E.i. Dupont De Nemours and Company

Robert A Covington, Jr

Okan Max Ekiner

Colin Anolick

David W Williston

Cecil L Long

Ferromagnetic chromium dioxide is produced in a continuous operation by feeding a preheated paste of hydrated chromium oxides and additives into a twin screw reactor, reacting at elevated temperature and pressure for a short time while venting oxygen and steam, injecting water near the end of the reaction zone to form a viscous chromium dioxide-water mixture, and cooling while passing through a pressure letdown extruder.

Continuous synthesis of chromium dioxide

In-line continuous coagulation and agglomeration of fluoroelastomers produced by emulsion polymerization permits direct processing of fluoroelastomer latex into mechanical dewatering devices. Coagulant is injected into the fluoroelastomer latex countercurrent and under high pressure atomization and residence time prior to mechanical dewatering is controlled.

In-line coagulation process for fluoroelastomer emulsions

A method is provided for isolating an elastomer from a mixture of the elastomer and water containing up to about 90% by weight water by feeding the mixture into a thermally controlled, vertical separator containing a rotating screw, simultaneously feeding excess water under pressure into the separator, withdrawing concentrated elastomer containing less than about 10% by weight total volatiles (including water) from the metering section of the separator and withdrawing feed water and excess water from a water discharge port located near the upper end of the separator. In addition, apparatus for isolating elastomers from mixtures of elastomers and water is provided.

Mechanical dewatering apparatus for elastomer slurries

Mechanical dewatering process for elastomer slurries

An improvement in a process for the copolymerization of ethylene and an .alpha.-olefin having 3 to 18 carbon atoms and optionally also a nonconjugated diene having only one readily polymerizable double bond in the presence of a catalyst and a liquid organic medium to an elastomeric copolymer insoluble in the liquid polymerization medium, having a portion of said medium occluded therein, and tending to agglomerate on solid surfaces, wherein simultaneously and continuously

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Wilmington, DE, United States of America

Robert A Covington, Jr