| 摘要 |
There are described transparent copolyamides which consist of recurring structural elements of the formula I <IMAGE> (I) and II <IMAGE> (II) wherein R1 to R4 independently of one another are each hydrogen or alkyl having 1-4 C atoms, R5 and R6 independently of one another are each ethyl, n-propyl, isobutyl, -CH(R7)(R8) or -CH2CH(R9)(R10), R7 is alkyl having 1-8 C atoms, R8 is alkyl having 1-4 C atoms, R9 is hydrogen or alkyl having 1-4 C atoms, and R10 is alkyl having 2-8 C atoms, and wherein the proportion of structural elements (I) where R5/R6 NOTEQUAL -CH2CH(R9)(R10) is 10-40 percent by weight, and where R5/R6 =-CH2CH(R9)(R10) it is 35-55 percent by weight, relative to the total weight of the polymer. The novel copolyamides are characterized by good thermoplastic processing characteristics, low water absorption, good stability to hydrolysis, and negligible dependence of the mechanical and electrical properties on the surrounding humidity, and are suitable for producing transparent moulded articles. |
