Low pilling and flame-retardant material modified polyesters, process for their preparation and moulded articles therefrom

The invention relates to linear, fibre-forming polyesters which have been modified so as to be low-pilling and low-flammability, which comprise dicarboxylic acid and diol components and which contain, in their polymer chain, modifying units formed by transesterification or esterification reactions from compounds of the formula I and/or II and/or III, in which R and R are identical or different and are each a monovalent aliphatic, araliphatic or aromatic hydrocarbon radical having 1 to 12 carbon atoms or R and R together are a divalent aliphatic, araliphatic or aromatic radical, R is an (n + 1) - valent organic radical, A is a group which is capable of ester formation, n is an integer from 1 to 3, R and R are identical or different and are each hydrogen or a monovalent aliphatic, araliphatic or aromatic hydrocarbon radical having 1 to 12 carbon atoms, y is an integer from 1 to 10, R is hydrogen or a monovalent aliphatic, araliphatic or aromatic hydrocarbon radical having 1 to 12 carbon atoms, and the index z is 0 or an integer from 1 to 2*i, where the index i is a sufficiently small integer. The invention furthermore relates to processes for the preparation of these polyesters and to their use.