Composite polyester films and their method of preparation and their use as a support for the final application coating.

摘要

Composite polyester films with improved low-friction properties consisting of an orientated polyester film comprising on one of its sides a low-friction coating of a water-dissipatable copolyester having a plurality of oxysulphonyl group chain units and a plurality of recurrent chain units of general formula (I), wherein R1?, R2?, R3?, R4? are the same or different and represent alkyl, cycloalkyl and arylalkyl radicals; A is a divalent hydrocarbon radical bonded by a carbon-silicon bond to the vicinal silicon atom, which is free of aliphatic unsaturation and can include a heteroatom selected from the group consisted of O, Si and N; Z and Z1? are the same or different and represent the divalent functional groups -O- and (a); n is an integer or a fraction between 5 and 200. These composite films can be used as a support for magnetic coatings.