Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2005-12-20
2009-12-08
Teskin, Fred M (Department: 1796)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S082000, C526S083000, C526S901000
Reexamination Certificate
active
07629422
ABSTRACT:
Embodiments of our invention relate to processes for transitioning among polymerization catalyst systems including processes for transitioning among olefin polymerization reactions using Ziegler-Natta catalysts systems and chromium-based catalyst systems. Among embodiments contemplated are a method of transitioning from a first catalyst to a second catalyst in an olefin polymerization reactor, comprising: adding to the reactor a deactivating agent (DA) selected from one of carbon monoxide, carbon dioxide, or combinations thereof; adding to the reactor a cocatalyst adsorbing agent (CAA), comprising an inorganic oxide selected from one of silica, alumina or combinations thereof; wherein the first catalyst comprises at least one conventional Ziegler-Natta catalyst, and a cocatalyst, wherein the second catalyst comprises at least one chromium-based catalyst, wherein the reactor is a gas-phase, fluidized bed reactor, and wherein the CAA is substantially free of transition metals. In another embodiment a method of transitioning from a first catalyst to a second catalyst in an olefin polymerization reactor is contemplated, comprising: adding a transition aid agent (TAA) wherein the TAA is selected from one of alkoxylated amines, alkoxylated amides, or combinations thereof, wherein the first catalyst comprises at least one Ziegler-Natta catalyst comprising the catalyst, a cocatalyst and optionally a support, and the second catalyst comprises at least one chromium-based catalyst.
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Agapiou Agapios K.
Cann Kevin J.
Goode Mark G.
Hussein F. David
Santana Robert L.
Arechederra, III Leandro
Faulkner Kevin M.
Teskin Fred M
Univation Technologies LLC
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