The present invention relates to a process for producing a propylene polymer, such as a propylene homopolymer, a propylene-ethylene random copolymer or a heterophasic propylene copolymer using a specific class of metallocene complexes in combination with a cocatalyst system comprising a boron containing cocatalyst and an aluminoxane cocatalyst, preferably in a multistage polymerization process including a gas phase polymerization step.

The purpose of the present invention is to provide a method for efficiently producing an olefin (co)polymer containing a constituent unit derived from 1-butene, the (co)polymer having a molecular weight that is sufficiently high even for high temperature conditions that are beneficial for industrial production methods. This purpose can be achieved by means of a method for producing an olefin (co)polymer containing a constituent unit derived from 1-butene, wherein at least 1-butene and, if necessary, an α-olefin having 2 or more carbon atoms (excluding 1-butene) and other monomers are (co)polymerized in the presence of an olefin polymerization catalyst that contains (A) a crosslinked metallocene compound represented by general formula [I] and (B) at least one type of compound selected from among (b-1) an organic aluminum oxy compound, (b-2) a compound that forms an ion pair upon a reaction with the crosslinked metallocene compound (A), and (b-3) an organic aluminum compound, at a polymerization temperature of 55-200° C. and a polymerization pressure of 0.1-5.0 MPaG.

Processes of synthesizing long-chain branched polymers. The processes include contacting together one or more C.sub.2-C.sub.14 alkene monomers, at least one diene, optionally a solvent, and a multi-chain catalyst optionally in the presence of hydrogen, wherein the multi-chain catalyst comprises a plurality of polymerization sites; producing at least two polymer chains of the C.sub.2-C.sub.14 alkene monomers, each polymer chain polymerizing at one of the polymerization sites; synthesizing the long-chain branched polymers by connecting the two polymer chains with the diene, the joining of the two polymer chains being performed in a concerted manner during the polymerization; and producing tri-functional long chain branches and tetra-functional long chain branches from the diene, wherein the long-chain branched polymers have a ratio of tri-functional to tetra-functional long chain branches from 0.05:1 to 100:0; and adjusting the ratio of tri-functional and tetra-functional long chain branches. The diene has a structure according to formula (I):

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It has become desirable to limit or exclude aromatic solvents, such as toluene, from polymerization reactions. For polymerization reactions employing a non-metallocene transition metal complex as a precursor to a polymerization catalyst, exclusion of aromatic solvents may be difficult due to the limited solubility of such complexes in aliphatic hydrocarbon solvents. Aliphatic hydrocarbon solutions suitable for conducting olefin polymerization reactions, particularly solution polymerization reactions, may comprise: a non-metallocene transition metal complex dissolved in an aliphatic hydrocarbon solvent at a concentration ranging from about 2 mM to about 20 mM at 25° C. in the presence of an organoaluminum compound. A molar ratio of aluminum of the organoaluminum compound to transition metal of the transition metal complex is about 1:1 or greater, and the organoaluminum compound comprises at least about 8 carbons per aluminum.

It has become desirable to limit or exclude aromatic solvents, such as toluene, from polymerization reactions. For polymerization reactions employing a non-metallocene transition metal complex as a precursor to a polymerization catalyst, exclusion of aromatic solvents may be difficult due to the limited solubility of such complexes in aliphatic hydrocarbon solvents. Aliphatic hydrocarbon solutions suitable for conducting olefin polymerization reactions, particularly solution polymerization reactions, may comprise: a non-metallocene transition metal complex dissolved in an aliphatic hydrocarbon solvent at a concentration ranging from about 2 mM to about 20 mM at 25° C. in the presence of an organoaluminum compound. A molar ratio of aluminum of the organoaluminum compound to transition metal of the transition metal complex is about 1:1 or greater, and the organoaluminum compound comprises at least about 8 carbons per aluminum.

The present invention relates to a process for producing a propylene polymer, such as a propylene homopolymer, a propylene-ethylene random copolymer or a heterophasic propylene copolymer using a specific class of metallocene complexes in combination with a cocatalyst system comprising a boron containing cocatalyst and an aluminoxane cocatalyst, preferably in a multistage polymerization process including a gas phase polymerization step.

Compositions and methods for selective olefin (e.g., ethylene) polymerization comprising metal organic frameworks (MOFs) are generally provided. In some embodiments, a MOF comprises a plurality of metal ions, each coordinated with at least one ligand comprising at least two unsaturated N-heterocyclic aromatic groups arranged about an organic core.

Compositions and methods for selective olefin (e.g., ethylene) polymerization comprising metal organic frameworks (MOFs) are generally provided. In some embodiments, a MOF comprises a plurality of metal ions, each coordinated with at least one ligand comprising at least two unsaturated N-heterocyclic aromatic groups arranged about an organic core.

The purpose of the present invention is to provide a method for efficiently producing an olefin (co)polymer containing a constituent unit derived from 1-butene, the (co)polymer having a molecular weight that is sufficiently high even for high temperature conditions that are beneficial for industrial production methods. This purpose can be achieved by means of a method for producing an olefin (co)polymer containing a constituent unit derived from 1-butene, wherein at least 1-butene and, if necessary, an -olefin having 2 or more carbon atoms (excluding 1-butene) and other monomers are (co)polymerized in the presence of an olefin polymerization catalyst that contains (A) a crosslinked metallocene compound represented by general formula [I] and (B) at least one type of compound selected from among (b-1) an organic aluminum oxy compound, (b-2) a compound that forms an ion pair upon a reaction with the crosslinked metallocene compound (A), and (b-3) an organic aluminum compound, at a polymerization temperature of 55-200 C. and a polymerization pressure of 0.1-5.0 MPaG.

A polyethylene copolymer may comprise about 90 wt % to about 99.99 wt % ethylene and about 0.01 wt % to about 10 wt % an alpha-olefin that is not ethylene, wherein the polyethylene has: a density of about 0.930 g/cm.sup.3 to about 0.955 g/cm.sup.3, a melt flow index (2.16 kg at 190 C.) of about 10 g/10 min to about 50 g/10 min, a melt flow index ratio (MIR) of about 15 to about 25, a weight average molecular weight to number average molecular weight ratio (Mw/Mn) of about 2 to about 4, a wt % of TREF elution at 90 C. and less of about 10 wt % to about 80 wt %, and a wt % of TREF elution at 95 C. and greater of about 3 wt % or more. Said polyethylene may be especially well-suited for making bicomponent fibers, which may be useful producing in nonwoven fabrics.