| 摘要 |
PROBLEM TO BE SOLVED: To obtain a liquid crystal alignment agent used for forming a liquid crystal alignment film which facilitates the liquid crystal orientation control, coping with the surface irregularities of a base plate as the result of the increase in density of picture elements, produces neither static electricity nor dusts, and is excellent in mass-productivity by using a polymer having a radiation- functional conjugated enone structure. SOLUTION: This agent comprises a polymer having such a functional conjugated enone structure of formula I, II, III or IV (wherein P<1> to P<4> , and Q<1> to Q<4> are each an organic group containing an aromatic ring; and R<1> to R<8> are each H or alkyl) that it is optically excited by radiation and then releases energy to return to a stable state in the principal chain or on the side chain. The polymer used preferably comprises a polyimide because of excellent heat resistance, although there is no limitation. A desired polyimide is obtained by using a tetracarboxylic acid dianhydride component having a structure of the formula or a diamine component. The liquid crystal alignment agent is produced by dissolving the polymer in an organic solvent, and adding thereto if necessary, e.g. a thermosetting crosslinking agent for strengthening the coating film, and a silane compound for improving the adherence. |
