Aromatischer Polyamidfilm und/oder Polyimidfilm und magnetisches Aufzeichnungsmedium mit einem solchen Film als Träger

摘要

An aromatic polyamide and/or aromatic polyimide film suitable as a support in a magnetic recording medium excellent in runnability and scratch resistance and good in S/N ratio cowprises an aromatic polyamide and/or aromatic polyimide as a main component, with particles present in the film, which film has characteristics which satisfy the following formulae: $$ or$ $ $ where\; dmax\; is\; the\; depth\; from\; a\; first\; surface\; of\; the\; film\; at\; which\; the\; particle\; density\; shows\; the\; first\; maximal\; value;\; dmin\; is\; the\; depth\; at\; which\; the\; particle\; density\; shows\; the\; first\; minimal\; or\; minimum\; value\; in\; a\; range\; from\; dmax\; to\; 1\; mu\; m\; from\; the\; said\; first\; surface;\; the\; linear\; differential\; coefficient\; of\; the\; particle\; density\; distribution\; curve\; has\; an\; inflection\; point\; at\; which\; the\; quadratic\; differential\; coefficient\; of\; the\; particle\; density\; distribution\; curve\; is\; a\; negative,\; which\; inflection\; point\; occurs\; at\; a\; depth\; d",\; deeper\; than\; dmax,\; and\; within\; a\; range\; between\; the\; depth\; at\; which\; rho\; (d)\; is\; 4/5\; of\; rho\; (dmax),\; and\; dmin;\; and\; rho\; (d)\; is\; the\; particle\; density\; at\; each\; depth.$$$$$