Back to results
US 4,363,902 AGranted
Process and heavy metal catalyst for the polymerization of .alpha.-olefins, particularly polyethylene
AssigneeWacker Chemie AG
InventorDieter Kurz
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeWacker Chemie AG
InventorDieter Kurz
Estimating the term…
Poly-.alpha.-olefins, particularly polyethylene, having a broad molecular-weight distribution, can be prepared in the presence of a catalyst solid which is manufactured in two reaction steps, from a primary solid containing magnesium and chlorine which has been reacted, in a reaction stage A, with alkoxy compounds of elements of Groups I to VI of the Mendeleev Periodic Table which contains at least one secondary or tertiary alkoxy group, and with halogen-containing metal compounds of elements of IV and/or V sub-group(s) of the Mendeleev Periodic Table and, in reaction stage B, with halogen-containing metal compounds of elements of IV and/or V sub-group(s) of the Mendeleev Periodic Table, and/or metal organyl compounds of metals of the II and/or III main group(s) of the Mendeleev Periodic Table. The sequence of the reaction stages A and B is not critical for the success of the process according to the invention.
An improvement in the process for the polymerization of an at least one .alpha.-olefin comprising reacting said .alpha.-olefin under elevated temperatures and pressures in the presence of a solid polymerization catalyst consisting essentially of a solid compound containing (1) element(s) of the IV and/or V sub-group(s) of the Mendeleev Periodic Table, (2) magnesium, (3) halogen, (4) oxygen, and possibly (5) element(s) of the II and/or III main group(s) of the Mendeleev Periodic Table, which solid compound is activated with at least one organometallic compound where said metal is from the II and/or III main group(s) of the Mendeleev Periodic Table, and recovering a polymerizate, the improvement consisting of preparing said solid compound prior to activation, by reacting a primary solid containing magnesium and halogen prepared from at least one hydrocarbon-soluble magnesium compound and at least one halogen compound selected from the group consisting of a chlorohydrocarbon having from 1 to 6 carbon atoms of which at least one carbon atom has at least two directly bonded chlorine atoms, a carbon chloride compound having from 1 to 6 carbon atoms, and mixtures thereof, in two successive and separate reacting stages A and B, in either order, where a solid based on magnesium compound(s) is reacted in reaction stage A in suspension in at least one liquid hydrocarbon with
An improvement in the process for the polymerization of an at least one .alpha.-olefin comprising reacting an .alpha.-olefin selected from the group consisting of ethylene and mixtures of ethylene with up to 10 mol percent of .alpha.-alkenes having from 3 to 6 carbon atoms under elevated temperatures and pressures in the presence of a solid polymerization catalyst consisting essentially of a solid compound containing (1) element(s) of the IV and/or V sub-group(s) of the Mendeleev Periodic Table, (2) magnesium, (3) halogen, (4) oxygen, and possibly (5) element(s) of the II and/or III main group(s) of the Mendeleev Periodic Table, which solid compound is activated with at least one organometallic compound where said metal is from the II and/or III main group(s) of the Mendeleev Periodic Table, and recovering a polymerizate, the improvement consisting of preparing said solid compound prior to activation, by reacting a primary solid containing magnesium and halogen prepared from at least one hydrocarbon-soluble magnesium compound and at least one halogen compound selected from the group consisting of a chlorohydrocarbon having from 1 to 6 carbon atoms of which at least one carbon atom has at least two directly bonded chlorine atoms, a carbon chloride compound having from 1 to 6 carbon atoms, and mixtures thereof, in two successive and separate reacting stages A and B, in either order, where a solid based on magnesium compound(s) is reacted in reaction stage A in suspension in at least one liquid hydrocarbon with
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
Drawings are temporarily unavailable. Open the PDF at USPTO
Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double
Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
Term ended 10 Dec 2000 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The polymerization of .alpha.-olefins, especially ethylene, in the gaseous phase or in hydrocarbons as diluents and dispersants, with the aid of solid catalysts that contain elements of IV and/or V sub-group(s) of the Mendeleev Periodic Table, magnesium, halogen, oxygen and, optionally, boron or aluminum, and that have been activated with an alkyl aluminum, is known.
Because the properties of the polyolefins thus prepared are very strongly dependent on the catalyst used, various catalyst systems have already been proposed for the polymerization of the .alpha.-olefins.
In the polymerization of .alpha.-olefins, especially ethylene, the majority of the previously known solid catalysts activated with an alkyl aluminum yield products having a narrow molecular-weight distribution, that is to say, the mean polymerization degree of a polyolefin mixture produced in a polymerization batch lies within a narrow range. This narrow molecular-weight distribution of the polymerizate means that extruded products prepared therefrom have rough surfaces as a result of "melt fractures", so that these polymerizates are unsuitable for many uses, for example, for the manufacture of hollow articles and sheet materials.
The melt index MFI.sub.5 mentioned in the Examples is determined in accordance wih DIN (Deutsche Industrie Norm (German Industrial Standard) 53 735 at 190.degree. and 49.03 N (5 kp) stress.
The flow factor F.sub.21.6 is the quotient of the melt indices at 211.82 N (21.6 kp) and 49.03 N (5 kp) stress and can be employed as a measure of the molecular weight distribution.
The catalyst which is used in the polymerization according to the invention can be manufactured, for example, in the following manners: