Abstract: The invention relates to a high-molecular-weight, linear, neodymium-catalysed polybutadiene having a high proportion, >95%, of cis-1,4 units having a low proportion, <1%, of 1,2-vinyl content, and also having a small molar-mass-polydispersity index (MPI), characterized in that Mooney viscosity (ML1+4 100° C.) of the polybutadiene is from 70 to 90 and The molar-mass-polydispersity index of the polybutadiene is smaller than 10.

Abstract: The present invention relates to a process for preparing an activating support for metallocene complexes in the polymerisation of olefins comprising the steps of: I) providing a support prepared consisting in particles formed from at least one porous mineral oxide; II) optionally fixing the rate of silanols on the surface of the support; III) functionalising the support with a solution containing a fluorinated functionalising agent; IV) heating the functionalised and fluorinated support of step c) under an inert gas and then under oxygen; V) retrieving an active fluorinated support. That activating support is used to activate a metallocene catalyst component for the polymerisation of olefins.

Abstract: A method for preparing a diene elastomer, such as a butadiene homopolymer or copolymer, in particular, a polybutadiene, with a high level of cis-1,4 linkages that has both a Mooney viscosity greater than or equal to 40 and a polydispersity index of less than 2.1. The method comprises a reaction of a catalyst system with at least one conjugated diene monomer to be polymerized and the catalyst system is based on at least: optionally one preforming conjugated diene; one salt of one or more rare earth metals; an inert hydrocarbon-based solvent; an alkylating agent comprising an allyl derivative of aluminum of formula R?nAlR?3-n, where R? is a saturated or unsaturated alkyl group or else a hydride, where R? is an allyl group and where n is an integer inclusively between 1 and 3; and a halogen donor that belongs to the family of alkylaluminum halides, excluding alkylaluminum sesquihalides.

Abstract: This invention relates to A process for manufacturing a vinyl-rich polybutadiene rubber, comprising polymerizing butadiene in a solvent using a catalyst system comprising an iron-based catalyst as catalyst and a phosphite as ligand, said catalyst system comprising: (A) an organoiron compound; (B) an organoaluminum compound; and (C) a phosphite selected from a group consisting of dialkyl phosphite, trialkyl phosphite, diaryl phosphite, triaryl phosphite and mixtures thereof; wherein, the mole ratio of component B to component A is 5:100; and that of component C to component A is 0.5:10; and 80 wt % of macromolecules of the rubber have a vinyl group.

Abstract: This invention is based upon the unexpected discovery that alkylated diphenylamines can be used in conjunction with nickel based catalyst systems which contain (a) an organonickel compound, (b) an organoaluminum compound, and (c) a fluorine containing compound to produce cis-1,4-polybutadiene having reduced molecular weight and an increased level of branching. This results in the cis-1,4-polybutadiene exhibiting good processability without sacrificing cold flow characteristics. Additionally, the alkylated diphenylamine which remains in the rubber acts in a manner which provides it with antioxidant protection. In other words, the use of alkylated diphenylamines accomplishes the three major objectives that are realized by employing para-styrenated diphenylamines (reduced molecular weight, regulated polymer macrostructure through branching and antidegradant protection).

Abstract: A metallocene catalyst may be temporarily and reversibly passivated by contact with an effective amount of an unsaturated hydrocarbon passivating compound.

Abstract: In a method of adding catalysts for the polymerization of C2-C20-olefins, the catalyst is firstly introduced into a container A and the cocatalysts used are subsequently mixed with an inert solvent in a container B, and the contents of the container B are introduced into the container A and mixed with the catalyst there and the mixture is introduced from there into the actual polymerization reactor.

Abstract: The present invention relates to a catalyst composition of an activator, a catalyst compound and a support in a liquid. The catalyst composition of the invention is utilized as prepared, in the liquid, in a process for polymerizing olefin(s), preferably a slurry polymerization process.

Abstract: The invention provides for polymerization catalyst compositions, and for methods for introducing the catalyst compositions into a polymerization reactor. More particularly, the method combines a catalyst component containing slurry and a catalyst component containing solution to form the completed catalyst composition for introduction into the polymerization reactor. The invention is also directed to methods of preparing the catalyst component slurry, the catalyst component solution and the catalyst compositions, to methods of controlling the properties of polymer products utilizing the catalyst compositions, and to polymers produced therefrom.

Abstract: The invention relates to a process for preparing a support material having an increased number of reactive groups and to a process for preparing coreactive surfaces that may have catalytic or cocatalytic properties.

Abstract: A process for preparing pillared chromium phyllosilicate clay &agr;-olefin catalysts is disclosed. This process utilizes palygorskite and sepiolite clays. The pillaring of said clays comprises the steps of: (a) preparing a hydrolyzed first solution by dissolving a chromium salt and a base in water, heating said first solution to a temperature in the range of about 20° C. to about 100° C. while stirring continuously until the solution reaches a pH in the range of about 1.5 to about 2.5 and thereby producing a master batch; (b) diluting said master batch with water to produce a diluted second solution and heating said diluted second solution to produce a heated second solution; (c) adding a solid clay selected from the group consisting of sepiolites and palagorskites to said heated second solution, and continuing heating; (d) recovering said pillared chain silicate clay; and (e) drying said pillared chain silicate clay to form first product.

Abstract: Method for preparing a catalyst component for homo or copolymerization of olefins, said catalyst component comprising at least one metallocene compound on porous inorganic carrier, wherein said metallocene compound is mixed as pure compound in the absence of solvents with said carrier at a temperature which is at least 50° C. but below the vaporization temperature of the metallocene compound in reactor conditions for a sufficient time to obtain said catalyst component having said metallocene evenly distributed onto carrier particles.

Abstract: The present invention relates to a catalyst composition of an activator, a catalyst compound and a support in a liquid. The catalyst composition of the invention is utilized as prepared, in the liquid, in a process for polymerizing olefin(s), preferably a slurry polymerization process.

Abstract: The present invention relates to a process to produce polyethylene through homopolymerization or copolymerization of ethylene with alpha-olefins in the presence of a titanium amide catalyst supported by an organic polymer material, for the production of moldings, such as through extrusion, injection molding, film blowing, sintering under pressure or ram extrusion. The catalyst according to the present invention contains a partially chloromethylated styrene divinyl benzene copolymer as the organic polymer material, a complex compound supported by it, which contains Mg, Al and Ti.

Abstract: A process for preparing syndiotactic vinylidene aromatic polymers comprising contacting one or more vinylidene aromatic monomers with a concentrated catalyst premix composition comprising a Group 4 metal complex and an activating cocatalyst.

Abstract: Process for the polymerization of olefins using a catalytic system comprising a solid precursor containing at least one neutral halogenated metallocene derived from a transition metal and at least one ionizing agent, and an organometallic compound derived from a metal chosen from groups IA, IIA, IIB, IIIA, and IVA of the Periodic Table.

Abstract: The invention provides a process for commercial production of syndiotactic polyolefins using a metallocene catalyst supported on silica treated with MAO. The invention includes contacting the supported metallocene catalyst with an aluminum alkyl and aging the catalyst prior to polymerization. In addition, the catalyst is prepolymerized in a tubular reactor prior to being introduced into the polymerization reaction zone.

Abstract: Provided are heterogeneous catalysts for homo- and copolymerization of olefins as well as a method for preparing these catalysts, which comprise at least one metallocene compound of a Group 4A, 5A or 6A (Hubbard) transition metal on a solid inorganic support. The method comprises the steps of vaporizing the metallocene compound, treating the support material with the vaporized metallocene compound at a temperature which is sufficiently high to keep the metallocene compound in the vaporous state, contacting the support material with an amount of the vaporized metallocene compound which is sufficient to allow for a reaction between the metallocene compound and at least a substantial part of the available surface sites capable of reacting therewith, removing the rest of the metallocene compound not bound to the support, and optionally treating the product thus obtained with an activating agent. The catalysts are active even if very low amounts of activator agents, such as alumoxane, are used.

Abstract: A method for producing a polyolefin, which comprises polymerizing or copolymerizing at least one olefin in the presence of a catalyst system comprising (A) a solid catalyst component of a titanium catalyst component obtained by reacting at least one aluminum halide compound with a homogeneous solution containing magnesium, titanium and alkoxy groups, wherein the aluminum halide compound is added to the homogeneous solution to provide a halogen atom in a mol ratio of from 0.2 to 0.4 to one mol of the alkoxy groups contained in the homogeneous solution to precipitate particles in the former step, and the aluminum halide compound is further added to provide a halogen atom in a mol ratio of from 1 to 20 to one mol of the alkoxy groups to treat the resultant mixture containing the precipitated particles in the latter step, and (B) at least one organic aluminum compound catalyst component.

Abstract: The present invention provides methods for the homopolymerization and/or copolymerization of olefins. In preferred methods of the invention the polymerizable olefins have the general formula of CH.sub.2 .dbd.CR.sub.1 R.sub.2, wherein R.sub.1 and R.sub.2 are the same or different, and are hydrogen or a C.sub.1 -C.sub.10 alkyl. In particularly preferred embodiments, the methods further comprise contacting the polymerizable olefin with a procatalyst and a co-catalyst. In other embodiments, the methods further involve the use of an electron donor.

Abstract: By utilizing the techniques of this invention, trans-1,4-polybutadiene can be synthesized continuously to a high level of conversion utilizing a low level of a highly active cobalt-based catalyst system. The trans-1,4-polybutadiene made with the cobalt-based catalyst system of this invention also typically has a molecular weight which is acceptable for use in tire applications without the need for employing a molecular weight regulator. It is also not typically necessary to utilize a gel inhibitor, such as carbon disulfide, in the polymerizations of this invention. Since a low level of residual cobalt is present in the trans-1,4-polybutadiene which is made utilizing the catalyst system of this invention, it is much more stable than trans-1,4-polybutadiene made with standard cobalt-based catalyst systems.

Abstract: Cis-1,4-polybutadiene can be synthesized by polymerizing 1,3-butadiene monomer with a three component nickel catalyst system containing (a) an organonickel compound, (b) an organoaluminum compound, and (c) a fluorine containing compound. However, the molecular weight of the cis-1,4-polybutadiene prepared is typically too high to be utilized as a non-oil extended rubber. This invention is based upon the discovery that para-styrenated diphenylamine acts to reduce the molecular weight and to improve the processability of cis-1,4-polybutadiene prepared with such nickel based catalyst systems. The use of para-styrenated diphenylamine as a modifier in such polymerizations does not change the microstructure of the cis-1,4-polybutadiene produced.

Abstract: An improved polymerization process for making essentially nonagglomerated ethylene polymers, especially EPR polymers, based on the use of a stage-modified high activity vanadium catalyst, under polymerization conditions that normally would yield an undesirable amount of agglomerated polymer.

Abstract: The polymerization of certain alpha-olefins in a gas phase involves the problem of agglomeration of the product into particles disadvantageous from the viewpoint of its handling. In the present invention this problem has been solved by means of a new type of process for the homo- or copolymerization of alpha-olefins. In the process the catalyst system is pretreated by contacting and reacting a transition-metal compound which is solid or on a solid carrier with an organoaluminum compound, and possibly an electron donor, in a liquid medium, and by drying the thus formed reaction product to produce a solid catalyst system. The thus pretreated solid and active catalyst system is then fed together with an alpha-olefin in the gaseous state into a gas-phase reactor, and polymerization is carried out by contacting them with each other.

Abstract: Ultra-high-molecular-weight polyolefin fine powder characterized in that said fine powder has an intrinsic viscosity measured in decalin at 135.degree. C. of at least 10 dl/g and an average particle diameter in the range of 1-80 .mu.m, at least 20 weight % of the powder passing through 350 Tyler mesh screen.

Abstract: The invention concerns a process for manufacturing low density linear polyethylene by copolymerizing ethylene and 1-butene, comprising the steps of:(a) dimerizing ethylene to 1-butene in the presence of a soluble catalyst comprising: an alkyl titanate, an aluminum compound of formula AlR.sub.3 or AlR.sub.2 H, wherein R is a hydrocarbyl radical, and an ether;(b) contacting at least a portion of the product obtained in step (a) with an inorganic compound, at least partly insoluble;(c) contacting the insoluble mixture obtained in step (b) with an halogenated aluminum compound of formula Al.sub.2 R'.sub.6-n X.sub.n, wherein R' is a hydrocarbyl radical, X a halogen atom, and n a number from 3 to 6, when an halogenated aluminum compound is not already present in said mixture;(d) using the resultant product, containing at least one inorganic carrier, at least one halogenated aluminum compound and at least one titanium compound, as catalyst in the polymerization reactor.

Abstract: An olefin polymerization catalyst prepared by reacting an admixture of anhydrous magnesium dihalide and hydrous magnesium dihalide with reactants including benzoic acid ester, an alkoxytitanium compound, an organoaluminum halide, and a titanium halide.

Abstract: Provided is an olefin-polymerization catalyst comprising the combination of the following components [I] and [II]:[I] a solid component obtained by intercontacting and reacting the following components (1) through (4):(1) a compound obtained by treating an oxide of an element of Groups II-IV in the Periodic Table with a compound represented by the general formula R.sup.1.sub.m Si(OR.sup.2).sub.n.sup.X.sub.4-m-n wherein R.sup.1 and R.sup.2 are each a hydrocarbon radical having 1 to 24 carbon atoms, a hydrocarbon radical containing oxygen, sulfur or nitrogen, or hydrogen, X is a halogen atom, m is 0.ltoreq.m<4 and n is 0.ltoreq.n.ltoreq.4, provided 0.ltoreq.m+n.ltoreq.4,(2) a reaction product obtained by the reaction of a magnesium halide and a compound represented by the general formula Me(OR.sup.3).sub.n.sup.X.sub.z-n wherein Me is an element of Groups I-VIII in the Periodic Table, with the limitation that silicon, titanium and vanadium are excluded, R.sup.

Abstract: An improved method for the preparation of homopolymers and copolymers of alpha olefins by means of a catalyst system comprising a titanium halide, an aluminum alkyl, and a phenolic compound which has a tendency to crystallize at low temperatures in the reactor feed system is disclosed. The improvement comprises prereacting a portion of the aluminum alkyl with the phenolic compound such that the components remain catalytically inactive and then activating the catalyst by adding the remainder of the aluminum alkyl to prereacted components in situ in the polymerization reactor, thereby preventing the crystallization of the phenolic compound at low temperatures in the feed system for the reactor.

Abstract: A Ziegler type supported catalytic component for polymerization of an .alpha.-olefin is prepared by allowing an organo-magnesium compound expressed by a generic formula of R'MgX' (wherein R' represents a hydrocarbon group having 1 to 20 carbon atoms and X' either a halogen atom chosen out of chlorine, bromine and iodine or a hydrocarbon group having 1 to 20 carbon atoms) to react with carbon tetrahalide in the presence of an electron donor compound to obtain a solid product through a solid-liquid separation process; by heat treating the separated solid product with a carbon halide; by treating the heat treated solid product with phenols at 90.degree. to 180.degree. C.; and by treating this phenol treated product further with a halogenated titanium compound. Homo- or co-polymerization of an .alpha.-olefin is carried out in the presence of a catalyst composition consisting of the above catalytic component and an organo-aluminum compound. With this catalytic component, stereospecific polymerization of an .alpha.

Abstract: A silica composition is calcined at a temperature high enough to remove some but not all of the hydroxyl content. Generally temperatures of at least 400.degree. C. are required and temperatures above 1000.degree. C. are undesirable, the most preferred temperature being about 600.degree.-800.degree. C. The thus calcined silica is then treated with chromyl chloride at an elevated temperature and finally given a treatment in a carbon monoxide ambient. While the final composition contains chlorine which is normally considered a catalyst poison, the material is surprisingly active as an olefin polymerization catalyst.

Abstract: Polyolefin granules having an average particle size diameter greater than 600 microns, preferably about 1000 microns or greater are obtained by polymerizing monoolefins in the presence of a titanium catalyst having an average particle size diameter of greater than about 35 microns and preferably 40 to 65 microns. The titanium catalysts are obtained by reducing titanium tetrahalide in the presence of a suitable organometallic reducing compound such as diethylaluminum chloride under controlled conditions of temperature, reduction rate and concentrations to obtain a titanium halide reduced solids product seeds having an average particle size diameter of about 20 microns or greater and thereafter simultaneously and without interruption adding to the seeds containing system titanium tetrahalide and organometallic reducing compound such as diethylaluminum halide at a rate such that the reduction of titanium tetrahalide to titanium trihalide is about 6.times.10.sup.-4 to about 0.

Abstract: A catalyst component is a transition metal composition which is obtained by reacting together an inert particulate material, an organic magnesium compound, a halogen-containing compound such as carbon tetrachloride silicon tetrachloride or boron trichloride and a specified transition metal compound such as VOCl.sub.3, bis(n-butoxy) titanium dichloride or zirconium tetrabenzyl. The catalyst component obtained can be used, together with an organic metal compound, to give an olefin polymerization catalyst. The catalyst can be used to effect the polymerization of olefin monomers, for example, the copolymerization of ethylene with an alpha-olefin monomer such as butene-1 in a fluidized bed reactor.

Abstract: Olefins are polymerized in the presence of chromium-containing catalysts which have been improved by depositing the chromium onto the inorganic oxide support in the vapor phase rather than as an inorganic or organic compound. The resulting polymers exhibit a higher molecular weight as compared to those polymers prepared in the presence of such chromium-containing catalysts prepared in the conventional manner.

Abstract: A process for the preparation of a drag reducing substance which comprises:(a) a transition metal catalyst slurry containing:1. crystalline titanium halide having the general formula TiXn where n=2.5 to 3.0 and X is halogen,2. a hydrocarbon diluent, and3. an ether;(b) a co-catalyst;(c) alpha-monoolefinic hydrocarbons containing from 2 to 30 carbon atoms under suitable polymerization conditions providing for an ultrahigh molecular weight polymer that is soluble in hydrocarbons; and(d) ceasing the polymerization at a polymer content of 20 percent by weight or less.

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 new catalyst and a method of polymerizing olefins in which the catalyst is prepared (1) by forming a mixture by dispersing on a finely divided, difficult to reduce, inorganic support of silica, alumina, thoria, zirconia, titania, magnesia or mixtures of these a tetravalent or lower valent organic chromium compound, (2) calcining the mixture of (1) in an oxidizing or inert atmosphere and at an elevated temperature to produce a chromium compound on the support, (3) reacting the product of (2) with an alkyl ester of titanium, boron, vanadium or mixtures thereof or boric acid at an elevated temperature, and (4) activating the product of (3) with a dry gas that contains oxygen by heating at an elevated temperature the product of (3) in this dry gas.

Abstract: A catalyst for the polymerization of olefins is described wherein a titanium(IV) compound is reduced with an organoaluminum compound in the presence of atactic poly-.alpha.-olefin. Polymerization with the catalyst is also disclosed.

Abstract: A silica-containing composition suitable for supporting chromium to produce a catalyst capable of giving high melt flow olefin polymers for such applications as injection molding and the like requiring a narrow molecular weight distribution, is produced by treating a silica-containing material at an elevated temperature with either (1), CO, (2) a bromine or iodine component, or (3) an oxygen-containing sulfur component, more specifically a carbon, oxygen and sulfur-containing component. Thereafter, anhydrous chromium can be added, for instance, by means of a hydrocarbon solution of a soluble chromium compound, and the resulting composition activated in air to produce a catalyst. The bromine or iodine treated silica contains bound bromine or iodine if the treating agent is HBr, HI, an organic halide of Br or I or elemental Br or I used in conjunction with a reducing agent.

Abstract: For the polymerization of ethylene, as such or with one or more alpha-olefines, a novel catalyst composition is suggested, which has a high yield of polymer per weight unit of catalyst. Such compositions are prepared from a titanium compound in which the valency of Ti is 3 or more, said compound being reacted with the vapors of one or more metals of the group consisting of Al, Cr, Mn, V, Ti, Zr, Mo, Zn and Ca in the presence of a halogen donor which is preferably an organic halide, certain inorganic halides being capable of being used provided that the halide metal has at least two degrees of valency. The composition is used in association with an aluminium hydrocarbyl halide. Yields as high as 30,000 grams of polymer per gram of elemental Ti can be obtained.

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: A catalyst, a process of preparing the catalyst and a method of making polymers and copolymers of 1-olefins with the catalyst in which the catalyst is prepared by producing finely divided particles of chromium metal by a sublimation process and dispersing the sublimate of chromium particles with an organic liquid and providing a mixture comprising the chromium sublimate particles and a support such as silica. The mixture is then heat activated in an oxidizing atmosphere. In another aspect of the invention the chromium sublimate particles and support particles are further modified by having a titanium compound as a part of the mixture of chromium sublimate particles and support particles.

Abstract: A solid catalyst for polymerization of olefins prepared by treatment of a titanium trichloride composition with a mixture of (1) a halogen, an interhalogen compound or a halogenated hydrocarbon compound, and (2) an ether which, in combination with organoaluminum compounds as activators, can be used to polymerize olefins for the efficient production of highly crystalline olefin polymers.

Abstract: Polymerization catalysts are prepared by impregnation of a silica or aluminum support with a vanadium, titanium and/or chromium salt decomposable upon calcination to the oxide, calcining the impregnated support at about 500.degree.-700.degree. C., impregnating the calcined support with a solution of aluminum hydride and heating the resultant material to about 300.degree. C.-500.degree. C. in hydrogen. The catalyst is extremely active for the polymerization of lower molecular weight olefins such as ethylene and ethylene-propylene mixtures.

Abstract: A catalyst for polymerizing one or more 1-olefins and prepared by the process of (1) forming an initial mixture of a finely divided support such as silica and a chromium.sup.+3 compound of either of the formulas ##STR1## or Cr(OOCR).sub.3 or a mixture in an amount to provide about 0.1-30 weight percent of chromium in the finished catalyst and in which each R is individually selected from hydrogen or a hydrocarbyl group of 1-20 carbon atoms and the necessary hydrogen atoms, followed by (2) heating the mixture of (1) in a stream of dry, inert, and non-oxidizing gas and heating to a temperature of about 230.degree.-540.degree. C., and then (3) forming a second combination by adding a titanium compound to the product of (2) at a temperature ranging from 95.degree.-370.degree. C., and then (4) activating the mixture of (3) by heating in a dry, oxidizing atmosphere such as dry air to a temperature of about 370.degree.-1100.degree. C.

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: Particles of titanium trichlorides usable for the stereospecific polymerization of alpha-olefines, especially propylene, having been dried until their liquid content is less than 1% by weight relative to the weight of titanium trichloride present in said particles, as well as a process for the preparation of such particles and a process for stereospecific polymerization in the presence thereof.

Abstract: A process for the manufacture of homopolymers and copolymers of .alpha.-monoolefins by polymerizing the monomer or monomers by means of a Ziegler-Natta catalyst comprising (I) a titanium trichloride component and (II) an aluminum-alkyl component, wherein the titanium trichloride component (I) employed is obtained by (1) in a first stage moistening a suitable conventional catalyst component, consisting entirely or substantially of titanium trichloride, with a hydrocarbon mixture comprising a liquid alkane hydrocarbon and a liquid benzene hydrocarbon and (2) in a second stage drying the catalyst component, moistened with the hydrocarbon mixture, under an inert gas, with constant mechanical mixing, within a certain period, at a temperature which is from 5.degree. to 50.degree. C. above the boiling point of the highest-boiling hydrocarbon present in the hydrocarbon mixture which has been used to moisten the component.

Abstract: High melt flow olefin polymers suitable for such applications as injection molding, and the like requiring a narrow molecular weight distribution are produced using a catalyst made by reducing and reoxidizing a chromium catalyst on either a titanium-silica cogel or a self-reduced silica-containing composition. In the first embodiment, a cogel formed by coprecipitating silica and titania, and containing a chromium compound, is treated in a nonoxidizing atmosphere, such as CO, hydrogen, N.sub.2 or a material decomposable to these materials, and thereafter reoxidized. In the second embodiment, a titanium-free chromium containing catalyst is first heated in air or the like to dry the catalyst and oxidize the chromium after which it is heated in an inert atmosphere wherein the composition is self-reduced to give chromium in a lower valence state. The resulting self-reduced composition is then heated in a reducing ambient and then reoxidized as in the first embodiment.

Abstract: A silica-containing composition suitable for supporting chromium to produce a catalyst capable of giving high melt flow olefin polymers for such applications as injection molding and the like requiring a narrow molecular weight distribution, is produced by treating a silica-containing material at an elevated temperature with either (1), CO, (2) a bromine or iodine component, or (3) an oxygen-containing sulfur component, more specifically a carbon, oxygen and sulfur-containing component. Thereafter, anhydrous chromium can be added, for instance, by means of a hydrocarbon solution of a soluble chromium compound, and the resulting composition activated in air to produce a catalyst. The bromine or iodine treated silica contains bound bromine of iodine if the treating agent is HBr, HI, an organic halide of Br or I or elemental Br or I used in conjunction with a reducing agent.