The present disclosure relates to a catalyst composition and a process for preparation thereof. The catalyst composition of the present disclosure is stable, and produces polyolefin having narrow molecular weight distribution during the polymerization. The process of the present disclosure is simple, cost-effective, and rapid.

The present disclosure relates to a catalyst composition and a process for preparation thereof. The catalyst composition of the present disclosure is stable, and produces polyolefin having narrow molecular weight distribution during the polymerization. The process of the present disclosure is simple, cost-effective, and rapid.

A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm.sup.3 determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 30; 3) Mz from 2,000,000 to 4,500,000 g/mol; 4) η.sub.0.02 from 160,000 to 300,000 Pa.Math.s; and 5) long-chain branching index, LCBI, equal to or greater than 0.75.

Catalyst systems containing a titanium alkoxymagnesium halide supported catalyst component can be used for the polymerization of olefins. The catalyst can be prepared from a microcrystalline solid alkoxymagnesium halide support having a lattice spacing in the 5 nm to 15 nm range.

Disclosed are support-activators and catalyst compositions comprising the support-activators for polymerizing olefins in which the support-activator includes clay heteroadduct, prepare from a colloidal phyllosilicate such as a colloidal smectite clay, which is chemically-modified with a heterocoagulation agent. By limiting the amount of heterocoagulation reagent relative to the colloidal smectite clay as described herein, the smectite heteroadduct support-activator is a porous and amorphous solid which can be readily isolated from the resulting slurry by a conventional filtration process, and which can activate metallocenes and related catalysts toward olefin polymerization. Related compositions and processes are disclosed.

Disclosed are support-activators and catalyst compositions comprising the support-activators for polymerizing olefins in which the support-activator includes clay heteroadduct, prepare from a colloidal phyllosilicate such as a colloidal smectite clay, which is chemically-modified with a heterocoagulation agent. By limiting the amount of heterocoagulation reagent relative to the colloidal smectite clay as described herein, the smectite heteroadduct support-activator is a porous and amorphous solid which can be readily isolated from the resulting slurry by a conventional filtration process, and which can activate metallocenes and related catalysts toward olefin polymerization. Related compositions and processes are disclosed.

Processes for producing an activated chromium catalyst are disclosed, and these processes comprise contacting a supported chromium catalyst with a gas stream containing from 25-60 vol % oxygen at a peak activation temperature of 550-900° C. to produce the activated chromium catalyst. The linear velocity of the gas stream is 0.18-0.4 ft/sec, and the oxygen linear velocity of the gas stream is 0.05-0.15 ft/sec. The resultant activated chromium catalyst and an optional co-catalyst can be contacted with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

Processes for producing an activated chromium catalyst are disclosed, and these processes comprise contacting a supported chromium catalyst with a gas stream containing from 25-60 vol % oxygen at a peak activation temperature of 550-900° C. to produce the activated chromium catalyst. The linear velocity of the gas stream is 0.18-0.4 ft/sec, and the oxygen linear velocity of the gas stream is 0.05-0.15 ft/sec. The resultant activated chromium catalyst and an optional co-catalyst can be contacted with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

A solid catalyst component for the polymerization of olefins CH.sub.2═CHR, wherein R is hydrogen or a hydrocarbon radical with 1-12 carbon atoms, made from or containing Mg, Ti, Bi, a halogen and an electron donor.

An activator-nucleator formulation comprising an activating effective amount of (A) an alkylaluminum(chloride) compound (compound (A)); and a nucleating effective amount of a compound (B) selected from at least one of compounds (B1) to (B3): (B1) calcium (1R,2S)-cis-cyclohexane-1,2-dicarboxylate (1:1); (B2) calcium stearate (1:2), and (B3) zinc stearate (1:2); wherein the compound (A) is effective for activating a Ziegler-Natta procatalyst to give a Ziegler-Natta catalyst; and wherein the compound (B) is effective for lowering isothermal crystallization peak time period of a semicrystalline polyethylene polymer made in a polymerization process by the Ziegler-Natta catalyst. A method of polymerizing ethylene, and optionally 0, 1, or more alpha-olefin comonomers, in a polymerization process conducted in a polymerization reactor, the method comprising contacting ethylene, and optionally 0, 1, or more alpha-olefin comonomers, with the Ziegler-Natta catalyst system to give a semicrystalline polyethylene polymer. The semicrystalline polyethylene polymer made by the method of polymerizing.