Methods of post-polymerization extruder injection in polyethylene terephthalate production
AssigneeWellman, Inc.
InventorsCarl Steven Nichols, Tony Clifford Moore, Robert Joseph Schiavone, Walter Lee Edwards
Life of this patent
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Abstract
The invention is a novel method for the late introduction of additives into polyethylene terephthalate. The method employs a reactive carrier that functions as a delivery vehicle for one or more additives. The reactive carrier reacts with the polyethylene terephthalate, thereby binding the reactive carrier in the polyethylene terephthalate resin and preventing the emergence of the reactive carrier and additives from the polyethylene terephthalate during subsequent thermal processing.
Claims58
A method for introducing additives into polyethylene terephthalate, comprising combining at an extruder polyethylene terephthalate polymers and a reactive carrier having a molecular weight of less than about 10,000 g/mol, the reactive carrier being the delivery vehicle for one or more additives.
A method for introducing additives into polyethylene terephthalate, comprising introducing to an extruder polyethylene terephthalate polymers and a reactive carrier, wherein:
- the reactive carrier is the delivery vehicle for one or more additives;
- the reactive carrier has an average molecular weight of less than about 10,000 g/mol;
- and
- the reactive carrier is introduced to the extruder in quantities such that its concentration in the polyethylene terephthalate polymers is less than about one weight percent.
A method for introducing additives into polyethylene terephthalate, comprising:
- reacting a terephthalate component and a diol component to form polyethylene terephthalate precursors;
- polymerizing the polyethylene terephthalate precursors via melt phase polycondensation to form polymers of polyethylene terephthalate;
- and
- thereafter introducing to an extruder the polyethylene terephthalate polymers and a reactive carrier having a molecular weight of less than about 10,000 g/mol, the reactive carrier being the delivery vehicle for one or more additives.
Dependencies are inferred from the claim text.