| 摘要 |
PURPOSE:To provide the above sheet having a low density, a high whiteness and excellent in thermal dimensional stability by forming a film support from a polyester film specified in its heat shrinkage factor and specific gravity. CONSTITUTION:A polyester film having low specific gravity and excellent heat stability and whiteness obtained by adding a non-compatible polymer and a specific gravity lowering agent to polyester is used as a base material film and a sublimable dye receiving layer is laminated to the polyester film. This film support has a heat shrinkage factor of below 2% at 150 deg.C and specific gravity of 0.95 or less. When the specific gravity is higher than 0.95, a soft feeling and flexibility are not imparted to the film and, when the heat shrinkage factor becomes 2% or more, the thermal dimensional stability of the film becomes inferior. As the non-compatible polymer, poly-4-methylterpene-1, cellulose triacetate and a modified substance thereof are especially pref. and the m.p. thereof must be 200 deg.C or more. The specific gravity lowering agent is a compound added to polyester to lower the specific gravity thereof and polyethylene glycol is especially pref. |
