摘要:
The invention provides for polymerization catalyst compositions, and for methods for introducing the catalyst compositions into a polymerization reactor. More particularly, the method combines a catalyst component containing slurry and a catalyst component containing solution to form the completed catalyst composition for introduction into the polymerization reactor. The invention is also directed to methods of preparing the catalyst component slurry, the catalyst component solution and the catalyst compositions, to methods of controlling the properties of polymer products utilizing the catalyst compositions, and to polymers produced therefrom.
摘要:
Gas phase polymerization processes are disclosed which utilize unsupported soluble transition metal coordination catalysts. The catalysts are introduced into the reactor as a solution.
摘要:
Ethylene copolymers having a very low molecular weight are continuously prepared in a fluidized bed in the presence of reduced concentrations of hydrogen, at improved catalyst activity and polymer productivity, by effecting polymerization in the presence of a dialkylzinc compound.
摘要:
An ethylene polymerization catalyst comprising a supported precursor of vanadium trihalide/electron donor complex and alkylaluminum or boron halides, when combined with alkylaluminum cocatalyst and alkyl halide promoter, provides enhanced polymerization and productivity plus superior polyethylene.
摘要:
A process for the gas phase production of a sticky, but fluidizable, polymer comprising (i) introducing at least one gaseous monomer, which is a precursor for the polymer, into a bed of particles located in a fluidized bed reactor at a velocity sufficient to cause the particles to separate and act as a fluid; (ii) introducing into the bed a catalyst adapted to cause the monomer to polymerize; (iii) contacting the catalyst with the monomer at a temperature below the sticking temperature of the polymer and at a temperature and pressure sufficient to polymerize the monomer in the presence of the catalyst whereby the polymer is produced; and (iv) passing the polymer from the fluidized bed reactor into at least one fluid bed reactor wherein a fluidizing gas is passed through a bed of particles at a velocity sufficient to cause the particles to separate and act as a fluid; the polymer is passed through the fluid bed reactor in an essentially plug flow mode; and the polymer is maintained in an agitated state.
摘要:
An ethylene polymerization catalyst comprising a supported precursor of vanadium trihalide/electron donor complex and alkylaluminum or boron halides, when combined with alkylaluminum cocatalyst and alkyl halide promoter provides enhanced polymerization and productivity plus superior polyethylene.
摘要:
A method for making a support impregnated Ziegler-Natta-type catalyst precursor including at least two transition metals and a support material wherein the resulting catalyst precursor is free-flowing is provided. Also provided is a process for producing a Ziegler-Natta type procatalyst by halogenating the free flowing catalyst precursor. The Ziegler-Natta type procatalyst and the reaction product of at least one monomer in the presence of the Ziegler-Natta type procatalyst and cocatalyst are also provided.
摘要:
The present invention relates to a process of producing an ethylene polymer composition in multiple stages of which the first stage is a slurry polymerization stage, in the presence of a catalyst system comprising a) a solid catalyst precursor comprising a transition metal selected from titanium and vanadium; magnesium, a halide, optionally an electron donor, and a solid particulate material comprising an inorganic oxide, wherein the median particle diameter of the solid catalyst precursor based upon the total volume of solid catalyst precursor, D50, is from 1 to 13 micrometers; and b) an organoaluminium compound.
摘要:
A process for making a Ziegler-Natta-type catalyst precursor including contacting a Group 4 metal compound with one or more Titanium compounds selected from the group of TiCl3 (Al-activated or hydrogen-reduced), and Ti(OR)4 where R is ethyl, isopropyl or butyl in the presence of an alcohol solution having at least one C2-C4 alcohol and at least one of MgCl2 and magnesium compounds which form MgCl2 in the presence of the alcohol solution to form a catalyst precursor solution is provided. Also provided are catalysts made from the precursors produced by the process. Also provided are polymers made using the catalysts.
摘要:
The invention provides a composition comprising a blend, which comprises a high molecular weight ethylene-based polymer, and a low molecular weight ethylene-based polymer, and wherein the high molecular weight ethylene-based polymer has a density less than, or equal to, 0.955 g/cm3, and wherein the blend has a high load melt index (I21) greater than, or equal to, 15 g/10 min, and wherein the blend has a molecular weight distribution (Mw/Mn) greater than, or equal to, 15. The invention also provides a composition comprising a blend, which comprises a high molecular weight ethylene-based polymer and a low molecular weight ethylene-based polymer, and wherein the high molecular weight ethylene-based polymer component has a density less than, or equal to, 0.945 g/cm3, and a melt index (I2) less than, or equal to, 0.1 g/10 min, and wherein the blend has a high load melt index (I21) less than, or equal to, 15 g/10 min, and a melt index (I5) less than, or equal to 1 g/10 min, and a molecular weight distribution (Mw/Mn) greater than, or equal to, 15. Additional compositions are disclosed.