PURPOSE: To provide a recording liquid which has prolonged continuous recordability and discharge stability after long-term recording suspension and is suitable for use in writing utensiles and ink jet recording, containing a specified monoazo compd.
CONSTITUTION: 0.5W20wt% compd. (dye) of the formula [wherein R1 is H, OH, NH2; R2 is H, SO3M (wherein M is alkali metal, ammonium, amine); R3, R4 are each H, OH, NH2, NO2, SO3M; R5 is H, NH2; R6, R7 are each SO3M] is dissolved in a recording liquid. Since said compd. has an azo linkage in the molecule, it can be thought that even when the recording liquid is instantaneously exposed to high temperature above 250°C in a thermal action part in a recording head and the compd. is decomposed, the molecular chain is mainly broken at the azo linkage part. Therefore, the decomposition products of said compd. are relatively stable per se and most of them contain highly hydrophilic groups such as SO3M or OH so that they are highly soluble in the recording liquid. Thus, stable recording becomes possible without forming precipitates.
SAKAEDA TAKESHI
KOIKE SHIYOUJI
ARAI KAZUE
SATOU TOMOKO
YOKOYAMA YASUMASA
