E.i. Dupont De Nemours and Company

John Harvey Eng

Daniel Albert Green

Robert E Trotter

Gary J Wilson

Emily A Blum

Gene Parrish

Carl J Giardino

Dennis Gerard Madeleine

Michael Joseph Molitor

The process creates a radial temperature gradient in an extruded strand in a direction normal to the direction of motion thereof (that is, normal to the longitudinal direction thereof) so that upon exiting the first quench region the surface of the strand has solidified while at least the preponderant portion of the interior of the strand remains above the cold crystallization temperature, TThen, in the annealing region, heat from the warmer interior will be transferred to the cooler surface, causing the surface to heat up into the range of T, thereby inducing the surface to undergo crystallization. Once the surface has undergone crystallization, the strand is thoroughly quenched in a second quench region so that the strand will be ready for pelletization, accumulation or other handling steps.

Process for preparing pellets of poly(trimethylene terephthalate)

An apparatus is described having an extrusion means for extruding a molten polymer strand; a pelletizer; and a trough disposed to convey a polymer strand from the extrusion means to the pelletizer; the trough has an interior bottom surface; a water dispensing means disposed to provide a layer of water on a first portion of the interior bottom surface that is proximate to the extrusion means; a mesh or perforated surface disposed in the trough downstream from the water dispensing means, disposed to permit the separation of water from a water-immersed strand incident upon it; and a second portion of the interior bottom surface downstream from that mesh or perforated surface, disposed to contain a layer of water.

Apparatus for preparing pellets of poly(trimethylene terephthalate)

This invention relates to a continuous process for production of poly(trimethylene terephthalate), wherein gaseous 1,3-propanediol by product resulting from the process is condensed in a condenser, and a portion of the condensed by-product is recycled back into the process.

Continuous process for producing poly(trimethylene terephthalate)

This invention relates to a continuous process for production of poly(trimethylene terephthalate), wherein gaseous 1,3-propanediol by-product resulting from the process is condensed in a condenser, the total amount of any trimethylene terephthalate cyclic dimer and poly(trimethylene terephthalate) in the condensed by-product 1,3-propanediol is adjusted, and a portion of the condensed by-product is recycled to the condenser while another portion is recycled back into the process.

Continuous manufacture of poly(trimethylene terephthalate)

This invention relates to a continuous process for production of poly(trimethylene terephthalate), wherein gaseous 1,3-propanediol by product resulting from the process is condensed in a condenser, and a portion of the condensed by-product is recycled to the condenser while anther portion is recycled back into the process.

Poly(trimethylene therephthalate) continuous manufacturing process

A process for preparing a catalyst, comprising sequentially: (a) saturating a TiOsupport with aqueous ruthenium solution; (b) treating the ruthenium saturated TiOsupport with an aqueous base solution; and (c) curing the ruthenium saturated TiOto impregnate the TiOwith ruthenium. Preferably, subsequent to step (c) the process comprises sequentially (d) washing the ruthenium impregnated TiOwith water, (e) drying the washed ruthenium impregnated TiO, and (f) heat treating the ruthenium impregnated TiOunder reducing conditions at temperatures of 150-800&#xb0; C. A catalyst prepared by the process. A process for the production of 1,3-propanediol, comprising: (a) providing 3-hydroxypropanal and the catalyst, and (b) hydrogenating the 3-hydroxypropanal in the presence of the catalyst.

Catalyst for the production of 1,3-propanediol by catalytic hydrogenation of 3-hydroxypropanal

A process that can be used for direct esterification of a dicarboxylic acid such as terephthalic acid with a glycol such as 1,3-propanediol. The process comprises (1) contacting, at an elevated temperature, optionally in the presence of a preformed oligomer, the acid with the glycol to produce a product mixture comprising (i) a water-glycol vapor mixture, which or a portion of which exits the product mixture at the temperature to form a water-glycol vapor mixture and (ii) a liquid product mixture comprising an oligomer having a degree of polymerization of from about 1.9 to about 3.5 and comprising repeat units derived from the acid; (2) separating the glycol from the water-glycol mixture to produce a recovered glycol; and (3) returning the recovered glycol to the product mixture such that the liquid product mixture comprises an excess free glycol.

Esterification process

A catalyst composition prepared from (a) titanium tetrahydrocarbyloxide, (b) zirconium tetrahydrocarbyloxide, and (c) tetraalkyl ammonium hydroxide, wherein the molar ratio of Zr:Ti is from about 0.02:1 to about 5:1 and the molar ratio of TAAH:(Ti+Zr) is from about 0.05:1 to about 2:1.

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Wilmington, DE, United States of America

John Harvey Eng