Abstract:
Provided is a method for making a polyolefin comprising contacting one or more olefins in a reactor containing a catalyst; polymerizing the one or more olefins to produce an olefin polymer characterized by a first melt flow ratio (MFR) and a first haze; and altering the reaction temperature in the reactor to shift the first MFR to a MFR that is different than the first MFR and to shift the first haze to a haze that is different than the first haze.
Abstract:
Provided is a method for making a polyolefin comprising contacting one or more olefins in a reactor containing a catalyst; polymerizing the one or more olefins to produce an olefin polymer characterized by a first melt flow ratio (MFR) and a first haze; and altering the reaction temperature in the reactor to shift the first MFR to a MFR that is different than the first MFR and to shift the first haze to a haze that is different than the first haze.
Abstract:
Bimodal polyethylene compositions and methods for making the same are provided. In at least one specific embodiment, the bimodal polyethylene composition can include a high molecular weight component having a weight average molecular weight (Mw) of from about 400,000 to about 950,000. The bimodal polyethylene composition can also include a low molecular weight component having a weight average molecular weight (Mw) of from about 3,000 to about 100,000. The high molecular weight component can be present in an amount ranging from about 25 wt % to about 40 wt % of the bimodal polyethylene composition. The bimodal polyethylene composition can also have a percent die swell of less than about 80%.
Abstract:
The present invention provides polymerization catalyst compounds, catalyst systems including these catalyst compounds, and to their use in the polymerization of ethylene and at least one comonomer. In particular, the invention provides a catalyst system comprising a poor comonomer incorporating catalyst compound and a good comonomer incorporating catalyst compound. Preferably, the low comonomer incorporating catalyst compound is a metallocene containing at least one substituted or unsubstituted fused ring cyclopentadienyl based ligand which is substantially directed to the front of the molecule, contains a long bridging group, or which contains a methyl substitution pattern which correlates to poor comonomer incorporation. The invention also provides methods of selecting the poor comonomer incorporating metallocene to pair with the good comonomer incorporating metallocene to produce polymers that are easy to process into a variety of articles, especially polyethylene based film, having enhanced properties.
Abstract:
In one embodiment of the present invention, there is provided a composition comprising a major amount of an ethylene alpha olefin copolymer and a minor amount of a lower molecular weight ethylene alpha olefin or a neutralized sulfonated ethylene alpha olefin.
Abstract:
A plunger of a known mass is held in a guide sleeve of a test device at a predetermined height over the sample of settable plastic material being tested. The plunger is gently released onto the sample without impact to apply a static force thereon similar to a "handgrip" pressure applied on a molded part during handling. The static pressure is applied on the sample released at selected times and places after reactive components of the sample are mixed for reaction to effect a series of indentations on the sample whose depths are measured and plotted as points on a depth versus time graph to define a cure curve of the sample. Curing rate is determined from the initial slope of the curve. Cure completion is determined where the curve levels off. A measure of the likelihood of handling damage is established by the portion of the indentations after a given time period.
Abstract:
Polymer blends and films made therefrom are provided. The polymer blend can include a first polyethylene having a density of less than about 0.940 g/cm3, a melt index (I2) greater than 0.75 g/10 min, and a melt index ratio (I21/I2) of less than 30. The polymer blend can also include a second polyethylene having a density of less than about 0.940 g/cm, a melt index (I2) of less than 1 g/10 min, a melt index ratio (I21/I2) greater than 30, and a molecular weight distribution (Mw/Mn) of less than 4.5.
Abstract:
Methods of tailoring polyethylenes are contemplated utilizing 0.5 to 70 volume percent oxygen containing gases. The tailoring occurs in a melt-conveying zone of a mixer/extruder, and not in the feed or melting zones of a mixer/extruder. The effect of tailoring is to decrease the haze and/or increase the gloss of blown films made from the tailored polyethylenes compared to similar polyethylenes that are extruded/mixed in the substantial absence of oxygen or oxygen containing gases.
Abstract:
The present invention provides polymerization catalyst compounds, catalyst systems including these catalyst compounds, and to their use in the polymerization of ethylene and at least one comonomer. In particular, the invention provides a catalyst system comprising a poor comonomer incorporating catalyst compound and a good comonomer incorporating catalyst compound. Preferably, the low comonomer incorporating catalyst compound is a metallocene containing at least one substituted or unsubstituted fused ring cyclopentadienyl based ligand which is substantially directed to the front of the molecule, contains a long bridging group, or which contains a methyl substitution pattern which correlates to poor comonomer incorporation. The invention also provides methods of selecting the poor comonomer incorporating metallocene to pair with the good comonomer incorporating metallocene to produce polymers that are easy to process into a variety of articles, especially polyethylene based film, having enhanced properties.
Abstract:
A polymer of ethylene and at least one alpha olefin having at least 5, carbon atoms obtainable by a continuous gas phase polymerization using supported catalyst of an activated molecularly discrete catalyst such as a metallocene in the substantial absence of an aluminum alkyl based scavenger which polymer has a Melt Index (MI) as herein defined of from 0.1 to 15; a Compositional Distribution Breadth Index (CDBI) as defined herein of at least 70%, a density of from 0.910 to 0.930 g/ml; a Haze value as herein defined of less than 20%; a Melt Index ratio (MIR) as herein defined of from 35 to 80; an averaged Modulus (M) as herein defined of from 20 000 to 60 000 psi (pounds per square inch) and a relation between M and the Dart Impact Strength in g/mil (DIS) complying with the formula: DIS≧0.8×[100+e(11.71-0.000268×M+2.183×10−9×M2)].