| abstract |
The invention provides a liquid crystal alignment agent for photo-alignment, a liquid crystal alignment film for photo-alignment and a liquid crystal display element. The present invention is a kind of liquid crystal aligning agent, this liquid crystal aligning agent contains polyamic acid or its derivative, and described polyamic acid or its derivative is made cyclobutane tetracarboxylic dianhydride or contains cyclobutane tetracarboxylic di It is obtained by reacting a mixture of tetracarboxylic dianhydrides such as tetracarboxylic dianhydrides with specific aromatic diamines having an alkyl chain having 4 or more carbon atoms in the molecule. Using this liquid crystal alignment agent, it is possible to form a photo-alignment film with good sensitivity to chemical changes caused by light irradiation, excellent alignment of liquid crystal molecules, and high light transmittance. And, by using this photo-alignment film in a liquid crystal display element, a liquid crystal display element excellent in display characteristics can be obtained. |