Spheroidal catalyst for olefin polymerization
A solid, spheroidal polymerization catalyst having a particle size distribution characterized by a Dm*/Dn of less than 3.0, the catalyst comprising a phosphinimine catalyst, a cocatalyst and a magnesium chloride support. A process for the polymerization of ethylene with one or more alpha olefin catalyzed by a solid, spheroidal polymerization catalyst having a particle size distribution characterized by a Dm*/Dn of less than 3.0, the catalyst comprising a phosphinimine catalyst, a cocatalyst and a magnesium chloride support.
1. A spheroidal olefin polymerization catalyst having a particle size distribution characterized by a Dm*/Dn of less than 3.0, wherein said catalyst comprises: a phosphinimine catalyst, a cocatalyst, and a spheroidal magnesium chloride support, wherein the magnesium chloride support comprises particles with a mass average diameter Dm from about 5 to about 100 μm, a particle size distribution characterized by a Dm/Dn of less than 3.0, and comprises less than 2% by weight of an electron donor compound.
2. The spheroidal olefin polymerization catalyst of claim 1 , wherein the electron donor compound is a non-protic ether.
3. The spheroidal olefin polymerization catalyst of claim 1 , wherein the magnesium chloride support comprises particles with a mass average diameter of from about 5 to about 50 μm.
4. The spheroidal olefin polymerization catalyst of claim 1 , wherein the magnesium chloride support comprises less than 1.5% by weight of an electron donor compound.
5. The spheroidal olefin polymerization catalyst of claim 1 having a particle size distribution characterized by a Dm*/Dn of less than 2.0.
6. The spheroidal olefin polymerization catalyst of claim 1 having a particle size distribution characterized by a Dm*/Dn of less than 1.5.
7. The spheroidal olefin polymerization catalyst of claim 1 , wherein the magnesium chloride support comprises particles with a particle size distribution characterized by a Dm/Dn of less than 2.0.
8. The spheroidal olefin polymerization catalyst of claim 1 wherein the phosphinimine catalyst has the formula: (L)(PI)MX 2 , where M is Ti, Zr or Hf; PI is a phosphinimine ligand having the formula R 3 P═N—, where R is independently selected from the group consisting of hydrogen, halogen, and C 1 -C 20 hydrocarbyl; L is a ligand selected from the group, consisting of cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl, and substituted fluorenyl; and X is an activatable ligand.
9. The spheroidal olefin polymerization catalyst of claim 1 wherein the phosphinimine catalyst has the formula: (L)((t-Bu) 3 P═N)TiX 2 , where L is a cyclopentadienyl ligand, a substituted cyclopentadienyl ligand, an indenyl ligand, or a substituted indenyl ligand; and X is an activatable ligand.
10. The spheroidal olefin polymerization catalyst of claim 1 wherein the phosphinimine catalyst has the formula: (L)((t-Bu) 3 P═N)TiX 2 , where L is a substituted cyclopentadienyl ligand, or a substituted indenyl ligand; and X is an activatable ligand.
11. The spheroidal olefin polymerization catalyst of claim 1 wherein the cocatalyst is selected from the group consisting of ionic activators, alkylaluminoxanes and mixtures thereof.
12. A process for polymerizing ethylene and at least one alpha-olefin to produce an ethylene copolymer, said process comprising contacting a spheroidal olefin polymerization catalyst with ethylene and at least one alpha-olefin in a polymerization reactor, wherein said spheroidal olefin polymerization catalyst has a particle size distribution characterized by a Dm*/Dn of less than 3.0 and comprises: a phosphinimine catalyst, a cocatalyst, and a spheroidal magnesium chloride support; wherein the magnesium chloride support comprises particles with a mass average diameter Dm from about 5 to about 100 μm, a particle size distribution characterized by a Dm/Dn of less than 3.0, and comprises less than 2% by weight of an electron donor compound.
13. The process of claim 12 wherein the phosphinimine catalyst has the formula: (L)(PI)MX 2 , where M is Ti, Zr or Hf; PI is a phosphinimine ligand having the formula R 3 P═N—, where R is independently selected from the group consisting of hydrogen, halogen, and C 1 -C 20 hydrocarbyl; L is a ligand selected from the group consisting of cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl, and substituted fluorenyl; and X is an activatable ligand.
14. The process of claim 12 wherein the phosphinimine catalyst has the formula: (L)((t-Bu) 3 P═N)TiX 2 , where L is a cyclopentadienyl ligand, a substituted cyclopentadienyl ligand, an indenyl ligand, or a substituted indenyl ligand; and X is an activatable ligand.
15. The process of claim 12 wherein the phosphinimine catalyst has the formula: (L)((t-Bu) 3 P═N)TiX 2 , where L is a substituted cyclopentadienyl ligand, or a substituted indenyl ligand; and X is an activatable ligand.
16. The process of claim 12 wherein the cocatalyst is selected from the group consisting of ionic activators, alkylaluminoxanes and mixtures thereof.