JP2565242B

PURPOSE:To obtain a wavelength multiple recording material high in modulation degree and recording saturation point by using a coproporpyrin derivatives as a photosensitive material. CONSTITUTION:The photosensitive material composed of the coproporphyrin derivatives, embodied by the tetraalkoxycarbonyl-ethylcoproporphyrin, represented by one of formulae I - IV, (coproporphyrin esters I - IV) is uniformly dispersed into an optical transparent dispersion medium, thus permitting the obtained wavelength multiple recording material to be high in the modulation degree and the recording saturation point. The coproporphyrin derivatives has 4 kinds of isomers due to the positions substituted by methyl and alkyl propionate groups and is obtd. by carrying out alkylesterification of the terminal of the propyronyl group.