| 摘要 |
<p>Flameproof high mol. wt. polycarbonates based on halogen-free dihydroxydiaryl cpds. and nucleus-halogenated bis-4-hydroxyaryl-alkanes additionally contain 1 - 20 (5 - 15) mol.% dihydroxydiphenyls, pref. 4,4'-dichydroxydiphenyl, dihydroxydiphenyl ether and/or aromatic dicarboxylic acids, esp. benzene dicarboxylic acids, pref. terephthalic acid, as condensed difunctional cpds. Copolycarbonates obtd. have (1) higher flame-resistance and less tendency to drip in contact with flame, without raising halogen content; (2) redn. of halogenated component content allows development of polycarbonates with improved strength.</p> |
