Abstract:
A high pressure polymerization process to form an ethylene-based polymer comprises the steps of: A. Injecting a first feed comprising ethylene and optionally a chain transfer agent system (CTA system) into a first autoclave reactor zone operating at polymerization conditions to produce a first zone reaction product, the CTA system of the first reactor zone having a transfer activity Z1; and B. (1) Transferring at least part of the first zone reaction product to a second reactor zone selected from a second autoclave reactor zone or a tubular reactor zone and operating at polymerization conditions, and, optionally, (2) freshly injecting a second feed into the second reactor zone to produce a second zone reaction product, with the proviso that the second reactor zone contains a CTA system having a transfer activity Z2; and with the proviso that the ratio of Z1/Z2 is less than 1.
Abstract:
The invention relates to a continuous polymerization process for preparing a random ethylene interpolymer with propylene and/or 1-butene which comprises: (A) polymerizing ethylene, and as an α-olefin comonomer propylene and/or 1-butene under continuous random polymerization conditions in the presence of single site catalyst system employing an ionic activator having cyclic ligands shielding a central charge bearing atom, at a temperature of 140° C. to 250° C. at a conversion of ethylene of 80 to 99% and a comonomer conversion of from at least 30% and (B) devolatilizing the polymer to provide an ethylene copolymer having a density of from 0.85 to 0.92 g/cm3, an MI of from 0.01 to 100 g/10 min, preferably from 0.1 to 20, and an I21/I2 of from 30 to 400. The invention also relates to polymers made by such processes containing as α-olefin comonomer propylene and/or 1-butene, having a density of from 0.85 to 0.92 g/cm3, an MI of from 0.01 to 100 g/10 min and an I21/I2 of from 30 to 400 obtained by solution polymerization using a transition metal complex as a catalyst and a non-coordinating anion to provide a level of NCA derived residue, as determined by boron content, less than 0.5 ppm. as determined by ICP, preferably undetectable by ICP. The polymers may be blended with EP rubber elastomers and be used for electrical cable insulation.
Abstract:
A polymer having a density of from about 0.94 g/cm3 to about 0.96 g/cm3 and a primary structure parameter 2 (PSP2 value) of greater than about 8.5, wherein an article formed from the polymer has an environmental stress crack resistance of equal to or greater than about 1000 hours when measured in accordance with ASTM D 1693 condition A. A polymer having at least one lower molecular weight component and at least one higher molecular weight component and having a PSP2 value of equal to or greater than about 8.5, wherein an article formed from the polymer has an environmental stress crack resistance of greater than about 1000 hours when measured in accordance with ASTM D 1693 condition A.
Abstract translation:密度为约0.94g / cm 3至约0.96g / cm 3,一次结构参数2(PSP2值)大于约8.5的聚合物,其中由聚合物形成的制品具有等于 或根据ASTM D1693条件A测量时大于约1000小时。具有至少一种较低分子量组分和至少一种较高分子量组分并且PSP2值等于或大于约8.5的聚合物,其中 根据ASTM D 1693条件A测量时,由聚合物形成的制品具有大于约1000小时的环境应力抗裂性。
Abstract:
A method of preparing a catalyst comprising aging a silica support in an alkaline solution to produce an alkaline aged silica support, removing at least a portion of the alkaline solution from the alkaline aged silica support to produce a dried silica support, and activating the silica support to produce a catalyst composition, wherein alkaline aging lowers the surface area of the silica support to less than about 50% of the original value and wherein activation of the silica support is carried out in batches of equal to or greater than about 500 lbs for a time period of less than about 8 hours. A method of preparing a polymer comprising alkaline aging a silica support material, adding chromium to the silica support material prior to the alkaline aging, after the alkaline aging, or both to form a chromium-silica support, rapidly activating the chromium-silica support to produce an activated olefin polymerization catalyst, contacting the activated olefin polymerization catalyst with at least one monomer in a reaction zone under conditions suitable to produce a polymer, and recovering the polymer.
Abstract:
An ethylene-α-olefin copolymer comprising monomer units derived from ethylene and monomer units derived from an α-olefin having 3 to 20 carbon atoms, having a density (d) of 850 to 970 kg/m3, having a melt flow rate (MFR) of 0.01 to 100 g/10 min, having a bimodal molecular weight distribution, and having a ratio (Mw/Mn) of the weight average molecular weight (Mw) thereof to the number average molecular weight (Mn) thereof of 31 to 70, wherein the number (NLCB) of branches having 5 or more carbon atoms measured by 13C-NMR is from 0.7 to 1.0 per 1000 carbon atoms. This copolymer is superior in a balance between a melt tension, an extrusion load at extruding, and a mechanical strength.
Abstract:
Process for controlling the (co)polymerization of olefins in a continuous polymerization reactor wherein the olefin (co)polymerization is performed in an industrial plant reactor in the presence of a polymerization catalyst characterized in that at least one operating parameter of the plant is controlled by means of a measurement of the chain branching level (CBL) of the produced polymer.
Abstract:
A catalyst composition comprising one or more metal complexes of a multifunctional Lewis base ligand comprising a bulky, planar, aromatic- or substituted aromatic-group and polymerization processes employing the same, especially continuous, solution polymerization of one or more α-olefins at high catalyst efficiencies are disclosed.
Abstract:
Processes for polymerizing propylene. About 40 wt % to about 80 wt % propylene monomer, based on total weight of propylene monomer and diluent, and about 20 wt % to about 60 wt % diluent, based on total weight of propylene monomer and diluent, can be fed into a reactor. The propylene monomer can be polymerized in the presence of a metallocene catalyst and an activator within the reactor at a temperature of about 80° C. or more and a pressure of about 13 MPa or more to produce a polymer product in a homogenous system. About 20 wt % to about 76 wt % (preferably About 28 wt % to about 76 wt %) propylene monomer, based on total weight of the propylene monomer, diluent, and polymer product, can be present at the reactor exit at steady state conditions.
Abstract:
The purpose of the invention is to provide an ethylene-α-olefin copolymer, which has a high melt tension but a small neck-in, and a molded object produced by extrusion molding of the copolymer. An ethylene-α-olefin copolymer having a monomer unit based on ethylene and a monomer unit based on an α-olefin having 3 to 20 carbon atoms, which has a melt flow rate (MFR) of 0.1 to 100 g/10 min, a density (d) of 850 to 940 kg/m3, a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 2 to 12, and a value g* defined by the following formula (I) of 0.50 to 0.75: g*=[η]/([η]GPC×gSCB*) (I).
Abstract:
This invention relates to a process to polymerize olefins comprising contacting propylene, at a temperature of 65° C. to 150° C. and a pressure of 1.72 to 34.5 MPa, with: 1) a catalyst system comprising one or more activators and one or more nonmetallocene metal-centered, heteroaryl ligand catalyst compounds, where the metal is chosen from the Group 4, 5, 6, the lanthanide series, or the actinide series of the Periodic Table of the Elements, 2) optionally one or more comonomers selected from ethylene and C4 to C12 olefins, 3) diluent or solvent, and 4) optionally scavenger, wherein: a) the olefin monomers and any comonomers are present in the polymerization system at 30 wt % or more, b) the propylene is present in the feed at 80 wt % or more, c) the polymerization occurs at a temperature above the solid-fluid phase transition temperature of the polymerization system and a pressure greater than 1 MPa below the cloud point pressure of the polymerization system, and d) the polymerization occurs: (1) at a temperature below the critical temperature of the polymerization system, or (preferably and) (2) at a pressure below the critical pressure of the polymerization system.