High viscosity polyester compositions.

摘要

Polyester compositions with a high viscosity in the molten state obtainable by the reaction at high temperature of a polyester resin, previously dried, with at least one polycarboxylic anhydride and at least one compound having the general formula (I): <CHEM> wherein X represents a divalent organic radical selected from those having the formula -CR1R2-CR3R4- or -CR1R2-CR3R4-CR5R6- with R1, R2, R3, R4, R5 and R6, the same or different, representing a hydrogen atom or methyl; n is zero or 1; Z represents an aliphatic bivalent radical, linear or branched, or cyclic, containing of from 1 to 16 carbon atoms and, optionally, hetero-atoms such as oxygen, sulphur or nitrogen, or Z represents an aromatic or alkylaromatic radical containing from 6 to 20 carbon atoms.