| 摘要 |
PROBLEM TO BE SOLVED: To provide a cavity-containing composite polyester film for improving handleability and having excellent characteristics (printability, whiteness, reproducibility and concealability and the like) as synthetic paper and a base film for a heat sensitive transfer recording material having excellent handleability and sensitivity characteristics. SOLUTION: The base film for the heat sensitive transfer recording material comprises a cavity-containing layer (layer A) made of a composition containing a polyester resin and a non-compatible thermoplastic resin, and a polyester film (layer B) laminated on at least one side surface of the layer A by a co- extrusion method and containing white inorganic fine particles of 5 to 45 wt.% of a composite film. An apparent specific gravity of the overall film is 0.85 to 1.35 and the cavity laminating number density of the layer A is 0.20 piece/μm or more. Further, the base film for the heat sensitive transfer recording material has a dynamic hardness on a surface of the layer B of the film of 5.0 or less and glossiness of the surface or 30 % or more. |
