| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new diazonium salt hardly providing fear of explosibility, capable of being degraded by a light having a comparatively long wave length, providing a high density in image color development, hardly increasing stain at the ground part after fixing, further providing extremely fast image, and useful for a thermosensitive recording medium. SOLUTION: This new diazonium salt is a compound of formula I (R<1> and R<2> are each an alkyl or an aryl; T and U are each H, a halogen, an alkyl or an aryl; V is an atomic group for completing a 5- or 6-membered heterocycle which may has a substituent group or may be condensed with another ring; X<-> is an anion), preferably a compound of formula II (X<-> is hexafluorophosphate ion or the like), e.g. a compound of formula III. The compound of formula I is obtained by diazotizing a corresponding aniline in a acidic solvent by using sodium nitrite, nitrosyl sulfate, isoamyl nitrite or the like. |
