Abstract: Provided is a process for preparing copolymers of ethylene with ?-olefin. More specifically, provided are transition metal compound being useful as catalyst for preparing those copolymers, a catalyst composition comprising the same, and a process for preparing elastic copolymers of ethylene with ?-olefin, having the density of not more than 0.910, which can be adopted to a wide variety of applications including film, electric wires, and hot-melt adhesives. The catalyst composition is a catalytic system which comprises transition metal catalyst comprising a cyclopentadiene derivative and at least one anionic ligand(s) of aryloxy group with an aryl derivative at ortho-position, and boron or aluminum compound as an activator. Provided is a process for copolymerizing ethylene with ?-olefin to produce copolymer having narrow molecular weight distribution and uniform density distribution with the density of not more than 0.910, with high activity and excellent reactivity on higher ?-olefin.

Abstract: Provided are transition metal catalytic systems for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins. More specifically, provided are Group 4 transition metal catalysts, which is characterized in that the Group 4 transition metal catalyst comprises around the Group 4 transition metal a cyclopentadiene derivative, and at least one naphthoxide ligand(s) having aryl substituent(s) that function(s) as an electron donor and serve(s) to stabilize the catalyst system by surrounding an oxygen atom that links the ligand to the transition metal at 2-position, and there is no cross-linkage between the ligands; catalytic systems comprising such transition metal catalyst and aluminoxane cocatalyst or boron compound cocatalyst; and processes for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins by using the same.

Abstract: Provided are transition metal catalytic systems for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins. More specifically, provided are Group 4 transition metal catalysts, which is characterized in that the catalyst comprises around the Group 4 transition metal a cyclopentadiene derivative, and at least one aryloxide ligand(s) having a fluorenyl group or a derivative thereof (which is ready to be substituted at 9-position) that functions as an electron donor and serves to stabilize the catalytic system by surrounding an oxygen atom that links the ligand to the transition metal at ortho-position, and there is no cross-linkage between the ligands; catalytic systems comprising such transition metal catalyst and aluminoxane cocatalyst or boron compound cocatalyst; and processes for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins by using the same.

Abstract: Provided are transition metal catalytic systems for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins. More specifically, provided are Group 4 transition metal catalysts, which is characterized in that the catalyst comprises around the Group 4 transition metal a cyclopentadiene derivative, and at least one aryloxide ligand(s) having a fluorenyl group or a derivative thereof (which is ready to be substituted at 9-position) that functions as an electron donor and serves to stabilize the catalytic system by surrounding an oxygen atom that links the ligand to the transition metal at ortho-position, and there is no cross-linkage between the ligands; catalytic systems comprising such transition metal catalyst and aluminoxane cocatalyst or boron compound cocatalyst; and processes for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins by using the same.

Abstract: Disclosed is a continuous process for manufacturing aliphatic polycarbonate by polymerizing carbon dioxide and one or more epoxide compound in the presence of catalyst, in which carbon dioxide, one or more epoxide compound, and the catalyst are continuously supplied to polymerization reactor to produce aliphatic polycarbonate, separate unreacted carbon dioxide and epoxide compound and recycle them as raw materials.

Abstract: The present invention related to a method of manufacturing a polycarbonate including the process of copolymerizing epoxide compound and CO2 using cobalt(III) or chromium(III), where the ligands contains at least 3 ammonium cations, central metal has formal ?1 charge, and conjugated anions of the two cationic ammonium groups are acid-base homoconjugation, as catalyst. According to the present invention, the initial induction time can be reduced when the said polycarbonate is manufactured and it is possible to improve the activity of the catalyst and the molecular weight of the obtained polymer.

Abstract: Provided are ethylene copolymers and a process for preparing the same. More specifically, provided are ethylene copolymers exhibiting excellent processibility and physical properties due to its multimodal molecular weight distribution index, through a multi-stage process by using reactors connected in series or in parallel in the presence of catalyst composition containing transition metal catalyst, and a process for preparing the same.

Abstract: Provided is a process for preparing copolymers of ethylene with ?-olefin. More specifically, provided are transition metal compound being useful as catalyst for preparing those copolymers, a catalyst composition comprising the same, and a process for preparing elastic copolymers of ethylene with ?-olefin, having the density of not more than 0.910, which can be adopted to a wide variety of applications including film, electric wires, and hot-melt adhesives. The catalyst composition is a catalytic system which comprises transition metal catalyst comprising a cyclopentadiene derivative and at least one anionic ligand(s) of aryloxy group with an aryl derivative at ortho-position, and boron or aluminum compound as an activator. Provided is a process for copolymerizing ethylene with ?-olefin to produce copolymer having narrow molecular weight distribution and uniform density distribution with the density of not more than 0.910, with high activity and excellent reactivity on higher ?-olefin.

Abstract: Provided are transition metal catalytic systems for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins. More specifically, provided are Group 4 transition metal catalysts, which is characterized in that the catalyst comprises around the Group 4 transition metal a cyclopentadiene derivative, and at least one aryloxide ligand(s) having a fluorenyl group or a derivative thereof (which is ready to be substituted at 9-position) that functions as an electron donor and serves to stabilize the catalytic system by surrounding an oxygen atom that links the ligand to the transition metal at ortho-position, and there is no cross-linkage between the ligands; catalytic systems comprising such transition metal catalyst and aluminoxane cocatalyst or boron compound cocatalyst; and processes for preparing ethylene homopolymers or copolymers of ethylene with ?-olefins by using the same.

Abstract: Provided are a complex prepared from ammonium salt-containing ligands and having such an equilibrium structural formula that the metal center takes a negative charge of 2 or higher, and a method for preparing polycarbonate via copolymerization of an epoxide compound and carbon dioxide using the complex as a catalyst. When the complex is used as a catalyst for copolymerizing an epoxide compound and carbon dioxide, it shows high activity and high selectivity and provides high-molecular weight polycarbonate, and thus easily applicable to commercial processes. In addition, after forming polycarbonate via carbon dioxide/epoxide copolymerization using the complex as a catalyst, the catalyst may be separately recovered from the copolymer.