| abstract |
Fully aromatic thermotropic polyesters are based on n (A) from 30 to 60 mol % of 4-hydroxybenzoic acid, n (b) from 20 to 35 mol % of a mixture of n (B 1 ) terephthalic acid and n (B 2 ) isophthalic acid, n the molar ratio of B 1 to B 2 being from 1.04:1 to 19:1, and n (C) from 20 to 35 mol % of a mixture of n (C 1 ) hydroquinone, n (C 2 ) 4,4'-dihydroxydiphenyl and n (C 3 ) from 0.5 to 5 mol % of n (C 31 ) 2,7-dihydroxynaphthalene and/or n (C 32 ) 1,3-dihydroxybenzene and/or n (C 33 ) and aromatic dihydroxy compound of the general formula I ##STR1## where X is --CH 2 --, --C(CH 3 ) 2 --, --S--, --SO 2 --, --O-- or --CO--, and/or n (C 34 ) a compound of the general formula II ##STR2## where Y is NH 2 or OH, the molar ratio of C 1 to C 2 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. |