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US 8,026,323 B2Granted
Propylene ethylene polymers and production process
AssigneeExxonMobil Chemical Patents Inc.
InventorsSudhin Datta, Bruce A. Harrington, Weiguo Hu, Periagaram S. Ravishankar, George Rodriguez
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Abstract
Ethylene propylene copolymers, substantially free of diene, are described. The copolymers will have a uniform distribution of both tacticity and comonomer between copolymer chains. Further, the copolymers will exhibit a statistically insignificant intramolecular difference of tacticity. The copolymers are made in the presence of a metallocene catalyst.
Claims40
A process comprising:
- a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising:
- i) an organometallic Group 4 transition metal compound;
- and
- ii) an activating cocatalyst, wherein said catalyst complex is capable of producing stereospecific polypropylene;
- and
- b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 35° C. to less than 110° C., and a weight average molecular weight of:
- Mw>6.10*P*e(3370/T)
- wherein:
- Mw=the weight average molecular weight
- T=the polymerization reaction temperature in degrees Kelvin
- P=the steady state propylene concentration in the polymerization reaction zone in moles per liter.
8 more elements
A process comprising:
- a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising:
- i) an organometallic Group 4 transition metal compound;
- and
- ii) an activating cocatalyst, precursor ionic compound comprising a halogenated tetra-aryl-substituted Group 13 anion wherein each aryl substituent contains at least two cyclic aromatic rings,
- wherein said catalyst complex is capable of producing stereospecific polypropylene;
- and
- b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 35° C. to less than 110° C., and a weight average molecular weight of:
- Mw>6.10*P*e(3370/T)
- wherein:
- Mw=the weight average molecular weight
- T=the polymerization reaction temperature in degrees Kelvin
- P=the steady state propylene concentration in the polymerization reaction zone in moles per liter.
9 more elements
A process comprising:
- a) polymerizing propylene and ethylene comonomers in a solution process at a reaction temperature at or above 60° C., with a polymerization catalyst complex comprising:
- i) an organometallic Group 4 transition metal compound;
- and
- ii) an activating cocatalyst comprising N,N-dimethylanilinium tetrakis(perfluoronapthyl)borate;
- wherein said catalyst complex produces stereospecific polypropylene;
- and
- b) recovering a propylene copolymer containing units derived from propylene in an amount greater than or equal to 75 weight percent, and units derived from ethylene in an amount of from 5 to 25 weight percent, wherein the copolymer has a melting point of from greater than 35° C. to less than 110° C., and a triad tacticity of greater than 85%.
4 more elements
Dependencies are inferred from the claim text.