A polymerization catalyst system, a method of using the polymerization catalyst system, and a polymer produced with the catalyst system. The polymerization catalyst system has a non-metallocene catalyst and a metallocene catalyst. The metallocene catalyst has the formula: wherein R.sup.1 and R.sup.2 are each independently, phenyl, methyl, chloro, fluoro, or a hydrocarbyl group.

A method for altering the melt flow ratio (MFR) of ethylene copolymers made in a gas phase reactor using a supported Ziegler-Natta catalyst treated with a catalyst modifier. The method involves changing the amount of the catalyst modifier added to the supported Ziegler-Natta polymerization catalyst to effect changes in the MFR of the resulting polymer.

A catalyst composition for polymerizing a polyolefin having excellent processability and impact strength, a process for producing a polyolefin and a polyolefin resin thereof are disclosed. The catalyst composition comprises at least one first organometallic compound of following formula 1; at least one second organometallic compound of following formula 2; and aluminoxane. The polyolefin resin satisfies following properties (i) to (iv) and (vi), (i) melt flow index (ASTM D1238), measured at 190 C., under a load of 2.16 kg: 0.1 to 1.5 g/10 min, (ii) density: 910 to 930 kg/m.sup.3, (iii) the ratio (Mw/Mn), as measured by gel permeation chromatography (GPC):3.0 to 7.0, (iv) the ratio (Mz/Mw), as measured by GPC: 2.2 to 4.5, and (vi) when the TREF curve of multimodal distribution is deconvoluted, the area of TREF curve having a peak at 50 to 74 C. is 40 to 75% of the total area of the TREF curve.

A process for the polymerization of olefins in gas phase carried out in a reactor having two interconnected polymerization zones, a first zone (riser) and a second zone (downcomer), wherein growing polymer particles: a) flow through the riser under fast fluidization conditions established by feeding a mixture of gas and liquid; b) leave the riser and enter the downcomer, through which the growing polymer particles flow downward in a densified form; and c) leave the downcomer and are reintroduced into the riser, thereby establishing a circulation of polymer between the riser and the downcomer; the reactor is operated at a temperature between 0 C. and 5 C. above the dew point of the riser gas at the operating pressure, and in the riser, besides the growing polymer particles and gas flow, an amount of liquid is present.

This disclosure provides for polymerization processes of polyolefins wherein the melt index can be regulated. For example, there is provided a process for producing a polyethylene, the process comprising: (1) in a polymerization reactor, contacting (a) a polymerization catalyst, (b) ethylene, (c) an optional -olefin comonomer, and (d) (x+y) ppm by weight of an antistatic agent on an ethylene basis; and (2) applying reaction conditions to the reaction mixture suitable to produce the polyethylene having a desired set of characteristics, such as desired target melt index. The disclosed polymerization processes allow for production of polyolefins having higher melt indices, and in the alternative to produce polyolefins having a desired target melt index at lower polymerization temperatures.

Catalyst systems and methods for making and using the same are described. A method includes selecting a catalyst blend using a blend polydispersity index (bPDI) map. The polydispersity map is generated by generating a number of polymers for at least two catalysts. Each polymer is generated at a different hydrogen to ethylene ratio. At least one catalyst generates a higher molecular weight polymer and another catalyst generates a lower molecular weight polymer. A molecular weight for each polymer is measured. The relationship between the molecular weight of the polymers generated by each of the catalysts and the ratio of hydrogen to ethylene is determined. A family of bPDI curves for polymers that would be made using a number of ratios of a blend of the at least two catalysts for each of a number of ratios of hydrogen to ethylene. A ratio for the catalyst blend of the catalysts that generates a polymer having a bPDI that matches a polymer fabrication process is selected, and the product specific polyolefin is made using the catalyst blend.

A process for preparing a catalyst system including contacting one or more catalysts having a Group 3 through Group 12 metal atom or lanthanide metal atom with a methylalumoxane and one or more support material compositions to a concentration of methylalumoxane of about 4 mmol to about 15 mmol aluminum per gram of support material is provided. The support material composition may have a macroporosity of from about 0.18 cc/g to about 0.50 cc/g. In other embodiments, a process for polymerizing at least one olefin to produce a polyolefin composition including contacting one or more olefins with the aforementioned catalyst system is also provide.

The present disclosure provides processes for polymerizing olefin(s). Methods can include contacting a first composition and a second composition in a line to form a third composition. The first composition can include a contact product of a first catalyst, a second catalyst, a support, a first activator, a mineral oil. The second composition can include a contact product of an activator, a diluent, and the first catalyst or the second catalyst. Methods can include introducing the third composition from the line into a gas-phase fluidized bed reactor, introducing a condensing agent to the line and/or the reactor, exposing the third composition to polymerization conditions, and/or obtaining a polyolefin. Polyethylene compositions including at least 65 wt % ethylene derived units, based upon the total weight of the polyethylene composition, are provided.

A homopolypropylene has i) a molecular weight distribution of less than 2.4; ii) a melt index (measured at 230 C. under a load of 2.16 kg in accordance with ASTM D1238) of 5 to 3000 g/10 min; iii) a remaining stress ratio of 0.5% or less; and iv) a complex viscosity of 5 to 600 Pa.Math.s at an angular frequency of 1 rad/s and a complex viscosity of 5 to 300 Pa.Math.s at an angular frequency of 100 rad/s. A method for preparing the homopolyproylene is also provided. A molded article and a non-woven fabric are also provided.

Catalyst systems and methods for making and using the same. A method of methylating a catalyst composition while substantially normalizing the entiomeric distribution is provided. The method includes slurrying the organometallic compound in dimethoxyethane (DME), and adding a solution of RMgBr in DME, wherein R is a methyl group or a benzyl group, and wherein the RMgBr is greater than about 2.3 equivalents relative to the organometallic compound. After the addition of the RMgBr, the slurry is mixed for at least about four hours. An alkylated organometallic is isolated, wherein the methylated species has a meso/rac ratio that is between about 0.9 and about 1.2.