摘要:
Methods of forming a catalyst, catalysts, polymerization processes and polymers formed therefrom are described herein. The method of forming a catalyst generally includes contacting an alkyl magnesium compound with an alcohol to form a magnesium alkoxide compound; contacting the magnesium alkoxide compound with a first titanium alkoxide and a first agent to form a reaction product “A”, wherein the titanium alkoxide and the first agent are nonblended individual components prior to contacting the magnesium alkoxide; and sequentially contacting the reaction product “A” with a second agent, followed by a third agent, and subsequently a first reducing agent to form a catalyst component.
摘要:
Methods of forming a catalyst, catalysts, polymerization processes and polymers formed therefrom are described herein. The method of forming a catalyst generally includes contacting an alkyl magnesium compound with an alcohol to form a magnesium alkoxide compound; contacting the magnesium alkoxide compound with a first titanium alkoxide and a first agent to form a reaction product “A”, wherein the titanium alkoxide and the first agent are nonblended individual components prior to contacting the magnesium alkoxide; and sequentially contacting the reaction product “A” with a second agent, followed by a third agent, and subsequently a first reducing agent to form a catalyst component.
摘要:
Polymerization processes in a bulk loop reactor are described herein. In particular, a method of contacting a flow of metallocene with a flow of propylene is provided. This method includes directing the flow of metallocene towards a junction, directing the flow of propylene towards the junction and maintaining a portion of the flow of metallocene separate from a portion of the flow propylene within a portion of the junction downstream of the flow of propylene into the junction. In another embodiment, a method of introducing a quantity of antifouling agent into a catalyst mixing system is provided. In this embodiment a portion of the antifouling agent is introduced at or downstream of a point of contact of a stream of propylene with a stream of catalyst. The antifouling agent may be a member, alone or in combination with other members, selected from Stadis 450 Conductivity Improver, Synperonic antifouling agent, and Pluronic antifouling agent.
摘要:
Embodiments of the invention generally include multi-component catalyst systems, polymerization processes and heterophasic copolymers formed by the processes. The multi-component catalyst system generally includes a first catalyst component selected from Ziegler-Natta catalyst systems including a diether internal electron donor and a metallocene catalyst represented by the general formula XCpACpBMAn, wherein X is a structural bridge, CpA and CpB each denote a cyclopentadienyl group or derivatives thereof, each being the same or different and which may be either substituted or unsubstituted, M is a transition metal and A is an alkyl, hydrocarbyl or halogen group and n is an integer between 0 and 4. The multi-component catalyst system further includes a second catalyst component generally represented by the formula XCpACpBMAn, wherein X is a structural bridge, CpA and CpB each denote a cyclopentadienyl group or derivatives thereof, each being the same or different and which may be either substituted or unsubstituted, M is a transition metal and A is an alkyl, hydrocarbyl or halogen group and n is an integer between 0 and 4 and wherein the second catalyst component exhibits a higher ethylene response than the first catalyst component.
摘要:
Catalyst systems and methods of forming the catalyst systems are described herein. The methods generally include contacting a support material with an activator to form a support composition, contacting a component with at least a portion of an aluminum containing compound including TIBAl, wherein the component is selected from the support composition, the transition metal catalyst compound and combinations thereof and contacting the support composition with a transition metal catalyst compound to form a supported catalyst system.
摘要:
Method employing a supported metallocene catalyst composition in the production of an isotactic ethylene propylene co-polymer. The composition comprises a metallocene component supported on a particulate silica support having average particle size of 10-40 microns, a pore volume of 1.3-1.6 ml/g, a surface area of 200-400 m 2/g. An alkylalumoxane cocatalyst component is incorporated on the support. The isospecific metallocene is characterized by the formula: B(CpRaRb)(FlR′2)MQn (1) or by the formula: B′(Cp′R′aR′b)(Fl′)M′Q′n′ (2) In the formulas Cp and Cp′ are substituted cyclopentadienyl groups, Fl and Fl′ are fluorenyl groups, and B and B′ are structural bridges. R′ are substituents at the 2 and 7 positions, Ra and R′a are substituents distal to the bridge, and Rb and R′b are proximal to the bridge. M and M′ are transition metals, Q′ is a halogen or a C1-C4 alkyl group; and n′ is an integer of from 0-4.
摘要:
Catalyst systems and methods of forming the catalyst systems are described herein. The methods generally include contacting a support material with an activator to form a support composition, contacting a component with at least a portion of an aluminum containing compound including TIBAl, wherein the component is selected from the support composition, the transition metal catalyst compound and combinations thereof and contacting the support composition with a transition metal catalyst compound to form a supported catalyst system.
摘要:
Supported stereospecific catalysts and processes for the stereotactic propagation of a polymer chain derived from ethylenically unsaturated monomers such as the polymerization of propylene to produce syndiotactic polypropylene or isotactic polypropylene. The supported catalyst comprises a stereospecific metallocene catalyst component and a co-catalyst component comprising an alkylalumoxane. Both the metallocene catalyst component and the co-catalyst component are supported on a particulate polyorganosilsesquioxane support comprising spheroidal particles of a polyorganosilsesquioxane having an average. diameter with the range of 0.3-20 microns. The polyorganosilsesquioxane support is characterized by relatively low surface area, specifically a surface area less than 100 square meters per gram. The metallocene component can take the form of a single metallocene or two or more metallocenes which are co-supported on the polyorganosilsesquioxane support.
摘要:
Propylene polymerization processes, polymers and films formed therefrom are described herein. The propylene polymerization processes generally include contacting propylene and an amount of ethylene with a first metallocene catalyst and a second metallocene catalyst within a polymerization reaction vessel to form a propylene based polymer, wherein the amount is an amount effective to form the propylene based polymer including from about 2 wt. % to about 6 wt. % ethylene, the second metallocene catalyst is capable of incorporating a greater amount of ethylene into the propylene based polymer than the first metallocene catalyst and wherein the first metallocene catalyst is capable of forming a propylene/ethylene random copolymer exhibiting a melting temperature that is greater than that of a propylene/ethylene random copolymer formed from the second metallocene catalyst.
摘要:
The invention is directed to a metallocene catalyst system comprising an inert silica support having pores with a peak pore volume of greater than about 0.115 mL/g at a pore diameter between about 250 Angstroms and about 350 Angstroms, and an alumoxane activator, with the metallocene being bound substantially throughout the support. The activator is grafted to the support in a solvent at a reflux temperature of toluene to obtain an aluminoxane on silica, and a metallocene component is added to make a MCS having a metallocene loading of about 2 wt %. This facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized that is at least about 20 percent higher than the catalytic activity for a metallocene loading of about 1 wt % where the activator is grafted to the support at room temperature.