Patent ID: 6958178

Claim:
A heat-shrinkable polyester film roll, comprising: an alkali-earth metal compound and a phosphorus compound, at an alkali-earth metal atom M 2 content of 20 to 400 ppm (mass basis) and a phosphorus atom P content of 5 to 350 ppm (mass basis) in the film, wherein: (1) when square samples cut off from said film roll in a size of 10 cm×10 cm are immersed in hot water at 85° C. for 10 seconds, subsequently in water at 25° C. for 10 seconds, and withdrawn, the heat shrinkage percentage of the samples in the maximum shrinkage direction is 20% or more; and (2) when the termination end of rolling of the film which is obtained from a steady region wherein physical properties of the film are stabilized in the firm-running direction is designated as end <A>, and the initiation end of rolling thereof as end <B>; the first cut-off point of sample is placed at a position 2 m or less inner from end <A> above, and the final cut-off point at a position 2 m or less inner from end <B> above, and additionally a plurality of sample cut-off points at an interval of about 100 m from the first cut-off point; rectangular samples 20 cm in length in the maximum shrinkage direction of the film and 5 cm in width are cut off from the cut-off points; and the variations in thickness of respective samples in the maximum shrinkage direction are measured, the thickness distribution width of each sample represented by the following formula is 7% or less, Thickness distribution width=(Maximum thickness−Minimum thickness)/Average thickness×100.