PURPOSE: To improve the sensitivity, the recoloring property and the color reproducibility of the titled material, by incorporating a specified cyan coupler in the titled material.
CONSTITUTION: The titled material contains one or more kinds of the cyan coupler shown by the formula wherein R1 and R2 are each a monovalent org. group which has ≤-0.36 the sum of Hammett's value θσ p of each groups R1 and R2, or said group in which at least one of said groups has a proton capable of allowing to hydrogen bonding, R3 is alkyl or aryl group which may be substd. Z is hydrogen atom or a group capable of releasing by allowing to a prescribed coupling reaction. Said coupler is preferably incorporated in a red sensitive emulsion layer, and displays the excellent effect in case of apply ing said coupler to a color printing paper.
MASUKAWA TOYOAKI
NAKAYAMA NORITAKA
IIZUKA HIROYUKI