| abstract |
The present invention provides a compound of the formula (Ia) which can be used as a dye,n□n(R1a, R2a, R3a and R4a each independently represent an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 5 to 10 carbon atoms, except that R1a, R2a, R3a, and R4a are all the same groups). |