摘要:
A catalyst component is prepared by treating a magnesium halide with a Lewis Base compound and a transition metal compound and subjecting the treated productto at least one washing step using a halogenated ethylene, for example tetrachloroethlene, at a temperature of greaterthan 80°C. The transition metal compound can be titanium tetrachloride and the Lewis Base compound an ester of an aromatic carboxylic acid, for example ethyl benzoate or di-isobutyl phthalate. The treatment can be effected in the presence of a non-metallic halide such as thionyl chloride. The treatment can be effected using a milling process. The product can be used for the polymerisation of olefin monomers such as propylene.
摘要:
A transition metal composition has the composition M m ,X p ,TYn'Z where M is a metal of Groups Ib, IIa, IIIb, Vila or VIII of the Periodic Table, X is an anion, T is a transition metal of Groups IVA-VIA of the Periodic Table, Y is an anion, Z is a melt-producing compound, m' is greater than zero and less than 100, n' is greater than zero and less than 8 (m' + 1), and p' is m' x(valency of M)/(valency of X). The compositions of this type may be transformed into a liquid by heating and the hot liquid sprayed and the spray cooled. The sprayed material has a useful particle form and may be used as a component of a polymerisation catalyst to polymerise an unsaturated monomer such as ethylene.
摘要:
Catalysts comprising a transition metal compound supported on a carrier, and an organometallic compound have been used in the polymerisation of olefins. When the carrier particles are spherical olefin polymers can be produced in the form of spherical particles, but known spherical carrier particles either are insufficiently robust or are difficult and expensive to prepare. In accordance with the invention spherical carrier particles are prepared by:-
(i) forming a suspension of molten particles of an adduct of a halogen-containing magnesium compound and an active hydrogen-containing organic compound in an organic liquid medium in the presence of at least one auxiliary component selected from surface-active agents and siloxanes, and (ii) quenching the resulting suspension to solidify the adduct particles.
The resulting spherical carrier particles are robust and readily prepared in reproducible manner from conventional starting material. When used in catalysts for the polymerisation of olefins they provide polymers having a good balance of physical properties.
摘要:
The invention relates to an ethylene polymer having an intrinsic viscosity of at least 4 dl/g, which has a maximum draw ratio of at least 20, is pulverulent, has a bulk density of at most 300 kg/m3 and has an amount of catalyst residues of less than 50 ppm. The invention also relates to a method for the preparation of a pulverulent ethylene polymer having an intrinsic viscosity of at least 4 dl/g through polymerization of ethylene or of a mixture of ethylene and not more than 2 mol % higher olefins at a temperature below 80 °C and an ethylene pressure below 0.2 MPa in the presence of a catalyst having a specific surface area of at most 150 m2/g. It further relates to articles composed of the ethylene polymer.
摘要:
Ziegler Natta catalysts for production of polyolefins, particularly polyethylene and copolymers thereof. Catalysts having improved activities are produced in a multi-stage procedure in which a porous supporting material is impregnated with a precursor composition, and then this is further treated one or more times with subpore volumes of secondary solutions of precursor components. Claims to the process for producing the catalysts, and to a process for making polyolefins using the catalysts are also presented.
摘要:
Catalysts component of the (co)polymerization of alpha-olefins CH₂=CHR, wherein R is hydrogen or an alkyl radical having from 1 to 8 carbon atoms, comprising a product of the composition: VCl y . z(b) wherein (b) represents an organic compound selected from alkyl, aryl and acyl halides, y is a number higher than 2 and lower than 4, and preferably comprised between 2.5 and 3.5 and z is a number higher than zero and lower than or equal to 2, and preferably between 0.002 and 1. Components can be obtained as products of the reaction, carried out at temperatures higher than 10°C, between VCl₄ and the compound (b). Particularly preferred among compounds (b) are benzoyl chloride, p-methoxybenzoyl chloride and p-chloro benzoyl chloride. From the components of the invention, either supported or not, catalysts having high activity particularly useful for the production of ethylene polymers showing broad molecular weight distribution can be prepared.
摘要:
Catalyst systems containing a Ziegler-Natta catalyst component are disclosed. Such catalyst systems can contain a co-catalyst and a supported catalyst containing a fluorided silica-coated alumina, a magnesium compound, and vanadium and/or tetravalent titanium.