| 摘要 |
PURPOSE:To rapidly form an image superior in light fastness by forming a layer contg. a diazo compd., a specified coupler, and a transition metal capable of forming a chelate compd. with a dye to be formed by the coupling of them on a support. CONSTITUTION:A layer formed on a support contains a diazo compd., a coupler having a pyrone ring represented by any of formulae I , II, and III (R1 is 1-5C alkyl, phenyl, benzyl, pyridinyl, or benzothiazolyl; R2 is pyridyl or benzothiazolyl; R3 is -COONa, -CN, -SO3Na, or -COOR4; and R4 is H, 1-4C alkyl), and a transition metal capable of forming a chelate compd. with an azo dye to be formed between them. In such a coupler, =C=O<-> in an ionized state rapidly couples with the diazo compd., and further, chelates with said transition metal to form a stable image. The image thus formed does not fade against irradiation of UV rays, etc., and has good light fastness. |
