摘要:
A catalyst system comprising:(a) a catalyst precursor consisting essentially of the reaction product of vanadium (acetylacetonate).sub.3 and a compound having the formula AlR.sub.(3-a) X.sub.a wherein each R is independently alkyl having 1 to 14 carbon atoms; each X is independently chlorine, bromine, or iodine; and a is 1 or 2; the atomic ratio of aluminum to vanadium in the precursor is 1:1 to 3:1; and the oxidation state of the vanadium in the reaction product is plus 2;(b) optionally, a support for said precursor; and(c) a halide substituted hydrocarbyl aluminum cocatalyst; and(d) optionally, a promoter, which is a chlorinated ester having at least 2 chlorine atoms; a saturated or unsaturated aliphatic halocarbon having at least 3 carbon atoms and at least 6 halogen atoms; or a haloalkyl substituted aromatic hydrocarbon wherein the haloalkyl substituent has at least 3 halogen atoms.
摘要:
A process comprising contacting a mixture comprising ethylene, propylene, and, optionally, a diene, in the gas phase, under polymerization conditions, with a catalyst system comprising:(a) a catalyst precursor, in independent or prepolymer form, consisting of vanadium (acetylacetonate).sub.3 ;(b) optionally, a support for said precursor;(c) a cocatalyst consisting essentially of (i) an alkylaluminum halide having the formula AlR.sub.(3-a) X.sub.a wherein each R is independently alkyl having 1 to 14 carbon atoms; each X is independently chlorine, bromine, or iodine; and a is 1 or 2, and (ii) optionally, a trialkylaluminum provided that the molar ratio of alkylaluminum halide to trialkylaluminum is at least about 1.5:1; and(d) optionally, a promoter, which is a chlorinated ester having at least 2 chlorine atoms; a saturated or unsaturated aliphatic halocarbon having at least 3 carbon atoms and at least 6 halogen atoms; or a haloalkyl substituted aromatic hydrocarbon wherein the haloalkyl substituent has at least 3 halogen atoms.
摘要:
A process for producing polyethylene having a broad molecular weight distribution is provided, in which ethylene and optionally a comonomer are contacted in two reactors connected in series, one reactor containing a titanium-based catalyst and the other reactor containing a vanadium-based catalyst and a halohydrocarbon promoter, or alternatively, both reactors containing a mixed metal catalyst comprising both titanium and vanadium. In the latter case, the halohydrocarbon promoter is present in only one of the reactors to activate the vanadium sites of the catalyst and deactivate the titanium sites of the catalyst simultaneously.
摘要:
Catalyst systems and methods for making and using the same. The catalyst system can include a single site catalyst compound, a support comprising fluorinated alumina, and an aluminoxane. The aluminoxane can be present in an amount of about 10 mmol or less per gram of the support.
摘要:
The present invention is broadly directed to various methods and systems for gas and liquid phase polymer production. In certain embodiments, the methods are performed in conjunction with a polymerization reactor system such as gas phase reactor system or liquid phase reactor system. The invention is also broadly directed to various systems in which polymer properties are manipulated by addition of DEALE directly to a polymerization reactor system.
摘要:
Disclosed herein are various methods and systems for gas and liquid phase polymer production. In certain embodiments, the methods comprise manipulating properties of polymers produced by adjusting the hydrogen feed rate.
摘要:
Embodiments of the present invention include a method of polymerizing olefins comprising contacting olefins with a catalyst composition made by the process of combining a hindered polyalicyclic alkyl catalyst precursor with a particulate inorganic oxide for a deposition time greater than 2 hours to form a catalyst composition. Embodiments of the present invention also include catalyst compositions comprising a hindered polyalicyclic alkyl catalyst precursor made by the process of combining the hindered polyalicyclic alkyl catalyst precursor with a particulate inorganic oxide for a deposition time greater than 2 hours to form the catalyst composition. In one embodiment, the hindered polyalicyclic alkyl catalyst precursor is formed by first combining an acid, a compound having the formula RX, and a metal oxide selected from the group consisting of Group 3 to Group 10 oxide compounds to produce a catalyst precursor; characterized in that R is selected from the group consisting of hindered polyalicyclic alkyls, and substituted derivatives thereof, and X is selected from the group consisting of any suitable leaving group.
摘要:
Broad molecular weight polyethylene and polyethylene having a bimodal molecular weight profile can be produced with chromium oxide based catalyst systems employing alkyl silanols. The systems may also contain various organoaluminum compounds. Catalyst activity and molecular weight of the resulting polyethylene may also be tuned using the present invention.
摘要:
A process comprising continuously contacting with a catalyst, under polymerization conditions, ethylene or a mixture comprising ethylene and one or more alpha-olefins in a first fluidized bed reactor and a mixture comprising ethylene and one or more alpha-olefins in a second fluidized bed reactor, the first and second reactors being connected in series, said catalyst comprising:(A) a catalyst precursor comprising:(i) a vanadium compound, which is the reaction product of(a) VX.sub.3 wherein each X is independently chlorine, bromine, or iodine; and(b) an electron donor, which is a liquid, organic Lewis base in which VX.sub.3 is soluble;(ii) a modifier having the formula BX.sub.3 or AlR.sub.(3-a) wherein each X is as defined above; each R is independently alkyl having 1 to 14 carbon atoms; and a is 1 or 2; and(iii) a silica or alumina support for said vanadium compound and modifier;(B) a cocatalyst having the formula AlR.sub.3 wherein R is as defined above; and(C) a promoter having the formula R'.sub.b CX'.sub.(4-b) wherein R' is hydrogen or an unsubstituted or halo substituted alkyl having 1 to 6 carbon atoms; X' is a halogen; and b is 0, 1, or 2, wherein,in the first reactor,a homopolymer or copolymer is made having a relatively high melt index in the range of about 1 to about 100 grams per 10 minutes; a density of at least 0.950 gram per cubic centimeter; and a melt flow ratio in the range of about 50 to about 100; andin the second reactor,a copolymer is made having a relatively low melt index in the range of about 0.001 to about 0.01 gram per 10 minutes; a density of at least 0.925 gram per cubic centimeter; and a melt flow ratio in the range of about 50 to about 100,wherein, in the second reactor, the first reactor homopolymer or copolymer and the second reactor copolymer are blended in situ.