The invention relates to a polymerisable LC medium with negative optical dispersion, a polymer film with negative optical dispersion obtainable from such a medium, and the use of the polymerisable LC medium and polymer film in optical, electro optical, electronic, semiconducting or luminescent components or devices.

Provided is a liquid crystal alignment agent that makes it possible to obtain a liquid crystal alignment film having a superior balance among solvent resistance, liquid crystal alignment properties, and voltage holding ratio. The liquid crystal alignment agent contains a polymer [P] including: at least one ring structure of an oxetane ring and an oxirane ring; (B) a functional group that reacts with at least one of the oxetane ring and the oxirane ring by heating; and (C) an optically aligning group.

The invention relates to a polymerizable LC medium with negative optical dispersion, a polymer film with negative optical dispersion obtainable from such a medium, and the use of the polymerizable LC medium and polymer film in optical, electro optical, electronic, semiconducting or luminescent components or devices.