| 摘要 |
A phonograph or video disc comprises at least one unsaturated nitrile copolymer and has therein an unsaturated nitrile content of from 40 to 90 percent by weight, and the disc exhibits a Clash-Berg flex temperature of from 50 DEG to 120 DEG C, an absorbed impact energy of at least 0.5kg.cm. when tested with a test specimen thereof of a 2-mm. thickness by a Dynstat impact test according to BS-1330-1946, and a Shore D hardness of from 75 to 95. |
