US 8,557,950 B2 · High intrinsic viscosity melt phase polyester polymers with acceptable acetaldehyde generation rates

Abstract

A method for the production of solid polyester polymer particles comprising: a) polycondensing a molten polyester polymer composition in the presence of a polycondensation catalyst composition comprising antimony species; b) continuing the polycondensation of the molten polyester polymer composition to an It.V. of 0.68 dL/g or more; and c) after reaching an It.V. of 0.68 dL/g or more, adding a catalyst stabilizer or deactivator to the polymer melt; and d) after reaching an It.V. of 0.68 dL/g or more, solidifying the melt into solid polyester polymer particles which do not contain organic acetaldehyde scavengers. In a further embodiment, after solidification of the polyester from the melt phase polycondensation process: e) the amount of residual acetaldehyde in the particles in the solid state is reduced to a level of 10 ppm or less without increasing the It.V. of the particles by more than 0.03 dL/g. Such particles having an AA (acetaldehyde) generation rate of 20 ppm or less upon being melted after solidification following the melt phase production and a free AA level reduced after melt phase production to 10 ppm or less are introduced into a melt processing zone to make articles such as bottle preforms having acceptable levels of residual AA.

Claims56

Dependent claims

A method for the production of solid polyester polymer particles comprising:

(a) polycondensing a molten polyester polymer composition in the presence of at least one polycondensation catalyst composition comprising antimony species;
(b) continuing the polycondensation of the molten polyester polymer composition to an intrinsic viscosity (It.V.) of 0.68 dL/g or more;
(c) after reaching an intrinsic viscosity (It.V.) of 0.68 dL/g or more, adding at least one antimony catalyst stabilizer or deactivator to the polymer melt;
and
(d) after reaching an intrinsic viscosity (It.V.) of 0.68 dL/g or more, solidifying the melt into solid polyester polymer particles that do not contain organic acetaldehyde scavengers, wherein the intrinsic viscosity (It.V.) of the solid polyester polymer particles is increased in the solid state by 0.05 dL/g or less.

2 more elements

Dependencies are inferred from the claim text.

High intrinsic viscosity melt phase polyester polymers with acceptable acetaldehyde generation rates

Life of this patent

High intrinsic viscosity melt phase polyester polymers with acceptable acetaldehyde generation rates

Life of this patent

Abstract

Claims56