Process for preparing membranes from tetrahalobisphenol polycarbonates

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United States of America Patent

PATENT NO 4975228
SERIAL NO

07226348

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ATTORNEY / AGENT: (SPONSORED)

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Abstract

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A process for the preparation of a membrane comprising bisphenol-based polycabonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is Cl or Br, and the membrane prepared by such process. The process generally comprises: forming a mixture comprising (i) a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogeneated, wherein the halogen is Cl or Br, and (ii) a solvent for such polycarbonate, wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; heating the mixture to a temperature at which the mixture is a homogeneous fluid and extrudable, extruding the heated mixture into a shape suitable for membrane use; passing the formed membrane through a quench zone wherein the mixture undergoes phase separation, and the major portion of the solvent is removed from the formed membrane; wherein the membrane formed is a membrane with a discriminating region capable of separating oxygen from nitrogen. Such membranes have excellent mechanical and thermal properties.

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Patent Owner(s)

  • MG GENERON, INC.

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Beck, Henry N Walnut Creek, CA 19 473
Sanders, Jr Edgar S Pittsburg, CA 14 162
Wan, Hawk S Antioch, CA 6 193

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