suitable optical anisotropy 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 large negative dielectric anisotropy as a first component, and a specific compound having high maximum temperature or low viscosity as a second component, and may contain a specific compound having negative dielectric anisotropy as a third component, or a specific compound having a polymerizable group as an additive.

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 and large dielectric anisotropy, or the liquid crystal composition 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 optical anisotropy as a first component, and a specific compound having positive dielectric anisotropy as a second component, and may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having positive dielectric anisotropy as a fourth component, or a specific compound having negative dielectric anisotropy as a fifth component.

The present invention relates to a liquid crystal (LC) medium comprising a polymerizable compound, to a process for its preparation, to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in an LC display of the polymer sustained alignment (PSA) type, and to an LC display, especially a PSA display, comprising it.