| 摘要 |
PURPOSE:To form a sharp cyan image and to improve the durability thereof by using a specific cyan coupler. CONSTITUTION:The cyan coupler expressed by formula I is used for negative and positive color films, color photographic paper, etc. This coupler is more specifically expressed by formula II, etc., and is further specifically expressed by formula III, etc. In formulas, R1 denotes an electron attrating group such as sulfonyl and sulfonyloxy; at least one of R2 and R3 are likewise the electron attracting group; Z denotes a nonmetallic atomic group necessary for forming a nitrogenous heterocycle; X denotes H, a substituent which can be eliminated by reaction with the oxidant of a color developing agent; (n) denotes 1, 2. The cyan image which is sharp and is stable to heat and moisture is obtd. if such coupler is used. |
