| 摘要 |
A method for removing non-fluorescent triazine derivative impurities having the structural formula: <IMAGE> wherein R1 is a hydroxy group or a halogen atom, R2 is a hydroxy group or the group -NR4R5, each of R4 and R5 being a hydrogen atom, alkyl, substituted alkyl, aryl or substituted aryl group, or R4 or R5 being combined in a heterocyclic ring, and R3 is an alkyl, substituted alkyl, aryl or substituted aryl group, FROM FLUORESCENT AGENTS BELONGING TO THE CLASS OF COMPOUNDS OF 4,4'-DI(SYM-TRIAZINYLAMINO) STILBENE-2,2'- DISULPHONIC ACIDS AND SALTS THEREOF, BY WASHING SAID FLUORESCENT AGENT WITH A DILUTE AQUEOUS SOLUTION OF AN ALKALI METAL HYDROXIDE UNDER ATMOSPHERIC PRESSURE AND AT A TEMPERATURE NOT EXCEEDING 75 DEG C. |
