| abstract |
The present invention provides a label that is thin, yet excels in crack resistance during transport. This polyester label is characterized in that requirements (1) to (6) are satisfied. (1) The thickness of a base film of the label is 8-30 μm; (2) the limiting viscosity of polyester constituting the label is 0.58 dl/g or greater; (3) the tensile elongation at break in both the main shrinkage direction of the label and a direction orthogonal to the main shrinkage direction is 5% or greater; (4) when the absorbance at 1340 cm -1 and absorbance at 1410 cm -1 of the base film constituting the label are determined by a polarized ATR method, the difference between the absorbance ratio (1340 cm -1 /1410 cm -1 ) in the main shrinkage direction of the label and the absorbance ratio (1340 cm -1 /1410 cm -1 ) in the direction orthogonal to the main shrinkage direction is 0.2 or greater; (5) the difference in specific heat capacity ΔCp before and after Tg, when the reversible heat capacity curve of the base film constituting the label is measured using a temperature-modulated differential scanning calorimeter, is 0.2 J/(g·°C) or greater; (6) the difference between the maximum value and the minimum value of the vertical-direction length of the label is 3 mm or less. |