Polyethylene terephthalate polyester useful for making hollow containers, e.g. bottles, has a low intrinsic viscosity and a low acetaldehyde content

摘要

Polyester comprises at least 925% by number of recurring units derived from aliphatic diols of terephthalic acid and which has an intrinsic viscosity between 0.45 0,70d / dl / G and LGAcetaldehyde and a tenor in less than 3 ppm, preferably less than 1.5 ppm.The procedure to obtain it in the form of pellets under aceltaldehido Polyester with a low intrinsic viscosity within the range just mentioned,Is to carry out polymerization on a cast of a Polyester which presents a Lower intrinsic viscosity (iv) to form Granules 0,80dl / g, Said PolyesterTo implement these GranulesThese Granules through heating heat treatment at a temperature between 130C and designed to reduce the concentration of acetaldehyde to a value less than 3Ppm and obtain an intrinsic viscosity of Polyester IV below 0.70 DL / G.These Polyesters are used in particular for the manufacture of Hollow containers such as bottles and more particularly to the bottles that contain Food ProductsNticios sensitive to acetaldehyde.