Biaxial orientierter Mehrschichtfilm aus Polyester und magnetischer Aufzeichnungsträger mit demselben Basisfilm

摘要

A biaxially oriented laminated polyester film comprising a first thin polyester layer containing large-diameter inert particles and small-diameter inert particles; a second polyester layer containing large-diameter inert particles; and a third thin polyester layer containing large-diameter inert particles and small-diameter inert particles, the biaxially oriented laminated polyester film satisfying the following expression (1), $wherein:\; W1\; is\; the\; content\; (wt.\%)\; of\; the\; large-diameter\; inert\; particles\; in\; the\; first\; thin\; polyester\; layer,\; W2\; is\; the\; content\; (wt.\%)\; of\; the\; large-diameter\; inert\; particles\; in\; the\; second\; polyester\; layer,\; D13\; is\; a\; total\; of\; the\; thickness\; (\; mu\; m)\; of\; the\; first\; thin\; polyester\; layer\; and\; the\; thickness\; (\; mu\; m)\; of\; the\; third\; thin\; polyester\; layer,\; and\; D2\; is\; the\; thickness\; (\; mu\; m)\; of\; the\; second\; polyester\; layer.\; This\; film\; is\; useful\; as\; a\; base\; film\; for\; a\; magnetic\; medium.$