Automatic copolyamide

An aromatic copolyamide which is soluble in an organic polyamide solvent and consists essentially of at least 95 mol% of recurring structural units the formulae Ia, Ib and Ie without or with up to 5 mol% of recurring structural units of the formula Id

• [--OC--R.sup.1 --CO--NH--R.sup.2 --NH--] (Ia), [--OC--R.sup.1 --CO--NH--R.sup.3 --NH--] (Ib),
• [--OC--R.sup.1 --CO--NH--R.sup.4 --NH--] (Ic), [--OC--R.sup.1 --CO--NH--R.sup.5 --NH--] (Id),
• where at least 95 mol% of all radicals R.sup.1 have a structure of the formula IIa and up to 5 mol% of all the radicals R.sup.1 have the structure of the formula IIb
• --Ar.sup.1 -- (IIa), --Ar.sup.2 -- (IIb),
• where Ar.sup.1 is a divalent aromatic radical having valence bonds in the para or a comparable coaxial or parallel position relative to one another and which is optionally substituted by one or two inert radicals, and Ar.sup.2 is a divalent aromatic radical having valence bonds in the meta or a comparable kinked position relative to one another and which is optionally substituted by one or two inert radicals, R.sup.2 is a radical of formula III ##STR10## R.sup.3 is a radical of the formula IV ##STR11## where each R.sup.6 is, independently of the other, hydrogen or an inert radical and Z is selected from the group consisting of --O--, --S--, --CO--, --SO.sub.2 --, --C.sub.n H.sub.2n -- and --O--Ar.sup.1 --O--, where n is an integer from 1 to 10 and Ar.sup.1 is as defined above, R.sup.5 is a radical selected from one of the structures defined for Ar.sup.2, and R.sup.7 is an unsubstituted divalent aromatic radical having valence bonds in the para of a comparable coaxial or parallel position relative to one another, with the proviso that the mole fractions of the radicals R.sup.2, R.sup.3 and R.sup.7, based on the sum total of these radicals, lie within the following limits:
• Radical R.sup.2 :
• from 5 to 70 mol%,
• Radical R.sup.3 :
• from 15 to 70 mol%, and
• Radical R.sup.7 :
• from 5 to 70 mol%.