| 摘要 |
PURPOSE:To easily synthesize a film, to uniformly orient a liquid crystal and to increase a tilt angle. CONSTITUTION:Such a polyimide is used that has biphenyl rings with univalent substituents having a positive number sigmap of Hamett's law in side chains. This polyimide is produced by allowing an aromatic diamine component coupled with biphenyl rings with univalent substituents having a positive number op of Hamett's law, for example, an aromatic diamine expressed by formula to react with and tetracarboxylic acid or its deriv. to obtain a polyimide precursor and then closing the rings in the precursor. The precursor has 0.05 to 5.0dl/g reduced viscosity (in N-methylpyrrolidone at 30 deg.C and 0.5g/dl concn). In formula, X is a single bond or bivalent group selected from -O-, -COO-, and -CONH-, and Z is a univalent substituent having a positive number sigmap of Hamett's law. |
