Abstract: In one embodiment of this invention a surface silicated alumina composition, as opposed to conventional silica alumina, is provided. Such composition may also be fluorided and/or phosphated or phosphited. The resulting compositions are broadly useful but are of particular applicability as supports for chromium olefin polymerization catalysts. In another aspect alumina is fluorided and used with hexavalent chromium catalyst and a co-catalyst or in the alternative with an organochromium catalyst. If desired the support in this embodiment can also be phosphated or phosphited. In another embodiment, aluminum phosphate is formed in the pores of alumina. In contrast with alumina catalyst supports of the prior art, the supports of this invention allow for the production of olefin polymers at high rates of productivity. Also novel high density ultrahigh molecular weight polymers are produced.

Abstract: Polymerizable compositions comprising (a) hydroxypropyl methacrylate; (b) a C.sub.8 to C.sub.10 alkyl ester of acrylic or methacrylic acid; (c) a crosslinking agent; (d) a promoter; and (e) a free-radical initiator.

Abstract: Cyclic olefin metathesis polymerization catalyst comprising metal compounds wherein said metals consist essentially of a minor amount of a transition metal which Will initiate ring-opening metathesis polymerization of a cyclic olefin and a major amount of at least one second metal which will propagate the polymerization, wherein said catalyst is essentially devoid of pyrophoric metal compounds, e.g. metal alkyls, and preformed metal carbenes. A preferred transition metal is ruthenium. Said second metal can comprise aluminum, copper, hafnium, iron (III), iridium, manganese, molybdenum, nickel, niobium, rhenium, rhodium, tantalum, titanium, tungsten, yttrium, a Lanthanide, zinc or zirconium or a mixture thereof. Using such catalyst cyclic olefin, e.g. norbornene derivatives, can be polymerized, e.g. in an extruder, even in the presence of water.

Abstract: High surface are aluminas are pre-calcined to form gamma-alumina. In one embodiment, the gamma-alumina is treated with an anhydrous solution of a fluorine-containing compound. In a second embodiment, alumina is precipitated in the pores of the gamma-alumina and then treated with a fluorine-containing compound. In a third embodiment a cogel of aluminum trifluoride and aluminum hydroxide is prepared. The three inventive fluorided alumina supports can be impregnated with a transition metal, preferably chromium, to form a catalyst system which can be used to polymerize mono-1-olefins.

Abstract: High surface are aluminas are pre-calcined to form gamma-alumina. In one embodiment, the gamma-alumina is treated with an anhydrous solution of a fluorine-containing compound. In a second embodiment, alumina is precipitated in the pores of the gamma-alumina and then treated with a fluorine-containing compound. In a third embodiment a cogel of aluminum trifluoride and aluminum hydroxide is prepared. The three inventive fluorided alumina supports can be impregnated with a transition metal, preferably chromium, to form a catalyst system which can be used to polymerize mono-1-olefins.

Abstract: High surface are aluminas are pre-calcined to form gamma-alumina. In one embodiment, the gamma-alumina is treated with an anhydrous solution of a fluorine-containing compound. In a second embodiment, alumina is precipitated in the pores of the gamma-alumina and then treated with a fluorine-containing compound. In a third embodiment a cogel of aluminum trifluoride and aluminum hydroxide is prepared. The three inventive fluorided alumina supports can be impregnated with a transition metal, preferably chromium, to form a catalyst system which can be used to polymerize mono-1-olefins.

Abstract: High surface are aluminas are pre-calcined to form gamma-alumina. In one embodiment, the gamma-alumina is treated with an anhydrous solution of a fluorine-containing compound. In a second embodiment, alumina is precipitated in the pores of the gamma-alumina and then treated with a fluorine-containing compound. In a third embodiment a cogel of aluminum trifluoride and aluminum hydroxide is prepared. The three inventive fluorided alumina supports can be impregnated with a transition metal, preferably chromium, to form a catalyst system which can be used to polymerize mono-1-olefins.

Abstract: Olefins are polymerized using, as a catalyst, a pi-olefin complex of a transition metal supported on aluminophosphate. The most effective complexes are cycloheptatrienyl-(1,3-cycloheptadiene)chromium(-1) compounds and alkyl-substituted derivatives thereof. A metal alkyl co-catalyst, such as triethylborane or triethylaluminum, can also be present. The catalyst is best suited for forming ethylene polymers and copolymers. Both the polymerization process using the described catalyst, and the catalyst system, per se, constitute different aspects of the invention.

Abstract: Initiator compositions for materials which can be polymerized cationically are described, these containingi) an anhydride of a polycarboxylic acid, a polyisocyanate, a cyclic carbonate, a lactone or a mixture of such compounds, and dissolved thereinii) at least one compound of the formula I[M.sup.+n (L).sub.x ].sup.n+ nX.sup.- (I)in which n is 2 or 3, M is a metal cation selected from the group consisting of Zn.sup.2+, Mg.sup.2+, Fe.sup.2+, Co.sup.2+, Ni.sup.2+, Cr.sup.2+, Ru.sup.2+, Mn.sup.2+, Sn.sup.2+, VO.sup.2+, Fe.sup.3+, Al.sup.3+ and Co.sup.3+, X.sup.- is an anion which is selected from the group consisting of AsF.sub.6.sup.-, SbF.sub.6.sup.-, BiF.sub.6.sup.- and derivatives derived from these anions in which a fluorine atom is replaced by hydroxyl groups, or in which up to 50% of the anions X.sup.-, based on the total amount of anions, can also be any desired anions, L is water or an organic .sigma.

Abstract: A method of making a VI improver is disclosed. The one-step method of this invention includes reacting ethylene, an olefin other than ethylene and N-phenylphenylene methacrylamide in the presence of a cocatalyst system including a combination of a first group and a second group, said first group consisting of triethylaluminum, ethylaluminum, sesquichloride, diethylaluminum chloride, diethylzinc, ethylzinc chloride, triisobutylaluminum and mixtures thereof, and said second group consisting of titanium trichloride, titanium tetrachloride, vanadium tetrachloride, vanadium oxychloride, tetrabutyl titanate and mixtures thereof.

Abstract: An energy polymerizable composition and process therefore, comprising a cationically polymerizable material and a catalytically effective amount of an ionic salt of an organometallic complex cation as polymerization initiator, said ionic salt of an organometallic complex cation being capable of adding an intermediate strength nucleophile or upon photolysis capable of liberating at least one coordination site, said metal in said organometallic complex cation being selected from elements of Periodic Groups IVB, VB, VIB, VIIB, and VIIIB are disclosed. Certain of the organometallic metallic polymerization initiators are novel cationic salts.

Abstract: Olefin polymerization catalysts, processes for preparing the catalysts and processes for producing polyolefins utilizing the catalysts are provided. The catalysts are basically comprised of a pentadienyl derivative-transition metal complex adsorbed on an activated inorganic refractory compound.

Abstract: In one embodiment of this invention a surface silicated alumina composition, as opposed to conventional silica alumina, is provided. Such composition may also be fluorided and/or phosphated or phosphited. The resulting compositions are broadly useful but are of particular applicability as supports for chromium olefin polymerization catalysts. In another aspect alumina is fluorided and used with hexavalent chromium catalyst and a co-catalyst or in the alternative with an organochromium catalyst. If desired the support in this embodiment can also be phosphated or phosphited. In another embodiment, aluminum phosphate is formed in the pores of alumina. In contrast with alumina catalyst supports of the prior art, the supports of this invention allow for the production of olefin polymers at high rates of productivity. Also novel high density ultrahigh molecular weight polymers are produced.

Abstract: Fines are reduced in refractory materials by mixing the refractory material with an acid composition in a liquid polar organic compound and thereafter working the mixture until a decrease in volume occurs. The resulting product can be shaped and subjected to conventional finishing treatments. The resulting product exhibits reduced fines and thus is an improved material for use as a catalyst support. The resulting catalyst is of particular utility in the production of film grade ethylene polymer.

Abstract: The reaction of the organolanthanide complexes [.eta..sup.5 --(CH.sub.3).sub.5 C.sub.5 ].sub.2 MCl.sub.2.sup.- Li((C.sub.2 H.sub.5).sub.2 O).sub.2.sup.+, M=La, Nd, Sm, Lu, with LiCH[Si(CH.sub.3).sub.3 ].sub.2 provides a straight-forward route to ether-free and halide- free bis(pentamethylcyclopentadienyl) lanthanide alkyls, (.eta..sup.5 (CH.sub.3).sub.5 C.sub.5).sub.2 MCH--[Si(CH.sub.3).sub.3 ].sub.2. The (.eta..sup.5 (CH.sub.3).sub.5 C.sub.5).sub.2 NdCH[Si(CH.sub.3).sub.3 ].sub.2 complexes react with H.sub.2 under mild conditions to yield the corresponding hydrides [(.eta..sup.5 (CH.sub.3).sub.5 C.sub.5).sub.2 MH].sub.2. These complexes have been found to be extremely active homogeneous olefin polymerization catalysts, as well as catalysts for olefin and acetylene hydrogenation.

Abstract: Ethylene is copolymerized or interpolymerized with at least one olefinic comonomer having about 3 to 18 carbon atoms to produce linear low density polyethylene copolymers and terpolymers in a slurry process using liquid propane as the diluent. The copolymer products have desirable physical properties including relatively narrow molecular weight distributions and low elasticities.

Abstract: Preparation of polyethylene in the presence of selected nickel-containing catalysts.

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: A catalyst support based on aluminum polyphosphate or polyphosphoric acid-impregnated alumina is provided by two alternative techniques. In the first embodiment, an aluminum polyphosphate composition is heated in a dry atmosphere and thereafter impregnated with a zerovalent chromium component under anhydrous conditions. The resulting catalyst is active for olefin polymerization. In the second embodiment, alumina is impregnated with a polyphosphoric acid composition. This resulting polyphosphoric acid impregnated alumina can be used as a support for zerovalent chromium or can be impregnated with a chromium component and oxidized to give an active hexavalent chromium species. The resulting catalysts are advantageous because of their unusual sensitivity to hydrogen thus allowing great leeway in molecular weight control.

Abstract: A process for the polymerization or copolymerization of an olefinically unsaturated monomer which comprises contacting the monomer with a chromium metal catalyst composition which is the product obtained by adsorbing a chromium metal complex which contains allyl hydrocarbon radicals with an inert inorganic oxide support which has --OH groups on its surface and which is free from adsorbed water, said monomer being an olefinically unsaturated monomer other than a polar vinyl monomer.

Abstract: Incorporation of an ester plasticizer having a solubility parameter from about 7.8 to about 10.2 (cal/cc).sup.1/2 increases the flexibility and impact strength of poly(dicyclopentadiene). In a preferred embodiment of the method for poly(dicyclopentadiene) synthesis, the plasticizer is incorporated into at least one of two parts of a metathesis-catalyst system: a catalyst/monomer solution or an activator/monomer solution. The two parts are then combined in the mixing head of a reaction injection molding machine and injected into a mold where the reaction mixture rapidly sets up into a thermoset polymer with greater flexibility and impact strength than is found in the corresponding unplasticized poly(dicyclopentadiene).

Abstract: Aluminum orthophosphate is prepared by combining a source of orthophosphate ions with an aluminum salt to form a concentrated mass, gelling, and thereafter converting the resulting hydrogel to a xerogel by removing water. The resulting aluminum phosphate is particularly suited for use as a base for a chromium olefin polymerization catalyst.

Abstract: Incorporation of an ester plasticizer having a solubility parameter from about 7.8 to about 10.2 (cal/cc).sup.1/2 increases the flexibility and impact strength of poly(dicyclopentadiene). In a preferred embodiment of the method for poly(dicyclopentadiene) synthesis, the plasticizer is incorporated into at least one or two parts of a metathesis-catalyst system: a catalyst/monomer solution or an activator/monomer solution. The two parts are then combined in the mixing head of a reaction injection molding machine and injected into a mold where the reaction mixture rapidly sets up into a thermoset polymer with greater flexibility and impact strength than is found in the corresponding unplasticized poly(dicyclopentadiene).

Abstract: A process for the preparation of electrically conductive polymers by polymerizing acenaphthylene, N-vinyl-heterocyclics, eg. N-vinylcarbazole or N-vinylpyridine, or N,N-divinylaniline at from -80.degree. to +100.degree. C. in the presence of a cationtic catalyst, wherein from 1 to 50 percent by weight of an oxidizing Lewis acid, preferably FeCl.sub.3, FeBr.sub.3, SbCl.sub.5, SbF.sub.5, AsF.sub.5 or CF.sub.3 -SO.sub.3 H, or a combination of AlCl.sub.3 or TiCl.sub.4 with the said compounds or with CrO.sub.3 or OsO.sub.4 is used as the catalyst. In a preferred embodiment of the process, thin films of the monomers to be polymerized, applied to glass or to a polymeric base, preferably to a plastic film, are treated with gaseous SbCl.sub.5, SbF.sub.5 or AsF.sub.5.

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: In a process for polymerizing a 1-olefin with a catalyst system comprising a reaction product of a porous alumina and an organometallic compound of the formula (RCH.sub.2).sub.4 M wherein M is Ti, Zr, or Hf and R is a group which is such that there is no hydrogen atom attached to an atom which is in the .beta.-position to M, and more specifically, R is aryl, aralkyl, tertiary alkyl, for example, trialkylmethyl, or trialkylsilyl, the improvement characterized in that the alumina has an average pore diameter of at least about 150 A and/or at least about 10% of the total pore volume of the alumina is provided by pores having diameters greater than about 200 A.

Abstract: A transition metal compound containing at least one .pi.-bonded arene is contacted with an inorganic oxide, hydroxide, oxyhalide, hydroxyhalide or halide. The transition metal compound can be a compound such as titanium(O)ditoluene or TiCl.sub.2.2AlCl.sub.3 durene. The inorganic compound is preferably of high surface area and this may be inherent in the compound or can be achieved by a grinding procedure. The inorganic compound can be treated with a halogen containing compound either before, during or after the contacting with the transition metal compound. The product of the contacting is useful either as catalyst for the polymerization of unsaturated hydrocarbon monomers or as a component of such a catalyst. When used as a component of an olefine polymerization catalyst, the transition metal product can be mixed with an organo-aluminum compound and a Lewis Base compound such as an ester.

Abstract: A fractionable, elastomeric polymer of 1-butene consisting essentially of 30% to 80%, by weight, of an ether-soluble fraction having an intrinsic viscosity exceeding 1.5 and an infrared crystallinity value of about 1% to 15%; and 20% to 70%, by weight, of an ether-insoluble fraction having an infrared crystallinity value of about 20% to 55%; said polymer having an nmr isotacticity of about 20% to 50% and an intrinsic viscosity exceeding 1.5; elastomeric copolymers of 1-butene; polymer blends containing said elastomeric polymers; and a catalytic process for making said elastomeric polymers.

Abstract: Olefin polymerization catalysts are prepared by depositing an organophosphoryl chromium product and a non-volatile aluminum-containing product obtained from the reaction of an aluminum alkoxide and an aluminum salt of a lower aliphatic monocarboxylic acid 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.

Abstract: Novel catalysts are provided for the polymerization of olefins such as ethylene. The catalysts consist essentially of a chromium compound supported upon an inorganic carrier containing aluminum and phosphorus moieties, at least a portion of the chromium having a valence of less than 6. The inorganic carrier is an amorphous precipitate of aluminum phosphate or an amorphous precipitate containing aluminum and phosphorus moieties in an atomic ratio in the range of about 5:1 to 1:1. The catalysts are particularly useful for polymerizing ethylene in a Particle Form Process in that the catalyst has essentially no polymerization induction period and provides ethylene polymers having a desirably broad molecular weight distribution and a desirably high melt flow shear ratio.

Abstract: Olefin polymerization catalysts are prepared by depositing an organophosphoryl chromium product and an aluminum acetyl acetonate 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.

Abstract: Olefin polymerization catalysts are prepared by depositing an organophosphoryl chromium product and a non-volatile aluminum-containing product obtained from the reaction of an aluminum alkoxide and an aluminum salt of a lower aliphatic monocarboxylic acid 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.

Abstract: Supported catalyst compositions incorporating preformed materials comprising the reaction product of organophosphorus compounds such as the organophosphates and organophosphites with chromium trioxide, wherein the organic moiety is a hydrocarbon radical, e.g., alkyl, aralkyl, aryl, cycloalkyl, or the like or combinations thereof. Typical supports constitute an inorganic material of high surface area, especially a high pore volume (>1.96 cc/g) silica xerogel. Catalytically promoted polymerizations of 1-olefins proceed efficiently to products of specially adapted utility for molding, and particularly the production of blow molded articles. The polymerization activity of the catalyst compositions is promoted by heating in a dry, oxygen containing atmosphere. The catalysts are utilized alone or in conjunction with other catalytic ingredients such as organometallic and/or organo non-metallic reducing agents.

Abstract: In the production of elastomeric polypropylene by polymerizing propylene in the presence of a catalyst system which is the reaction product of a metal oxide and and an organometallic compound of Zr, Ti or Hf under conditions such that the reaction medium contains liquid propylene, a fluid, mobile slurry of polypropylene in propylene is formed by mixing the components of the catalyst system together in the presence of the propylene to be polymerized.

Abstract: At least one conjugated diene is polymerized in the presence of a catalyzing amount of a catalyst consisting essentially of at least one Lewis acid and at least one cyclopolyolefin nickel complex.

Abstract: Olefin polymerization catalysts are prepared by depositing an organophosphoryl chromium product and an aluminum acetyl acetonate 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.

Abstract: An improved method for preparing ethylene polymers with certain supported chromium [II] catalysts wherein the improvement comprises employing said catalyst in the presence of phenolic antioxidant.

Abstract: New coordination complex compounds formed between first row transition metal salts and naphthyridine compounds substituted with electron donor groups at positions ortho and para to the nitrogen positions.

Abstract: A new catalyst and method of making polymers therewith and the process of preparing the catalyst in which the catalyst is prepared by dispersing on a finely divided carrier material, particularly a difficultly reducible inorganic support such as silica, a reaction product of (1) a chromium carboxylate reactant and (2) an organic nitrogen cmpound reactant capable of forming a complex such as a chelate with the chromium and activating the resulting mixture by heating at an elevated temperature in a non-oxidizing atmosphere.

Abstract: Catalysts, especially for olefin polymerization are prepared by coating an aluminum compound on a selected high pore volume silica gel, and calcining the support at temperatures of from about 200.degree. to 2000.degree. F. The preferred catalyst is prepared with an inorganic support material as aforesaid, thereafter depositing an organophosphoryl chromium compound thereon, and activating the thus-treated support by heating in a non-reducing, preferably oxygen-containing, atmosphere at temperatures of from about 800.degree. to 2000.degree. F. The activated, supported catalyst composition may, but need not necessarily, be combined with a metallic and/or non-metallic reducing agent, to provide a catalyst system useful in the polymerization of 1-olefins.

Abstract: A new catalyst and a method of polymerizing olefins in which the catalyst is prepared by forming a mixture by dispersing on a finely divided, difficult to reduce, inorganic support of the class consisting of silica, alumina, thoria, zirconia, titania, magnesia and mixtures or composites thereof, an organic chromium compound pyrolytically decomposable in the substantial absence of oxygen to deposit a catalytically active residue along with a carbon residue as a contaminant on the support, then activating the mixture by subjecting the mixture to non-oxidative pyrolysis to and at a temperature within the range of about 600.degree.-2000.degree. F.

Abstract: A catalyst and the method of making same and a method of making polymers of 1-olefins with said catalyst in which the catalyst is prepared by chemically modifying a finely divided, difficultly reducible, inorganic support of the nature of silica, alumina, thoria, titania, magnesia and mixtures thereof by adding to the support a zirconium compound before dispersing on the modified support a chromium chelate derived from a beta-dicarbonyl compound that may be either acyclic or cyclic, the chelate being essentially of the formula ##STR1## WHEREIN R is individually selected from hydrogen, alkyl, alkenyl, aryl, cycloalkyl and cycloalkenyl radicals and combinations of these radicals with each R containing 0-20 carbon atoms and a corresponding valence-satisfying number of hydrogen atoms, R' is selected from alkylene, alkenylene, arylene, cycloalkylene and cycloalkenylene radicals and combinations of these bivalent radicals with R' containing 1-20 carbon atoms and a corresponding valence-satisfying number of hydrogen

Abstract: Ethylene is polymerised or copolymerised using a transition metal catalyst at a pressure in the range 300-1000 atmospheres and a temperature of at least 100.degree. C in the presence of a volatile inert diluent such as pentane, or at least one 1-olefine comonomer such as buten-1, or both. The catalyst can be a Ziegler type catalyst, an organo-compound of a transition metal such as a substituted silylmethyl, cyclopentadienyl, arene, norbornyl, .pi.-allyl or benzyl compound and may be supported on a suitable support such as silica, alumina, or magnesia. Other catalysts which may be used are supported chromium or molybdenum oxides. If a solid catalyst is used it is preferred to use a material which has been finely dispersed.

Abstract: A new catalyst and method of making polymers therewith and the process of preparing the catalyst in which the catalyst is prepared by dispersing on a finely divided carrier material, particularly a difficultly reducible inorganic support such as silica, an organic chromium (II) or (III) salt or derivative of a carboxylic acid or an N-substituted carboxylic acid or a nitrogen-heterocyclic carboxylic acid and activating the resulting mixture by heating at an elevated temperature in a non-oxidizing atmosphere.

Abstract: An olefin polymerization catalyst is prepared by depositing a poly (di-.mu.-dihydrocarbylphosphinatohydroxyaquochromium (III)) compound or the corresponding anhydrous compound upon an inorganic support material and calcining the impregnated support material in a non-reducing atmosphere above 300.degree. C. up to the decomposition temperature of the support material to provide an activated catalyst. The catalyst exhibits high productivity and produces polymers having high melt indices.

Abstract: A new catalyst and method of making polymers therewith and the process of preparing the catalyst in which the catalyst is prepared by dispersing on a finely divided carrier material, particularly a difficultly reducible inorganic support such as silica, an organic chromium complex such as a chelate derived from orthohydroxyphenyl or 2'-hydroxyphenyl carbonyl compounds, including ketone, aldehyde and amide types, and their derivatives, and activating the resulting mixture by heating at an elevated temperature in a non-oxidizing atmosphere.

Abstract: Method for the cationic polymerization of at least one olefinic monomer and more particularly the homopolymerization of a mono-olefinic monomer such as isobutylene and the copolymerization thereof with a di-olefinic monomer (diene) such as butadiene and optionally another mono-olefinic monomer in the presence of, as initiator of a halide of tetravalent vanadium, titanium and zirconium, an activator and under the influence of visible ultraviolet or infra-red light.

Abstract: Method for the cationic polymerization of at least one olefinic monomer and more particularly the homopolymerization of a mono-olefinic monomer such as isobutylene and the copolymerization thereof with a di-olefinic monomer (diene) such as butadiene and optionally another mono-olefinic monomer in the presence of, as initiator of a halide of tetravalent vanadium, titanium and zirconium, an activator and under the influence of visible ultraviolet or infra-red light.

Abstract: A new catalyst and method of making polymers therewith and the process of preparing the catalyst in which the catalyst is prepared by dispersing on a finely divided carrier material, particularly a difficulty reducible inorganic support such as silica, an organic chromium compound or complex such as a chelate derived from an N-nitroso-substituted N-arylhydroxylamine, N-nitroso-substituted hydroxamic acid, N-aryl-substituted hydroxamic acid, or an aromatic hydroxamic acid with or without an N-substituent and activating the resulting mixture by heating at an elevated temperature in a non-oxidizing atmosphere.

Abstract: Polymerization of ethylene using a transition metal hydrocarbyl complex, especially zirconium tetrabenzyl, supported on alumina consisting of substantially spherical particles having diameters in the range 20-150 .mu.m. The particulate polymer produced by the process contains substantially no "fines" (i.e. particles <100 .mu.m diameter) and has improved pourability.