摘要:
A process for preparing modified polymer by withdrawing a slip stream of polymer melt from the discharge line of a continuous polymerization reactor, admixing in a highly modified polymeric additive into the polymer melt within the slip stream, then introducing the modifier containing slip stream late in the manufacturing process prior to the slip stream withdrawal point. The improved processes of the invention have particular utility for large-scale, continuous reactor where transitions and short production runs are economically prohibitive thereby limiting the product breath. The process is particularly suited for producing a family of copolyesters using a continuous melt phase production process.
摘要:
In one embodiment, there is provided a process comprising introducing polyester polymer particles containing residual acetaldehyde into a vessel at a temperature within a range of 130° C. to 195° C. to form a bed of particles within the vessel, flowing a gas through at least a portion of the particle bed, and withdrawing finished particles from the vessel having a reduced amount of residual acetaldehyde. In this process, it is not necessary to introduce a hot flow of gas at high flow rates otherwise required to heat up cool particles to a temperature sufficient to strip acetaldehyde. Rather, this process provides a benefit in that, if desired, gas introduced into the vessel at low flow rates and low temperatures can nevertheless effectively strip acetaldehyde in a reasonable time because the hot particles quickly heat a the gas to the particle temperature.
摘要:
Polyester compositions are disclosed that include polyester polymers or copolymers having incorporated therein titanium nitride particles that provide one or more of the following advantages: improving the reheat properties of the compositions, improving the color of the compositions through reduced yellowness, and improving the UV-blocking properties of the compositions. Processes for making such compositions are also disclosed. The titanium nitride particles may be incorporated in the polyester by melt compounding, or may be added at any stage of the polymerization, such as during the melt-phase of the polymerization. A range of particle sizes may be used, as well as a range of particle size distributions. The polyester compositions are suitable for use in packaging made from processes in which a reheat step is desirable, or decreased yellowness is desired, or increased resistance to the effects of ultraviolet light is desired, or any combination of the foregoing.
摘要:
A method for efficiently incorporating a UV absorber into a polyester resin. The method includes forming a reaction mixture comprising a diol component, a diacid component selected from the group consisting of dicarboxylic acids, dicarboxylic acid derivatives, and mixtures thereof, an antimony containing compound, a phosphorus containing compound, a metal containing compound, and a UV absorber. The reaction mixture is polymerized in a polycondensation reaction system. In another embodiment of the present invention, the UV absorber is added while the reaction products from one reactor are transferred to the next reactor in the polycondensation reaction system. The present invention is also directed to novel UV absorbing compounds as well as articles made from the polyester resin.
摘要:
The present invention is a method for efficiently incorporating a UV absorber into a polyester resin. The method includes forming a reaction mixture comprising a diol component, a diacid component selected from the group consisting of dicarboxylic acids, dicarboxylic acid derivatives, and mixtures thereof, an antimony containing compound, a phosphorus containing compound, a metal containing compound, and a UV absorber. The reaction mixture is polymerized in a polycondensation reaction system. In another embodiment of the present invention, the UV absorber is added while the reaction products from one reactor are transferred to the next reactor in the polycondensation reaction system. A polyester composition having the UV absorber incorporated therein is also disclosed.
摘要:
The present invention is a method for efficiently incorporating a nitrogen containing methine light absorber into a polyester resin. The method includes forming a reaction mixture comprising combining a diol component, a diacid component selected from the group consisting of dicarboxylic acids, dicarboxylic acid derivatives, and mixtures thereof, an antimony containing compound, a phosphorus containing compound, a metal containing compound, and a nitrogen containing methine light absorber. The reaction mixture is polymerized in a polycondensation reaction system. In another embodiment the light absorber is added while the reaction products of one reactor are being transferred to the next reactor in the polycondensation reaction system. The present invention is also directed articles made from the polyester resin.
摘要:
Polyester compositions having desirable injection molding properties and that retain good crystallization rates and natural stretch ratio characteristics are described. These polyesters are suitable for the manufacture of beverage containers, bulk continuous filaments, and other articles that can benefit from such improved properties.
摘要:
Spheroidal polyester polymer particles, as well as preforms and stretch blow molded bottles made from the spheroidal particles, are provided which have: A) an It.V. of at least 0.72 dL/g, and either B) at least two melting peaks (on a DSC first heating scan), wherein one of said at least two melting peaks is a low peak melting point having a peak temperature 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, or C) a low degree of crystallinity within a range of at least 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 in the polyester polymer, and OH is the total mole % of hydroxyl functional compound residues other than ethylene glycol residues, based on 100 mole % of the hydroxyl functional compounds residues; or both B) and C); and optionally but preferably D) 10 ppm or less of residual acetaldehyde.
摘要:
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. The preforms and bottles made from these particles can be obtained by melt processing these particles at either lower overall power, faster screw speeds, lower residence time, or lower overall cycle time to thereby reduce the level of residual acetaldehyde generated in the melt.
摘要:
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. suitable for containers, yet lose less It.V. during melt processing than existing polyesters.