摘要:
A linear low density polyethylene composition suitable for injection molding applications comprising less than or equal to 100 percent by weight of the units derived from ethylene, less than 35 percent by weight of units derived from one or more α-olefin comonomers, and characterized by its density, molecular weight distribution (Mw/Mn), a melt index (I2), a molecular weight distribution (Mz/Mw), vinyl unsaturation, and zero shear viscosity ratio (ZSVR). The linear low density polyethylene composition exhibits low hexane extractable levels.
摘要:
Disclosed is an effective thermal grease comprising a hyperbranched olefinic fluid and a thermally conductive filler. Property-modifying additives and fillers may also be included. The hyperbranched olefinic fluid is selected to have an average of at least 1.5 methine carbons per oligomer molecule and at least 40 methine carbons per one thousand total carbons. The thermal grease exhibits a flash point of 180° C. or higher, a pour point of 0° C. or lower, and a kinematic viscosity at 40° C. of no more than 200 cSt (0.0002 m 2/s). The composition may offer improved thermal conductivity, reduced tendency to migrate, and lower cost when compared with many other thermal greases, including silicone-based thermal greases.
摘要:
A homogeneous polymerization catalyst system for polymerization or copolymerization of at least one alpha olefin has a Lewis acid, an alkyl aluminum in a hexane or a heptane, and at least one dry metallocene. The at least one dry metallocene has a transition metal compound. The Lewis acid is capable of forming an ion pair with the at least one dry metallocene. The homogeneous polymerization catalyst system produces a poly alpha olefin from alpha olefin monomers or mixed alpha olefins. A produced poly alpha olefin has a kinematic viscosity at 100 degrees Celsius ranging from 1 cSt to 1000 cSt.
摘要:
A process may include contacting an olefin monomer and a racemic bridged metallocene catalyst at a temperature of 80° C. to 150° C. in the presence of hydrogen. The racemic bridged metallocene catalyst may include a metallocene compound (A) and an activator component (B). The process may include recovering an effluent containing polyalpha-olefins (PAOs). The metallocene compound (A) may be represented by the formula R(Cp1)(Cp2)MX1X2. In the formula, R may be a C1-C20 alkylene bridging group; Cp1 and Cp2 may be the same or different substituted or unsubstituted tetrahydroindenyl rings; M may be a transition metal; and X1 and X2 may be independently selected from hydrogen, halogen, hydride radicals, hydrocarbyl radicals, substituted hydrocarbyl radicals, halocarbyl radicals, substituted halocarbyl radicals, silylcarbyl radicals, substituted silylcarbyl radicals, germylcarbyl radicals, substituted germylcarbyl radicals.
摘要:
The invention provides a process, and transition metal complex, to form an ethylene-based polymer, said process comprising polymerizing ethylene, and optionally at least one comonomer, in the presence of at least one molecular transition metal complex selected from Formula 1, as described herein.
摘要:
A method for producing highly reactive olefin polymers wherein at least 50 mol. % of the polymer chains have terminal double bonds, and a novel polymerization initiating system for accomplishing same.
摘要:
This invention relates to a self cleaning reactor and to a process for the oligomerization of ethylene that employs a self-cleaning reactor. The reactor includes a mass of inert, particulate cleaning bodies that are entrained by the liquid in the reactor and scour the internal surfaces of the reactor during normal operation. This scouring action reduces the level of fouling on the reactor surfaces. Foulant material (polyethylene) is removed from the process on a continuous basis but the cleaning bodies remain within the reactor.
摘要:
A porous solid catalyst component comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two electron donor compounds one of which being selected from 1,3-diethers and the other being selected from succinates, characterized by the fact that the molar ratio ID/Ti is from 0.30 to 0.90, where ID is the total molar amount of succinate and 1,3-diether, the molar ratio of the 1,3-diether donor to the succinate donor is higher than, or equal to, 0.60.
摘要:
The invention describes a novel dissymmetric nickel-based complex and the method of preparation thereof from at least one diphosphinamine ligand B1 of formula (R1)(R′1)P—N(R3)—P(R2)(R′2), or an iminobisphosphine ligand B2 of formula (R3)N═P(R1)(R′1)—P(R2)(R′2). The invention also concerns the use of said complex in a method for oligomerisation of olefins.
摘要:
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.