Process for upgrading prepolymer particles
AssigneeStandard Oil Company (Indiana)
InventorsRussell V. Malo, Gary A. Gustafson, Ronald E. Bockrath
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Abstract
A horizontal, agitated, twin-shaft, jacketed vessel with adjustable vanes performs the functions of drying, crystallization, and solid phase polymerization for upgrading prepolymer particles.
Claims9
A process for upgrading polyester prepolymer particles comprising continuously conveying polyester prepolymer particles through a thermovane processor under an inert gas sweep at a temperature below the softening point of the polyester and sufficient to achieve crystallization and/or solid-state polymerization without sticking of the particles.
A process for upgrading partially crystallized poly(ethylene terephthalate) copolyester particles having a degree of crystallization of at least about 5 percent, said process comprising continuously conveying the particles through two serially-connected thermovane processors, without sticking, under an inert gas sweep and at a temperature below 235.degree. C. wherein the particles are dried, crystallized, and polymerized in the first thermovane processor and thereafter further polymerized in the second thermovane processor.
Dependencies are inferred from the claim text.