Diaminobenzene derivatives of general formula [1]; polyimides comprising repeating units of general formula [2] and prepared by reacting a diamine component containing the derivatives in an amount of at least 1 mole % with a tetracarboxylic acid or a derivative thereof to form a polyimide precursor having a reduced viscosity of 0.05 to 5.0 dl/g (as determined at 30 DEG C in N-methylpyrrolidone at a concentration of 0.5 g/dl), and subjecting this precursor to ring-closing reaction; and alignment films for liquid crystals containing the polyimides: wherein P is a single bond or a divalent organic group selected among -O-, -COO- and -CONH-; Q is a cyclic substituent selected among optionally substituted aromatic and aliphatic rings and heterocycles: R is an aliphatic ring; R is C1-C22 linear alkyl; A is a tetravalent organic group constituting a tetracarboxylic acid; and B is a divalent organic group constituting the diaminobenzene derivative.