A modified Ziegler-Natta procatalyst that is a product mixture of modifying an initial Ziegler-Natta procatalyst with a molecular (pro)catalyst, and optionally an activator, the modifying occurring before activating the modified Ziegler-Natta procatalyst with an activator and before contacting the modified Ziegler-Natta procatalyst with a polymerizable olefin. Also, a modified catalyst system prepared therefrom, methods of preparing the modified Ziegler-Natta procatalyst and the modified catalyst system, a method of polymerizing an olefin using the modified catalyst system, and a polyolefin product made thereby.

A modified Ziegler-Natta procatalyst that is a product mixture of modifying an initial Ziegler-Natta procatalyst with a molecular (pro)catalyst, and optionally an activator, the modifying occurring before activating the modified Ziegler-Natta procatalyst with an activator and before contacting the modified Ziegler-Natta procatalyst with a polymerizable olefin. Also, a modified catalyst system prepared therefrom, methods of preparing the modified Ziegler-Natta procatalyst and the modified catalyst system, a method of polymerizing an olefin using the modified catalyst system, and a polyolefin product made thereby.

The present invention relates to a process for the continuous preparation of a polyolefin from one or more α-olefin monomers in a reactor system, the process for the continuous preparation of polyolefin comprising the steps of: feeding a polymerization catalyst to a fluidized bed through an inlet for a polymerization catalyst; feeding the one or more monomers to the reactor, polymerizing the one or more monomers in the fluidized bed to prepare the polyolefin; withdrawing polyolefin formed from the reactor through an outlet for polyolefin; withdrawing fluids from the reactor through an outlet for fluids and transporting the fluids through first connection means, an heat exchanger to cool the fluids to produce a cooled recycle stream, and through second connection means back into the reactor via an inlet for the recycle stream; wherein a thermal run away reducing agent (TRRA) is added to the reactor in a discontinuous way.

The present invention relates to a process for the continuous preparation of a polyolefin from one or more α-olefin monomers in a reactor system, the process for the continuous preparation of polyolefin comprising the steps of: feeding a polymerization catalyst to a fluidized bed through an inlet for a polymerization catalyst; feeding the one or more monomers to the reactor, polymerizing the one or more monomers in the fluidized bed to prepare the polyolefin; withdrawing polyolefin formed from the reactor through an outlet for polyolefin; withdrawing fluids from the reactor through an outlet for fluids and transporting the fluids through first connection means, an heat exchanger to cool the fluids to produce a cooled recycle stream, and through second connection means back into the reactor via an inlet for the recycle stream; wherein a thermal run away reducing agent (TRRA) is added to the reactor in a discontinuous way.

A resin powder for three-dimensional molding includes ethylene-propylene copolymer particles. The volume average particle size of the ethylene-propylene copolymer particles is within a range of 5 to 200 μm. The ethylene content molar ratio (ethylene/(ethylene+propylene)) in the ethylene-propylene copolymer particles is within a range of 0.001 to 0.04. The melt flow rate (MFR) is within a range of 3 to 40 g/10 min at 230° C.

A resin powder for three-dimensional molding includes ethylene-propylene copolymer particles. The volume average particle size of the ethylene-propylene copolymer particles is within a range of 5 to 200 μm. The ethylene content molar ratio (ethylene/(ethylene+propylene)) in the ethylene-propylene copolymer particles is within a range of 0.001 to 0.04. The melt flow rate (MFR) is within a range of 3 to 40 g/10 min at 230° C.

A catalyst system for olefin polymerization contains a main catalyst and a cocatalyst. The cocatalyst contains a twelve-membered ring compound represented by formula (M). The catalyst system is suitable for preparing polypropylene products having high stereoregularity and low ash, and can regulate the melt index of the products within a wide range by adjusting the amount of hydrogenation. It is also suitable for copolymerization systems to improve the copolymerization yield.

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A catalyst system for olefin polymerization contains a main catalyst and a cocatalyst. The cocatalyst contains a twelve-membered ring compound represented by formula (M). The catalyst system is suitable for preparing polypropylene products having high stereoregularity and low ash, and can regulate the melt index of the products within a wide range by adjusting the amount of hydrogenation. It is also suitable for copolymerization systems to improve the copolymerization yield.

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A Ziegler-Natta catalyst composition is disclosed. The catalyst composition is formed from a procatalyst containing a magnesium moiety and a titanium moiety. At least one internal electron donor is incorporated into the procatalyst. During a titanation procedure in conjunction with the internal electron donor, a titanium extractant is used to remove or deactivate low activity or atactic titanium active sites.

A Ziegler-Natta catalyst composition is disclosed. The catalyst composition is formed from a procatalyst containing a magnesium moiety and a titanium moiety. At least one internal electron donor is incorporated into the procatalyst. During a titanation procedure in conjunction with the internal electron donor, a titanium extractant is used to remove or deactivate low activity or atactic titanium active sites.