PURPOSE: To obtain an image forming material superior in durability, heat resistance, and water resistance with a sharp and good-contrast image by specifying the surface roughness of a layer A-side surface of a biaxially oriented composite film formed by laminating polyester layers A, B each containing a specific amount of calcium carbonate of a specific average particle diameter.
CONSTITUTION: A biaxially oriented composite film is formed by laminating a polyester layer A containing 25wt.% or less calcium carbonate of 1.5μm or less average particle diameter on at least one surface of a polyester layer B containing 5-30wt.% calcium carbonate of 0.3-3.5μm average particle diameter. In said film, the surface on the side of the layer A is 0.15μm or less in surface roughness Ra, 35% or more in glossiness, and 0.7-1.35g/m3 in optical density. It is preferable that the average particle diameter of the calcium carbonate incorporated in the polyester forming the layer A is smaller than that of the calcium carbonate incorporated in the polyester forming the layer B. On the layer A-side surface of the composite film, an image forming layer or a recording accepting layer is formed by a normal method to obtain an image forming material.
MATSUSHIMA KEISUKE
YAMAGISHI HIDEKI
