Abstract: Polyesters prepared using germanium catalyst in the finishing stage at temperatures less than 285° C. exhibit low loss of Ge catalyst and excellent low acetaldehyde generating characteristics.

Abstract: A process for crystallizing a polyester polymer by introducing a molten polyester polymer, such as a polyethylene terephthalate polymer, into a liquid medium at a liquid medium temperature greater than the Tg of the polyester polymer, such as at a temperature ranging from 100° C. to 190° C., and allowing the molten polyester polymer to reside in the liquid medium for a time sufficient to crystallize the polymer under a pressure equal to or greater than the vapor pressure of the liquid medium. A process flow, underwater cutting process, crystallization in a pipe, and a separator are also described.

Abstract: A process for crystallizing a polyester polymer by introducing a molten polyester polymer, such as a polyethylene terephthalate polymer, into a liquid medium at a liquid medium temperature greater than the Tg of the polyester polymer, such as at a temperature ranging from 100° C. to 190° C., and allowing the molten polyester polymer to reside in the liquid medium for a time sufficient to crystallize the polymer under a pressure equal to or greater than the vapor pressure of the liquid medium. A process flow, underwater cutting process, crystallization in a pipe, and a separator are also described.

Abstract: Polyesters whose polycondensation is catalyzed by titanium-containing catalysts and which are susceptible to acetaldehyde formation during polycondensation or subsequent molding operations are prepared with low finished acetaldehyde content and reduced acetaldehyde generation by adding an ammonium or amine salt of an oxyphosphorus-acid. Polyesters, especially polyethylene terephthalate, may be produced with high inherent viscosity in reduced processing time, without the necessity of further polymerization in the solid state.

Abstract: A polyester polymer composition containing polyester polymers such as polymers having repeating ethylene terephthalate units, aluminum atoms in an amount of at least 3 ppm based on the weight of the polymer, the polyester polymers having an It.V. of at least 0.72 dL/g obtained through a melt phase polymerization and a residual acetaldehyde level of 10 ppm or less. Also provided are polyester polymer compositions containing polyester polymers and: (i) aluminum atoms (ii) alkaline earth metal atoms or alkali metal atoms or alkali compound residues, and (iii) a catalyst deactivator such as a phosphorus compound. The phosphorus compound is added to the polyester melt either late in the polycondensation or upon remelting a solid polyester polymer. The polyester polymer exhibits good L* brightness, clarity, and low levels of acetaldehyde generated upon melting.

Abstract: A polyester composition containing: a) aluminum atoms; and b) alkaline earth atoms or alkali metal atoms or alkali compound residues such as lithium atoms; and c) particles comprising titanium, zirconium, vanadium, niobium, hafnium, tantalum, chromium, tungsten, molybdenum, iron, or nickel atoms or combinations thereof, where the particles improve the reheat rate of the polyester composition. The polyester polymer compositions may also contain phosphorus catalyst deactivators/stabilizers. The polyester compositions and the articles made from the compositions such as bottle preforms and stretch blow molded bottles have improved reheat rate while maintaining low haze, high L*, a b* below 3, and have low levels of acetaldehyde. In the process for making the polyester polymer, the polymer melt is polycondensed in the presence of a) and b), with the particles c) added in a melt phase process or added to the polymer in an injection molding machine or extruder.

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.

Abstract: A melt phase process for making a polyester polymer melt phase product by adding an antimony containing catalyst to the melt phase, polycondensing the melt containing said catalyst in the melt phase until the It.V. of the melt reaches at least 0.75 dL/g. Polyester polymer melt phase pellets containing antimony residues and having an It.V. of at least 0.75 dL/g are obtained without solid state polymerization. The polyester polymer pellets containing antimony residues and having an It.V. of at least 0.70 dL/g obtained without increasing the molecular weight of the melt phase product by solid state polymerization are fed to an extruder, melted to produce a molten polyester polymer, and extruded through a die to form shaped articles. The melt phase products and articles made thereby have low b* color and/or high L* brightness, and the reaction time to make the melt phase products is short.

Abstract: A melt phase process for making a polyester polymer melt phase product by adding an antimony containing catalyst to the melt phase, polycondensing the melt containing said catalyst in the melt phase until the It.V. of the melt reaches at least 0.75 dL/g. Polyester polymer melt phase pellets containing antimony residues and having an It.V. of at least 0.75 dL/g are obtained without solid state polymerization. The polyester polymer pellets containing antimony residues and having an It.V. of at least 0.70 dL/g obtained without increasing the molecular weight of the melt phase product by solid state polymerization are fed to an extruder, melted to produce a molten polyester polymer, and extruded through a die to form shaped articles. The melt phase products and articles made thereby have low b* color and/or high L* brightness, and the reaction time to make the melt phase products is short.

Abstract: A bulk of polyester polymer particles comprising polyester polymer comprising greater than 75% virgin polyester polymer, the particles having: A) an It.V. of at least 0.72 dl/g, and B) 10 ppm or less of residual acetaldehyde; and C) at least two melting peaks, wherein one of said at least two melting peaks is a low peak melting point within a range of 140° C. to 220° C. and having a melting endotherm area of at least the absolute value of 1 J/g. The particles may also have a degree of crystallinity within a range of 20% and a maximum degree of crystallinity Tcmax defined by the equation: Tcmax=50%?CA?OH where CA is the total mole % of all carboxylic acid residues other than terephthalic acid residues, based on 100 mole % of carboxylic acid residues, and OH is the total mole % of all hydroxyl functional compound residues other than ethylene glycol residues, based on 100 mole % of hydroxyl functional compounds residues.

Abstract: A melt phase process for making a polyester polymer melt phase product by adding an antimony containing catalyst to the melt phase, polycondensing the melt containing said catalyst in the melt phase until the It.V. of the melt reaches at least 0.75 dL/g. Polyester polymer melt phase pellets containing antimony residues and having an It.V. of at least 0.75 dL/g are obtained without solid state polymerization. The polyester polymer pellets containing antimony residues and having an It.V. of at least 0.70 dL/g obtained without increasing the molecular weight of the melt phase product by solid state polymerization are fed to an extruder, melted to produce a molten polyester polymer, and extruded through a die to form shaped articles. The melt phase products and articles made thereby have low b* color and/or high L* brightness, and the reaction time to make the melt phase products is short.

Abstract: There is now provided a polyester polymer particle having an It.V., a surface, and a center, wherein the It.V. at the surface of the particle is less than 0.25 dL/g higher than the It.V. at the center of the particle. The polyester polymer particle is desirably crystalline to prevent the particles from sticking to each other while drying, and desirably contains less than 10 ppm acetaldehyde. A polyester container, preferably a preform or beverage bottle, is made by feeding crystallized polyester particles having an It.V. of at least 0.70 dL/g to an extrusion zone, melting the particles in the extrusion zone to form a molten polyester polymer composition, and forming a sheet or a molded part from extruded molten polyester polymer, wherein at least a portion of the polyester particles have an It.V. at their surface which does not vary from their It.V. at their center by more than 0.25 dL/g, and the particles have not been solid state polymerized. Such polyester compositions have an It.V.

Abstract: A process for crystallizing a polyester polymer by introducing a molten polyester polymer, such as a polyethylene terephthalate polymer, into a liquid medium at a liquid medium temperature greater than the Tg of the polyester polymer, such as at a temperature ranging from 100° C. to 190° C., and allowing the molten polyester polymer to reside in the liquid medium for a time sufficient to crystallize the polymer under a pressure equal to or greater than the vapor pressure of the liquid medium. A process flow, underwater cutting process, crystallization in a pipe, and a separator are also described.

Abstract: A process for thermally crystallizing a polyester polymer by introducing pellets into a liquid medium having a temperature of at least 140° C. within a liquid medium zone and crystallizing the submerged pellets at or above the vapor pressure of the liquid medium without increasing the molecular weight of the pellets, and while the pressure on at least a portion of the pellets is equal to or greater than the vapor pressure of the liquid medium, separating at least a portion of said pellets and at least a portion of the liquid medium from each other. The crystallization is desirably conducted in the liquid medium zone without mechanically induced agitation. Optionally, the pellets are formed by an underfluid pelletizer.