Abstract: Processes for the formulation of Ziegler-type catalysts from a plurality of catalyst components including transition metal, organosilicon electron donor, and organoaluminum co-catalyst components. The components are mixed together in the course of formulating the Ziegler-type catalyst to be charged to an olefin polymerization reactor. Several orders of addition of the catalyst components can be used in formulating the Ziegler catalyst. One involves mixing of the transition metal component with the organoaluminum co-catalyst to formulate a mixture having an aluminum/transition metal mole ratio of at least 200. This mixture is combined with the organosilicon electron donor component to produce a Ziegler-type catalyst formulation having an aluminum/silicon mole ratio of no more than 50. There may be an initial pre-polymerization of the catalyst prior to introducing the catalyst into an olefin polymerization reactor.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R″m)2MeQ. The catalysts include a bridge structure between the (C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: A process for the catalytic cracking of an olefin-containing feedstock which is selective towards light olefins in the effluent, the process comprising contacting a hydrocarbon feedstock containing at least one olefin with a MFI-type crystalline silicate catalyst having a silicon/aluminum atomic ratio of at least about 180, which has been obtained by pretreating so as to increase the silicon/aluminum atomic ratio thereof by heating the catalyst in steam and de-aluminating the catalyst by treating the catalyst with a complexing agent for aluminum, at an inlet temperature of from 500 to 600° C. and at an olefin partial pressure of from 0.1 to 2 bars to produce an effluent with an olefin content of lower molecular weight than that of the feedstock.

Abstract: A process for the catalytic cracking of at least one olefin in an olefinic stream containing impurities, the cracking process being selective towards light olefins in the effluent, the process comprising contacting a feedstock olefinic stream containing at least one sulphur-, nitrogen- and/or oxygen-derivative impurity with a crystalline silicate catalyst of the MFI-type, the catalyst having a silicon/aluminum atomic ratio of at least about 180, to produce an effluent stream having substantially the same olefinic content by weight as, but a different olefin distribution than, the feedstock stream.

Abstract: A polypropylene fibre including a polypropylene blend comprising up to 15% by weight of sPP at least 10% by weight of a first isotactic polypropylene produced by a metallocene catalyst, and optionally a second isotactic polypropylene produced by a Ziegler-Natta catalyst.

Abstract: A multilayer polyolefin film of the type suitable for packaging application in which heat seals are formed, and in its preparation the multilayer film comprises a flexible substrate layer formed of a crystalline thermoplastic polymer having an interface surface. A heat-sealable surface layer is bonded to the interface surface of the substrate layer and is formed of a syndiotactic propylene polymer effective to produce a heat seal with itself at a sealing temperature of less than 110° C. The surface layer has a thickness which is less than the thickness of the substrate layer. The heat-seal layer can be formed of syndiotactic polypropylene polymerized in the presence of a syndiospecific metallocene catalyst and having a melt flow index of less than 2 grams/10 minutes. The multilayer film can take the form of a a biaxially-oriented film.

Abstract: A process for producing polypropylene having increased melt strength, the process comprising irradiating polypropylene with an electron beam having an energy of at least 5 MeV and with a radiation dose of from 5 to 100 kGray in the presence of a grafting agent for forming long chain branches on the polypropylene molecules.

Abstract: A catalyst for olefin polymerization of the formula: R″(C4R′mC5C4R′n)XMeQ wherein X is an hetero atom ligand with one or two lone pair electrons selected from the elements of Group VA or VIA which is substituted or non-substituted: (C4Rm′C5C4Rn′) is a 3,6-substituted fluorenyl; R′ is hydrogen or hydrocarbyl radical having 1-20 carbon atoms, a halogen, an alkoxy, an alkoxy alkyl or an alkylamino or alkylsilyo radical, each R′ being the same or different and m and n independently are 1, 2, 3 or 4, with bilateral symmetry maintained; R″ is a structural bridge between S and (C4R′mC5C4R′n) to impart stereorigidity; Q is a hydrocarbyl radical having 1-20 carbon atoms or a halogen; Me is a Group IIIB, IVB, VB, or VIB metal having any of its theoretically possible oxidation states. Olefin monomers polymerised using these catalysts to form syndiotactic/atactic block polymers of high molecular weight and comprising at least 70% of syndiotactic triads.

Abstract: A process for producing a Ziegler-Natta catalyst, the process comprising reacting an organo magnesium compound with a halogenated compound to produce crystalline magnesium halide having an intense diffraction line in an x-ray spectrum thereof at lattice distance within the range of from 2.56 to 3.20 Angstroms and titanating the magnesium halide by mixing the magnesium halide with a titanium compound whereby the titanated magnesium halide hasp in an x-ray spectrum thereof, a halo appearing at a lattice distance within the range from 2.56 to 3.30 Angstroms.

Abstract: A method of continually measuring the cetane number of a diesel fuel, the method comprising the steps of: (a) providing a diesel engine having means for selectively supplying at least three diesel fuels to the engine, a first actuator for varying the injection timing of the engine, a second actuator for varying the fuel flow of the engine, and a third actuator for varying the compression ratio of the engine; (b) providing a first supply of a diesel fuel of known cetane number, a second supply of a diesel fuel of different known cetane number and a third supply of a diesel fuel of unknown cetane number to be measured, the third supply being connected to a diesel fuel blending system; (c) in a first cycle selectively and alternately supplying the first, second and third supplies to the diesel engine, and for each supply, controlling the first actuator to achieve an injection timing of a predetermined angle before top dead centre, controlling the second actuator to achieve a predetermined fuel flow and contro

Abstract: A process for the production of biaxially-oriented polypropylene film involving the provision of a polypropylene polymer produced by the polymerization of propylene in the presence of a metallocene catalyst characterized by a bridged racemic bis(indenyl) ligand substituted at the proximal position. The polypropylene contains 0.5 to 2% 2,1 insertions and has an isotacticity of at least 96% meso pentads and at least 99% meso diads. The film is formed by stressing the polymer produced from a slot die in the machine direction at a stretch ratio of about 5 or 6 and in the transverse direction at a stretch ratio of about 8 or 9 to produce a biaxially-oriented film having a non-uniform melt temperature of a peak value of less than 160° C. The polypropylene polymer has meltflow index of less than 5 grams per 10 minutes and has an average molecular weight within the range of 100,000-400,000 grams per mole.

Abstract: The present invention relates to a method for the production of polypropylene fibers resulting in improved shrinkage percentages and to polypropylene fibers themselves having improved shrinkage percentages. The method includes providing a polypropylene polymer with a melt flow index of no more than about 25 grams per 10 minutes. This polymer should include isotactic polypropylene produced by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The polymer is then heated to a molten state and extruded to form a fiber preform. The preform is spun and subsequently drawn at a take-away speed and a drawing speed providing a draw ratio of no more than about 3, and more preferably no more than about 2.5, to produce a continuous polypropylene fiber.

Abstract: The present invention provides a process for preparing polyolefins having a multimodal or at least bimodal molecular weight distribution by contacting in a reaction mixture under polymeriation conditions at least one olefin and a catalyst system comprising a supported catalyst-component comprising an alumoxane and at least two metallocenes containing the same transition metal and selected from the group consisting of mono, di, and tri-cyclopentadienyls and substituted cyclopentadienyls of a transition metal and wherein at least one of the metallocenes is bridged and at least one of the metallocenes is unbridged.

Abstract: Bituminous compositions modified with self-adhesive cold-application polymers generally used for manufacturing of watertight roofing panels, said compositions comprising a mixture containing a rubbery styrene-diene polymeric mixture, one or more tackifying resins, and bitumen.

Abstract: Amphiphilic, polyhedron-shaped p-sulfonatocalix[4]arene building blocks, which have been shown previously to assemble into bilayers in an antiparallel fashion, assemble in a parallel alignment into spherical and helical tubular structures on the addition of pyridine N-oxide and lanthanide ions. The addition of greater amounts of pyridine N-oxide changed the curvature of the assembling surface and led to the formation of extended tubules. The inventive compositions and methods are useful for drug delivery and construction of nano-devices.

Abstract: Processes for the polymerization of olefins with Zeigler-type catalyst systems which involve transition metal catalyst components comprising 4, 5 or 6 transition metals incorporating internal electron donors to provide desired polymerization characteristics, including yield and polymer characteristics. Specific olefins used in the polymerization process are C2-C4 alpha olefins such as propylene in the production of stereoregular polypropylene. The catalyst system comprised a transition metal component having an internal electron donor in an amount providing an internal donor/transition metal mole ratio of no more than 2/3. This is combined with an organoaluminum co-catalyst component to provide a precusor mixture having an aluminum/transition metal mole ration of at least 100. The precusor mixture is combined with an organosilicon external electron donor component in an amount to provide an aluminum/silicon mole ration of no more than 200.

Abstract: Vapor phase alkylation of an aromatic substrate in a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds providing mixing zones between adjacent catalyst beds. An aromatic substrate and a C2-C4 alkylating agent is supplied to an inlet side of a gas phase reaction zone causing vapor phase alkylation of the aromatic substrate as the aromatic substrate and the alkylating agent flow through the reaction zone from one catalyst bed to the next. A quench fluid comprising one or both of the aromatic substrate and the alkylating agent is supplied into the interior of the mixing zone through a plurality of flow paths. One portion of the flow paths is directed upwardly and another portion downwardly within the mixing zone. The quench fluid is supplied to the mixing zone through a plurality of dispersion channels spaced laterally from one another.

Abstract: The present invention relates to a process for preparing silica-alumina carriers preferably under the form of extrudates. Further, the present invention also provides hydrogenation catalysts prepared thereof. These catalysts are used in an improved process for the reduction of the aromatic hydrocarbons content present in hydrocarbon streams.

Abstract: A hydrofining process in which a sulfur- and hydrocarbon-containing processing stream is supplied to a multi-stage hydrotreating reactor incorporating separate stages of cobalt molybdenum catalysts. Hydrogen may be supplied concurrently or counter-currently with the hydrocarbon-containing processing stream. The processing stream is passed into contact with an initial catalyst stage comprising a cobalt molybdenum desulfurization catalyst present in a minor amount of the total composite amount of catalysts within the reactor. Thereafter the processing stream is passed through a subsequent catalyst stage comprising a major amount of cobalt molybdenum hydrocracking catalyst. The effluent stream having a reduced sulfur content is then withdrawn from the hydrotreating reactor. The initial and subsequent catalyst stages are separated by an intervening sector within the reactor containing an inert particulate refractory material, specifically silica particles generally spheroidal in shape.

Abstract: Metallocene catalysts useful for the preparation of syndiotactic/atactic block polyolefins have the general formula R″(C4R′mC5C4R′n)XMeQ wherein X is an hetero-atom ligand with one or two lone pair electrons selected from the elements of Group VA or VIA which can be substituted or non-substituted; (C4Rm′C5C4Rn′) is a fluorenyl or a symmetrically substituted fluorenyl or cyclopentadienyl ring; R′ is hydrogen or hydrocarbyl radical having from 1-20 carbon atoms, a halogen, an alkoxy, and alkoxy alkyl or an alkylamino or alkylsilylo radical, each R′ may be the same or different and m and n independently are 0, 1, 2, 3 or 4, with the proviso that the bilateraly symmetry is maintained; R″ is a structural bridge between X and the (C4R′mC5C4R′n) ring to impart stereorigidity; Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; Me is a Group IIIB, IVB, VB, or VIB metal as positioned in the Periodic Table of Elements; and Me can be in any o