This invention relates to a catalyst system including the reaction product of a support (such as a fluorided silica support that preferably has not been calcined at a temperature of 400° C. or more), an activator and at least two different transition metal catalyst compounds; methods of making such catalyst systems, polymerization processes using such catalyst systems and polymers made therefrom.

Polymerization process control methods for making polyethylene are provided. The process control methods include performing a polymerization reaction in a polymerization reactor to produce the polyethylene, where ethylene, and optionally one or more comonomers, in the polymerization reaction is catalyzed by an electron donor-free Ziegler-Natta catalyst and an alkyl aluminum co-catalyst. A melt flow ratio (I.sub.21/I.sub.2) of the polyethylene removed from the polymerization reactor is measured and an amount of long chain branching (LCB) of the polyethylene from the polymerization reactor is controlled by adjusting a weight concentration of the alkyl aluminum co-catalyst present in the polymerization reactor. In addition, an electron donor-free Ziegler-Natta catalyst productivity of the polyethylene being produced in the polymerization reactor is measured from which the amount of LCB of the polyethylene from the polymerization reactor is determined using the measured electron donor-free Ziegler-Natta catalyst productivity and a predetermined relationship between the electron donor-free Ziegler-Natta catalyst productivity and the LCB.

Polymerization process control methods for making polyethylene are provided. The process control methods include performing a polymerization reaction in a polymerization reactor to produce the polyethylene, where ethylene, and optionally one or more comonomers, in the polymerization reaction is catalyzed by an electron donor-free Ziegler-Natta catalyst and an alkyl aluminum co-catalyst. A melt flow ratio (I.sub.21/I.sub.2) of the polyethylene removed from the polymerization reactor is measured and an amount of long chain branching (LCB) of the polyethylene from the polymerization reactor is controlled by adjusting a weight concentration of the alkyl aluminum co-catalyst present in the polymerization reactor. In addition, an electron donor-free Ziegler-Natta catalyst productivity of the polyethylene being produced in the polymerization reactor is measured from which the amount of LCB of the polyethylene from the polymerization reactor is determined using the measured electron donor-free Ziegler-Natta catalyst productivity and a predetermined relationship between the electron donor-free Ziegler-Natta catalyst productivity and the LCB.

The present disclosure provides an olefin polymer having excellent film processability and physical properties, and a preparation method of the same.

The present disclosure provides an olefin polymer having excellent film processability and physical properties, and a preparation method of the same.

Rotomolded articles, especially flexible rotomolded articles are made from an ethylene interpolymer product having a melt index, I.sub.2 of from 2.5 to 8.0 g/10 min, a density of from 0.905 to 0.920 g/cm.sup.3; and a Dilution Index, Yd, greater than 0. The ethylene interpolymer product comprises: (I) a first ethylene interpolymer; (II) a second ethylene interpolymer, and; (III) optionally a third ethylene interpolymer.

Rotomolded articles, especially flexible rotomolded articles are made from an ethylene interpolymer product having a melt index, I.sub.2 of from 2.5 to 8.0 g/10 min, a density of from 0.905 to 0.920 g/cm.sup.3; and a Dilution Index, Yd, greater than 0. The ethylene interpolymer product comprises: (I) a first ethylene interpolymer; (II) a second ethylene interpolymer, and; (III) optionally a third ethylene interpolymer.

Provided is a hybrid catalyst composition including a first transition metal compound represented by Formula 1 and a second transition metal compound represented by Formula 2, the compounds being different from each other in the Formulae. The hybrid catalyst composition including the first and second transition metal compounds may exhibit high catalytic activity and may prepare a polyolefin having processability and mechanical properties.

Provided is a hybrid catalyst composition including a first transition metal compound represented by Formula 1 and a second transition metal compound represented by Formula 2, the compounds being different from each other in the Formulae. The hybrid catalyst composition including the first and second transition metal compounds may exhibit high catalytic activity and may prepare a polyolefin having processability and mechanical properties.

Ethylene-based polymers are characterized by a melt index less than 1 g/10 min, a density from 0.94 to 0.965 g/cm.sup.3, a Mw from 100,000 to 250,000 g/mol, a relaxation time from 0.5 to 3 sec, and an average number of long chain branches (LCBs) per 1,000,000 total carbon atoms in a molecular weight range of 300,000 to 900,000 g/mol that is greater than that in a molecular weight range of 1,000,000 to 2,000,000 g/mol, or an average number of LCBs per 1,000,000 total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000 g/mol of less than or equal to about 5 and a maximum ratio of η.sub.E/3η at an extensional rate of 0.1 sec.sup.−1 from 1.2 to 10. These polymers have substantially no long chain branching in the high molecular weight fraction of the polymer, but instead have significant long chain branching in a lower molecular weight fraction, such that polymer melt strength and parison stability are maintained for the fabrication of blow molded products and other articles of manufacture. These ethylene polymers can be produced using a dual catalyst system containing a single or two atom bridged metallocene compound with two indenyl groups, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.