| 摘要 |
A water-soluble disazo dye which, in the form of the free acid, has the general formula: wherein the sulphonic acid group in ring A is in a meta or para position relative to the azo group, R represents hydrogen or hydroxyl, R1 represents hydrogen, optionally substituted alkyl, aralkyl or aryl, R2 represents hydrogen or optionally substituted alkyl, R3 represents hydrogen, halogen, lower alkyl or lower alkoxy and R4 represents lower alkyl or aryl. |
