| 摘要 |
A film roll comprising a laminated film that is wound in a roll-like form, wherein the laminated film comprises a piezoelectric polymer film and a functional layer (X) provided on at least one main surface of the piezoelectric polymer film, the piezoelectric polymer film contains a helical chiral polymer (A) having a weight average molecular weight of 50,000 to 100,000 and having an optical activity, has a degree of crystallinity of 20 to 80% as determined by a DSC method, and has a product of the aforementioned degree of crystallinity and a normalized molecular orientation MORc of 40 to 700 in which the normalized molecular orientation MORc is determined under the condition where the reference thickness measured with a microwave transmission-type molecular orientation meter is 50 μm. When the piezoelectric polymer film obtained by removing the functional layer (X) from the film roll is heated at 100°C for 30 minutes, the percentage of dimensional change is 1.0% or less as measured in the MD direction. |
