Oriented film including polystyrene polymer having syndiotactic configuration

摘要

An oriented polystyrene film including a polystyrene polymer having a syndiotactic configuration, the film having a thickness of 25 mu m or more, and a rectangular sample (1) of the film having a value C expressed by equation (I) of 0.007 or less: $wherein\; Amax\; is\; obtained\; by\; designating\; four\; squares\; (11,12,13,14)\; respectively\; in\; four\; apices\; of\; the\; rectangular\; sample,\; each\; square\; having\; sides\; of\; 100\; mm\; in\; length,\; and\; setting\; an\; orientation\; direction\; of\; molecules\; of\; a\; first\; square\; to\; 0\; DEG\; ,\; Amax\; being\; an\; absolute\; value\; of\; a\; maximum\; angle\; among\; angles\; defined\; by\; the\; orientation\; direction\; of\; molecules\; of\; the\; first\; square\; and\; an\; orientation\; direction\; of\; molecules\; of\; each\; of\; the\; other\; three\; squares,\; R\; is\; expressed\; by\; equation\; (II)\; but\; is\; defined\; as\; 1\; when\; exceeding\; 1:$ D\; is\; a\; distance\; (mm)\; between\; a\; center\; of\; gravity\; of\; the\; first\; square\; (P1)\; and\; a\; center\; of\; gravity\; of\; the\; square\; (P2)\; having\; the\; orientation\; direction\; which\; defines\; Amax\; with\; the\; first\; square,\; and\; HSmax\; is\; a\; size\; change\; ratio\; of\; a\; square\; sample\; which\; is\; cut\; from\; the\; rectangular\; sample\; and\; dry-heated\; at\; a\; temperature\; of\; 150\; DEG\; C\; for\; 30\; minutes,\; the\; square\; sample\; being\; designated\; in\; an\; apex\; of\; the\; rectangular\; sample\; and\; having\; sides\; of\; 100\; mm\; in\; length.$$