General Electric Company

Eric Thomas Gohr

Patrick Joseph McCloskey

Niles R Rosenquist

Hua Wang

Johannes Martinus Dina Goossens

Dennis Joseph Coyle

Rajendra Kashinath Singh

Gregory J Stoddard

Fernando Alves Silva

Shahrzad Zarkoob

Ricky Joe Renschler

David Michel Dardaris

Robert Hossan

Devesh Mathur

Pin-pin Wu

Vijaykumar Hanagandi

Gary Eugene Spilman

Timothy Hans Lemmen

David A Bradley

Michael F Shannon

Chad David Mistele

A method to reduce haze in the production of fire resistant polycarbonate compositions comprising flame retardant salts, wherein the salt is blended with a first polycarbonate to form a concentrate, and the concentrate is then added to a second polycarbonate resin.

Method for reducing haze in a fire resistant polycarbonate composition

A method for removing volatile components from wet, polymer powders using a vacuum vented extruder is described. Polymer powders containing substantial amounts of water, 1-20% by weight, are rapidly converted to polymer compositions containing less than about 0.5% by weight water at high throughput rates while avoiding complications resulting from excessive steam backflow through the extruder feed throat. The method provides a screw design comprising a powder seal section upstream of kneading and melting sections of the extruder. Steam generated as the polymer is heated flows downstream to one or more vacuum vents for removal. The partially devolatilized polymer melt is then subjected to additional melt kneading and vacuum venting. The method converts wet polycarbonate powder containing residual methylene chloride to essentially dry polycarbonate powder containing less than about 1 ppm methylene chloride.

Method for removing water and other volatile components from polymer powders

The application relates to methods for producing a polycarbonate resin having a narrowed molecular weight distribution, specifically, the application relates to the use of a redistribution catalyst and a feedback loop control mechanism to prepare narrow molecular weight distribution resin.

Redistributed polycarbonate resin

A method for removing volatile components from wet, solid polymeric materials on a vacuum vented extruder is described. Polymeric materials containing substantial amounts of water, 1-20 % by weight, are rapidly converted to polymer compositions containing less than about 0.5% by weight water at high throughput rates while avoiding complications resulting from excessive steam backflow through the extruder feed throat. The method utilizes a screw design comprising only forward flighted screw elements in an initial polymer melting and kneading zone. Steam generated as the polymer is heated and sheared flows downstream to a first vacuum vent for removal. The partially devolatilized polymer melt is then subjected to additional kneading and vacuum venting. The claimed method converts wet polycarbonate powder containing residual methylene chloride to essentially dry polycarbonate powder containing less than about 1 ppm methylene chloride.

Method for removing volatile components from solid polymeric materials

A die clamp assembly for an extruder comprises at least one passage through which product being extruded flows. The die clamp assembly is attached to an extruder and comprises a last barrel that is connectable to the extruder. The last barrel comprising a flange and the extruder and last barrel define at least one passage through which product flows; at least one die body comprising at least one die body passage that communicates with the at least one passage; and at least one die plate that comprises at least one die plate passage that communicates with the die body passage and at least one opening so product can be extruded from the at least one opening. A clamp collar assembly connects corresponding peripheral surfaces of the last barrel to the die body, and comprises a closed position that connects the last barrel to the die body and an open position that permits separation of the last barrel and the die body. Further, a pivot assembly pivotally supports the clamp collar assembly for movement in a first direction and a second direction and the die body for movement in the second direction. The die body and the die plate are pivotable away from the last barrel when the clamp collar assembly has been pivoted to the open position.

Die clamp assembly

A die clamp assembly for an extruder comprises at least one passage through which product being extruded flows. The die clamp assembly is attached to an extruder and comprises at least one adapter plate that is connectable to the extruder. The die clamp assembly also comprises at least one adapter plate passage that communicates with the passage of the extruder; at least one die body comprising at least one die body passage that communicates with the adapter plate passage; and at least one die plate that comprises at least one die plate passage that communicates with the die body passage and at least one opening so product can be extruded from the at least one opening. A clamp collar assembly connects corresponding peripheral surfaces of the adapter plate to the die body, and comprises a closed position that connects the adapter plate to the die body and an open position that permits separation of the adapter plate and the die body. Further, a pivot assembly pivotally supports the clamp collar assembly for movement in a first direction and a second direction and the die body for movement in the second direction. The die body and the die plate are pivotable away from the adapter plate when the clamp collar assembly has been pivoted to the open position.

An aromatic polycarbonate composition having less than 400 parts per billion each of ionic impurities, particularly sulfate, chloride and fluoride ions prepared by devolatilizing the ionic impurities from a polycarbonate composition employing an aqueous medium of about 1% by weight based on the weight of the polycarbonate composition. Preferably the devolatilizing is carried out in an extruder during compounding the polycarbonate composition and preferably under a vacuum. Also, the extruded strands of polycarbonate resin are quenched in a deionized water bath.

Reducing ionic impurities content in aromatic polycarbonate resins

Polycarbonate compositions are redistributed by melt equilibration using diethyldimethylammonium hydroxide as the redistribution catalyst. This catalyst affords an odorless polycarbonate product having a very low residual amine level.

Polycarbonate redistribution using diethyldimethylammonium hydroxide as

The efficiency of a redistribution catalyst during polycarbonate redistribution is improved by employing an extruder screw design that provides a melt seal between the extruder throat and the vacuum port. A melt seal exists when the free volume within the extruder is sufficiently filled with molten resin so as to prevent the passage of gases between sections of the extruder.

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Evansville, IN, United States of America

Eric Thomas Gohr