Abstract: The invention relates to a catalyst component which is a tract product of reagents comprising silica which has a pore volume which exceeds 2.9 cc/gram and an average pore diameter which exceed 400 Angstroms;a metallocene of a first transition metal, activated by an alumoxane,a contact product of dialkylmagnesium and trialkylsilanol,a second transition metal source which exhibits a hydrogen response which is different from that of the metallocenean olefin of 4 to 20 carbon atoms. This catalyst component is activated by an aluminum alkyl activator.

Abstract: Ethylene polymers or copolymers having very broad molecular weight distributions in a broad range of melt-indicies are produced by using mixtures of MgO-supported Ziegler catalyst and a chromium oxide catalyst in which the usual poisoning of the catalysts does not occur.

Abstract: A blend for blown film which exhibits improved MD/TD tear balance. The blend is a bimodal molecular weight ethylene resin containing two fractions of different molecular weight. The weight fraction of a higher molecular weight component of the blend is about 0.35 to 0.75.

Abstract: A supported catalyst for polymerizing 1-olefins, for example, ethylene, is prepared by depositing a chromium compound and a titanium compound on a refractory oxide support which is substantially non-spherical, and which has a relatively broad particle size distribution range. The catalyst is preferably combined, either outside of the polymerization vessel or in situ, with a sufficient amount of at least one magnesium composition of the formula RMgR', where R and R' are the same or different and they are C.sub.1 to C.sub.12 hydrocarbyl groups, to provide a molar ratio of magnesium to chromium in the catalyst composition of about 0.01:1 to about 25:1. The resulting catalyst composition has good feedability and fluidization characteristics, and it produces resins of relatively high HLMI at relatively low temperatures.

Abstract: A modified supported catalyst composition for polymerizing olefins, particularly alpha-olefins, for example, ethylene or ethylene and 1-hexane, is prepared by combining a chromium compound-containing catalyst with a modifier which is an oxide of an element of Group IIIA of the Periodic Table of the Elements. The modifier contains a small quantity of water. The resulting modified catalyst composition produces polymer resins having higher values of High Load Melt Index -HLMI (I.sub.21) than catalyst compositions without the modifier.There is also disclosed a process for polymerizing olefins, at relatively lower temperatures than was heretofore possible, to obtain resins of relatively high HLMI, using the above-identified modified catalyst composition. The resulting polymers can be used for the fabrication of blow-molded products, e.g., household and industrial containers.

Abstract: MgO treated with an organic acid, e.g., 2-ethyoxybenzoic acid, is used as a support for an Al-Ti Ziegler catalyst in which the Ti component is the product of an alkanol having 5 to 12 carbon atoms and TiCl.sub.4 to give HDPE with narrow MWD and large particle size for injection molding.

Abstract: Process of polymerizing a monomer charge including ethylene by (1) drying an inorganic oxide having surface hydroxyl groups to form a support that is substantially free of adsorbed water, (2) reacting the surface hydroxyl groups of the support with at least a substantially stoichiometric amount of at least one organometallic compound corresponding to the formula R.sub.x MR'.sub.y R".sub.z, wherein M is a metal of Group III of the periodic table, R is an alkyl group containing 1 to 12 carbon atoms, R' and R" are independently selected from the group consisting of H, Cl, and alkyl and alkoxy groups containing 1 to 12 carbon atoms, x has a value of 1 to 3, and y and z both represent values of 0 to 2, the sum of which is not greater than 3-x, (3) reacting the thus-treated support with at least about 0.001 mol, per mol of organometallic compound, of at least one vanadium compound corresponding to a formula selected from (RO).sub.n VOX.sub.3-n and (RO).sub.m VX.sub.4-m, in which formulas R represents a C.sub.1 -C.

Abstract: Catalyst compositions which are particularly useful for the preparation of ethylene polymers having a narrow molecular weight distribution are obtained by (1) drying an inorganic oxide having surface hydroxyl groups, e.g., silica, alumina, magnesia, etc., to remove adsorbed water, (2) reacting the surface hydroxyl groups with at least a stoichiometric amount of an organometallic compound having at least one alkyl group attached to a Group III metal, e.g., a trialkylaluminum, (3) reacting the thus-treated inorganic oxide with a vanadium halide, such as (a) VOCl.sub.3, VOBr.sub.3, and/or mono-, di-, and/or trihydrocarbyloxy derivatives thereof and/or (b) VCl.sub.4, VBr.sub.4, and/or mono-, di-, tri-, and/or tetrahydrocarbyloxy derivatives thereof, and (4) reacting that reaction product with at least about 0.1 mol, per mol of organometallic compound, of an alcohol containing 1 to 18 carbon atoms.

Abstract: A unique high efficiency catalyst for the polymerization of alpha-olefins has been developed based on the use of methanol treated magnesium oxide as support, an equimolar mixture of titanium tetrachloride and tetrabutyltitanate as titanium source impregnated on the support, and an organoaluminum compound as reducing agent. The polyethylene produced by this catalyst has narrow molecular weight distribution, high bulk density, high melt index, and minimum catalyst residue due to the high polymer to catalyst ratio. The copolymers produced by this catalyst have narrow molecular weight distribution, but have lower bulk density, low melt index and low density.