摘要:
Olefin polymerization comprising catalysts based on a metallocene, an alumoxane and a support are disclosed. The process for the preparation of a supported olefin ploymerization catalyst comprises: a) a metallocene/activator reaction product, a solvent capable of dissolving it, and a porous support are brought into mutual contact, and b) the solvent is removed, and wherein step a) is carried out so that the porous support is impregnated with a volume of the metallocene/activator reaction product and solvent, which does not exceed the total pore volume of the support.
摘要:
Aluminoxanes having C2-C10 alkyl groups can conveniently be used in supported olefin polymerization catalyst compositions prepared by contacting a support comprising a solid compound which is one of pure aluminium oxide, a mixed aluminium oxide, an aluminium salt, a magnesium halide, or a C1-C8 alkoxy magnesium halide, in any order with at least a) an organometallic compound, b) a metallocene, and c) an aluminoxane, and recovering said supported olefin polymerization catalyst composition.
摘要:
Rotational moulding process for polymerizing or copolmerizing ethylene for manufacturing ethylene polymers or copolymers having a controlled particle size and morphology. Ethylene is polymerized or copolymerized under ethylene polymerizing conditions in the presence of a supported metallocene catalyst, where the average particle size of the catalyst particles is selected within the range of 14-40 &mgr;m and the residence time at the polymerization is selected so as to achieve a polymer where average particle size is between 0.2-0.5 mm and the proportion of fractions between 0.1-0.6 is at least 80%.
摘要:
Alumoxanes having C2-C12 alkyl groups can conveniently be used in supported olefin polymerization catalyst compositions prepared by contacting, either previous to or immediately before the beginning of the olefin polymerization, a support comprising a porous carrier with (a) an organometallic compound of the general formula R1MXv−1, (b) a metallocene of the general formula (CpY)mM′X′nZo and an alumoxane of the following general formula in any order.
摘要:
This invention concerns process for producing polyethylene compositions, films prepared thereof and process for the preparation of the films. The process comprises subjecting ethylene, optionally hydrogen and comonomers to polymerization or copolymerization reactions in a multistage polymerization. At least one polymerization stage is conducted essentially in the absence of hydrogen. The polymerization reactions are carried out in the presence of a single-site catalyst capable of forming a composition comprising a low molecular weight component with MFR2 of at least 10 g/10 min and a density higher than the density of the composition and a high molecular weight component. The melt flow rate of the composition is in the range MFR2=0.1-5.0 g/10 min and the density of the composition is 915-960 kg/m3. The invention makes it possible to produce polyethylene compositions for manufacturing films with a good balance between optical and mechanical properties.
摘要:
The present invention relates to an olefin polymerization catalyst composition comprising a metallocene and an aluminoxane containing alkyl groups with at least two (2) carbon atoms which provides more uniformity than methylaluminoxane, offers greater control and reproducibility of olefin polymerization and greater storage stability. The present invention also provides a method for the preparation of the olefin polymerization catalyst composition.
摘要:
Process for manufacturing ethylene copolymers by polymerizing ethylene and a minor amount of C.sub.3 -C.sub.6 alphaolefins in particle form in slurry reactor in the presence of an ethylene polymerizing catalyst. According to the invention the polymerization is carried out in propane diluent by using a metallocene catalyst activated with an alumoxane compound.
摘要:
The invention relates to metallocene compounds having the formula (I): (CpYq)mMRnBo (I) wherein: Cp or each same or different Cp is a non-substituted or substituted, fused or non-fused, homo(iso)cyclic or heterocyclic cyclopentadienyl ligand, indenyl ligand, tetrahydroindenyl ligand, fluorenyl ligand or octahydrofluorenyl ligand, Y or each same or different Y is a substituent at the cyclopentadienyl ring of said ligand Cp having the following structure (II): wherein: D is an element of Group 14 of the Periodic Table (IUPAC), R1, R2 and R3 are the same or different and are each one of a hydrogen, a halogen, a substituted or unsubstituted C1-C10 hydrocarbyl group, a substituted or unsubstituted C1-C10 hydrocarbyloxy group, a C1-C12 organosilicon group, or at least two of R1, R2 and R3 form together with D a C4-C20 ring structure; M is a transition metal of Group 4 of the Periodic Table (IUPAC) and is bound to the ligand Cp or ligands Cp in an &eegr;5 bonding mode; R or each same or different R is bound to M and is one of a hydrogen, a halogen, a substituted or unsubstituted C1-C10 hydrocarbyl group, a substituted or unsubstituted C1-C10 hydrocarbyloxy group, a C1-C12 organosilicon group, or two R form together with M a C4-C20 metallocyclic ring structure; B is a bridge atom or group between two Cp ligands or between one Cp ligand and M; q is, when Cp is non-bridged, 0-5 for the cyclopentadienyl ligand, 0-3 for the indenyl or tetrahydroindenyl ligand and 0-1 for the fluorenyl or octahydrofluorenyl ligand, q is, when Cp is bridged, 0-4 for the cyclopentadienyl ligand, 0-2 for the indenyl or tetrahydroindenyl ligand and 0 for the fluorenyl or octahydrofluorenyl ligand; m is 1 or 2; m·q≧1; o is 0 or 1; and n is 4-m-o, except when there is one bridge B between two Cp ligands, in which case n is 4-m, their intermediates, preparation and use.
摘要:
Provided are heterogeneous catalysts for homo- and copolymerization of olefins as well as a method for preparing these catalysts, which comprise at least one metallocene compound of a Group 4A, 5A or 6A (Hubbard) transition metal on a solid inorganic support. The method comprises the steps of vaporizing the metallocene compound, treating the support material with the vaporized metallocene compound at a temperature which is sufficiently high to keep the metallocene compound in the vaporous state, contacting the support material with an amount of the vaporized metallocene compound which is sufficient to allow for a reaction between the metallocene compound and at least a substantial part of the available surface sites capable of reacting therewith, removing the rest of the metallocene compound not bound to the support, and optionally treating the product thus obtained with an activating agent. The catalysts are active even if very low amounts of activator agents, such as alumoxane, are used. Furthermore, the polymerization performance of the catalysts can be regulated during the preparation of the catalysts. Thus, by using different support pretreatment temperatures, or by using two or more different metallocenes, and by altering the order in which they are added on the support, it is possible to control and regulate the activity of the catalysts and the polymer properties, such as molecular weight and molecular weight distribution.
摘要:
The present invention concerns heterogeneous catalysts for polymerization of olefins. The catalysts include at least one Group IVa metal compound on a solid inorganic oxidic support. According to the invention the catalysts are prepared by vapourizing at least one solid Group IVa metal halide compound and routing the vapour of the metal halide compound into a reaction chamber, wherein the vapour is reacted with the support at a temperature of about 250.degree. to about 450.degree. C. in order to bind said metal halide compound to said support. Any metal compound not bound to said support as well as any volatile reaction products emanating from the reaction between said metal halide compound and said support are then removed from the reaction chamber in the vapour phase. Optionally, the product obtained is treated with an organic aluminum compound to increase the catalytic activity of said catalyst. The catalysts thus prepared are very well suited for polymerization of ethylene or copolymerization of ethylene with other alpha-olefins, such as propylene, butylene, 4-methyl-1-pentene and hexene. A polymerization process employing the novel catalyst will provide products of the Ultra High Molecular Weight-type (UHMWPE) having very broad MWD.