Abstract:
Disclosed herein are catalyst compositions containing boron bridged, cyclopentadienyl-indenyl metallocene compounds with an alkenyl substituent. These catalyst compositions can be used for the polymerization of olefins. For example, ethylene homopolymers produced using these catalyst compositions can be characterized by a density less than 0.97 g/cm3 and a melt index greater than 50 g/10 min.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes can employ a catalyst system containing two or three metallocene components, resulting in ethylene-based copolymers that can have a medium density and improved stress crack resistance.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes use a catalyst system containing three metallocene components, often resulting in polymers having a reverse comonomer distribution and a broad and non-bimodal molecular weight distribution.
Abstract:
A catalyst composition may include a precontacted mixture of an olefin polymerization catalyst and an agent including an ammonium salt. The catalyst activity of the catalyst composition in the presence of water may be greater than if no ammonium salt were present in the catalyst composition. The ammonium salt may include a tetraalkylammonium salt, and the olefin polymerization catalyst may include a metallocene compound.
Abstract:
A bimodal polyethylene copolymer comprising a lower molecular weight (LMW) component and a higher molecular weight (HMW) component, the copolymer having a z-average molecular weight (Mz) of from about 1,000 kg/mol to about 2,500 kg/mol, a weight fraction of the LMW component (LMW fr.) of from about 0.60 to 0.85, a ratio of a weight average molecular weight (Mw) of the HMW component (HMW Mw) to a Mw of the LMW component (LMW Mw) of from about 14 to about 25, a zero shear viscosity (η0) of from about 5×105 Pa-s to about 1×107 Pa-s and a HMW Mw of from about 800 kg/mol to about 1,500 kg/mol.
Abstract:
Disclosed herein are ethylene-based polymers having a density greater than 0.945 g/cm3, a high load melt index less than 25 g/10 min, a peak molecular weight ranging from 52,000 to 132,000 g/mol, and an environmental stress crack resistance of at least 250 hours. These polymers have the processability of chromium-based resins, but with improved impact strength and stress crack resistance, and can be used in large-part blow molding applications.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes can use a dual catalyst system containing a zirconium or hafnium based metallocene compound and a titanium based half-metallocene compound containing an indenyl group.
Abstract:
Disclosed herein are ethylene-based polymers having a higher molecular weight component and a lower molecular weight component, and characterized by a density greater than 0.945 g/cm3, a melt index less than 1.5 g/10 min, and a ratio of high load melt index to melt index ranging from 40 to 175. These polymers have the processability of chromium-based resins, but with improved stiffness and stress crack resistance, and can be used in blow molding and other end-use applications.
Abstract translation:本文公开了具有较高分子量组分和较低分子量组分的乙烯基聚合物,其特征在于密度大于0.945g / cm 3,熔体指数小于1.5g / 10min,高负载熔体 熔体指数指数范围从40至175.这些聚合物具有铬基树脂的加工性,但具有改善的刚度和抗应力开裂性,并且可用于吹塑和其它终端应用。
Abstract:
A metallocene-catalyzed polyethylene copolymer having a zero shear viscosity (ηo) of from about 1×102 Pa-s to about 5×103 Pa-s and a ratio of a z-average molecular weight to a number average molecular weight (Mz/Mn) of from about 4 to about 15, and when tested in accordance with ASTM F1249 displays a moisture vapor transmission rate of less than or equal to about 0.9 g-mil/100 in2/day. A metallocene-catalyzed polyethylene copolymer which when tested in accordance with ASTM F1249 has a moisture vapor transmission rate (MVTR) that is decreased by at least 5% when compared to an MVTR determined in accordance with ASTM F1249 of an otherwise similar metallocene-catalyzed polyethylene homopolymer.
Abstract:
Disclosed herein are broad molecular weight distribution olefin polymers having densities in the 0.895 to 0.930 g/cm3 range, and with improved impact and tear resistance. These polymers can have a ratio of Mw/Mn in the 8 to 35 range, a high load melt index in the 4 to 50 range, less than about 0.008 LCB per 1000 total carbon atoms, and a reverse comonomer distribution.
Abstract translation:本文公开了具有在0.895至0.930g / cm 3范围内的密度并具有改善的耐冲击性和抗撕裂性的宽分子量分布烯烃聚合物。 这些聚合物可以具有8至35范围内的Mw / Mn比,4至50范围内的高负荷熔体指数,每1000个总碳原子小于约0.008LCB,反向共聚单体分布。