摘要:
Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-(2-aryloxy)quinoline or 2-(2-aryloxy)dihydroquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.
摘要:
A method of preparing supported catalysts useful for olefin polymerization is described. The catalysts comprise a Group 4 metal complex that incorporates a tridentate dianionic ligand. An activator mixture is first made from a boron compound having Lewis acidity and an excess of an alumoxane. The activator mixture is then combined with a support and the Group 4 metal complex to give a supported catalyst. The method provides an active, supported catalyst capable of making high-molecular-weight polyolefins.
摘要:
A multistage process for the homo or copolymerization of ethylene carried out in the presence of a catalyst system comprising at least one polymerization catalyst (A) based on a late transition metal component having a tridentate ligand which bears at least two ortho.ortho-disubstituted aryl radicals, at least one Ziegler polymerization catalyst (B), and at least a Lewis acid activating compound (C), wherein the molar ratio of the metal of the activating compound (C) to the late transition metal of catalyst (A) is different in the two polymerizations steps. Catalysts (A) and (B) may be selectively controlled by varying the amount of activating compound (C).
摘要:
Polyethylene which comprises ethylene homopolymers and copolymers of ethylene with α-olefins and has a molar mass distribution width Mw/Mn of from 6 to 100, a density of from 0.89 to 0.97 g/cm3, a weight average molar mass Mw of from 5000 g/mol to 700 000 g/mol and has from 0.01 to 20 branches/1000 carbon atoms and at least 0.5 vinyl groups/1000 carbon atoms, wherein the 5-50% by weight of the polyethylene having the lowest molar masses have a degree of branching of less than 10 branches/1000 carbon atoms and the 5-50% by weight of the polyethylene having the highest molar masses have a degree of branching of more than 2 branches/1000 carbon atoms, a process for its preparation, catalysts suitable for its preparation and also fibers, moldings, films or polymer blends in which this polyethylene is present.
摘要:
A process for the polymerization of olefins using a metal complex of group 3, 4, 5, 6, 7, 8, 9 or 10 of the Periodic Table comprising at least one group C═NR1, C═PR1, C═O, C═S or a heteroaromatic ring system containing at least one atom from the group consisting of N, P, O and S, can be used for controlling the width of the molar mass distribution of the resulting polymers.
摘要:
Catalyst for the polymerization and/or copolymerization of olefins which is obtainable by application to a finely divided inorganic support and concluding calcination at temperatures of from 350 to 1050° C. and has a chromium content of from 0.1 to 5% by weight and a zirconium content of from 0.5 to 10% by weight, in each case based on the element in the finished catalyst, with the molar ratio of zirconium to chromium being from 0.6 to 5.
摘要:
Process for preparing a supported catalyst for the polymerization and/or copolymerization of olefins which has a chromium content of from 0.01 to 5% by weight, based on the element, which comprises (a) preparing a homogeneous solution comprising an organic or inorganic chromium compound and at least one further organic or inorganic compound of elements selected from among Mg, Ca, Sr, B, Al, Si, P, Bi, Sc, V, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta, W in a protic or aprotic polar solvent, (b) bringing the solution from a) into contact with a finely divided inorganic support to form a catalyst precursor, (c) if appropriate, removing the solvent from the catalyst precursor and (d) calcining the catalyst precursor at temperatures of from 350 to 950° C., preferably 400 to 900° C., under oxidative conditions.
摘要:
Molding composition comprising polyethylene and having a density in the range from 0.915 to 0.955 g/cm, an MI in the range from 0 to 3.5 g/10 min, an MFR in the range from 5 to 50, a polydispersity Mw/Mn in the range from 5 to 20, and a z-average moiar mass Mz of less than 1 million g/mol, a process for preparing such a composition, a catalyst suitable for the preparation of the same, as well as films comprising this molding composition.
摘要:
Monocyclopentadienyl complexes in which the cyclopentadienyl system is substituted by at least one bridged donor, where the bridge contains at least one atom of group 14 of the Periodic Table and at least one atom of group 15 or 16 of the Periodic Table, and a catalyst system comprising at least one of the monocyclopentadienyl complexes, and also methods of preparing them, the use of the catalyst system for the polymerization or copolymerization of olefins and a process for preparing polyolefins by polymerization or copolymerization of olefins in the presence of the catalyst system and the preparation of the associated cyclopentadienyl system.
摘要:
Monocyclopentadienyl complexes containing a cyclopentadienyl system comprising at least one fused heterocycle and at least one uncharged donor which can be used in catalyst systems for the polymerization or copolymerization of olefins.