Patent Application
20100292416
Embodiments of the present invention generally relate to apparatus and methods for olefin polymerization.
In gas-phase polymerization, a gaseous stream containing one or more monomers is passed through a fluidized bed under reactive conditions in the presence of a catalyst. A polymer product is withdrawn from the reactor while fresh monomer is introduced to the reactor to replace the removed polymerized product. Unreacted monomer and catalyst is withdrawn from the fluidized bed and recycled back to the reactor.
Process upsets in the reactor are often related to the buildup of catalyst and polymer in the top of the reactor where the outlet nozzles to the recycle loop is located. This buildup can occur, for example, due to insufficient mixing and/or insufficient sweeping of the gas along the walls where catalyst can continue to react and fuse with polymer fines. As a result, large agglomerations known as “dome sheets” accumulate or form on the reactor walls near the top of the reactor. When these dome sheets fall into the fluidized bed, fluidization can be disrupted, which can require the reactor to be shut down.
There is a need, therefore, for improved systems and methods for reducing or eliminating the formation of dome sheets within a fluidized bed reactor.
Apparatus and methods for olefin polymerization are provided. In at least one specific embodiment, a fluidized bed reactor can include a cylindrical section, a dome, a transition section between the cylindrical section and the dome, at least three outlet nozzles disposed on the dome, and a recycle line in fluid communication with the at least three outlet nozzles.
In at least one specific embodiment, a method for olefin polymerization can include forming a fluidized bed within a fluidized bed reactor. The fluidized bed can include a plurality of solid particles. The fluidized bed reactor can include a cylindrical section, a dome, a transition section between the cylindrical section and the dome, at least three outlet nozzles disposed on the dome, and a recycle line in fluid communication with the at least three outlet nozzles. The method can also include removing a recycle stream from the fluidized bed reactor through the at least three outlet nozzles.
A detailed description will now be provided. Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims. Each of the inventions will now be described in greater detail below, including specific embodiments, versions and examples, but the inventions are not limited to these embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the inventions, when the information in this patent is combined with available information and technology.
The outlet nozzles 110, 115, 120 can have any suitable cross-sectional shape. For example, the cross-sectional shape of the outlet nozzles 110, 115, 120 can be circular, elliptical, oval, triangular, square, rectangular, or any other desirable cross-sectional shape. In one or more embodiments, the cross-sectional shape of the outlet nozzles 110, 115, 120 can be the same or different with respect to one another. For example, the cross-sectional shape of the first outlet nozzle 110 can be circular and the cross sectional shape of the second and third outlet nozzles 115, 120 can be elliptical. In a preferred embodiment, the cross-sectional shape of the outlet nozzles 110, 115, 120 is circular.
The size of each outlet nozzle 110, 115, 120 can be the same or different. For example, each outlet nozzle 110, 115, 120 can have a diameter ranging from a low of about 0.3 m, about 0.46 m, or about 0.61 m to a high of about 1.07 m, about 1.22 m, about 1.37 m, about 1.52 m, or about 1.68 m. The cross-sectional area of each outlet nozzle 110, 115, 120 can range from a low of about 0.07 m2, about 0.17 m2, about 0.3 m2 to a high of about 0.9 m2, about 1.2 m2, about 1.5 m2, about 1.8 m2, or about 2.2 m2. The cross-sectional shape and size of the outlet nozzles 110, 115, 120 can be based at least in part on various factors, which can include but are not limited to, the size of reactor 100, level or amount of desired production of one or more products, flow rates, material availability, and cost. In at least one specific embodiment, the first outlet nozzle 110 can have a diameter of about 1.07 m and the second and third nozzles 115, 120 can have a diameter of about 0.61 m. In at least one other specific embodiment, the first, second, and third outlet nozzles 110, 115, 120 can each have a diameter of about 0.61 m.
The size of each outlet nozzle 305, 310, 315, 320 can be the same or different. For example, each outlet nozzle 305, 310, 315, 320 can have a diameter ranging from a low of about 0.3 m, about 0.46 m, or about 0.61 m to a high of about 1.07 m, about 1.22 m, about 1.37 m, about 1.52 m, or about 1.68 m. The cross-sectional area of each outlet nozzle 305, 310, 315, 320 can range from a low of about 0.07 m2, about 0.17 m2, about 0.3 m2 to a high of about 0.9 m2, about 1.2 m2, about 1.5 m2, about 1.8 m2, or about 2.2 m2. The cross-sectional shape and size of the outlet nozzles 305, 310, 315, 320 can be based at least in part on various factors, which can include but are not limited to, the size of reactor 100, level or amount of desired production of one or more products, flow rates, material availability, and cost.
The outlet nozzles 305, 310, 315, 320 can be disposed on the dome 135 in any desired configuration. The outlet nozzles 305, 310, 315, 320 can be disposed about the center of the dome 135, such that each outlet nozzle is positioned at a corner of a “square” formed by the nozzles 305, 310, 315, 320. The outlet nozzles 305, 310, 315, 320 can be disposed about the center of the dome 135, such that each outlet nozzle is positioned at a corner of a “rectangle” formed by the nozzles 305, 310, 315, 320. The first outlet nozzle 305 can be centrally disposed on the top of the dome 135 and the second, third, and fourth outlet nozzles 310, 315, 320 can be disposed equidistant from the first nozzle 305, in a “triangle” arrangement about the first outlet nozzle 305. The outlet nozzles 305, 310, 315, 320 can be disposed about the dome 135 such that one nozzle is disposed in each quadrant of the dome 135. In a preferred embodiment, the outlet nozzles are arranged equidistant from the center of the dome 135 and each other, in a “square” arrangement.
The size of each outlet nozzle 405, 410, 415, 420, 425 can be the same or different. For example, each outlet nozzle 405, 410, 415, 420, 425 can have a diameter ranging from a low of about 0.3 m, about 0.46 m, or about 0.61 m to a high of about 1.07 m, about 1.22 m, about 1.37 m, about 1.52 m, or about 1.68 m. The cross-sectional area of each outlet nozzle 405, 410, 415, 420, 425 can range from a low of about 0.07 m2, about 0.17 m2, about 0.3 m2 to a high of about 0.9 m2, about 1.2 m2, about 1.5 m2, about 1.8 m2, or about 2.2 m2. The cross-sectional shape and size of the outlet nozzles 405, 410, 415, 420, 425 can be based at least in part on various factors, which can include but are not limited to, the size of reactor 100, level or amount of desired production of one or more products, flow rates, material availability, and cost.
The outlet nozzles 405, 410, 415, 420, 425 can be disposed on the dome 135 in any desired configuration. For example, four outlet nozzles 410, 415, 420, 425 can be disposed about a centrally located or centrally disposed nozzle 405, such that each nozzle 410, 415, 420, 425 is positioned at a corner of a “square” formed by those nozzles. Outlet nozzles 410, 415, 420, 425 can be disposed about the centrally disposed nozzle 405, such that each outlet nozzle 410, 415, 420, 425 is positioned at a corner of a “rectangle” formed by the nozzles 410, 415, 420, 425. The outlet nozzles 410, 415, 420, 425 can be disposed about the centrally disposed nozzle 405, such that one outlet nozzle is disposed in each quadrant of the dome 135, with the centrally disposed outlet nozzle 405 positioned at the intersection of each quadrant of the dome. In another embodiment, the five nozzles 405, 410, 415, 420, 425 can be arranged equidistant from the center of the dome 135 and each other in a “circular” configuration.
Although not shown, any number of outlet nozzles having the same or varying cross-sectional areas can be disposed on the dome 135. In one or more embodiments, two outlet nozzles, three outlet nozzles, four outlet nozzles, five outlet nozzles, six outlet nozzles, seven outlet nozzles, eight outlet nozzles, nine outlet nozzles, ten outlet nozzles, eleven outlet nozzles, twelve outlet nozzles, thirteen outlet nozzles, fourteen outlet nozzles, or fifteen outlet nozzles can be disposed about the dome 135.
Although not shown, any one or more of the outlet nozzles 110, 115, 120, 305, 310, 315, 320, 405, 410, 415, 420, and/or 425 discussed and described above with reference to
In one or more embodiments, the dome 135 of an existing reactor 100 can be retrofitted to include more than one outlet nozzle, for example, three outlet nozzles 110, 115, 120 disposed thereabout. For example, an existing reactor 100 having only one outlet nozzle 110 centrally disposed on the dome 135 can be retrofitted to include a second and third outlet nozzle 115, 120 disposed on either side of the single outlet nozzle 110. Reducing or reduction flanges can be used to connect the existing outlet nozzle 110 to the recycle line 155, should it be desirable to reduce the cross-section of the existing outlet nozzle 110.
To generate the results depicted in
The bracket 1005, shown in
Referring to
The dimensions shown by brackets 610, 810, 1010, and 1110 in
As can be seen in
The increase in the wall shear stress provided by both the three nozzle and four nozzle designs as compared to the standard single nozzle configuration reduces the probability of particulates depositing on the wall of the reactor that can lead to the formation of dome sheets within the reactor. Both the three nozzle and four nozzle designs produce a greater wall shear stress that starts at a lower point along the reactor wall, which is expected to produce a reduction in particulates that deposit along the wall of the reactor as well as a reduction in the amount of particulate carryover through the nozzles and into the recycle line.
In one or more embodiments, the reactor 1340 can include a reaction zone 1345 in fluid communication with a velocity reduction zone or “top head” 1350. The reaction zone 1345 can include a bed of growing polymer particles, formed polymer particles and catalyst particles fluidized by the continuous flow of polymerizable and modifying gaseous components in the form of make-up feed and recycle fluid through the reaction zone 1345. In one or more embodiments, the reactor 1340 can be similar to the reactor 100 discussed and described above with reference to
A feed or make-up stream via line 1310 can be introduced into the polymerization system at any point. For example, the feed or make-up stream via line 1310 can be introduced to the bed in the reaction zone 1345 or to the expanded section 1350 or to any point within the recycle stream 1315. Preferably, the feed stream or make-up stream 1310 is introduced to the recycle stream 1315 before or after the heat exchanger 1375. In
The term “feed stream” as used herein refers to a raw material, either gas phase or liquid phase, used in a polymerization process to produce a polymer product. For example, a feed stream may be any olefin monomer including substituted and unsubstituted alkenes having two to 12 carbon atoms, such as ethylene, propylene, butene, pentene, 4-methyl-1-pentene, hexene, octene, decene, 1-dodecene, styrene, derivatives thereof, and combinations thereof. The feed stream can also include non-olefinic gas such as nitrogen and/or hydrogen. The feed stream may enter the reactor 1340 at multiple and different locations. For example, monomers can be introduced into the polymerization zone in various ways including direct injection through a nozzle (not shown) into the fluidized bed. The feed stream 1310 can further include one or more non-reactive alkanes that may be condensable in the polymerization process for removing the heat of reaction. Illustrative non-reactive alkanes include, but are not limited to, propane, butane, isobutane, pentane, isopentane, hexane, isomers thereof, derivatives thereof, and combinations thereof.
The fluidized bed has the general appearance of a dense mass of individually moving particles as created by the percolation of gas through the bed. The pressure drop through the bed is equal to or slightly greater than the weight of the bed divided by the cross-sectional area. It is thus dependent on the geometry of the reactor. To maintain a viable fluidized bed in the reaction zone 1345, the superficial gas velocity through the bed must exceed the minimum flow required for fluidization. Preferably, the superficial gas velocity is at least two times the minimum flow velocity. In one or more embodiments, the superficial gas velocity can range from about 0.3 m/s to about 2 m/s, about 0.35 m/s to about 1.7 m/s, or from about 0.4 m/s to about 1.5 m/s. Ordinarily, the superficial gas velocity does not exceed 1.5 m/s (5.0 ft/sec) and usually no more than 0.76 m/s (2.5 ft/sec) is sufficient.
In general, the height to diameter ratio of the reaction zone 1345 can vary in the range of from about 2:1 to about 5:1. The range, of course, can vary to larger or smaller ratios and depends upon the desired production capacity. The cross-sectional area of the top head 1350 is typically within the range of about 2 to about 3 multiplied by the cross-sectional area of the reaction zone 1345.
The velocity reduction zone or top head 1350 has a larger inner diameter than the reaction zone 1345. As the name suggests, the velocity reduction zone or top head 1350 slows the velocity of the gas due to the increased cross sectional area. This reduction in gas velocity allows particles entrained in the upward moving gas to fall back into the bed, allowing primarily only gas to exit overhead of the reactor 1340 through recycle gas stream 1315. In one or more embodiments, the recycle gas stream recovered via line 1315 can contain less than about 10% wt, less than about 8% wt, less than about 5% wt, less than about 4% wt, less than about 3% wt, less than about 2% wt, less than about 1% wt, less than about 0.5% wt, or less than about 0.2% wt of the particles entrained in reaction zone 1345.
The recycle stream via line 1315 can be compressed in the recycle compressor 1370 and then passed through the heat exchanger 1375 where heat is removed before it is returned to the bed. The heat exchanger 1375 can be of the horizontal or vertical type. If desired, several heat exchangers can be employed to lower the temperature of the recycle gas stream in stages. It is also possible to locate the recycle compressor 1370 downstream from the heat exchanger or at an intermediate point between several heat exchangers 1375. After cooling, the recycle stream 1315 is returned to the reactor 1340. The cooled recycle stream 1315 absorbs the heat of reaction generated by the polymerization reaction.
Preferably, the recycle stream 1315 is returned to the reactor 1340 and to the fluidized bed through a fluid distributor plate or fluid deflector 1380. The fluid deflector 1380 is preferably installed at the inlet to the reactor 1340 to prevent contained polymer particles from settling out and agglomerating into a solid mass and to prevent liquid accumulation at the bottom of the reactor 1340 as well to facilitate easy transitions between processes which contain liquid in the recycle stream 1315 and those which do not and vice versa. An illustrative deflector suitable for this purpose is described in U.S. Pat. Nos. 4,933,415 and 6,627,713.
A catalyst or catalyst system can be introduced to the fluidized bed within the reactor 1340 through one or more injection nozzles (not shown) in fluid communication with line 1330. The catalyst or catalyst system is preferably introduced as pre-formed particles in one or more liquid carriers (i.e. a catalyst slurry). Suitable liquid carriers can include mineral oil and liquid hydrocarbons including, but not limited to, propane, butane, isopentane, hexane, heptane octane, or mixtures thereof. A gas that is inert to the catalyst slurry such as, for example, nitrogen or argon can also be used to carry the catalyst slurry into the reactor 1340. In one or more embodiments, the catalyst or catalyst system can be a dry powder. In one or more embodiments, the catalyst or catalyst system can be dissolved in the liquid carrier and introduced to the reactor 1340 as a solution.
Under a given set of operating conditions, the fluidized bed is maintained at essentially a constant height by withdrawing a portion of the bed as product via line 1335 at the rate of formation of the particulate polymer product. Since the rate of heat generation is directly related to the rate of product formation, a measurement of the temperature rise of the fluid across the reactor (the difference between inlet fluid temperature and exit fluid temperature) is indicative of the rate of particulate polymer formation at a constant fluid velocity if no or negligible vaporizable liquid is present in the inlet fluid.
Fluid can be separated from a particulate product recovered via line 1335 from the reactor 1340. The separated fluid can be introduced to the recycle line 1315. In one or more embodiments, this separation can be accomplished when fluid and product leave the reactor 1340 and enter the product discharge tanks 1355 (one is shown) through valve 1357, which may be a ball valve designed to have minimum restriction to flow when opened. Positioned above and below the product discharge tank 1355 can be conventional valves 1359, 1367. The valve 1367 allows passage of product into the product surge tanks 1360 (only one is shown).
In at least one embodiment, to discharge particulate polymer from reactor 1340, valve 1357 can be opened while valves 1359, 1367 are in a closed position. Product and fluid enter the product discharge tank 1355. Valve 1357 is closed and the product is allowed to settle in the product discharge tank 1355. Valve 1359 is then opened permitting fluid to flow from the product discharge tank 1355 to the reactor 1340. Valve 1359 can then be closed and valve 1367 can be opened and any product in the product discharge tank 1355 can flow into the product surge tank 1360. Valve 1367 can then be closed. Product can then be discharged from the product surge tank 1360 through valve 1364. The product can be further purged via purge stream 1363 to remove residual hydrocarbons and conveyed via line 1365 to a pelletizing system or to storage (not shown). The particular timing sequence of the valves 1357, 1359, 1367, 1364 can be accomplished by use of conventional programmable controllers which are well known in the art.
Another preferred product discharge system which can be alternatively employed is that disclosed and claimed in U.S. Pat. No. 4,621,952. Such a system employs at least one (parallel) pair of tanks comprising a settling tank and a transfer tank arranged in series and having the separated gas phase returned from the top of the settling tank to a point in the reactor near the top of the fluidized bed.
The fluidized-bed reactor can be equipped with an adequate venting system (not shown) to allow venting the bed during start up and shut down. The reactor does not require the use of stirring and/or wall scraping. The recycle line 1315 and the elements therein (recycle compressor 1370, heat exchanger 1375) can be smooth surfaced and devoid of unnecessary obstructions so as not to impede the flow of recycle fluid or entrained particles.
Various techniques for preventing fouling of the reactor and polymer agglomeration can be used. Illustrative of these techniques are the introduction of finely divided particulate matter to prevent agglomeration, as described in U.S. Pat. Nos. 4,994,534 and 5,200,477 and the addition of negative charge generating chemicals to balance positive voltages or the addition of positive charge generating chemicals to neutralize negative voltage potentials as described in U.S. Pat. No. 4,803,251. Antistatic substances may also be added, either continuously or intermittently to prevent or neutralize electrostatic charge generation. Condensing mode operation, such as disclosed in U.S. Pat. Nos. 4,543,399 and 4,588,790 can also be used to assist in heat removal from the fluid bed polymerization reactor.
The conditions for polymerizations vary depending upon the monomers, catalysts, catalyst systems, and equipment availability. The specific conditions are known or readily derivable by those skilled in the art. For example, the temperatures can be within the range of from about −10° C. to about 120° C., often about 15° C. to about 110° C. Pressures can be within the range of from about 0.1 bar to about 100 bar, such as about 5 bar to about 50 bar, for example. Additional details of polymerization can be found in U.S. Pat. No. 6,627,713, which is incorporated by reference at least to the extent it discloses polymerization details.
Considering the polymer product via line 1365, the polymer can be or include any type of polymer or polymeric material. Illustrative polymers can include polyolefins, polyamides, polyesters, polycarbonates, polysulfones, polyacetals, polylactones, acrylonitrile-butadiene-styrene resins, polyphenylene oxide, polyphenylene sulfide, styrene-acrylonitrile resins, styrene maleic anhydride, polyimides, aromatic polyketones, or mixtures of two or more of the above. Suitable polyolefins can include, but are not limited to, polymers comprising one or more linear, branched or cyclic C2 to C40 olefins, preferably polymers comprising propylene copolymerized with one or more C3 to C40 olefins, preferably a C3 to C20 alpha olefin, more preferably C3 to C10 alpha-olefins. More preferred polyolefins include, but are not limited to, polymers comprising ethylene including but not limited to ethylene copolymerized with a C3 to C40 olefin, preferably a C3 to C20 alpha olefin, more preferably propylene and or butene.
Preferred polymers include homopolymers or copolymers of C2 to C40 olefins, preferably C2 to C20 olefins, preferably a copolymer of an alpha-olefin and another olefin or alpha-olefin (ethylene is defined to be an alpha-olefin for purposes of this invention). Preferably, the polymers are or include homopolyethylene, homopolypropylene, propylene copolymerized with ethylene and or butene, ethylene copolymerized with one or more of propylene, butene or hexene, and optional dienes. Preferred examples include thermoplastic polymers such as ultra low density polyethylene, very low density polyethylene, linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, isotactic polypropylene, highly isotactic polypropylene, syndiotactic polypropylene, random copolymer of propylene and ethylene and/or butene and/or hexene, elastomers such as ethylene propylene rubber, ethylene propylene diene monomer rubber, neoprene, and blends of thermoplastic polymers and elastomers, such as for example, thermoplastic elastomers and rubber toughened plastics.
The catalyst system can include Ziegler-Natta catalysts, chromium-based catalysts, metallocene catalysts, and other single-site catalysts including Group 15-containing catalysts bimetallic catalysts, and mixed catalysts. The catalyst system can also include AlCl3, cobalt, iron, palladium, chromium/chromium oxide or “Phillips” catalysts. Any catalyst can be used alone or in combination with the others. In one or more embodiments, a “mixed” catalyst is preferred.
The term “catalyst system” includes at least one “catalyst component” and at least one “activator,” alternately at least one co-catalyst. The catalyst system can also include other components, such as supports, and is not limited to the catalyst component and/or activator alone or in combination. The catalyst system can include any number of catalyst components in any combination as described, as well as any activator in any combination as described.
The term “catalyst component” includes any compound that, once appropriately activated, is capable of catalyzing the polymerization or oligomerization of olefins. Preferably, the catalyst component includes at least one Group 3 to Group 12 atom and optionally at least one leaving group bound thereto.
The term “leaving group” refers to one or more chemical moieties bound to the metal center of the catalyst component that can be abstracted from the catalyst component by an activator, thereby producing the species active towards olefin polymerization or oligomerization. Suitable activators are described in detail below.
As used herein, in reference to Periodic Table “Groups” of Elements, the “new” numbering scheme for the Periodic Table Groups are used as in the CRC Handbook of Chemistry and Physics (David R. Lide, ed., CRC Press 81st ed. 2000).
The term “substituted” means that the group following that term possesses at least one moiety in place of one or more hydrogens in any position, the moieties selected from such groups as halogen radicals (for example, Cl, F, Br), hydroxyl groups, carbonyl groups, carboxyl groups, amine groups, phosphine groups, alkoxy groups, phenyl groups, naphthyl groups, C1 to C10 alkyl groups, C2 to C10 alkenyl groups, and combinations thereof. Examples of substituted alkyls and aryls includes, but are not limited to, acyl radicals, alkylamino radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonyl radicals, carbomoyl radicals, alkyl- and dialkyl-carbamoyl radicals, acyloxy radicals, acylamino radicals, arylamino radicals, and combinations thereof.
Suitable chromium catalysts can include di-substituted chromates, such as CrO2(OR)2; where R is triphenylsilane or a tertiary polyalicyclic alkyl. The chromium catalyst system may further include CrO3, chromocene, silyl chromate, chromyl chloride (CrO2Cl2), chromium-2-ethyl-hexanoate, chromium acetylacetonate (Cr(AcAc)3), and the like.
Metallocenes are generally described throughout in, for example, 1 & 2 Metallocene-Based Polyolefins (John Scheirs & W. Kaminsky, eds., John Wiley & Sons, Ltd. 2000); G. G. Hlatky in 181 Coordination Chem. Rev. 243-296 (1999) and in particular, for use in the synthesis of polyethylene in 1 Metallocene-Based Polyolefins 261-377 (2000). The metallocene catalyst compounds as described herein include “half sandwich” and “full sandwich” compounds having one or more Cp ligands (cyclopentadienyl and ligands isolobal to cyclopentadienyl) bound to at least one Group 3 to Group 12 metal atom, and one or more leaving group(s) bound to the at least one metal atom. Hereinafter, these compounds will be referred to as “metallocenes” or “metallocene catalyst components”. The metallocene catalyst component is supported on a support material in an embodiment, and may be supported with or without another catalyst component.
The Cp ligands are one or more rings or ring system(s), at least a portion of which includes π-bonded systems, such as cycloalkadienyl ligands and heterocyclic analogues. The ring(s) or ring system(s) typically comprise atoms selected from the group consisting of Groups 13 to 16 atoms, or the atoms that make up the Cp ligands are selected from the group consisting of carbon, nitrogen, oxygen, silicon, sulfur, phosphorous, germanium, boron and aluminum and combinations thereof, wherein carbon makes up at least 50% of the ring members. Or the Cp ligand(s) are selected from the group consisting of substituted and unsubstituted cyclopentadienyl ligands and ligands isolobal to cyclopentadienyl, non-limiting examples of which include cyclopentadienyl, indenyl, fluorenyl and other structures. Further non-limiting examples of such ligands include cyclopentadienyl, cyclopentaphenanthreneyl, indenyl, benzindenyl, fluorenyl, octahydrofluorenyl, cyclooctatetraenyl, cyclopentacyclododecene, phenanthrindenyl, 3,4-benzofluorenyl, 9-phenylfluorenyl, 8-H-cyclopent[a]acenaphthylenyl, 7H-dibenzofluorenyl, indeno[1,2-9]anthrene, thiophenoindenyl, thiophenofluorenyl, hydrogenated versions thereof (e.g., 4,5,6,7-tetrahydroindenyl, or “H4Ind”), substituted versions thereof, and heterocyclic versions thereof.
The “Group 15-containing catalyst” may include Group 3 to Group 12 metal complexes, wherein the metal is 2 to 8 coordinate, the coordinating moiety or moieties including at least two Group 15 atoms, and up to four Group 15 atoms. In one embodiment, the Group 15-containing catalyst component is a complex of a Group 4 metal and from one to four ligands such that the Group 4 metal is at least 2 coordinate, the coordinating moiety or moieties including at least two nitrogens. Representative Group 15-containing compounds are disclosed in, for example, WO 99/01460; EP A10 893 454; EP A10 894 005; U.S. Pat. No. 5,318,935; U.S. Pat. No. 5,889,128 U.S. Pat. No. 6,333,389 B2 and U.S. Pat. No. 6,271,325 B1. In one embodiment, the Group 15-containing catalyst includes a Group 4 imino-phenol complexes, Group 4 bis(amide) complexes, and Group 4 pyridyl-amide complexes that are active towards olefin polymerization to any extent.
The term “activator” includes any compound or combination of compounds, supported or unsupported, which can activate a single-site catalyst compound (e.g., metallocenes, Group 15-containing catalysts), such as by creating a cationic species from the catalyst component. Typically, this involves the abstraction of at least one leaving group (X group in the formulas/structures above) from the metal center of the catalyst component. The catalyst components of embodiments described are thus activated towards olefin polymerization using such activators. Embodiments of such activators include Lewis acids such as cyclic or oligomeric poly(hydrocarbylaluminum oxides) and so called non-coordinating activators (“NCA”) (alternately, “ionizing activators” or “stoichiometric activators”), or any other compound that can convert a neutral metallocene catalyst component to a metallocene cation that is active with respect to olefin polymerization.
Lewis acids may be used to activate the metallocenes described. Illustrative Lewis acids include, but are not limited to, alumoxane (e.g., “MAO”), modified alumoxane (e.g., “TIBAO”), and alkylaluminum compounds. Ionizing activators (neutral or ionic) such as tri(n-butyl)ammonium tetrakis(pentafluorophenyl)boron may be also be used. Further, a trisperfluorophenyl boron metalloid precursor may be used. Any of those activators/precursors can be used alone or in combination with the others.
MAO and other aluminum-based activators are known in the art. Ionizing activators are known in the art and are described by, for example, Eugene You-Xian Chen & Tobin J. Marks, Cocatalysts for Metal-Catalyzed Olefin Polymerization: Activators, Activation Processes, and Structure-Activity Relationships 100(4) Chemical Reviews 1391-1434 (2000). The activators may be associated with or bound to a support, either in association with the catalyst component (e.g., metallocene) or separate from the catalyst component, such as described by Gregory G. Hlatky, Heterogeneous Single-Site Catalysts for Olefin Polymerization 100(4) Chemical Reviews 1347-1374 (2000).
Illustrative Ziegler-Natta catalyst compounds are disclosed in Ziegler Catalysts 363-386 (G. Fink, R. Mulhaupt and H. H. Brintzinger, eds., Springer-Verlag 1995); or in EP 103 120; EP 102 503; EP 0 231 102; EP 0 703 246; RE 33,683; U.S. Pat. No. 4,302,565; U.S. Pat. No. 5,518,973; U.S. Pat. No. 5,525,678; U.S. Pat. No. 5,288,933; U.S. Pat. No. 5,290,745; U.S. Pat. No. 5,093,415 and U.S. Pat. No. 6,562,905. Examples of such catalysts include those comprising Group 4, 5 or 6 transition metal oxides, alkoxides and halides, or oxides, alkoxides and halide compounds of titanium, zirconium or vanadium; optionally in combination with a magnesium compound, internal and/or external electron donors (alcohols, ethers, siloxanes, etc.), aluminum or boron alkyl and alkyl halides, and inorganic oxide supports.
Conventional-type transition metal catalysts are those traditional Ziegler-Natta catalysts that are well known in the art. Examples of conventional-type transition metal catalysts are discussed in U.S. Pat. Nos. 4,115,639, 4,077,904, 4,482,687, 4,564,605, 4,721,763, 4,879,359 and 4,960,741. The conventional-type transition metal catalyst compounds that may be used include transition metal compounds from Groups 3 to 17, or Groups 4 to 12, or Groups 4 to 6 of the Periodic Table of Elements.
These conventional-type transition metal catalysts may be represented by the formula: MRx, where M is a metal from Groups 3 to 17, or a metal from Groups 4 to 6, or a metal from Group 4, or titanium; R is a halogen or a hydrocarbyloxy group; and x is the valence of the metal M. Examples of R include alkoxy, phenoxy, bromide, chloride and fluoride. Examples of conventional-type transition metal catalysts where M is titanium include TiCl4, TiBr4, Ti(OC2H5)3Cl, Ti(OC2H5)Cl3, Ti(OC4H9)3Cl, Ti(OC3H7)2Cl2, Ti(OC2H5)2Br2, TiCl3.1/3AlCl3 and Ti(OCl2H25)Cl3.
Conventional-type transition metal catalyst compounds based on magnesium/titanium electron-donor complexes are described in, for example, U.S. Pat. Nos. 4,302,565 and 4,302,566. Catalysts derived from Mg/Ti/Cl/THF are also contemplated, which are well known to those of ordinary skill in the art. One example of the general method of preparation of such a catalyst includes the following: dissolve TiCl4 in THF, reduce the compound to TiCl3 using Mg, add MgCl2, and remove the solvent.
Conventional-type co-catalyst compounds for the above conventional-type transition metal catalyst compounds may be represented by the formula M3M4vX2cR3b-c, wherein M3 is a metal from Group 1 to 3 and 12 to 13 of the Periodic Table of Elements; M4 is a metal of Group 1 of the Periodic Table of Elements; v is a number from 0 to 1; each X2 is any halogen; c is a number from 0 to 3; each R3 is a monovalent hydrocarbon radical or hydrogen; b is a number from 1 to 4; and wherein b minus c is at least 1. Other conventional-type organometallic cocatalyst compounds for the above conventional-type transition metal catalysts have the formula M3R3k, where M3 is a Group IA, IIA, IIB or IIIA metal, such as lithium, sodium, beryllium, barium, boron, aluminum, zinc, cadmium, and gallium; k equals 1, 2 or 3 depending upon the valency of M3 which valency in turn normally depends upon the particular Group to which M3 belongs; and each R3 may be any monovalent radical that include hydrocarbon radicals and hydrocarbon radicals containing a Group 13 to 16 element like fluoride, aluminum or oxygen or a combination thereof.
The mixed catalyst can be a bimetallic catalyst composition or a multi-catalyst composition. As used herein, the terms “bimetallic catalyst composition” and “bimetallic catalyst” include any composition, mixture, or system that includes two or more different catalyst components, each having a different metal group. The terms “multi-catalyst composition” and “multi-catalyst” include any composition, mixture, or system that includes two or more different catalyst components regardless of the metals. Therefore, the terms “bimetallic catalyst composition,” “bimetallic catalyst,” “multi-catalyst composition,” and “multi-catalyst” will be collectively referred to herein as a “mixed catalyst” unless specifically noted otherwise. In one preferred embodiment, the mixed catalyst includes at least one metallocene catalyst component and at least one non-metallocene component.
Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges from any lower limit to any upper limit are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below. All numerical values are “about” or “approximately” the indicated value, and take into account experimental error and variations that would be expected by a person having ordinary skill in the art.
Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims the benefit of Ser. No. 61/178,670, filed May 15, 2009, the disclosure of which is incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61178670 | May 2009 | US |
