PURPOSE: To improve reliability and capacitance data storage characteristic by applying a liquid monofunctional photosetting acryl ester monomer which has at least four carbon atoms in an ester group and in which a specific oligomer and photoinitiator are dissolved to a base body.

CONSTITUTION: The liquid monofunctional photosetting acryl ester monomer having at least the four carbon atoms in the ester group includes the oligomer having a mol.wt. of at least 500 and 0.05 to 10wt.% photoinitiator. The uncured soln. of this liquid has a viscosity of at least 10cp and surface tension of <36dyn/cm at a coating temp. The solid cured compsn. thereof has transparency of at least 88% to light of a wavelength of 488 to 830nm and pencil hardness of at least 2B. The liquid layer of this coating compsn. is applied to the base body, by which the high output efficiency, sensitivity and the reading out response of recording are obtd.