BigPatents India

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. No. of Pages : 92 No. of Claims : 96