BIAXIALLY-ORIENTED POLYESTER FILM FOR USE IN LAMINATING CURABLE RESIN

摘要

A biaxially-oriented polyester film for use in laminating a curable resin, the film comprising a polyethylene terephthalate resin and satisfying the requirements (1) to (3): (1) the thickness of the film is from 30 to 500 µm; (2) the plane orientation degree (?P) of the film is from 0.150 to 0.180; and (3) the ratio of the axial surface orientation degree between the front surface and the back surface of the film is from 0.80 to 0.98. When the thickness is 500 µm or less, potential warpage, which counteracts the curing and shrinking of a curable resin, is easy to occur, and when the thickness is 30 µm or more, the film can maintain flatness as a base material film. When the ratio of the axial surface orientation degree between the front surface and the back surface of the film is 0.98 or less, potential warpage, which can counteract when a curable resin is laminated, can occur, and when the ratio is 0.80 or more, the film can maintain flatness. When ?P is 0.150 or more, the film can maintain firmness as a film which can withstand the curing and shrinking of a curable resin, and when ?P is 0.180 or less, potential warpage, which counteracts the curing and shrinking of a curable resin, is easy to occur, and a laminate can have a favorable surface accuracy.