PURPOSE: To prepare the titled ink exhibiting clear color change by the ethylene oxide gas sterilization, by using an azo dye containing a specific 1,3,4-thiadiazole ring and aniline coupled at p-position, etc. as a discoloration dye.
CONSTITUTION: The objective ink contains prepferably 0.1W3wt%, based on the ink, of a discoloration dye consisting of an azo dye of formula I [R1 is H, lower alkyl, phenyl, benzyl, nitro, mercapto, lower alkylthio, etc.; the group of formula IIis benzene nucleus; R2 and R3 are H, (substituted) lower alkyl, phenyl, or benzyl; R2 and R3 of the group of formula III may together form a ring; the benzene nucleus of formula II may have non-dissociable substituent group] having a 1,3,4-thiadiazole ring and an aniline (derivative structure) coupled to the p- position.
EFFECT: Excellent storability of the printed product.
USE: Packaging material for the sterilization of medical and operating tools.
NAKAMURA SHIYUUJI
TSUGE TAKASHI
| JPS5695058A | 1981-08-01 |