Metallocene catalyst compositions, processes for making polyolefin resins using such catalyst compositions, and products produced thereby

Abstract

A catalyst composition for the polymerization of one or more 1-olefins (e.g., ethylene) comprises a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution. In another embodiment, the transition metal catalyst precursor is bimetallic and contains a non-metallocene transition metal catalyst component. When a bimetallic catalyst precursor is used, the resin product exhibits improved properties, and has a bimodal molecular weight distribution, long chain branching (LCB), and good bubble stability.

What is claimed is:  
     
         1 . A catalyst composition comprising a transition metal catalyst precursor and a cocatalyst, the transition metal catalyst precursor comprising a contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution.  
     
     
         2 . A catalyst composition comprising a bimetallic transition metal catalyst precursor and a cocatalyst, the bimetallic transition metal catalyst precursor comprising: (a) the contact product of an unsubstituted metallocene compound and an aluminum alkyl compound in a hydrocarbon solvent solution; and (b) a non-metallocene transition metal component.  
     
     
         3 . The catalyst composition according to  claim 1 , wherein said unsubstituted metallocene compound is a complex of a transition metal of the formula L x MQ y Q′ z , in which L represents an unsubstituted ligand group, M is a transition metal selected from the group consisting of Group 4 metals, and each of Q and Q′ is a halogen atom, an alkyl group, or a hydrogen atom and Q and Q′ may be the same or different, wherein x is at least 1 and y and z have values such that x+y+z is equal to the valence of M.  
     
     
         4 . The catalyst composition according to  claim 1 , wherein said transition metal atom M is zirconium, and said ligand group L is an unsubstituted cyclopentadienyl group.  
     
     
         5 . The catalyst composition according to  claim 1 , wherein said aluminum alkyl compound is a trialkylaluminum compound.  
     
     
         6 . The catalyst composition according to  claim 5 , wherein said trialkylaluminum compound is trimethylaluminum, triethylaluminum, triisobutylaluminum, or tri-n-octylaluminum.  
     
     
         7 . The catalyst composition according to  claim 2 , wherein said non-metallocene transition metal component (b) comprises the reaction product of an optional support, an organomagnesium compound, an alcohol, and a non-metallocene transition metal compound.  
     
     
         8 . A process for producing a 1-olefin polymer comprising contacting at least one 1-olefin with the catalyst composition of  claim 1  under polymerization conditions.  
     
     
         9 . A process for producing a 1-olefin polymer comprising contacting at least one 1-olefin with the catalyst composition of  claim 2  under polymerization conditions.  
     
     
         10 . A 1-olefin polymer produced according to the process of  claim 8 .  
     
     
         11 . An ethylene (co)polymer produced in a single reactor having a bimodal molecular weight distribution, a flow activation energy of at least about 27 kjoule/mole, a density of from about 0.89 to about 0.965 g/cc, a melt index of from about 0.01 to about 0.2 g/10 minutes, a high load melt index (HLMI) of from about 2 to about 100 g/10 minutes, and a melt flow ratio (MFR) of from about 40 to about 300.  
     
     
         12 . An article of manufacture made from the ethylene (co)polymer of  claim 10 .  
     
     
         13 . An article of manufacture according to  claim 11 , wherein said article is a film having a thickness of up to about 254 microns (10 mils) and an Elmendorf tear resistance in the machine direction of at least about 236,220 g/m (6 g/mil), and a Dart Drop impact resistance of at least about 50 g.