| 摘要 |
PROBLEM TO BE SOLVED: To improve safety in a mutagen test and an oral toxicity test by setting an imaginary part of a complex refractive index in a wavelength of a recorded light, a reproduced light to a specific value or below and providing a recording layer containing a specific azo metal complex salt. SOLUTION: An imaginary part k of a complex refractive index in a wavelength of a recorded light and/or a reproduced light is set to 0.20 or below. A recording layer containing an azo metal complex salt represented by the' formula (wherein R1, R2, R3 and R4 are each 1- or more C alkyl group, when total number of carbons of the R1 to R4 is A, total number of carbons of the R1 and R2 is A1, total number of the carbons of the R3 and R4 is A2, 6<=A<=18 is satisfied, wherein at least one of the A1 and A2 is not 2, M is cobalt or nickel, X1 and X2 are each nitro group or halogen group, k1 and k2 are each an integer of 0 to 4, and Z+ is tetraalkyl ammonium or cyanine dye ion.) is provided. |
