Polyester polymer and copolymer compositions containing metallic nickel particles
AssigneeEastman Chemical Company
InventorsZhiyong Xia, Donna Quillen
Life of this patent
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Abstract
Polyester compositions are disclosed that include polyester polymers or copolymers having incorporated therein metallic nickel particles that improve the reheat properties of the compositions. Processes for making such compositions are also disclosed. The nickel 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.
Claims44
A polyester composition having improved reheat, comprising:
- a polyester polymer;
- and
- metallic nickel particles, having a median particle size from about 0.005 μm to about 10 μm, dispersed in the polyester polymer.
A polyester composition having improved reheat, comprising:
- a polyester polymer;
- and
- metallic nickel particles, having a median particle size from about 0.05 μm to about 5 μm, dispersed in the polyester polymer.
A polyester composition having improved reheat, comprising:
- a polyester polymer;
- and
- metallic nickel particles, having a median particle size from about 0.05 μm to about 2 μm, dispersed in the polyester polymer.
A polyester composition having improved reheat, comprising:
- a polyester polymer in which poly(ethylene terephthalate) residues comprise at least 90 wt. % of the polyester polymer;
- and metallic nickel particles, having a median particle size from about 0.05 μm to about 2 μm, randomly dispersed in the polyester polymer in an amount from about 5 to about 50 ppm, wherein the polyester composition has a reheat index of 1.05 or more and an L* brightness level of 70 or more at the reheat rate index of 1.05.
A process for producing a polyester composition, comprising:
- an esterification step comprising transesterifying a dicarboxylic acid diester with a diol, or directly esterifying a dicarboxylic acid with a diol, to obtain one or more of a polyester monomer or a polyester oligomer;
- a polycondensation step comprising reacting the one or more of a polyester monomer or a polyester oligomer in a polycondensation reaction in the presence of a polycondensation catalyst to produce a polyester polymer having an It.V. from about 0.50 dL/g to about 1.1 dL/g;
- a particulation step in which the molten polyester polymer is solidified into particles;
- an optional solid-stating step in which the solid polymer is polymerized to an It.V. from about 0.70 dL/g to about 1.2 dL/g;
- and
- a particle addition step comprising adding and dispersing metallic nickel particles to provide an amount from about 1 ppm to about 100 ppm by weight of the polymer, wherein the particle addition step occurs before, during, or after any of the preceding steps.
A process for making a polyester preform, comprising feeding a molten or solid bulk polyester and a liquid, molten or solid polyester concentrate composition to a machine for manufacturing the preform, the concentrate composition comprising metallic nickel particles having a median particle size from about 0.005 μm to about 10 μm, to obtain a preform having from about 1 ppm to about 100 ppm metallic nickel particles, based on the weight of the polyester preform.
A process for producing a polyester composition, comprising adding a concentrate polyester composition to a melt phase process for the manufacture of virgin polyester polymers, said concentrate comprising metallic nickel particles having a median particle size from about 0.005 μm to about 10 μm, to obtain a polyester composition having from about 1 ppm to about 100 ppm metallic nickel particles, based on the weight of the polyester composition.
Dependencies are inferred from the claim text.