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AssigneeMontecatini Edison S.p.A.
InventorsAdolfo Mayr, Paolo Galli, Ermanno Susa, Giovanni Di Drusco, Ettore Giachetti
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Catalysts useful in the polymerization of olefins, more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The new catalysts are obtained by mixing a hydride or organometallic compound of a metal belonging to Groups I to III of the Mendelyeev Periodic System with the product obtained by contacting a titanium tetrahalide with a support comprising an anhydrous magnesium or zinc halide in an active form, under particular conditions.
A catalyst-forming component for use in preparing catalysts for the polymerization of olefins and which is the product obtained by contacting a titanium tetrahalide with an anhydrous magnesium dihalide in an active form characterized in that, in its X-rays powder spectrum, the diffraction line which is most intense in the spectrum of the normal, non-active magnesium dihalide is less intense and, in its place, a halo appears.
A catalyst-forming component for use in preparing catalysts for the polymerization of olefins, and which is the product obtained by cogrinding a titanium tetrahalide with an active form of a Mg dihalide selected from the group consisting of MgCl.sub.2 and MgBr.sub.2 said active forms being characterized in that in the X-rays powder spectrum of the active MgCl.sub.2 a halo appears in a range of lattice distances (d) comprised from d=2.56 A to d-2.95 A, and in that in the X-rays powder spectrum of the active MgBr.sub.2 a halo appears in a range of lattice distances (d) comprised from d=2.80 A to d=3.25 A, or in that the surface area is greater than 3 m.sup.2 /g.
A catalyst-forming component prepared by cogrinding TiCl.sub.4 with a support, the essential support material of which is an active magnesium dihalide selected from the group consisting of MgCl.sub.2 and MgBr.sub.2 and characterized in that, in the X-rays powder spectrum of the active MgCl.sub.2, a halo appears in a range of lattice distances (d) comprised from d=2.56 A to d=2.95 A, and in that, in the X-rays powder spectrum of the active MgBr.sub.2, a halo appears in a range of lattice distances (d) comprised from d=2.80 A to d=3.25 A;
Polymerization catalysts prepared by mixing
A catalyst useful for polymerizing olefins and prepared by mixing
A catalyst for polymerizing olefins and prepared by mixing
A catalyst for polymerizing olefins and prepared by mixing
A catalyst for polymerizing olefins and prepared by mixing
A process for the polymerization of olefins comprising polymerizing at least one olefin in an inert hydrocarbon solvent and in contact with a catalyst prepared by mixing
A process for the polymerization of olefins comprising polymerizing at least one olefin in an inert hydrocarbon solvent and in contact with a catalyst prepared by mixing
A process for the polymerization of olefins which comprises polymerizing at least one olefin in an inert hydrocarbon solvent and in contact with a catalyst prepared by mixing
Dependencies are inferred from the claim text.
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Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double
Carriers therefor: magnesium halide as support anhydrous or hydrated or complexed by means of a Lewis base for Ziegler-type catalysts
Synthetic resins or natural rubbers -- part of the class 520 series: comminution of transition metal containing catalyst
Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
Term ended 3 Nov 1998 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
British Pat. No. 904,510 discloses catalysts for the polymerization of olefins which consist of the product of reaction between organometallic compounds of metals belonging to Groups I to III inclusive of the Mendelyeev Periodic System with an inorganic salt of the MgCl.sub.2 type coated on the surface with a molecularly thin layer of a transition metal halide.
The amount of transition metal halide deposited on the inorganic support does not exceed 1% by weight of the support.
According to the British patent, the transition metal compound cannot be used in amounts greater than 1% without considerably reducing the activity of the catalyst. This results from the fact that the inorganic salts used in the British patent are never subjected to any treatment for converting them to active forms suitable for obtaining catalysts which are highly active even in the presence of very large amounts of the supported transition metal compound. Because of the low amount of the catalytically active transition metal compound present on the supports, and as disclosed in the British patent, it is necessary to use very large amounts of the supported catalysts in order to obtain polymer yields of practical interest. The use of such large amounts of the supported catalyst entails the necessity of purifying the polymer from catalyst residues at the end of the polymerization.
Into a centrifugal mill of 330 cc holding capacity, loaded with four porcelain balls, two with a diameter of 31.9 mm and two with a diameter of 40.9 mm, were introduced 48 g of anhydrous MgCl.sub.2 having a surface area of 1 m.sup.2 /g together with 8 g of TiCl.sub.4. The mixture was ground for two hours.
The analysis of the ground product gave the following results: Ti=2.7%; Cl=72%. Its surface area was 20 m.sup.2 /g. 0.06 of this ground product was then used to polymerize ethylene under the following conditions: Into a stainless steel autoclave having a holding capacity of 1.8 liters, and purffied with nitrogen, there were introduced 1000 cc of technical heptane and then 2 g of Al(iC.sub.4 H.sub.9).sub.3. Thereupon the temperature was brought up to 75.degree. C. and 0.06 g of the ground product suspended in 50 cc of n-heptane added. Immediately thereafter there were introduced 3 atm. of hydrogen and 10 atm. of ethylene. The temperature rose to about 85.degree. C. The pressure was then maintained constant at this value by continuously feeding ethylene. After two hours, the suspension was discharged from the autoclave. The polymer was separated by filtration and dried under vacuum at 100.degree. C.
Thereby were obtained 195 g of polyethylene having an intrinsic viscosity, in tetralin, at 135.degree. C., of 2.5 dl/g. The yield in polymer was 121,000 g/g of Ti.