BIAXIALLY ORIENTED WHITE POLYPROPYLENE FILM FOR THERMAL TRANSFER RECORDING AND RECEIVING SHEET FOR THERMAL TRANSFER RECORDING THEREFROM

摘要

[Problem to be Solved];To provide a biaxially oriented white film for thermal transfer recording which has low specific gravity required as a thermal transfer film, high whiteness and cushion factor, and is excellent in crease resistance, and has a high-level compatibility between high sensitivity and productivity when used as a substrate of a receiving sheet, and a receiving sheet for thermal transfer recording using the same.;[Means for Solving the Problem];(1) A biaxially oriented white polypropylene film for thermal transfer recording characterized in that it is a film comprising of polypropylene resin of which β-crystal ratio is 30% or more and melting temperature is 140 to 172°C, which has a substantially non-nucleus voids, a void ratio of 30 to 80% and a sum of strengths of longitudinal direction and of transverse direction of the film at 2% elongation (F2 value) being in the range of 10 to 70 MPa and a surface glossiness being in the range of 10 to 145 % (the first configuration).(2) A biaxially oriented white polypropylene film for thermal transfer recording characterized in that a skin layer (B layer) of which surface glossiness is 10 to 145 % is laminated to at least one side of a core layer (A layer) of polypropylene resin of which β-crystal ratio is 30% or more, melting temperature is 140 to 172°C, which has a substantially non-nucleus voids, a void ratio of 30 to 80%, and a sum of the strengths of longitudinal direction and of transverse direction of the film at 2% elongation (F2 value) being in the range of 10 to 70 MPa (the second configuration).(3) A biaxially oriented white polypropylene film for thermal transfer recording in which a skin layer (B layer) of which surface glossiness is in the range of 10 - 145 % is laminated to at least one side of a core layer (A layer) characterized in that a sum of strengths of longitudinal direction and of transverse direction of the film at 2% elongation (F2 value) is in the range of 30 to 100 MPa and that the film has β-crystal activity (the third configuration).(4) A biaxially oriented white polypropylene film for thermal transfer recording which is a film in which a skin layer (B layer) having a half-crystallization time of 60 seconds or less and a surface glossiness of 30 to 145 % is laminated at least on one side of a core layer (A layer) which consists of polypropylene resin having a substantially non-nucleus void, characterized in that it is a film of a specific gravity of 0.3 to 0.7 and has β-crystal activity (the fourth configuration).