Patent ID: 8546472

Claim:
A polyester comprising repeat units based on a) at least one aliphatic dicarboxylic acid and/or an ester-forming derivative thereof as component A1, b) at least one aromatic dicarboxylic acid and/or an ester-forming derivative thereof as component A2, c) at least one diol as component B, d) optionally at least one sulfo-containing compound as component A3, e) optionally at least one trifunctional crosslinking agent as component C1 and/or at least one difunctional chain extender as component C2, wherein component A1 comprises 2-methylsuccinic acid or an ester-forming derivative thereof, and wherein the chain extenders C2 used are compounds which have two or optionally more functional groups suitable for coupling with the carboxyl groups and/or hydroxyl groups of the polyester-forming components A1, A2, B and A3, where the functional groups in the chain extender may be the same or different.