The compounds of the formula I, and a liquid-crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises a) one or more compounds of the formula I ##STR00001## and b) one or more compounds of the formulae II-1 to II-4, ##STR00002##
in which the parameters have the meanings defined herein, are suitable for use in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect.

The compounds of the formula I, and a liquid-crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises a) one or more compounds of the formula I ##STR00001## and b) one or more compounds of the formulae II-1 to II-4, ##STR00002##
in which the parameters have the meanings defined herein, are suitable for use in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect.

A liquid crystal polymer (LCP) composite film is provided. The LCP composite film includes 88 to 99 weight percent of a liquid crystal polymer based on the total weight of the LCP composite film and 1 to 12 weight percent of a toughening agent based on the total weight of the LCP composite film. The toughening agent includes a copolymer selected from a group consisting of a thermoplastic polyolefin elastomer, a glycidyl methacrylate copolymer, a polystyrene elastomer, a polyester elastomer, and a mixture thereof.

A liquid crystal polymer (LCP) composite film is provided. The LCP composite film includes 88 to 99 weight percent of a liquid crystal polymer based on the total weight of the LCP composite film and 1 to 12 weight percent of a toughening agent based on the total weight of the LCP composite film. The toughening agent includes a copolymer selected from a group consisting of a thermoplastic polyolefin elastomer, a glycidyl methacrylate copolymer, a polystyrene elastomer, a polyester elastomer, and a mixture thereof.

There is provided a liquid crystal composition that exhibits a sufficiently low viscosity (η), a sufficiently low rotational viscosity (γ1), and a large elastic modulus (K.sub.33) without decreasing the refractive index anisotropy (Δn) and the nematic phase-isotropic liquid phase transition temperature (T.sub.ni) and without increasing the solid phase-nematic phase transition temperature (T.sub.cn). The liquid crystal display element that uses this liquid crystal composition satisfactorily obtains a pretilt angle and has a high voltage holding ratio (VHR) and high-speed response. Thus, a liquid crystal display element that has no or less alignment defects and display defects such as image sticking, and has high display quality and high response speed is obtained.

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.

The present invention aims to provide a polymerizable compound that has high storage stability without causing crystal precipitation when added to a polymerizable composition and to provide a polymerizable composition containing the polymerizable compound. A polymer film produced by polymerization of the polymerizable composition has a low haze, high thickness uniformity, low occurrence of nonuniform orientation, high surface hardness, high adhesiveness, and good appearances and fewer orientation defects even after ultraviolet irradiation. The present invention also aims to provide a polymer produced by polymerization of the polymerizable composition and an optically anisotropic body produced from the polymer.

The present invention aims to provide a polymerizable compound that has high storage stability without causing crystal precipitation when added to a polymerizable composition and to provide a polymerizable composition containing the polymerizable compound. A polymer film produced by polymerization of the polymerizable composition has a low haze, high thickness uniformity, low occurrence of nonuniform orientation, high surface hardness, high adhesiveness, and good appearances and fewer orientation defects even after ultraviolet irradiation. The present invention also aims to provide a polymer produced by polymerization of the polymerizable composition and an optically anisotropic body produced from the polymer.

The present invention is to find appropriate manufacturing conditions for obtaining a homogeneous scattering state, a homogeneous transparent state, and a homogeneous driving voltage state and to obtain a polymer dispersed liquid crystal display element that has homogeneous properties. A polymer dispersed liquid crystal display element having excellent homogeneity can be obtained by irradiating a light control layer-forming material containing a liquid crystal material and a polymerizable composition with ultraviolet light under specific ultraviolet irradiation conditions to polymerize the polymerizable composition.

A photo-alignment polymer has a repeating unit represented by Formula (1), in Formula (1), R.sup.1 represents a hydrogen atom or a substituent, X represents —O—, —S—, or —NR.sup.2—, in which R.sup.2 represents a hydrogen atom or a substituent, L.sup.1 represents a single bond or a divalent linking group, P represents a photo-aligned group, and A represents an acid-cleavage group which is decomposed by an action of acid to produce a polar group

##STR00001##