US Patent 11260638 Transparent, flexible, impact resistant, multilayer film comprising polycarbonate copolymers

A multilayer film can comprise: a plurality of layers, preferably 4 layers to 128 layers, comprising: a polymer A layer comprising a polycarbonate copolymer and a polymer B layer comprising a semi-crystalline polyester; wherein a differential solubility parameter (ΔδAB) of polymer A towards polymer B (ΔδAB) is greater than or equal to 2.6 MPa1/2; and an interdiffusion region between each polymer A and polymer B. The multilayer film has a dynamic flexure of greater than or equal to 200,000 cycles, as determine by bending 180° on a 10 mm radius cylinder at a rate of 1 hertz. The multilayer film has a total thickness of 40 μm to 70 μm, a transmission at 360 nm to 750 nm of greater than or equal to 89% and a haze of less than or equal to 1%.