Manufacture of cyclic ester oligomers
AssigneeE. I. Du Pont de Nemours and Company
InventorEdward G. Brugel
Life of this patent
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Abstract
Cyclic ester oligomers (CEOs) are manufactured from linear polyesters or their precursors by a continuous reactive extraction in which the linear polyesters are converted to the CEOs and the CEOs selectively removed from the mixture by extraction with a fluid. The fluid may be a liquid or a gas. The CEOs prodcued are useful as monomers, for example in a reaction injection molding process to rapidly form polyesters from low viscosity liquids.
Claims17
A process for the production of cyclic ester oligomers, comprising, subjecting a linear polyester to a continuous reactive extraction at a temperature at which said linear polyester is molten and which is sufficient to cause formation of said cyclic ester oligomers, wherein at least some of said linear polyester is converted to one or more cyclic ester oligomers and said extraction is carried out by a fluid which is one or both of a liquid and a gas to separate said cyclic ester oligomers from said linear polyester.
Dependencies are inferred from the claim text.