| 摘要 |
The invention provides transparent polyamides which have a specific viscosity of at least 0.4 dl/g (0.5% in m-cresol at 25 DEG C.). They consist of recurring structural units of the formula I <IMAGE> (I) and, as the case may be, of recurring structural units of the formula II <IMAGE> (II), wherein X1 represents <IMAGE> X2 represents <IMAGE> R1 and R8 represent in general alkyl radicals. R1 to R3 can also represent hydrogen, and R5 and R6 and R7 and R8, together with the carbon atom to which they are attached, also represent cycloalkyl. The polyamides are derived in their structure from 100 to 25 mol % of terephthalic acid and from isophthalic acid. The polyamides may contain only up to 75 mol % of structural elements of the formula II. They are suitable for the manufacture of transparent moulded articles.
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