Abstract: Processes for preparing a polyethylene in at least one continuously stirred tank reactor are described herein. The process may comprise the step of: polymerizing ethylene in the presence of at least one supported metallocene catalyst, a diluent, optionally one or more co-monomers, and optionally hydrogen, thereby obtaining the polyethylene, wherein the supported metallocene catalyst comprises a solid support, a co-catalyst and at least one metallocene, wherein the solid support has a surface area within the range of from 100 to 500 m2/g, and has a D50 value within the range of from 4 ?m to 18 ?m, with D50 being defined as the particle size for which fifty percent by weight of the particles has a size lower than the D50; and D50 being measured by laser diffraction analysis on a Malvern type analyzer. Polyethylene obtained by the disclosed process and articles comprising the polyethylene are also described.

Abstract: A polyethylene resin having a multimodal molecular weight distribution comprising at least two polyethylene fractions A and B, fraction A being substantially free of comonomer and having a lower weight average molecular weight and a higher density than fraction B, each fraction prepared in different reactors of two reactors connected in series in the presence of a Ziegler-Natta catalyst system, the polyethylene resin having a density of from 0.950 to 0.965 g/cm3 and a melt index MI2 of from 0.5 to 5 g/10 min.

Abstract: A supported catalyst system may include a titanated silica-containing catalyst support having at least 0.1 wt % of Ti and a specific surface area of from 150 m2/g to 800 m2/g. The Ti may be of a titanium compound of the general formula selected from RnTi(OR?)m, and (RO)nTi(OR?)m, wherein R and R? are the same or different and are selected from hydrocarbyl groups containing from 1 to 12 carbons or halogens, wherein n is 0 to 4, wherein m is 0 to 4, and wherein m+n equals 4. The supported catalyst system may include a catalyst activating agent and a metallocene. The supported catalyst system may be obtained by a process including titanating a silica-containing catalyst support with at least one vaporized titanium compound, and treating the titanated silica-containing catalyst support with a catalyst activating agent and a metallocene.

Abstract: A supported catalyst system includes a coprecipitated silica- and titania-containing support, alumoxane, and a metallocene. The supported catalyst system has a Ti content of at least 0.1 wt %.

Abstract: A process for preparing a polyethylene resin having a multimodal molecular weight distribution in at least two loop slurry reactors connected in series can include polymerizing ethylene in the presence of at least one supported metallocene catalyst, a diluent, optionally one or more co-monomers, and optionally hydrogen, thereby obtaining the polyethylene resin. The supported metallocene catalyst can have a particle size distribution of a span value lower than 2.5 and a D50 value within the range of from 5 ?m to 20 ?m.

Abstract: A polyethylene can be prepared with a metallocene catalyst system. The polyethylene can have a density of at least 0.945 g/cm3 measured according to ISO 1183, and a Si content of 5 to 40 ppm by weight.

Abstract: supported catalyst system may include a titanated silica-containing catalyst support having at least 0.1 wt % of Ti and a specific surface area of from 150 m2/g to 800 m2/g. The Ti may be of a titanium compound of the general formula selected from RnTi(OR?)m, and (RO)nTi(OR?)m, wherein R and R? are the same or different and are selected from hydrocarbyl groups containing from 1 to 12 carbons or halogens, wherein n is 0 to 4, wherein m is 0 to 4, and wherein m+n equals 4. The supported catalyst system may include a catalyst activating agent and a metallocene. The supported catalyst system may be obtained by a process including titanating a silica-containing catalyst support with at least one vapourised titanium compound, and treating the titanated silica-containing catalyst support with a catalyst activating agent and a metallocene.

Abstract: A process for preparing a supported catalyst system comprising the following steps: a. titanating a silica-containing catalyst support having a specific surface area of from 150 m2/g to 800 m2/g, preferably 280 to 600 m2/g, with at least one vaporized titanium compound of the general formula selected from RnTi(OR?)m and (RO)nTi(OR?)m, wherein R and R? are the same or different and are selected from hydrocarbyl groups containing from 1 to 12 carbon and halogens, and wherein n is 0 to 4, m is 0 to 4 and m+n equals 4, to form a titanated silica-containing catalyst support having at least 0.1 wt % of Ti based on the weight of the titanated silica-containing catalyst support, b. treating the support with a catalyst activating agent, preferably an alumoxane. c. treating the titanated support with at least one metallocene during or after step (b).

Abstract: The invention relates to a process for preparing polyolefin in a loop reactor. The polymer is prepared by polymerizing olefin monomers in the presence of a catalyst to produce a polyolefin slurry while pumping said slurry through said loop reactor by means of a pump. The present process is characterized in that the catalyst is fed in the loop reactor at a distance to the pump. The invention allows production of the polymer with advantageous properties while leading to fewer blockages of the reactor.

Abstract: A process for preparing a polyethylene resin having a multimodal molecular weight distribution in at least two loop slurry reactors connected in series can include polymerizing ethylene in the presence of at least one supported metallocene catalyst, a diluent, optionally one or more co-monomers, and optionally hydrogen, thereby obtaining the polyethylene resin. The supported metallocene catalyst can have a particle size distribution of a span value lower than 2.5 and a D50 value within the range of from 5 ?m to 20 ?m.

Abstract: An uncompounded particulate metallocene-produced polyethylene can have a multimodal molecular weight distribution and particle size distribution measured by obtaining at least four fractions by sieving. A set of Mw values including an Mw value for each fraction can be obtained. A set of Mn values including an Mn value for each fraction can be obtained. A ratio between a standard deviation value of the Mw set and a mean value of the Mw set can be equal to or less than 0.15. A ratio between a standard deviation value of the Mn set and a mean value of the Mn set can be equal to or less than 0.15. The uncompounded particulate metallocene-produced polyethylene can be prepared by a process that includes polymerization in an apparatus. The apparatus can include at least three serially connected loop reactors.

Abstract: This invention discloses caps and closures produced by injection molding with a bimodal high density polyethylene (HDPE) resin comprising a low molecular weight, high density polyethylene fraction substantially free of comonomer and a high molecular weight, low density polyethylene fraction, having a molecular weight distribution of at least 3.5, preferably greater than 4.0, prepared in two reactors connected in series in the presence of a metallocene-containing catalyst system, wherein the metallocene comprises a bisindenyl or a bis-tetrahydrogenated-indenyl component.

Abstract: The present invention relates to a process of preparing a polyolefin in a loop reactor by introducing anti-fouling agent through a sleeve provided around at least part of the shaft of the pump. Also, the invention relates to the use of anti-fouling agent to prevent or reduce fouling by feeding the anti-fouling agent against the impeller of the pump upon introduction to the loop reactor.

Abstract: The invention relates to A process for the polymerization of ethylene to produce a polyethylene resin in at least two slurry loop reactors connected to each other in series, the resin having a bimodal molecular weight distribution, a molecular weight distribution MWD of at least 7.0, an HLMI of from 1 to 100 g/10 min, and a density of from 0.935 to 0.960 g/cm3, wherein in one reactor 30 to 47 wt % based on the total weight of the polyethylene resin of a high molecular weight (HMW) polyethylene fraction is produced having an HL275 of from 0.05 to 1.8 g/10 min (the equivalent of HLMI of from 0.01 to 1.56 g/10 min), a density of from 0.925 to 0.942 g/cm3 and an MWD of at least 5.0, and in the other reactor a low molecular weight (LMW) polyethylene fraction is produced having an HLMI of from 10 to 1500 g/10 min and a density of from 0.960 to 0.975 g/cm3, in the presence of a Ziegler-Natta catalyst system.

Abstract: The invention relates to a process for preparing polyolefin in a loop reactor. The polymer is prepared by polymerizing olefin monomers in the presence of a catalyst to produce a polyolefin slurry while pumping said slurry through said loop reactor by means of a pump. The present process is characterized in that the catalyst is fed in the loop reactor at a distance to the pump. The invention allows production of the polymer with advantageous properties while leading to fewer blockages of the reactor.

Abstract: A polyethylene can be prepared with a metallocene catalyst system. The polyethylene can have a density of at least 0.945 g/cm3 measured according to ISO 1183, and a Si content of 5 to 40 ppm by weight.

Abstract: The invention relates to A process for the polymerisation of ethylene to produce a polyethylene resin in at least two slurry loop reactors connected to each other in series, the resin having a bimodal molecular weight distribution, a molecular weight distribution MWD of at least 7.0, an HLMI of from 1 to 100 g/10 min, and a density of from 0.935 to 0.960 g/cm3, wherein in one reactor 30 to 47 wt % based on the total weight of the polyethylene resin of a high molecular weight (HMW) polyethylene fraction is produced having an HL275 of from 0.05 to 1.8 g/10 min (the equivalent of HLMI of from 0.01 to 1.56 g/10 min), a density of from 0.925 to 0.942 g/cm3 and an MWD of at least 5.0, and in the other reactor a low molecular weight (LMW) polyethylene fraction is produced having an HLMI of from 10 to 1500 g/10 min and a density of from 0.960 to 0.975 g/cm3, in the presence of a Ziegler-Natta catalyst system.

Abstract: The invention relates to a process for preparing polyolefin in a loop reactor. The polymer is prepared by polymerizing olefin monomers in the presence of a catalyst to produce a polyolefin slurry while pumping said slurry through said loop reactor by means of a pump. The present process is characterized in that the catalyst is fed in the loop reactor at a distance to the pump. The invention allows production of the polymer with advantageous properties while leading to fewer blockages of the reactor.

Abstract: The invention relates to A process for the polymerisation of ethylene to produce a polyethylene resin in at least two slurry loop reactors connected to each other in series, the resin having a bimodal molecular weight distribution, a molecular weight distribution MWD of at least 7.0, an HLMI of from 1 to 100 g/10 min, and a density of from 0.935 to 0.960 g/cm3, wherein in one reactor 30 to 47 wt % based on the total weight of the polyethylene resin of a high molecular weight (HMW) polyethylene fraction is produced having an HL275 of from 0.05 to 1.8 g/10 min (the equivalent of HLMI of from 0.01 to 1.56 g/10 min), a density of from 0.925 to 0.942 g/cm3 and an MWD of at least 5.0, and in the other reactor a low molecular weight (LMW) polyethylene fraction is produced having an HLMI of from 10 to 1500 g/10 min and a density of from 0.960 to 0.975 g/cm3, in the presence of a Ziegler-Natta catalyst system.

Abstract: A metallocene-catalyzed polyethylene resin having a multimodal molecular weight and composition distribution, comprising from 45% by weight to 75% by weight of a low density fraction, said fraction having a density below or equal to 918 g/cm3 as measured following the method of standard test ISO 1183 at a temperature of 23° C., wherein the density of the polyethylene resin is from 0.920 to 0.945 g/cm3, wherein the Mw/Mn of the polyethylene is of from 2.8 to 6, wherein the melt index MI2 of the polyethylene resin of from 0.1 to 5 g/10 min measured following the method of standard test ISO 1133 Condition D at a temperature of 190° C. and under a load of 2.16 kg; and wherein the composition distribution breadth index (CDBI) of the polyethylene resin is below 70%, as analyzed by quench TREF (temperature rising elution fractionation) analysis.