| abstract |
A vertical alignment polyimide for LCD has the following structure: n n nwherein R 1 and R 2 are same or different tetravalent aromatic residues or alkyl residues; n is an integer, and 24≧n≧6; a:b=1:9 to 9:1, preferably from 4:1 to 1:1; and a+b=p+q. The polyimide has an inherent viscosity of 0.04-5 d/g. |