Abstract: A process for polymerizing or copolymerizing a member of the group consisting of an alpha olefin or mixtures thereof, consisting of the steps of:polymerizing an alpha olefin in a polymerization reactor using a polymerization catalyst, a cocatalyst, and an amount of hydrogen adjusted for molecular weight control as measured by melt flow;rapidly changing the melt flow of the polymerized alpha olefin from high to low melt flow by reacting a portion of the unreacted hydrogen in the reactor with a quantity of the alpha olefin present therein by interaction with a hydrogenation catalyst; andremoving the hydrogenation catalyst from the reactor through continuous exchange of the reactor contents.

Abstract: An ultra-high molecular weight polyethylene powder easily soluble in organic solvents and suitable for use in the preparation of fibers or films having a high strength and a high elastic modulus, said polyethylene powder having an intrinsic viscosity in the range of 5 to 30 dl/g in decalin at 135.degree. C. and being obtained by at least two-step polymerization reactions which are:a first step of polymerizing ethylene in the absence of hydrogen or at a reduced hydrogen concentration, using a catalyst containing a solid catalyst component and an organometallic compound, said solid catalyst component containing at least magnesium and titanium and/or vanadium, to produce 50-99.5 parts by weight, based on 100 parts by weight of a final polyethylene product, of polyethylene having an intrinsic viscosity of 12 to 32 dl/g in decalin at 135.degree. C.; anda second step of polymerizing ethylene at a higher hydrogen concentration that in said first step to produce 50-0.5 parts by weight of polyethylene.

Abstract: Novel high pore volume, high purity alumina gels and catalysts prepared therefrom are provided by a unique alumina gel preparation comprising hydrolyzing an aluminum alcoholate in a medium of a mixture of water and acetone, aging the resultant product and thereafter washing with acetone. Processes for the polymerization of olefins utilizing the afore-described alumina gels are also included herein.

Abstract: This invention relates to a novel highly active and more efficient catalyst system for polymerizing alpha-olefins to prepare high, medium, and low molecular weight polymers. This highly active olefin polymerization catalyst therefore can be used to prepare both olefin waxes as well as high molecular weight crystalline polyolefins. This highly efficient, highly active catalyst is prepared by reacting a vanadium tetrahalide with a titanium tetravalent member in a hydrocarbon medium. The product of this reaction is then combined with an activating component, such as triethyl aluminum, to form a highly active and efficient polyolefin catalyst.

Abstract: Granular stereoregular butene-1 polymers having a high isotactic content, and an extractables content of no more than about 15 weight percent in boiling ethyl ether, are produced over a continuous extended period of time in a low pressure gas phase fluidized bed process, in the absence of liquid diluent components, with a stereospecific olefin polymerization catalyst under a selected set of operating conditions.

Abstract: A superior high-rigidity and high-melt-viscoelasticity polypropylene for sheets to be post-processed and for blow molding is provided which polypropylene is produced by subjecting propylene to a multi-stage polymerization into polymer portions of two sections in the presence of a specified Ziegler Natta catalyst, the relationship between the intrinsic viscosities of the polymer portions of the respective sections being regulated within a specified range and also the amount ratio of the polymer portions of the respective sections being regulated.

Abstract: The disclosure is directed to an improvement in the gas phase polymerization of propylene using a Ziegler-Natta catalyst in the presence of hydrogen wherein the gaseous propylene is withdrawn from the reactor, cooled and condensed and returned as a liquid to the reactor in order to regulate the polymerization temperature. The amount of the gaseous phase in the condenser-cooler-accumulator system is kept constant by regulating the amount of gaseous phase returned to the reactor.

Abstract: Improved process for preparing an ethylene polymer wax which comprises polymerizing ethylene or copolymerizing ethylene with up to 10 mole % of an alpha-olefin having 3 to 20 carbon atoms in the presence of (A) a highly active titanium catalyst component activated by a magnesium compound and (B) an organoaluminum catalyst component composed of (B-1) an organoaluminum compound free from halogen bonded directly to the aluminum atom and (B-2) a halogen compound of an element selected from the group consisting of elements other than titanium of Groups III and IV of the Mendelejeff's periodic table, the atomic ratio of halogen to aluminum in the organoaluminum catalyst component (B) being from about 1:6 to about 9:10, provided that when said halogen compound is a halogen compound of carbon, this atomic ratio is from about 1:6 to about 10:1, and said polymerization or copolymerization being carried out under such conditions that the concentration of ethylene polymer wax in the polymerization or copolymerization sys

Abstract: In a process for producing an olefin polymer or copolymer by polymerizing an alpha-olefin having at least 3 carbon atoms or copolymerizing such alpha-olefins with each other or such an alpha-olefin with up to 20 mole % of ethylene and/or a diene in the presence of a catalyst comprising (1) a solid titanium catalyst component having magnesium, halogen, titanium, phosphorus and a carboxylic acid ester and (2) an organometallic compound of a metal of Groups I to III of the Mendelejeff's periodic table; the improvement wherein said catalyst is composed of (A) the solid titanium catalyst component (1) in which the molar ratio of the phosphorus to the carboxylic acid ester is from about 0.05 to about 2 and which has a specific surface area of not less than about 40 m.sup.2 /g, (B) the organometallic compound (2), and (C) an electron donor; and a catalyst used for aforesaid process.

Abstract: An improvement in a process for the preparation of an ethylene homopolymer or a copolymer of ethylene with an .alpha.-olefin containing 3 to 15 carbon atoms by contacting the monomer or mixture of monomers in solution, suspension or in gas phase at 20.degree. to 250.degree. C. at a pressure of 1 to 50 bar with a mixed catalyst comprising a chlorine containing titanium (III) compound and an organoaluminum compound in the presence of hydrogen, the improvement residing in employing as the organoaluminum compound a trialkylaluminum compound in an amount of 0.1 to 20 mol per mol titanium (III) compound and including in the polymerization mixture oxygen at a concentration of 0.001 to 0.1 volume percent based upon the amount of ethylene. By carrying out the polymerization by including oxygen in the polymerization reaction mixture and employing trialkylaluminum compound as the organoaluminum compound the mean molecular weight of the polymer can be regulated while obtaining a desired molecular weight distribution.

Abstract: In a process for polymerizing olefins in the gaseous phase in a first gas-phase polymerization zone and a second gas-phase polymerization zone, which are provided independently from each other, in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound of a metal of Groups I to III of the periodic table and in the co-presence of hydrogen gas while feeding the catalyst-containing polymer formed in the first zone to the second zone; the improvement wherein(i) a dilution zone for diluting a feed flow from the first gas-phase polymerization zone which comprises a mixture of the polymer, the catalyst, the olefin gas and hydrogen gas by feeding a fresh supply of olefin gas thereto is provided in a feed passage for feeding said flow from the first gas-phase polymerization zone to the second gas-phase polymerization zone,(ii) a part of the gas phase in said feed flow diluted in the dilution zone is recycled to the first gas-phase polymerization zone, and remainder i

Abstract: A fractionable elastic polypropylene which has an inherent viscosity of 1.5-9, exhibits no yield point, has a tensile set not exceeding 150% and contains about 10 to 80% by weight of a diethyl ether-soluble fraction having an inherent viscosity exceeding 1.50. This polypropylene is a direct reaction product and thus need not be separated into its component parts to be a useful elastomer. Also described is the diethyl ether-soluble polypropylene fraction of the direct reaction product which has about 0.5% to about 5% isotactic crystallinity and exhibits birefringence when a film formed from said fraction is viewed under crossed Nicol prisms in a polarizing microscope at about 25.degree. C. or is stretched between crossed polarizing sheets at about 25.degree. C. The diethyl ether-soluble fraction itself is a useful elastomeric material.

Abstract: Copolymers of ethylene and higher 1-olefins which are suitable for the manufacture of thin films, are preferably prepared in a two-step process, the first step yielding a polymer having a high molecular weight, the second step giving a polymer having a low molecular weight. The films obtained from these copolymers have improved mechanical properties as compared to films manufactured from known corresponding raw materials. The mechanical properties are furthermore uniform in longitudinal and in transverse direction.

Abstract: A TiCl.sub.3 olefin polymerization catalyst component is prepared by reducing TiCl.sub.4 with an aluminum trihydrocarbyl compound in a molar ratio of Ti:Al of 2.7:1 to 4.0:1 in the presence of diisoamyl ether and a hydrocarbon solvent by gradually adding TiCl.sub.4 to the aluminum trihydrocarbyl compound and at least a substantial proportion of the diisoamyl ether at a temperature of from 15.degree. to 50.degree. C. during a period of from 0.7 to 2.5 hours to produce a precipitate of TiCl.sub.3, and thereafter converting the precipitate into active TiCl.sub.3 by heating at a temperature of from 80.degree. to 110.degree. C. during at least 30 minutes. The active TiCl.sub.3, when combined with a conventional organoaluminum cocatalyst, provides a stereospecific catalyst for the polymerization of alpha monoolefins having high activity, good morphology and good stereospecificity.

Abstract: A polymerization catalyst and method which produces substantially pure silica that is uncontaminated with alkali metal or alkaline earth metal ions before associating with the resulting support silica the chromium compound which is either a chromium oxide or a chromium compound convertible to the oxide in the heat activating of the catalyst. In general, the catalyst is prepared by hydrolyzing an organosilicate ester to form suspended silica with the hydrolyzing being catalyzed with an aqueous acid solution containing mixed solvents. Next the resulting liquid is neutralized with an alkali free basic solution such as ammonium hydroxide at controlled low temperature. Then sufficient water is added to permit stirring the resulting gel and this is stirred and heated forming a suspended silica. The silica is then separated and dried, associated with the chromium compound and the mixture then heat activated in the presence of oxygen.

Abstract: Hydrocarbon-soluble compositions useful as the transition metal component in the Ziegler polymerization of .alpha.-olefins are provided by reacting molecular nitrogen or hydrogen with a transition metal compound such as titanium trichloride to form a dinitrogen or dihydrogen complex of the transition metal compound.

Abstract: A method is provided for treating a hydrogel with a saturated, aliphatic alcohol selected from the group consisting of 1-pentanol, 2-pentanol, 3-methyl-1-butanol, 4-methyl-2-pentanol, 2,2-dimethyl-1-propanol and 1-hexanol to remove water thereby producing a dried product that retains a porous structure and is particularly suitable upon impregnation with a polymerization catalyst for use in promoting the production of ethylene polymers of melt index in excess of about 6.6.

Abstract: Polymerization of a mono-.alpha.-olefine monomer is effected by contacting the gaseous monomer with a solid phase comprising polymer and catalyst at a pressure and temperature which are such that the temperature is in the range from tp + 0.1.degree. C up to tp + 5.0.degree. C, where tp is the temperature at which the monomer condenses at a pressure which is equal to the monomer partial pressure within the polymerization vessel.

Abstract: Olefin polymerization catalysts are prepared by depositing a chromium compound and an aluminum compound on an inorganic support material and heating the support material in a non-reducing atmosphere at a temperature above about 300.degree. C up to the decomposition temperature of the support material. The supported chromium and aluminum compound is then combined with a metallic and/or non-metallic reducing agent, to provide a catalyst system useful in the polymerization of 1-olefins.

Abstract: The polymerization of olefins to form polymers having a molecular weight greater than 50,000 wherein the polymerization is carried out in the presence of a catalyst component formed of a compound of a transition metal of the sub-groups IVa, Va and VIa, and a co-catalyst component of at least one organo-metallic compound of a metal from groups II and III of the periodic table, in which the co-catalyst is in the form of a liquid which is separately introduced into the reaction vessel on a carrier formed of an inert porous powder which is impregnated with the co-catalyst.

Abstract: Improved catalyst and method for the manufacture of polyethylene comprising a catalyst based on a solid substance containing titanium, magnesium and chlorine activated by aluminum alkyls or reaction products of dialkyl aluminum hydrides with diolefins having from 4 to 20 carbon atoms, and its use in the manufacture of polyethylene where said solid substance is produced by (1) reacting metallic magnesium with at least 2 mols of allyl chloride and at least 1.75 mols of a di-lower alkyl ether, per gram-atom of magnesium at a temperature between about 30.degree. C and about 100.degree. C, (2) aging the solid reaction product for at least 10 hours at a temperature between about 30.degree. C and about 140.degree. C, (3) treating the solid reaction product either together, or subsequent to the aging step, with at least 0.2 mols of a di-lower alkyl sulfite, per gram-atom of magnesium, (4) reacting the aged and treated solid reaction product with at least 0.5 mols ofTiCl.sub.x (OR).sub.

Abstract: Ultra high molecular weight, linear .alpha.-olefin polymers are produced without reactor fouling by polymerizing an .alpha.-olefin in the presence of Ziegler catalyst dispersed in an inert diluent and an amount of an inert gas not in excess of that which will dissolve in the inert liquid diluent.

Abstract: Process for polymerizing ethylene or mixtures of ethylene with other 1-olefins by contacting the monomer with a titanium modified catalyst that has been pretreated with a hydrocarbon other than the hydrocarbon used as polymerization diluent.

Abstract: A continuous process for recycling hydrogen for reuse in making blends of olefin copolymers of high and low molecular weights which comprises copolymerizing ethylene with at least one higher olefin monomer in a solvent in separate reactors in the presence of a coordination catalyst, at least one, but not all, of said reactors containing hydrogen in an amount sufficient to produce low molecular weight copolymer. The resulting solutions of high and low molecular weight copolymers are mixed, unreacted monomers and hydrogen are flashed from the mixture, and the copolymer blend is isolated from the unflashed residue.

Abstract: Homopolymers of 4-methylpentene-1 are prepared by homopolymerization of 4-methylpentene-1 at a temperature above room temperature, in the presence of hydrogen and in contact with a Ziegler/Natta catalyst system. The polymerization is carried out at a relatively very high temperature and in the presence of an inert gas, the polymerization system being under a specific total pressure, while the partial pressures of the inert gas and the hydrogen have specific values. In this way, homopolymers having large crystalline fractions are obtained in high yields per unit of catalyst system per unit time.

Abstract: Copolymers of 4-methylpentene-1 are prepared by copolymerization of 4-methylpentene-1 with one or more other C.sub.2-18 .alpha.-alkenes at a temperature above room temperature and in the presence of hydrogen using a Ziegler/Natta catalyst system. The polymerization is carried out at a relatively very high temperature and in the presence of an inert gas with the proviso that the partial pressures of the inert gas and of the hydrogen and the sum of the partial pressures of the inert gas, hydrogen and 4-methylpentene-1 have specific values. In this way, copolymers having large crystalline fractions are obtained in a high yield per unit of catalyst system per unit time.

Abstract: This invention provides a method for the preparation of polyolefins by polymerizing or copolymerizing an olefin or olefins in the presence of a catalyst composed of a titanium compound and/or vanadium compound component supported on a solid carrier and an organometallic compound component, said solid carrier comprising a reaction product obtained by reacting (1) an aluminum compound represented by the general formula Al(OOCR)(OR').sub.2 wherein R and R' being the same or different each represent alkyl, aryl or aralkyl and (2) a magnesium compound represented by the general formula Mg(OR').sub.2 where R" being the same as or different from R and/or R' is alkyl, aryl or aralkyl at a molar ratio of (1):(2) of substantially at least 2:1.

Abstract: A melt finish process is disclosed herein for working up solid, particulate polymer from a vapor state polymerization reactor, which reactor employs high yield catalysts, whereby the polymer is moved out of the reactor and into a post polymerization zone characterized by essentially adiabatic polymerization and the heat of such polymerization is used in raising the temperature of and melting said solid, particulate polymer to form molten polymer for further processing.