Catalyst systems for producing polyolefins having a broad molecular weight distribution

Claim 2

A catalyst system for the polymerization and copolymerization of olefins having 3-8 carbon atoms, said system comprising: (a) at least two different metallocene catalysts which are chiral and stereo-rigid and are described by the formula: R"(C.sub.5 (R').sub.4).sub.2 MeQ.sub.p wherein (C 5 (R') 4 ) is a cyclopentadienyl or substituted cyclopentadienyl ring; each R' is the same or different and is a hydrogen or hydrocarbyl radical having 1-20 carbon atoms; R" is a structural bridge between the two (C 5 (R') 4 ) rings imparting stereo-rigidity to said catalyst, and R" is selected from the group consisting of an alkylene radical having 1-4 carbon atoms, a silicon hydrocarbyl radical, a germanium hydrocarbyl radical, a phosphorus hydrocarbyl radical, a nitrogen hydrocarbyl radical, a boron hydrocarbyl radical, and an aluminum hydrocarbyl radical; Me is a group 4b, 5b, or 6b metal as designated in the Periodic Table of Elements; each Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0≦p≦3; and in at least one of said metallocene catalyst Me is hafnium; and (b) an organoaluminum compound selected from the group consisting of alumoxane, trimethyl aluminum, and mixtures thereof.

Claim 3

The catalyst system of claim 1, wherein Me is hafnium, zirconium or titanium.

Claim 4

The catalyst system of claim 1, wherein the system contains at least one zirconocene catalyst.

Claim 5

The catalyst system of claim 1, wherein R' is selected such that the group (C 5 (R') 4 ) in at least one of said catalysts is an indenyl radical or a hydrated indenyl radical.

Claim 6

The catalyst system of claim 1, wherein R" is an ethylene radical in at least one of said catalysts.

Claim 7

The catalyst system of claim 1, further comprising: (c) a solvent that increases the solubility of the catalyst in an olefin monomer.

Claim 8

The catalyst system of claim 6, wherein said solvent is selected from the group consisting of toluene, xylene, and methylene chloride.

Claim 9

The catalyst system of claim 1, wherein said organoaluminum compound is a mixture of alumoxane and trimethyl aluminum.

Claim 10

The catalyst system of claim 1, wherein the system exhibits a transformation over time in polymerizing olefins such that it produces over time a polymer product having different characteristics than the product initially produced by the system.

Claim 11

A catalyst system for the polymerization and copolymerization of olefins having 3-8 carbon atoms, said system comprising: (a) at least two different metallocene catalysts which are chiral and stereo-rigid and are described by the formula: R"(C.sub.S (R').sub.4).sub.2 MeQ.sub.p wherein (C 5 (R') 4 ) is a cyclopentadienyl or substituted cyclopentadienyl ring; each R' is the same or different and is a hydrogen or hydrocarbyl radical having 1-20 carbon atoms; R" is a structural bridge between the two (C 5 (R') 4 ) rings imparting stereo-rigidity to said catalyst, and R" is selected from the group consisting of an alkylene radical having 1-4 carbon atoms, a silicon hydrocarbyl radical, a germanium hydrocarbyl radical, a phosphorus hydrocarbyl radical, a nitrogen hydrocarbyl radical, a boron hydrocarbyl radical, and an aluminum hydrocarbyl radical; Me is a group 4b, 5b, or 6b metal as designated in the Periodic Table of Elements; each Q is a hydrocarbyl radical having 6-20 carbon atoms or is a halogen; 0≦p≦3; and in at least one catalyst Me is a group 4b metal and in at least one of the other catalysts Me is a group 5b or 6b metal; and (b) an organoaluminum compound selected from the group consisting of alumoxane, trimethyl aluminum, and mixtures thereof.

Claim 12

A catalyst system for the polymerization and copolymerization of olefins having 3-8 carbon atoms, said system comprising: (a) at least two different metallocene catalysts which are chiral and stereo-rigid and are described by the formula: R"(C.sub.S (R').sub.4).sub.2 MeQ.sub.p wherein (C 5 (R') 4 ) is a cyclopentadienyl or substituted cyclopentadienyl ring; each R' is the same or different and is a hydrogen or hydrocarbyl radical having 1-20 carbon atoms; R" is a structural bridge between the two (C 5 (R') 4 ) rings imparting stereo-rigidity to said catalyst, and R" is selected from the group consisting of an alkylene radical having 1-4 carbon atoms, a silicon hydrocarbyl radical, a germanium hydrocarbyl radical, a phosphorus hydrocarbyl radical, a nitrogen hydrocarbyl radical, a boron hydrocarbyl radical, and an aluminum hydrocarbyl radical; Me is a group 4b, 5b, or 6b metal as designated in the Periodic Table of Elements; each Q is a hydrocarbyl radical having 6-20 carbon atoms or is a halogen; 0≦p≦3; and in at least one catalyst Me is a group 4b metal and in at least one of the other catalysts Me is a group 5b or 6b metal; and (b) an organoaluminum compound selected from the group consisting of alumoxane, trimethyl aluminum, and mixtures thereof.