A liquid crystal display capable of reducing the occurrence of defective display due to variations in the initial alignment direction of a liquid crystal alignment control film in a liquid crystal display of an IPS scheme, realizing the stable liquid crystal alignment, providing excellent mass productivity, and having high image quality with a higher contrast ratio. The liquid crystal display has a liquid crystal layer disposed between a pair of substrates, at least one of the substrates being transparent, and an alignment control film formed between the liquid crystal layer and the substrate. At least one of the alignment control films 109 comprises photoreactive polyimide and/or polyamic acid provided with an alignment control ability by irradiation of substantially linearly polarized light.

A thermally stable diamine compound of formula (I′) is proposed as well as polymers, copolymers, polyamic acids, polyamic acid esters, or polyimides based on such compound. Also, a process of preparing orientation layers for liquid crystals including preparing orientation layers for liquid crystals from thermally stable alignment materials comprising diamine compounds of formula (I′).

Provided are a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element. The liquid crystal alignment agent at least comprises one of a polyamic acid solution and a polyimide solution. The polyamic acid solution is obtained by means of a polymerization reaction of diamine compound component A and dianhydride compound component B in a solvent, and the polyimide solution is obtained from the polyamic acid solution via a dehydration imidization treatment. The diamine component A at least comprises one of the diamine compounds represented by “formula 1”. The obtained liquid crystal alignment agent has a better liquid crystal alignment capability, an excellent effect on image sticking, and the effect that decomposition products resulting from light alignment are easy to remove. ##STR00001##

Provided are a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal display element. The liquid crystal alignment agent at least comprises one of a polyamic acid solution and a polyimide solution. The polyamic acid solution is obtained by means of a polymerization reaction of diamine compound component A and dianhydride compound component B in a solvent, and the polyimide solution is obtained from the polyamic acid solution via a dehydration imidization treatment. The diamine component A at least comprises one of the diamine compounds represented by “formula 1”. The obtained liquid crystal alignment agent has a better liquid crystal alignment capability, an excellent effect on image sticking, and the effect that decomposition products resulting from light alignment are easy to remove.

##STR00001##

The present invention provides a liquid crystal display device capable of maintaining a favorable voltage holding ratio for a long period of time and thereby reducing generation of image sticking not only at room temperature but also at high temperatures. The liquid crystal display device includes: paired substrates; a liquid crystal layer that is held between the paired substrates and contains liquid crystal molecules; and an alignment film disposed between at least one of the paired substrates and the liquid crystal layer, the alignment film containing quantum dots.

A liquid crystal display capable of reducing the occurrence of defective display due to variations in the initial alignment direction of a liquid crystal alignment control film in a liquid crystal display of an IPS scheme, realizing the stable liquid crystal alignment, providing excellent mass productivity, and having high image quality with a higher contrast ratio. The liquid crystal display has a liquid crystal layer disposed between a pair of substrates, at least one of the substrates being transparent, and an alignment control film formed between the liquid crystal layer and the substrate. At least one of the alignment control films 109 comprises photoreactive polyimide and/or polyamic acid provided with an alignment control ability by irradiation of substantially linearly polarized light.

The present invention provides a liquid crystal display device capable of maintaining a favorable voltage holding ratio for a long period of time and thereby reducing generation of image sticking not only at room temperature but also at high temperatures. The liquid crystal display device includes: paired substrates; a liquid crystal layer that is held between the paired substrates and contains liquid crystal molecules; and an alignment film disposed between at least one of the paired substrates and the liquid crystal layer, the alignment film containing quantum dots.

A liquid crystal photoalignment agent is provided. The liquid crystal photoalignment agent is a copolymer of a cyclobutane dianhydride (CBDA) and a CBDA derivative.