| 摘要 |
<p>Case 3-12077/ZFO/+ Canada Transparent copolyamides, processes for producing them, and the use thereof for the production of moulded articles There are described transparent copolyamides which are obtained by reaction of a mixture A) consisting of essentially stoichiometric amounts of a diamine (I) and isophthalic acid or terephthalic acid, or a mixture of isophthalic acid and terephthalic acid, with a mixtureB) consisting of essentially stoichiometric amounts of a diamine (II) and terephthalic acid or a mixture of terephthalic acid and isophthalic acid, or with a mixture C) consisting of essentially stoichiometric amounts of a diamine (III) and terephthalic acid or isophthalic acid or mixtures thereof, wherein R', R" and R1 to R11 have the meanings given in claim 1. The proportion of mixture C) is 60-80 per cent by weight and that of mixture B) is 50-80 percent by weight, with the proviso that with a proportion of mixture B) of up to 65 per cent by weight, at most 70 mol.% of isophthalic acid, or of an amide-forming derivative thereof, in a mixture A) can be replaced by terephthalic acid or by an amide-forming derivative thereof, The novel copolyamides are distinguished by good thermoplastic processing characteristics, by low water absorption and by good stability to hydrolysis, and are suitable for producing transparent moulded articles.</p> |
