摘要 |
Fully aromatic thermotropic polyesters based on (A) from 30 to 60 mol % of 4-hydroxybenzoic acid, (B) from 20 to 35 mol % of a mixture of (B1) terephthalic acid, (B2) isophthalic acid and (B3) from 0.5 to 5 mol % of a dicarboxylic acid of the general formula I <IMAGE> where X is -O-, -S-, -SO2-, -CO-, -CH2- or -C(CH3)2-, n is 0 or 1 and the two imide nitrogen atoms are meta or para to X, or their C1-C8-alkyl, C1-C8-alkoxy, aryl, chlorine or bromine derivatives which are substituted in the nucleus, the molar ratio of B1 to B2 being from 1.04:1 to 19:1, and (C) from 20 to 35 mol % of a mixture of (C1) hydroquinone and (C2) 4,4'-dihydroxydiphenyl, the molar ratio of C1 to C2 being from 0.1:1 to 2.67:1 and the molar ratio of B to C being from 0.9:1 to 1.1:1.
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