| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer film that can sufficiently suppress spring back in cold molding and has excellent deep drawing moldability at the time of cold molding. ! SOLUTION: The multilayer film includes a nylon layer (ONy) comprising an oriented nylon film, an aluminum layer (Al), a polyolefin layer (PO), and a polyethylene terephthalate layer (PET), in an order of PET/ONy/Al/PO. In stress-strain curves in predetermined four directions of the multilayer film obtained by tension tests on the multilayer film, an elastic modulus is 1000 MPa or more and 2000 MPa or less in all of the four directions; a tensile stress σ2 at a proportional limit is 20 MPa or more and 40 MPa or less in all of the four directions; and a stress ratio A (σ1/σ2), which is a ratio of a tensile stress σ1 when a strain ε2 is 0.5 to the tensile stress σ2 at the proportional limit, is 2.5 or less in all of the four directions. ! COPYRIGHT: (C)2015,JPO&INPIT |
