Provided are a composition for a liquid crystal alignment agent, a manufacturing method of a liquid crystal alignment film, a liquid crystal alignment film using the same, and a liquid crystal display device including the liquid crystal alignment film. More specifically, there are provided the manufacturing method of a liquid crystal alignment film capable of providing the liquid crystal alignment film in which light irradiation energy is able to be reduced, and alignment characteristic and stability are excellent and the voltage holding ratio and electrical characteristics are also excellent through a simple process including applying and drying the composition for a liquid crystal alignment agent on the substrate, directly performing light irradiation to conduct alignment treatment while a high-temperature heat treatment process is omitted, followed by curing by heat treatment, the liquid crystal alignment film, and the liquid crystal display device including the same.

To provide an optical film having excellent visibility in a wide angle direction. An optical film including at least one resin selected from the group consisting of a polyimide-based resin and a polyamide-based resin and having a total light transmittance of 85% or more and a haze of 0.5% or less, wherein when a direction parallel to a machine direction in a plane of the optical film during production of the optical film is defined as an MD direction and a direction vertical to the machine direction is defined as a TD direction, a first transmission image clarity value C.sub.60(MD) in a direction inclined 60° in the MD direction from a vertical direction to the plane of the optical film, a second transmission image clarity value C.sub.60(TD) in a direction inclined 60° in the TD direction from the vertical direction, and a third transmission image clarity value C.sub.0 of the vertical direction which are obtained when a width of an optical comb is 0.125 mm in accordance with JIS K 7374 satisfy Formulae,
Formula (1):
87%≤C.sub.60(MD)≤100%  (1),
Formula (2):
87%≤C.sub.60(TD)≤100%  (2), and
Formula (3):
0.8≤C.sub.60(MD)/C.sub.0≤1.0  (3).

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##

The present invention relates to a polymer having excellent liquid crystal alignment and electrical properties and thus is suitable for use as a liquid crystal alignment agent, a liquid crystal alignment agent containing the same, a liquid crystal aligning film formed from the liquid crystal alignment agent, and a liquid crystal display device containing the liquid crystal aligning film.

The present invention relates to a polymer having excellent liquid crystal alignment and electrical properties and thus is suitable for use as a liquid crystal alignment agent, a liquid crystal alignment agent containing the same, a liquid crystal aligning film formed from the liquid crystal alignment agent, and a liquid crystal display device containing the liquid crystal aligning film.

According to one embodiment, a liquid crystal display device includes a first substrate, a second substrate disposed to oppose the first substrate, a layer of liquid crystal located between the first substrate and the second substrate, and an alignment film disposed on the first substrate so as to be in contact with the layer of the liquid crystal. The liquid crystal has a refractive-index anisotropy Δn of 0.11 or more, the layer of the liquid crystal has a thickness d of 2.5 μm or less, and a product Δnd of the refractive-index anisotropy Δn and the thickness d is 0.20 or more but 0.31 or less. The transmissivity of light having a wavelength of 450 nm in the first substrate and the alignment film is 85% or more but 97% or less.

The present invention relates to a polymer having excellent liquid crystal alignment and electrical properties and thus is suitable for use as a liquid crystal alignment agent, a liquid crystal alignment agent containing the same, a liquid crystal aligning film formed from the liquid crystal alignment agent, and a liquid crystal display device containing the liquid crystal aligning film.

A liquid crystal aligning agent composition for forming a liquid crystal alignment film that can exhibit excellent alignment and electrical characteristics and simultaneously having enhanced durability, a method for preparing a liquid crystal alignment film using the liquid crystal aligning agent composition, and a liquid crystal alignment film comprising an aligned and cured product of the liquid crystal aligning agent composition and a liquid crystal display device comprising the liquid crystal alignment film.

An alignment film is given a 2-layer structure comprising a photoalignment film that is photoalignable and a low-resistivity alignment film whose resistivity is smaller than that of the photoalignment film. The photoalignment film is formed by a polyimide whose precursor is polyamide acid alkyl ester, the number molecular weight of the photoalignment film is large, and the stability of alignment of the photoalignment film by photoalignment is excellent. The low-resistivity alignment film is formed by a polyimide whose precursor is polyamide acid, the number molecular weight of the low-resistivity alignment film is small, and the resistivity of the low-resistivity alignment film is small. The 2-layer structure alignment film can be maintaining an excellent photoalignment characteristic, so DC afterimages can be controlled.

Provided is a liquid crystal aligning agent composition including a urea-based compound that contains two or more urea functional groups and has a structure in which a hydroxyalkyl group is substituted for a terminal amino group of a urea functional group, together with polyimide and its precursor polymer.