de name), made by Dai-ichi Kxc3x4gyxc3x4 Co.).
The ratio of the non-ionic and amphoteric surface active agents in the recording layer are preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.
It is preferable to adsorb a heat amplifier such as the metal powders and metal compound powders below to the photosensitive layer, the heat-insulating layer or the support surface in order to amplify heat generation.
The metal powders and metal compound powder will be described. By metal compound is meant a compound such as a metal, a metal oxide, a metal nitride, a metal sullfide or a metal carbide.
Examples of the metal compound includes such metals as Mg, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Tc, Ru, Pd, Ag, Cd, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au and Pb. Among these, metals that readily induce exothermic reactions such as an oxidation reaction by heat energy are preferable. Specific examples include Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ag, Sn and W. Metals having a high radiation absorbing efficiency and exhibiting large self-heating exothermic reaction such as Fe, Co, Ni, Ti and Zr are preferable among them.
The metal compounds may be of one metal only, or two or more components, or may be structured of a metal and a metal oxide, nitrode, sulfide or carbide. The self-activated thermal reaction thermal energy generated by such as oxidation is larger with an individual metal, but there is the danger of spontaneous combustion when the metal makes contact with air, since handling in air is complicated. Accordingly, it is preferable that the surface of such metal is covered with an oxide, nitride, sulfide or carbide to a depth of several nanometers from the surface.
The surface coating layer may be particles or a thin film such as a deposition film, but particles are preferable when the layer is formed together with an organic substance. The particle size is 10 xcexcm or less, preferably 0.005 to 5 xcexcm, and more preferably 0.01 to 3 xcexcm. When the part