The present invention provides an olefin polymer in which LCB (long chain branch) is introduced into mLLDPE (metallocene linear low-density polyethylene) to control the storage modulus, whereby the olefin polymer has excellent bubble stability and processing load characteristics and exhibits excellent processability during preparation of a film, and further has excellent mechanical properties and transparency.

Processes are provided which include copolymerization using two different metallocene catalysts, one capable of producing high Mooney-viscosity polymers and one suitable for producing lower Mooney-viscosity polymers having at least a portion of vinyl terminations. The two catalysts may be used together in polymerization to produce copolymer compositions of particularly well-tuned properties. For instance, polymerizations are contemplated to produce high-Mooney metallocene polymers that exhibit excellent processability and elasticity, notwithstanding their high Mooney viscosity. Other polymerizations are also contemplated in which lower-Mooney metallocene polymers are produced, which also exhibit excellent processability and elasticity, while furthermore having excellent cure properties suitable in curable elastomer compound applications. Many of the contemplated polymerizations include controlling the ratio of the two metallocene catalysts used in the polymerization so as to obtain the desired Mooney viscosity and desired rheology (indicated by Mooney Relaxation Area) of the copolymer compositions.

Methods for determining the concentration of transition metal compounds in a solution containing more than one transition metal compound are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems and for improving methods of preparing the multicomponent catalyst system.

The present invention provides a hybrid supported catalyst capable of easily preparing an olefin polymer capable of having improved melt strength even while having appropriate molecular weight distribution, and thus having improved bubble stability and exhibiting excellent blown film processability, and a method for preparing an olefin polymer using the same.

The present invention provides a metallocene supported catalyst that can prepare a polyolefin having excellent transparency even when processed into a film, as well as excellent processibility and mechanical properties, with high catalytic activity, and a method for preparing a polyolefin using the same.

Disclosed herein are ethylene-based polymers generally characterized by a Mw ranging from 70,000 to 200,000 g/mol, a ratio of Mz/Mw ranging from 1.8 to 20, an IB parameter ranging from 0.92 to 1.05, and an ATREF profile characterized by one large peak. These polymers have the dart impact, tear strength, and optical properties of a metallocene-catalyzed LLDPE, but with improved processability, melt strength, and bubble stability, and can be used in blown film and other end-use applications.

Processes of polymerizing olefin monomers. The process comprising reacting ethylene and optionally one or more olefin monomers in the presence of a catalyst system, wherein the catalyst system comprises: hydrocarbyl-modified methylaluminoxane having less than 25 mole percent trihydrocarbyl aluminum compounds AlR.sup.A1R.sup.B1R.sup.C1 based on the total moles of aluminum, where R.sup.A1, R.sup.B1, and R.sup.C1 are independently linear (C.sub.1-C.sub.40)alkyl, branched (C.sub.1-C.sub.40)alkyl, or (C.sub.6-C.sub.40)aryl; and one or more metal-ligand complexes according to formula (I):

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The invention relates to a process for transitioning from a first continuous polymerization reaction in a reactor, for example a gas-phase reactor conducted in the presence of a first catalyst to a second continuous polymerization reaction in the reactor conducted in the presence of a second catalyst, wherein the first and second catalysts are incompatible, the process comprising: (a) discontinuing the introduction of the first catalyst from a catalyst feeding system into a reactor and emptying the catalyst feeding system of the first catalyst; (b) introducing a first catalyst killer to the reactor to substantially deactivate the first catalyst in the reactor; (c) introducing a second catalyst killer to the catalyst feeding system to substantially deactivate the first catalyst in the catalyst feeding system; (d) introducing a second catalyst to the catalyst feeding system and (e) introducing the second catalyst to the reactor from the catalyst feeding system, wherein the second catalyst killer is the same as or different from the first catalyst killer.

This invention relates to a novel group 2, 3 or 4 transition metal metallocene catalyst compound having at least one arenyl ligand substituted with: 1) a cyclopropyl group and, optionally, 2) at at least one other group, such as a hydrocarbyl, a heteroatom or a heteroatom containing group.

This invention relates to methods to prepare and compositions pertaining to branched ethylene-propylene copolymers that include at least 50% ethylene content by weight as determined by FTIR; a g.sub.vis of less than 0.95; a M.sub.w of 125,000 to 300,000; a methylene sequence length of 6 or greater as determined by .sup.13C NMR, wherein the percentage of sequences of the length of 6 or greater is more than 32%; and can have greater than 50% vinyl chain end functionality.