Polyimide photo alignment film from 3,3',4,4'-benzophenone tetracarboxylic dianhydride and ortho-substituted aromatic diamines for liquid crystal displays

摘要

The present invention relates to polyimide photo alignment films for liquid crystal display devices comprising an aromatic tetracarboxylic dianhydride component containing 3,3'4,4'-benzophenone tetracarboxylic dianhydride and an aromatic diamine component containing at least one diamine of the group of formulae AI to AIII as given in the text. Further display devices and methods of their fabrication employing a photo alignment process are disclosed.