To obtain a dye (a bis-anthraquinone compound) excellent in thermostability, light resistance, chemical resistance.
The bis-anthraquinone compound is characteristically represented by formula (1) [wherein, R1-R4 is each H, a halogen, an alkyl group, hydroxyl group, an alkoxy group, amino group, an alkylamino group, a dialkylamino group, sulfonic acid group, carboxylic acid group, an ester group, an amide group, or the like; R5-R6 is each H, an alkyl group, hydroxyl group, an alkoxy group, an acyloxy group, an aryloxy group, amino group, an alkylamino group, a dialkylamino group, an acylamino group, an arylamino group, sulfonic acid group, carboxylic acid group, a halogen, an ester group, an amide group, or the like; X is single bond, an alkylene group, an aralkylene group, an allylene group, or the like].
TAKEDA AKIHIKO
KITO KATSUYUKI
