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)

An object of the present invention is to provide an optical film having excellent alignment, and a polarizing plate and an image display device using the same. The optical film of the present invention is an optical film having at least an optically anisotropic layer, and the optically anisotropic layer contains a smectic liquid crystal compound not including a fluorine atom and a compound partially having a cyclohexane ring in which the hydrogen atom is substituted with a linear alkyl group.

To suppress a phenomenon where an optical axis of the optically anisotropic layer is tilted when the optically anisotropic layer is produced by using a liquid crystalline compound showing smectic phase as a materials showing a higher level of orderliness. An optically anisotropic layer wherein a polymerizable composition, containing one or more polymerizable rod-like liquid crystal compound showing a smectic phase, is fixed in a state of smectic phase, and a direction of maximum refractive index of the optically anisotropic layer is inclined at 10° or smaller to the surface of the optically anisotropic layer, a method for manufacturing the same, a laminate and a method for manufacturing the same, a polarizing plate, a liquid crystal display device, and an organic EL display device.

Shown is a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large dielectric anisotropy and small frequency dependence, or has 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 positive dielectric anisotropy as a first component, and a specific compound having small viscosity 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 instant invention relates to liquid crystalline media comprising a chiral component, component A, consisting of one or more chiral compounds, optionally, a bimesogenic component, component B, consisting of one or more bimesogenic compounds, a liquid crystalline component, component C, consisting of one or more liquid crystalline, respectively mesogenic compounds, and a reactive mesogenic component, component D, comprising, one or more reactive mesogenic compounds,
as defined in claim 1, to their stabilization by polymerization and to the polymer-stabilised liquid crystal materials, as well as to liquid crystal displays comprising these liquid crystal media, respectively these stabilized materials, especially to USH-displays and in particular to active matrix displays and, last not least, to the processes of preparation of the respective composite systems and of the displays comprising these systems.

A problem is to provide a liquid crystal compound satisfying at least one physical property such as high stability to heat and light, a high clearing point (or high maximum temperature), a low minimum temperature of a liquid crystal phase, small viscosity, suitable optical anisotropy, large dielectric anisotropy, a suitable elastic constant and excellent compatibility with other liquid crystal compounds, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. A solution is a compound represented by formula (1). ##STR00001## In which, R.sup.1 is alkyl having 1 to 10 carbons or the like; Z.sup.1, Z.sup.2 and Z.sup.3 are independently a single bond, —COO—, —OCH.sub.2—, —CF.sub.2O— or the like, and at least one of Z.sup.1, Z.sup.2 and Z.sup.3 is —CF.sub.2O—; X.sup.1 is hydrogen, fluorine, —CF.sub.3 or —OCF.sub.3; and L.sup.1, L.sup.2, L.sup.3 and L.sup.4 are independently hydrogen, fluorine or chlorine.

The invention provides a liquid crystal compound satisfying at least one of physical properties such as a high stability to heat or light, a high clearing point (or a high maximum temperature), a low minimum temperature of a liquid crystal phase, a small viscosity, a suitable optical anisotropy, a small dielectric anisotropy, a suitable elastic constant and a good compatibility with other liquid crystal compounds, a liquid crystal composition including this compound, and a liquid crystal display device containing this composition. The invention provdes a compound represented by formula (1):

##STR00001##

where R.sup.1 and R.sup.2 is alkyl having 1 to 20 carbons or the like; one of L.sup.1 and L.sup.2 is both hydrogens, and the other is both fluorines; Z.sup.1 and Z.sup.2 are independently a single bond, —COO—, —OCO—, —OCH.sub.2—, —CH.sub.2O—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2CH.sub.2—, —CH═CH—, —C≡C— or the like.

The subject is to provide liquid crystal display device having a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio, a long service life and a small flicker rate.

The liquid crystal display device having a liquid crystal alignment film formed on the opposing surfaces of a pair of substrates, and a liquid crystal composition therebetween, wherein the liquid crystal alignment film includes a polymer derived from a polyamic acid having a photodegradable group, and the liquid crystal composition includes at least one compound represented by formula (1) as a first component:

##STR00001##

R.sup.1 is alkyl having 1 to 12 carbons or the like; ring A is 1,4-cyclohexylene, 1,4-phenylene or the like; Z.sup.1 is a single bond or the like; X.sup.1 and X.sup.2 are hydrogen or fluorine; Y.sup.1 is fluorine or the like; and a is 1, 2, 3 or 4.

An optical film of the present invention includes a positive A-plate and a positive C-plate, in which the Re(450), Re(550), and Re(650) of the positive A-plate satisfy the relationship of Re(450)≦Re(550)≦Re(650), the positive A-plate is formed of a cured product of a composition including the liquid crystal compound A, and the positive C-plate is formed of a cured product of a composition including the liquid crystal compound C.

The present invention relates to liquid crystalline (LC) medium, to a method of its production and to the use of such LC media in polymer network liquid crystalline (PNLC) light modulation elements operated in the normally transparent mode. Furthermore, the present invention relates to such light modulation elements, as such, to the use of such light modulation elements as light shutters for transparent OLED displays, to the use of such light modulation elements in smart windows, and to a method of production of such light modulation elements according to the present invention.