| 摘要 |
<p>A white laminated polyester film for metal lamination, comprising a layer (layer A) comprising a copolyester A and a layer (layer B) comprising a copolyester B, characterized in that (I) (i) the copolyester A is one containing 0 to 15 % by weight of rutile titanium oxide with an average particule diameter of 0.1 to 0.5 νm and having a melting point of 210 to 245 °C, and (ii) the copolyester B is one containing 10 to 50 % by weight of rutile titanium oxide with an average particle diameter of 0.1 to 0.5 νm and having a melting point of 210 to 245 °C and an intrinsic viscosity in the polymer portion of 0.46 to 0.66; (II) the following relationship holds between the intrinsic viscosity (νA) of the polymer portion in the copolyester A and the intrinsic viscosity (νB) of the polymer portion in the copolyester B: IνA - νBI < 0.15; and (III) the ratio of the apparent density (ς) to the theoretical density (ςo) of the whole laminated film satisfies the following relation: 0.65≤ς/ςo≤1.00, where ςo represents (a) wherein ς: apparent density of the whole laminated film, g/cm3, ς¿o?: theoretical density of the whole laminated film, g/cm?3¿, ς¿i?: density of polymer portion in each copolyester, g/cm?3¿, ς¿1?: density of rutile titanium oxide, g/cm?3, X¿i: thickness of each layer, νm, Wi: concentration of rutile titanium oxide in each copolyester, wt.%, and n: number of copolyester layers. This film is excellent in whitening power, formability, aroma retention, and heat resistance and is less likely to cause roll abrasion.</p> |
