E.i. Dupont De Nemours and Company

Jan M Stouffer

Elwood Neal Blanchard

Kenneth Wayne Leffew

David Neil Marks

Albert W Alsop

Jeffrey David Cohen

John M Iwasyk

Craig Robert Gochanour

Clara Young Lin

Disclosed is a process for the preparation of polyamide polymers via prepolymer formation in a reactor system comprising a reactor, flasher and separator, crystallization of the prepolymer under controlled temperature conditions and the subsequent conversion of these crystallized prepolymers to high molecular weight polymer.

Process for preparing polyamides

Disclosed herein is a novel physical form of low molecular weight poly(trimethylene terephthalate). This form may be produced from molten low molecular weight poly(trimethylene terephthalate) material by means of rapid heat transfer from the material. The poly(trimethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

Production of poly(trimethylene terephthalate)

Disclosed herein is a novel crystalline form of low molecular weight poly(ethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(ethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(ethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight. A higher molecular weight polymer product having a unique physical form can be produced by solid-state polymerization of the low molecular weight poly(ethylene terephthalate).

Production of poly (ethylene terephthalate)

Disclosed herein is a novel crystalline form of low molecular weight poly(trimethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(trimethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(trimethylene terephthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

This invention relates to a process and apparatus for forming a polyester polymer into particles. More particularly, this invention relates to a process and apparatus for forming crystalline, uniform pellets from an amorphous polyester melt. The polyester pellets have utility, for example, as feedstock for a process for producing higher molecular weight polyesters.

Process for forming crystalline polymer pellets

Production of poly(ethylene terephthalate)

Disclosed herein is a novel crystalline form of low molecular weight poly(ethylene 2,6-naphthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(ethylene 2,6-naphthalate) material by means of rapid heat transfer to or from the material. The poly(ethylene 2,6-naphthalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

Crystalline form of poly(ethylene 2,6-naphthalate) and a method for its

Apparatus for forming crystalline polymer pellets

The present invention relates to a process for forming robust, uniform, low molecular weight crystalline polyester particles. Such particles are useful for forming higher molecular weight polyesters, for example, by solid-state polymerization. Either conventionally-formed, essentially amorphous, non-molten polyester pellets at ambient temperatures or, alternatively, essentially amorphous molten polyester droplets, can be crystallized by rapidly subjecting the droplets or pellets to a thermal shock according to the process of the present invention.

Process for pellet formation from amorphous polyester

Disclosed herein is a novel crystalline form of low molecular weight poly(ethylene terephthalate). This crystalline form may be produced from molten or glassy low molecular weight poly(ethylene terephthalate) material by means of rapid heat transfer to or from the material. The poly(ethylene terephtalate) composition is suitable for use as a starting material for solid-state polymerization in order to produce polymers of higher molecular weight.

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Hockessin, DE, United States of America

Jan M Stouffer