Reducing triboelectricity and / or reactor fouling of polyolefin particles

Abstract

Methods described herein relate to reducing triboelectricity and / or reactor fouling of polyolefin particles, comprising: feeding an argon / nitrogen mixture upward through a distributor plate to a reaction zone to fluidize the polyolefin particles in the reaction zone, wherein the argon / nitrogen mixture consists of 5 vol% to not more than 65 vol% of argon, 95 vol% to not less than 10 vol% of nitrogen and 0 vol% to not more than 5 vol% of helium, the sum of all these vol% being equal to 100 vol% of the argon / nitrogen mixture.

Description

Technical Field

[0001] The present disclosure relates to methods for reducing triboelectrification of polyolefin particles and / or reactor fouling in a fluidized bed type gas phase polymerization reactor. Background Art

[0002] Polyolefins can be used in a variety of products. Polyolefins can be formed by reacting one or more types of monomers in a polymerization reaction. Different polymerization methods and different reaction components are used to prepare polyolefins with different properties. There is still a need for new and / or improved methods for preparing polyolefins. Summary of the Invention

[0003] The methods described herein relate to reducing triboelectrification of polyolefin particles and / or reactor fouling, the method comprising: feeding an argon / nitrogen mixture upward through a distributor plate into a reaction zone to fluidize polyolefin particles in the reaction zone, wherein the argon / nitrogen mixture consists of 5 volume % (vol%) to not more than 65 volume % of argon, 95 volume % to not less than 10 volume % of nitrogen, and 0 volume % to not more than 5 volume % of helium, wherein the sum of all these volume % is equal to 100 volume % of the argon / nitrogen mixture.

[0004] The methods described herein relate to reducing static electricity in a fluidized bed type gas phase polymerization reactor, the method comprising: feeding a startup gas into an FBT-GPP reactor to provide a startup gas environment, wherein the startup gas consists of 80 volume % (vol%) to 100 volume % of argon and 0 volume % to 20 volume % of nitrogen, wherein the sum of all these volume % is equal to 100 volume % of the startup gas.

[0005] The above summary of the invention of the present disclosure is not intended to describe every disclosed embodiment or every embodiment of the present disclosure. The following description more specifically illustrates exemplary embodiments. Throughout this application, guidance is provided by way of lists of examples, which can be used in various combinations. In each case, the listed lists are only representative groups and should not be construed as exclusive lists. Brief Description of the Drawings

[0006] Figure 1 A schematic diagram of an exemplary gas phase polymerization system according to multiple embodiments described herein is depicted.

[0007] Figure 2 A schematic diagram of an example system according to multiple embodiments described herein is depicted. Detailed Description

[0008] In the following description, numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will understand that the present disclosure may be practiced without these specific details, and that numerous variations or modifications may be made on the basis of the described embodiments.

[0009] For many applications, an aggregation reactor (e.g., a fluidized bed type gas phase polymerization reactor (FBT-GPP reactor)) can experience triboelectrification and / or reactor fouling. For example, contact between polyolefin particles, catalyst particles, and / or the reactor wall can cause static charges to build up within the fluidized bed reactor via triboelectrification. This electrostatic charging (via triboelectrification) can cause the particles to adhere to each other and / or to the reactor wall, which can be referred to as fouling. Electrostatic charging (via triboelectrification) can be detected, for example, using an electrostatic probe, such as by detecting electrostatic variations in the fluidized bed of an FBT-GPP reactor.

[0010] For example, fouling can be detected from the aggregated particles removed from the FBT-GPP reactor. Flaking is a known type of fouling. Flaking occurs when particles (e.g., polyolefin particles) adhere to the reactor wall. Flaking is undesirable and can cause many problems, such as reduced productivity and / or reactor blockage.

[0011] Numerous efforts have been made to reduce triboelectrification and / or reactor fouling, including using chemical additives, changing the catalyst chemistry or catalyst particles, or adjusting reactor process conditions. However, there is still a need to reduce triboelectrification and / or reactor fouling in fluidized bed type gas phase polymerization reactors. As used herein, "reduce" means, for example, to mitigate, alleviate, and / or inhibit as compared to other polymerization methods having relatively high triboelectrification and / or reactor fouling.

[0012] Reducing triboelectrification means that the static charge of the polyolefin particles is lower than the static charge of the polyolefin particles in a comparative method using an inert gas of 100% by volume of nitrogen in place of the argon / nitrogen mixture; and wherein the triboelectric charge of the polyolefin particles is measured on a sample of polyolefin particles taken from the FBT-GPP reactor, where the measurement is carried out according to the charge measurement test method described herein; or wherein the FBT-GPP reactor includes an electrostatic probe and the triboelectric charge of the polyolefin particles is measured by the electrostatic probe. For example, one or more embodiments provide that reducing triboelectrification means that the triboelectric charge of the polyolefin particles is reduced by at least 10%, alternatively at least 20%, alternatively at least 30% after fluidization with an argon / nitrogen mixture for 10 hours, relative to the triboelectric charge of comparative polyolefin particles fluidized for 10 hours in a comparative method using an inert gas of 100% by volume of nitrogen in place of the argon / nitrogen mixture. For example, one or more embodiments provide that reducing reactor fouling means that the amount of polyolefin material adhering to the FBT-GPP reactor after 10 hours is reduced by at least 10%, alternatively at least 20%, alternatively at least 30% relative to the amount of polyolefin material adhering to the FBT-GPP reactor in a comparative method using an inert gas of 100% by volume of nitrogen in place of the argon / nitrogen mixture after 10 hours, if any, and wherein the amount of adhering polyolefin material is equal to any one of amounts (a) to (d): (a) the weight of polyolefin particles adhering to the distributor plate, (b) the weight of polyolefin particles adhering to the reactor wall, (c) the sum of weights (a) to (b); or (iii) both (i) and (ii) are limited.

[0013] Reducing reactor fouling means that the amount of adhering polyolefin material in the FBT-GPP reactor is lower, if any, relative to the amount of adhering polyolefin material in a comparative method using an inert gas of 100% by volume of nitrogen in place of the argon / nitrogen mixture in the FBT-GPP reactor.

[0014] As further discussed herein, embodiments of the present disclosure relate to reducing triboelectrification and / or reactor fouling in a fluidized bed type gas phase polymerization reactor. As used herein, "reducing fouling" may refer to delaying the onset of fouling and / or slowing the fouling rate, where the fouling rate is the increase in fouling material per unit time.

[0015] For the purposes of the subject matter described herein and its claims, the new numbering scheme for the groups of the periodic table described in Chemical and Engineering News, 63(5), page 27 (1985) is used. Thus, "Group 4 metals" are the elements of Group 4 of the periodic table, such as Ti, Zr or Hf.

[0016] As used herein, the term "substituted" means that the indicated group has at least one moiety that replaces one or more hydrogens at any position, and these moieties are selected from groups such as the following: halogen radicals (especially F, Cl, Br), hydroxy groups, carbonyl groups, carboxyl groups, amino groups, phosphino groups, alkoxy groups, phenyl groups, naphthyl groups, C1 to C 10 alkyl groups, C2 to C 10 alkenyl groups and combinations thereof. Examples of substituted alkyls and aryls include, but are not limited to, acyl radicals, alkylamino radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonyl radicals, carbamoyl radicals, alkylcarbamoyl radicals and dialkylcarbamoyl radicals, acyloxy radicals, acylamino radicals, arylamino radicals and combinations thereof.

[0017] Polymerization conditions

[0018] For example, the polymerization conditions can be selected from any of the conditions described herein.

[0019] Figure 1 A schematic diagram of an exemplary gas-phase polymerization system according to various embodiments described herein is depicted. Figure 1 A flowchart of a gas-phase polymerization system 100 for preparing polyolefins according to one or more embodiments is shown. The polymerization system 100 can include a reactor 101, such as a fluidized-bed type gas-phase polymerization reactor, in fluid communication with one or more discharge tanks 155 (one shown), a compressor 170 (one shown), and a heat exchanger 175 (one shown). The polymerization system 100 can also include more than one reactor 101 arranged in series, in parallel, or independently of other reactor configurations, each reactor having its own associated discharge tank 155, compressor 170, and heat exchanger 175, or alternatively sharing any one or more of the associated discharge tank 155, compressor 170, and heat exchanger 175. For simplicity and ease of description, the polymerization system 100 will be further described in the context of a single reactor train.

[0020] One or more embodiments of the present disclosure use an argon / nitrogen mixture. The argon / nitrogen mixture consists of 5 volume percent (vol%) to no greater than 65 volume percent of argon, 95 volume percent to no less than 10 volume percent of nitrogen, and 0 volume percent to no greater than 5 volume percent of helium, where the sum of all these volume percents equals 100 volume percent of the argon / nitrogen mixture. All individual values and subranges are included; for example, the argon / nitrogen mixture consists of: argon with a lower limit of 5 volume percent, 15 volume percent, or 25 volume percent to an upper limit of 65 volume percent, 60 volume percent, or 50 volume percent; nitrogen with a lower limit of 10 volume percent, 25 volume percent, or 50 volume percent to an upper limit of 95 volume percent, 85 volume percent, or 75 volume percent; and helium with a lower limit of 0 volume percent, 0.5 volume percent, or 1 volume percent to an upper limit of 5 volume percent, 4.5 volume percent, or 4 volume percent, where the sum of all these volume percents (i.e., argon volume percent, nitrogen volume percent, and helium volume percent) equals 100 volume percent of the argon / nitrogen mixture.

[0021] One or more embodiments provide that the argon / nitrogen mixture is: 9 volume percent to no greater than 65 volume percent of argon; 10 volume percent to no greater than 60 volume percent of argon; 10 volume percent to no greater than 55 volume percent of argon; 10 volume percent to no greater than 50 volume percent of argon; 10 volume percent to no greater than 45 volume percent of argon; or 10 volume percent to no greater than 35 volume percent of argon, where the sum of the argon volume percent, nitrogen volume percent, and helium volume percent equals 100 volume percent of the argon / nitrogen mixture.

[0022] One or more embodiments provide that the argon / nitrogen mixture is: 90 volume percent to no less than 35 volume percent of nitrogen; 90 volume percent to no less than 40 volume percent of nitrogen; 90 volume percent to no less than 45 volume percent of nitrogen; 90 volume percent to no less than 50 volume percent of nitrogen; 90 volume percent to no less than 55 volume percent of nitrogen; or 90 volume percent to no less than 65 volume percent of nitrogen, where the sum of the argon volume percent, nitrogen volume percent, and helium volume percent equals 100 volume percent of the argon / nitrogen mixture.

[0023] The argon / nitrogen mixture is fed into reactor 101. The argon / nitrogen mixture can be fed upward through distributor plate 119 into the reaction zone of reactor 101 to fluidize the polyolefin particles in the reaction zone (i.e., to form and / or maintain fluidized bed 112). The argon / nitrogen mixture can be introduced into reactor 101 via one or more reactor inputs (e.g., below distributor plate 119). In other words, as discussed herein, the argon / nitrogen mixture enters reactor 101 through distributor plate 119; the argon / nitrogen mixture can enter the gas phase polymerization system through one or more inputs, which can have different locations within the system. One or more embodiments provide that a variety of other gases known in the art can be fed into reactor 101.

[0024] One or more embodiments provide for continuously feeding an argon / nitrogen mixture to reactor 101. For example, when reactor 101 is operating under steady-state polymerization conditions, the argon / nitrogen mixture is continuously fed to reactor 101 (e.g., at a rate to maintain fluidized bed 112).

[0025] One or more embodiments provide for feeding the argon / nitrogen mixture intermittently rather than continuously to reactor 101. For example, when reactor 101 is operating under polymerization conditions, i.e., when forming a polyolefin product, the argon / nitrogen mixture can be fed to reactor 101 at fixed time intervals. For example, a fixed amount of the argon / nitrogen mixture can be fed to reactor 101 at fixed time intervals. Various fixed time intervals and / or various fixed amounts of the argon / nitrogen mixture are fed intermittently to reactor 101 operating under polymerization conditions and can be used for various applications. For example, the lower limit of the fixed time interval can be 5 minutes, 15 minutes or 30 minutes and other values, and the upper limit can be 12 hours, 8 hours or 6 hours, and other values. For different applications, the intermittent feeding of the argon / nitrogen mixture to reactor 101 can be repeated different numbers of times.

[0026] When the argon / nitrogen mixture is fed intermittently rather than continuously to reactor 101, the argon / nitrogen mixture replaces all or a portion of the inert fluidizing gas fed into reactor 101. Replacing all or a portion of the inert fluidizing gas fed to reactor 101 with the argon / nitrogen mixture can keep fluidized bed 112 in, for example, steady-state fluidization conditions. Examples of inert gases include nitrogen, and other inert gases that can be used.

[0027] One or more embodiments provide for the intermittent feeding of the argon / nitrogen mixture to reactor 101 in response to process parameters, such as a deviation from steady-state polymerization process conditions. Examples of process parameters include, for example, an increase in static electricity at reactor wall 103, or an increase in temperature at reactor wall 103, and other process parameters. The increase in static electricity can be detected with a static electricity probe; the increase in temperature can be detected with a thermocouple. When the intermittent feeding of the argon / nitrogen mixture to reactor 101 is in response to process parameters, the argon / nitrogen mixture can be fed, for example, the flow rate can be maintained until steady-state polymerization process conditions are restored or partially restored, e.g., the static electricity has been reduced to a threshold static electricity level and / or the temperature has been reduced to a threshold temperature level.

[0028] Reactor 101 can include a cylindrical section (e.g., reaction zone) defined by wall 103, transition section 105, and a deceleration zone or dome 107. As Figure 1As shown, the reaction zone is disposed adjacent to the transition section 105. The transition section 105 can expand from a first diameter corresponding to the diameter of the reaction zone to a larger diameter adjacent to the dome 107. As described above, the location or junction where the reaction connects to the transition section 105 is referred to as the "neck" or "reactor neck" 104. The dome 107 has a spherical shape. One or more recycle fluid lines 115 and an exhaust line 118 can be in fluid communication with the top cover 107. The reactor 101 can include a fluidized bed 112 in fluid communication with the top cover 107.

[0029] Generally, the ratio of the height to the diameter of the reaction zone (i.e., the cylindrical section defined by the wall 103) can vary in the range of about 2:1 to about 5:1. Of course, this range can vary to larger or smaller ratios and depends at least in part on the required production capacity and / or the reactor size. The cross-sectional area of the dome 107 is generally in the range of about 2 to about 3 times the cross-sectional area of the reaction zone.

[0030] The deceleration zone or dome 107 has a larger inner diameter than the fluidized bed 112. As the name implies, the deceleration zone 107 slows down the gas velocity due to the increased cross-sectional area. This reduction in gas velocity allows the particles entrained in the upwardly moving gas to fall back into the bed, so that mainly only the gas can flow out from the top of the reactor 101 through the recycle fluid line 115. The recycle fluid recovered via the line 115 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 the fluidized bed 112.

[0031] The reactor feed via the line 110 can be introduced into the polymerization system 100 at any point. For example, the reactor feed via the line 110 can be introduced at any point within the cylindrical section 103, the transition section 105, the deceleration zone 107, the recycle fluid line 115, or any combination thereof. Preferably, the reactor feed 110 is introduced into the recycle fluid in the line 115 before or after the heat exchanger 175. In Figure 1 it is depicted that the reactor feed via the line 110 enters the recycle fluid in the line 115 after the heat exchanger 175. The catalyst feed via the line 113 can be introduced into the polymerization system 100 at any point. Preferably, the catalyst feed is introduced via the line 113 into the fluidized bed 112 within the reaction zone defined by the wall 103. For example, various components (e.g., cocatalyst) can be introduced into the reactor 101 through the inlet 114.

[0032] The circulating fluid via line 115 can be compressed in compressor 170 and then passed through heat exchanger 175, where heat exchange can occur between the circulating fluid and the heat transfer medium. For example, during normal operating conditions, a cold or cryogenic heat transfer medium via line 171 can be introduced into heat exchanger 175, where heat can be transferred from the circulating fluid in line 115 to produce a heated heat transfer medium via line 177 and a cooled circulating fluid via line 115. In another example, during reactor 101 idling, a warm or hot heat transfer medium via line 171 can be introduced into heat exchanger 175, where heat can be transferred from the heat transfer medium to the circulating fluid in line 115 to produce a cooled heat transfer medium via line 117 and a heated circulating fluid via line 115. The terms "cold heat transfer medium" and "cryogenic heat transfer medium" refer to a heat transfer medium having a temperature lower than that of the fluidized bed 112 within reactor 101. The terms "warm heat transfer medium" and "hot heat transfer medium" refer to a heat transfer medium having a temperature higher than that of the fluidized bed 112 within reactor 101. Heat exchanger 175 can be used to cool or heat fluidized bed 112, depending on the specific operating conditions of polymerization system 100, such as startup, normal operation, idling, and shutdown. Exemplary heat transfer media can include, but are not limited to, water, air, glycols, etc. Compressor 170 can also be positioned downstream of heat exchanger 175 or at an intermediate point between several heat exchangers 175.

[0033] After cooling, all or a portion of the circulating fluid via line 115 can be returned to reactor 101. The cooled circulating fluid in line 115 can absorb the heat of reaction generated by the polymerization reaction. The heat transfer medium in line 171 can be used to transfer heat to the circulating fluid in line 115, thereby introducing heat into polymerization system 100 rather than removing heat therefrom. Heat exchanger 175 can be any type of heat exchanger. Exemplary heat exchangers can include, but are not limited to, shell and tube, plate and frame, U-tube, etc. For example, heat exchanger 175 can be a shell and tube heat exchanger, where the circulating fluid via line 115 can be introduced into the tube side and the heat transfer medium can be introduced into the shell side of heat exchanger 175. If desired, several heat exchangers in series, parallel, or a combination of series and parallel can be employed to stepwise reduce or increase the temperature of the circulating fluid.

[0034] Preferably, the recycle gas via line 115 returns to reactor 101 and returns to fluidized bed 112 through a fluid distributor plate ("plate") 119. Plate 119 is preferably installed at the inlet of reactor 101 to prevent polyolefin particles from settling and aggregating into solid masses, to prevent liquid from accumulating at the bottom (e.g., bottom region) of reactor 101, and to facilitate an easy transition between processes containing liquid in recycle stream 115 and processes not containing liquid, and vice versa. Although not shown, the recycle gas via line 115 can be introduced into reactor 101 through a deflector disposed or located intermediate the end of reactor 101 and distributor plate 119.

[0035] The catalyst feed via line 113 can be introduced into fluidized bed 112 within reactor 101 through one or more injection nozzles (not shown) in fluid communication with line 113. The catalyst feed can be introduced as preformed particles (i.e., catalyst slurry) in one or more liquid carriers. Suitable liquid carriers can include mineral oil and / or liquid or gaseous hydrocarbons including, but not limited to, propane, butane, isopentane, hexane, heptane, octane, or mixtures thereof. A gas (such as, for example, nitrogen) inert to the catalyst slurry can also be used to carry the catalyst slurry into reactor 101. In one example, the catalyst can be a dry powder. In another example, the catalyst can be dissolved in a liquid carrier and introduced into reactor 101 as a solution. The catalyst via line 113 can be introduced into reactor 101 at a rate sufficient to sustain polymerization of monomers therein.

[0036] The fluid via line 161 can be separated from the polymer product recovered from reactor 101 via line 117. The fluid can include unreacted monomers, hydrogen, an induced condensation agent (“ICA”), and / or inert substances. The separated fluid can be introduced into reactor 101. The separated fluid can be introduced into a recycle line 115 (not shown). The separation of the fluid can be achieved when the fluid and the product leave reactor 101 and enter the product discharge tank 155 through valve 157, which can be, for example, a ball valve designed to have a minimum restriction on the flow rate when opened. Conventional valves 159 and 167 can be located above and below the product discharge tank 155. Valve 167 allows the product to pass through. For example, to discharge the polyolefin product from reactor 101, valve 157 can be opened while valves 159 and 167 are in the closed position. The product and the fluid enter the product discharge tank 155. Valve 157 is closed to allow the product to settle in the product discharge tank 155. Then valve 159 is opened to allow the fluid to flow from the product discharge tank 155 to reactor 101 via line 161. Then valve 159 can be closed and valve 167 can be opened, and any product in the product discharge tank 155 can flow in and be recovered via line 168. Then valve 167 can be closed. Although not shown, the product via line 168 can be introduced into a plurality of purification tanks or separation units in series, parallel, or a combination of series and parallel to further separate gases and / or liquids from the product. The specific timing sequence of valves 157, 159, and 167 can be achieved by using a conventional programmable controller well known in the art.

[0037] One or more embodiments provide that the FBT - GPP reactor includes a bottom region, a distributor plate, a wall defining a reaction zone, a wall defining a deceleration zone, a recycle line and a compressor, a line for introducing feed, and an outlet for removing polyolefin particles that are in fluid communication in sequence; wherein the recycle line fluidly connects the deceleration zone to the compressor and fluidly connects the compressor to the bottom zone.

[0038] Another preferred product discharge system that can be alternatively used is the system disclosed in U.S. Patent No. 4,621,952. Such a system uses at least a pair (parallel) of tanks, which includes a settling tank and a transfer tank arranged in series, and returns the separated gas phase from the top of the settling tank to a point near the top of the fluidized bed in the reactor.

[0039] Reactor 101 can be equipped with one or more exhaust lines 118 to allow venting of the bed during startup, idling, and / or shutdown. Reactor 101 may not use agitation and / or scraping of the wall. The recycle line 115 and the components therein (compressor 170, heat exchanger 175) can have smooth surfaces and no unnecessary obstructions so as not to impede the flow of the recycled fluid or entrained particles.

[0040] The polymerization conditions vary depending on the monomer, catalyst, catalyst system, and equipment availability. Specific conditions are known to those skilled in the art or can be readily derived. For example, the temperature can be in the range of about 70°C to about 120°C, about 75°C to about 120°C, and about 80°C to about 110°C. For example, the pressure can be in the range of about 10 kPag to about 10,000 kPag, such as about 500 kPag to about 5,000 kPag or about 1,000 kPag to about 2,200 kPag.

[0041] The amount of hydrogen in reactor 101 can be expressed as a molar ratio relative to the total polymerizable monomer (e.g., ethylene or a blend of ethylene and one or more comonomers). The amount of hydrogen used in the polymerization process can be the amount necessary to obtain the desired flow index of the polyolefin product. The molar ratio of hydrogen to total monomer (H2: monomer) can be ≥ about 0.0001, for example, ≥ about 0.0005, ≥ about 0.001, ≥ about 0.01, ≥ about 0.1, ≥ about 1.0, ≥ about 3.0, or about 5.0. Additionally or alternatively, the molar ratio of hydrogen to total monomer (H2: monomer) can be ≤ about 10, for example, ≤ about 5.0, ≤ about 3.0, ≤ about 1.0, ≤ about 0.1, ≤ about 0.01, ≤ about 0.001, or ≤ about 0.0005. The concentration ranges of the explicitly disclosed continuity aids include the ranges formed by any of the above pairs of values, for example, about 0.0001 to about 10.0, about 0.0005 to about 5.0, about 0.0005 to 0.001, about 0.001 to about 3.0, about 0.01 to about 1.0, etc. Expressed in another way, the amount of hydrogen in the reactor can be at most 5,000 ppm, or at most 4,000 ppm, or at most 3,000 ppm, or between 50 ppm and 5,000 ppm, or between 50 ppm and 2,000 ppm at any time. The amount of hydrogen in the reactor can be in the range from as low as about 1 ppm, about 50 ppm, or about 100 ppm to as high as about 400 ppm, about 800 ppm, about 1,000 ppm, about 1,500 ppm, about 2,000 ppm, about 5,000 ppm, or about 10,000 ppm, where the suitable ranges include combinations of any two values. The ratio of hydrogen to total monomer (H2: monomer) can be about 0.00001:1 to about 2:1, about 0.005:1 to about 1.5:1, or about 0.0001:1 to about 1:1.

[0042] Other exemplary techniques that can also be used are described in U.S. Patent Nos. 4,994,534, 5,200,477, and 4,803,251; and condensation mode operation, such as described in U.S. Patent Nos. 4,543,399 and 4,588,790.

[0043] Additional reactor details and ways of operating the reactor are described, for example, in U.S. Patent Nos. 3,709,853, 4,003,712, 4,011,382, 4,302,566, 4,543,399, 4,882,400, 5,352,749, and 5,541,270; and EP0802202.

[0044] Starting conditions

[0045] Startup conditions can be used before the steady-state polymerization conditions discussed previously herein are applied to the gas-phase polymerization system 100. As used herein, "startup conditions" refer to the conditions used when no polyolefin product is being produced. One or more embodiments provide that the startup conditions indicate that no polymerization catalyst is fed to the reactor 101, for example, when startup gas is fed to the reactor. For example, one or more embodiments provide that the startup conditions can include loading the reactor 101 with a seed bed of granular resin, which can be used to form a fluidized bed when no polymerization catalyst is fed to the reactor.

[0046] One or more embodiments provide for feeding startup gas to the reactor 101. For example, the startup gas can be fed upward through the distributor plate 119 into the reaction zone of the reactor 101. Feeding the startup gas to the reactor 101 can provide a reactor with a startup gas environment, for example, a reactor that does not contain gases other than the startup gas. Advantageously, compared to a similar reactor with similar conditions but without using startup gas, using startup gas can provide a lower static charge in the reactor 101, among other benefits. Advantageously, this relatively low static charge can provide a relatively fast startup.

[0047] The startup gas provided by embodiments of the present disclosure can consist of 80 volume percent (vol%) to 100 volume percent of argon and 0 volume percent to 20 volume percent of nitrogen, where the sum of all these volume percents equals 100 volume percent of the startup gas. All individual values and subranges are included; for example, the startup gas consists of: from a lower limit of 80 volume percent, 85 volume percent, or 90 volume percent to an upper limit of 100 volume percent, 98 volume percent, or 96 volume percent of argon; and from a lower limit of 0 volume percent, 2 volume percent, or 4 volume percent to an upper limit of 20 volume percent, 15 volume percent, or 10 volume percent of nitrogen, where the sum of all these volume percents equals 100 volume percent of the startup gas.

[0048] One or more embodiments provide for continuously feeding startup gas to reactor 101. In other words, a startup gas environment can be maintained during a startup interval (e.g., there are no gases other than the startup gas in the reactor). For different applications, the startup interval can have various values. For example, the lower limit of the startup interval can be 5 minutes, 15 minutes, or 30 minutes, among other values, and the upper limit can be 12 hours, 8 hours, or 6 hours, among other values.

[0049] One or more embodiments provide that the startup interval can continue until a startup parameter value is obtained. For example, the startup interval can continue until a startup electrostatic threshold is obtained. For different applications, the electrostatic threshold can have different values.

[0050] Embodiments provide that other startup conditions known in the art can be utilized.

[0051] Catalyst composition

[0052] The catalyst composition can be or include any catalyst or combination of catalysts. Exemplary catalysts can include, but are not limited to, Ziegler-Natta catalysts, chromium-based catalysts, metallocene catalysts, and other catalytic compounds with homogeneous polymerization sites (single-site catalysts, including Group 15-containing catalysts), bimetallic catalysts, and mixed catalysts. The catalyst can also include AlCl3, cobalt, iron, palladium, chromium / chromium oxide, or a "Phillips" catalyst. Any catalyst can be used alone or in combination with any other catalyst. A catalyst composition for olefin polymerization in spray-dried form can particularly benefit from the methods described herein.

[0053] The first and / or second catalyst composition can comprise a metallocene catalyst component. Metallocene catalysts can include "half-sandwich" and "full-sandwich" compounds having one or more Cp ligands (cyclopentadienyl and isoelectronic ligands with cyclopentadienyl) bonded to at least one Group 3 to Group 12 metal atom, and one or more leaving groups bonded to at least one metal atom.

[0054] A Cp ligand is one or more rings or ring systems, at least a portion of which includes a π-bonding system, such as a cycloalkadienyl ligand and heterocyclic analogues. The ring or ring system typically contains atoms selected from Group 13 to 16 atoms, and in some embodiments, the atoms constituting the Cp ligand are selected from the following: carbon, nitrogen, oxygen, silicon, sulfur, phosphorus, germanium, boron, aluminum, and combinations thereof, where carbon constitutes at least 50% of the ring members. For example, the Cp ligand can be selected from substituted and unsubstituted cyclopentadienyl ligands and ligands isosteric with cyclopentadienyl. Non-limiting examples of such ligands include cyclopentadienyl, cyclopentaphenanthrenyl, indenyl, benzoindenyl, fluorenyl, octahydrofluorenyl, cyclooctatetraenyl, cyclopentacyclododecenyl, phenalenyl, 3,4-benzo-fluorenyl, 9-phenylfluorenyl, 8-H-cyclopenta[a]acenaphthylenyl, 7-H-dibenzofluorenyl, indeno[1,2-9]anthracenyl, thienoindenyl, thienofluorenyl, their hydrogenated variants (e.g., 4,5,6,7-tetrahydroindenyl, or “H4 Ind”), their substituted variants (discussed and described in more detail below), and their heterocyclic variants.

[0055] The metal atom “M” of the metallocene compound can be selected from Group 3 to 12 atoms and lanthanide atoms; or can be selected from Group 3 to 10 atoms; or can be selected from Sc, Ti, Zr, Hf, V, Nb, Ta, Mn, Re, Fe, Ru, Os, Co, Rh, Ir, and Ni; or can be selected from Group 4, 5, and 6 atoms; or can be a Ti, Zr, or Hf atom; or can be Hf; or can be Zr. The oxidation state of the metal atom “M” can range from 0 to +7; or can be +1, +2, +3, +4, or +5; or can be +2, +3, or +4. Unless otherwise specified, the groups bonded to the metal atom “M” render the compound in one or more of the structures described below electrically neutral. The Cp ligand forms at least one chemical bond with the metal atom M to form a “metallocene catalyst component”. The Cp ligand is different from the leaving group bonded to the metal atom M in that the former is less prone to substitution / abstraction reactions.

[0056] The metallocene catalyst component can include a compound represented by Structure (I):

[0057] Cp A Cp B MX n (I)

[0058] wherein M is as described above; each X is bonded to M by a chemical bond; each Cp group is bonded to M by a chemical bond; and n is an integer of 0 or 1 to 4. In some embodiments, n is 1 or 2.

[0059] In Structure (I), Cp A and Cp BThe ligands represented can be the same or different cyclopentadienyl ligands or ligands isoelectronic with cyclopentadienyl, any one or both of which can contain heteroatoms and any one or both of which can be substituted by the group R. For example, Cp A and Cp B can each independently be selected from cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl and their respective substituted derivatives.

[0060] Independently, each Cp A and Cp B of structure (I) can be unsubstituted or substituted by any one or combination of the substituted groups R. Non-limiting examples of the substituted group R for use in structure (I) include hydrogen radical, hydrocarbon group, lower hydrocarbon group, substituted hydrocarbon group, hetero-hydrocarbon group, alkyl group, lower alkyl group, substituted alkyl group, heteroalkyl group, alkenyl group, lower alkenyl group, substituted alkenyl group, heteroalkenyl group, alkynyl group, lower alkynyl group, substituted alkynyl group, heteroalkynyl group, alkoxy group, lower alkoxy group, aryloxy group, hydroxy group, alkylthio group, lower alkylthio group, arylthio group, thioxy group, aryl group, substituted aryl group, heteroaryl group, aralkyl group, aralkene group, alkaryl group, alkarylene group, halide, haloalkyl group, haloalkenyl group, haloalkynyl group, heteroalkyl group, heterocycle, heteroaryl group, heteroatom-containing group, silyl group, boron group, phosphino group, phosphine, amino group, amine, cycloalkyl group, acyl group, aroyl group, alkyl mercaptan, dialkylamine, alkyl amide, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkylcarbamoyl group and dialkylcarbamoyl group, acyloxy group, acylamino group, aroylamino group and combinations thereof.

[0061] More specific non - limiting examples of the alkyl substituents R associated with structure (I) include methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl, phenyl, methylphenyl, and tert - butylphenyl groups, etc., including all their isomers, such as tert - butyl, isopropyl, etc. Other possible radicals include substituted alkyl and aryl groups, such as fluoromethyl, fluoroethyl, difluoroethyl, iodopropyl, bromohexyl, chlorobenzyl, and hydrocarbon - substituted organometallic radicals, including trimethylsilyl, trimethylgermyl, methyldiethylsilyl, etc.; and halocarbyl - substituted organometallic radicals, including tris(trifluoromethyl)silyl, methyl - bis(difluoromethyl)silyl, bromomethyldimethylgermyl, etc.; and disubstituted boron radicals, including, for example, dimethylboron; and disubstituted Group 15 radicals, including dimethylamine, dimethylphosphine, diphenylamine, methylphenylphosphine; Group 16 radicals, including methoxy, ethoxy, propoxy, phenoxy, methylthioether, and ethylthioether. Other substituents R include olefins, such as, but not limited to, ethylenically unsaturated substituents, including vinyl - terminated ligands, such as 3 - butenyl, 2 - propenyl, 5 - hexenyl, etc. In some embodiments, at least two R groups, for example, two adjacent R groups are linked to form a ring structure having 3 to 30 atoms, and the ring structure is selected from carbon, nitrogen, oxygen, phosphorus, silicon, germanium, aluminum, boron, and combinations thereof. Additionally, a substituent R group (such as 1 - butyl) can form a bonding association with element M.

[0062] Each X in the above - mentioned structure (I) and the following structures (II) to (Va - d) is independently selected from: for example, halide ions, hydrides, hydrocarbon groups, lower hydrocarbon groups, substituted hydrocarbon groups, heterohydrocarbon groups, alkyl groups, lower alkyl groups, substituted alkyl groups, heteroalkyl groups, alkenyl groups, lower alkenyl groups, substituted alkenyl groups, heteroalkenyl groups, alkynyl groups, lower alkynyl groups, substituted alkynyl groups, heteroalkynyl groups, alkoxy groups, lower alkoxy groups, aryloxy groups, hydroxyl groups, alkylthio groups, lower alkylthio groups, arylthio groups, thioxy groups, aryl groups, substituted aryl groups, heteroaryl groups, aralkyl groups, arylalkenes, alkaryl groups, alkarylalkenes, halides, haloalkyl groups, haloalkenyl groups, haloalkynyl groups, heteroalkyl groups, heterocycles, heteroaryl groups, heteroatom - containing groups, silyl groups, boron groups, phosphino groups, phosphines, amino groups, amines, cycloalkyl groups, acyl groups, arylacyl groups, alkylthiols, dialkylamines, alkylamides, alkoxycarbonyl groups, aryloxycarbonyl groups, carbamoyl groups, alkylcarbamoyl groups, and dialkylcarbamoyl groups, acyloxy groups, acylamino groups, arylacylamino groups, and combinations thereof. In some embodiments, X is C1 to C 12 alkyl, C2 to C 12 alkenyl, C6 to C 12 aryl, C7 to C 20 alkylaryl, C1 to C 12 alkoxy, C6 to C1 16 aryloxy, C7 to C 18Alkylaryloxy, C1 to C 12 Fluoroalkyl, C6 to C 12 Fluoroalkyl or C1 to C 12 Heteroatom-containing hydrocarbons, and their substituted derivatives. X can be selected from hydrides, halide ions, C1 to C6 alkyl groups, C2 to C6 alkenyl groups, C7 to C 18 Alkylaryl, C1 to C6 alkoxy groups, C6 to C 14 Aryloxy, C7 to C 16 Alkylaryloxy, C1 to C6 alkyl carboxylates, C1 to C6 fluorinated alkyl carboxylates, C6 to C 12 Aryl carboxylates, C7 to C 18 Alkylaryl carboxylates, C1 to C6 fluoroalkyl groups, C2 to C6 fluoroalkenyl groups or C7 to C 18 Fluoroalkylaryl; or X can be selected from hydrides, chlorides, fluorides, methyl, phenyl, phenoxy, benzoyloxy, toluenesulfonyl, fluoromethyl and fluorophenyl; or X can be selected from C1 to C 12 Alkyl groups, C2 to C 12 Alkenyl groups, C6 to C 12 Aryl groups, C7 to C 20 Alkylaryl, substituted C1 to C 12 Alkyl groups, substituted C6 to C 12 Aryl groups, substituted C7 to C 20 Alkylaryl and C1 to C 12 Heteroatom-containing alkyl groups, C1 to C 12 Heteroatom-containing aryl groups and C1 to C 12 Heteroatom-containing alkylaryl; or X can be selected from chlorides, fluorides, C1 to C6 alkyl groups, C2 to C6 alkenyl groups, C7 to C 18 Alkylaryl, halogenated C1 to C6 alkyl groups, halogenated C2 to C6 alkenyl groups and halogenated C7 to C 18 Alkylaryl; or X can be selected from fluorides, methyl, ethyl, propyl, phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, fluoromethyl (monofluoromethyl, difluoromethyl and trifluoromethyl) and fluorophenyl (monofluorophenyl, difluorophenyl, trifluorophenyl, tetrafluorophenyl and pentafluorophenyl). In some embodiments, at least one X is a halogenated aryloxy group or a derivative thereof. For example, at least one X can be pentafluorophenoxy.

[0063] The metallocene catalyst component of the first and / or second catalyst composition can include those metallocenes of structure (I), where Cp A and Cp B are bridged to each other by at least one bridging group (A) such that the structure is represented by structure (II):

[0064] Cp A (A)CpB MX n (II)

[0065] These bridged compounds represented by Structure (II) are referred to as "bridged metallocenes". Cp in Structure (II) A 、Cp B 、M, X, and n are as defined above for Structure (I); and wherein each Cp ligand is chemically bonded to M, and (A) is bonded to each Cp. Non-limiting examples of the bridging group (A) include divalent alkyl, divalent lower alkyl, divalent substituted alkyl, divalent heteroalkyl, divalent alkenyl, divalent lower alkenyl, divalent substituted alkenyl, divalent heteroalkenyl, divalent alkynyl, divalent lower alkynyl, divalent substituted alkynyl, divalent heteroalkynyl, divalent alkoxy, divalent lower alkoxy, divalent aryloxy, divalent alkylthio, divalent lower alkylthio, divalent arylthio, divalent aryl, divalent substituted aryl, divalent heteroaryl, divalent aralkyl, divalent aralkenyl, divalent alkaryl, divalent alkaralkenyl, divalent haloalkyl, divalent haloalkenyl, divalent haloalkynyl, divalent heteroalkyl, divalent heterocycle, divalent heteroaryl, divalent heteroatom-containing group, divalent hydrocarbon group, divalent lower hydrocarbon group, divalent substituted hydrocarbon group, divalent heterohydrocarbon group, divalent silyl, divalent boryl, divalent phosphino, divalent phosphine, divalent amino, divalent amine, divalent ether, and divalent thioether. Additional non-limiting examples of the bridging group A include divalent hydrocarbon groups containing at least one Group 13 to Group 16 atom, such as but not limited to at least one of carbon, oxygen, nitrogen, silicon, aluminum, boron, germanium, and tin atoms and combinations thereof; wherein the heteroatom may also be C1 to C 12 alkyl or aryl substituted to satisfy the neutral valence. The bridging group (A) may also contain the substituent group R as defined above for Structure (I), including halogen radicals and iron. More specific non-limiting examples of the bridging group (A) are represented by C1 to C6 alkylene, substituted C1 to C6 alkylene, oxygen, sulfur, R'2C═, R'2Si═, -Si(R')2Si(R'2)-, R'2Ge═, R'P═ (where "═" represents two chemical bonds), wherein R' is independently selected from hydride, hydrocarbon group, substituted hydrocarbon group, haloalkyl group, substituted haloalkyl group, hydrocarbon group-substituted organometal, haloalkyl group-substituted organometal, disubstituted boron, disubstituted Group 15 atom, substituted Group 16 atom, and halogen radical; and wherein two or more R' may be joined to form a ring or ring system. In some embodiments, the bridged metallocene catalyst component of Structure (II) has two or more bridging groups (A).

[0066] Other non-limiting examples of the bridging group (A) in Structure (II) include methylene, ethylene, ethylidene, propylidene, isopropylidene, diphenylmethylene, 1,2-dimethylethylene, 1,2-diphenylethylene, 1,1,2,2-tetramethylethylene, dimethylsilyl, diethylsilyl, methylethylsilyl, trifluoromethylbutylsilyl, bis(trifluoromethyl)silyl, bis(n-butyl)silyl, bis(n-propyl)silyl, bis(isopropyl)silyl, bis(n-hexyl)silyl, dicyclohexylsilyl, diphenylsilyl, cyclohexylphenylsilyl, tert-butylcyclohexylsilyl, bis(tert-butylphenyl)silyl, bis(p-tolyl)silyl, and the corresponding moieties in which the Si atom is replaced by a Ge or C atom; dimethylsilyl, diethylsilyl, dimethylgermyl, and diethylgermyl.

[0067] In some embodiments, the bridging group (A) in Structure (II) can also be cyclic, containing 4 to 10 ring members or 5 to 7 ring members. The ring members can be selected from the above elements, or from one or more of B, C, Si, Ge, N, and O. Non-limiting examples of ring structures that can be present as or as part of the bridging moiety are cyclobutylidene, cyclopentylidene, cyclohexylidene, cycloheptylidene, cyclooctylidene, and the corresponding rings in which one or two carbon atoms are replaced by at least one of Si, Ge, N, and O (especially Si and Ge). The bonding arrangement between the ring and the Cp group can be cis, trans, or a combination thereof.

[0068] The cyclic bridging group (A) can be saturated or unsaturated and / or carry one or more substituents and / or be fused to one or more other ring structures. If present, one or more substituents can be a hydrocarbon group (e.g., an alkyl group such as methyl) or a halogen (e.g., F, Cl). The above cyclic bridging moieties can optionally be fused to one or more Cp groups, which can be saturated or unsaturated and can be selected from groups having 4 to 10 ring members, more particularly 5, 6, or 7 ring members (selected from C, N, O, and S in one specific embodiment), such as, for example, cyclopentyl, cyclohexyl, and phenyl. In addition, these ring structures themselves can be fused, such as, for example, in the case of a naphthyl group. Further, these (optionally fused) ring structures can carry one or more substituents. Exemplary, non-limiting examples of these substituents are hydrocarbon groups (especially alkyl groups) and halogen atoms.

[0069] In some embodiments, the ligands Cp of Structures (I) and (II) A and Cp B can be different from each other, or in other embodiments can be the same as each other.

[0070] The metallocene catalyst component of the first and / or second catalyst composition may include a mono-ligand metallocene compound, such as a monocyclopentadienyl catalyst component, as described in WO 93 / 08221.

[0071] The metallocene catalyst component may be an unbridged "half-sandwich" metallocene represented by structure (III):

[0072] Cp A MQ q X n (III)

[0073] Wherein Cp A is defined as for the Cp group in structure (I) and is a ligand bonded to M; each Q is independently bonded to M; in one embodiment, Q is also bonded to Cp A ; X is a leaving group as described in structure (I) above; n ranges from 0 to 3, or is 1 or 2; q ranges from 0 to 3, or is 1 or 2.

[0074] Cp A may be selected from cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, their substituted variants, and combinations thereof. In structure (III), Q may be selected from ROO - , RO-, R(O)-, -NR-, -CR2-, -S-, -NR2, -CR3, -SR, -SiR3, -PR2, -H, and substituted and unsubstituted aryl groups, where R is selected from hydrocarbon groups, lower hydrocarbon groups, substituted hydrocarbon groups, hetero-hydrocarbon groups, alkyl groups, lower alkyl groups, substituted alkyl groups, heteroalkyl groups, alkenyl groups, lower alkenyl groups, substituted alkenyl groups, heteroalkenyl groups, alkynyl groups, lower alkynyl groups, substituted alkynyl groups, heteroalkynyl groups, alkoxy groups, lower alkoxy groups, aryloxy groups, hydroxy groups, alkylthio groups, lower alkylthio groups, arylthio groups, thioxy groups, aryl groups, substituted aryl groups, heteroaryl groups, aralkyl groups, aralkenes, alkaryl groups, alkarylenes, halides, haloalkyl groups, haloalkenyl groups, haloalkynyl groups, heteroalkyl groups, heterocycles, heteroaryl groups, heteroatom-containing groups, silyl groups, boryl groups, phosphino groups, phosphines, amino groups, amines, cycloalkyl groups, acyl groups, aroyl groups, alkylthiols, dialkylamines, alkylamides, alkoxycarbonyl groups, aryloxycarbonyl groups, carbamoyl groups, alkylcarbamoyl groups, and dialkylcarbamoyl groups, acyloxy groups, acylamino groups, aroylamino groups, and combinations thereof. R may be selected from C1 to C6 alkyl, C6 to C 12 aryl, C1 to C6 alkylamine, C6 to C 12 alkylarylamine, C1 to C6 alkoxy, C6 to C 12 aryloxy, etc. Non-limiting examples of Q include C1 to C 12 carbamate, C1 to C 12 carboxylate (e.g., pivalate), C2 to C 20 allyl and C2 to C20 Heteroallyl moiety.

[0075] It is contemplated that the metallocene catalyst components described above include their structural or optical or enantiomeric isomers (racemic mixtures), and in one embodiment may be pure enantiomers. As used herein, a single bridged asymmetrically substituted metallocene catalyst component having racemic and / or meso isomers does not itself constitute at least two different bridged metallocene catalyst components. A "metallocene catalyst compound", also referred to herein as a "metallocene catalyst component", may include any combination of any of the "embodiments" described herein.

[0076] A "Group 15-containing catalyst" that can be used as the first and / or second catalyst composition may include Group 3 to Group 12 metal complexes, where the metal is 2- to 8-coordinate and one or more coordinating moieties include at least two Group 15 atoms and at most four Group 15 atoms. For example, a Group 15-containing catalyst component can be a complex of a Group 4 metal and one to four ligands such that the Group 4 metal is at least 2-coordinate and one or more coordinating moieties include at least two nitrogens. Representative Group 15-containing compounds are disclosed in WO Publication No. WO 99 / 01460; European Publication No. EP0893454A1; EP 0894005A1; U.S. Patent Nos. 5,318,935; 5,889,128; 6,333,389 and 6,271,325.

[0077] Group 15-containing catalyst components can include Group 4 imino-phenol complexes, Group 4 bis(amide) complexes, and Group 4 pyridyl-amide complexes, which are somewhat active for olefin polymerization.

[0078] Group 15-containing catalyst components can be represented by Structures (VII) and (VIII):

[0079]

[0080] where E and Z are Group 15 elements, independently selected from nitrogen and phosphorus in one embodiment; and in a more specific embodiment, E and Z are nitrogen, and L and L' may or may not form a bond with M; y is an integer in the range of 0 to 2 (when y is 0, the groups L', *R, and R 3 are absent); M is selected from Group 3 to Group 5 atoms or Group 4 atoms, or selected from Zr and Hf; n is an integer in the range of 1 to 4, or 2 to 3; and each X is as defined above.

[0081] In Structure (VII), L can be selected from Group 15 atoms, Group 16 atoms, Group 15-containing alkylene groups, and Group 16-containing alkylene groups; where when L is a Group 16 atom, R 3is absent. In some embodiments, when R 3 is absent, L is selected from heterocyclic alkylene; or L is selected from nitrogen, phosphorus, anilino, pyridyl, quinolinyl, pyrrolyl, pyrimidinyl, purinyl, imidazolyl, indolyl; C1 to C6 alkyl-substituted groups selected from anilino, pyridyl, quinolinyl, pyrrolyl, pyrimidinyl, purinyl, imidazolyl, and indolyl; C1 to C6 alkylamine-substituted groups selected from anilino, pyridyl, quinolinyl, pyrrolyl, pyrimidinyl, purinyl, imidazolyl, and indolyl; amine-substituted anilino, pyridyl, quinolinyl, pyrrolyl, pyrimidinyl, purinyl, imidazolyl, and indolyl; hydroxyl-substituted groups selected from anilino, pyridyl, quinolinyl, pyrrolyl, pyrimidinyl, purinyl, imidazolyl, and indolyl; methyl-substituted phenylamine, its substituted derivatives, and their chemically bonded combinations.

[0082] In structure (VIII), in one embodiment, L' is selected from Group 15 atoms, Group 16 atoms, and Group 14 atoms; and in a more specific embodiment is selected from Group 15 and Group 16 atoms; and in yet another more specific embodiment is selected from the groups defined above by L, where "EZL" and "EZL'" can be referred to as "ligands", and the EZL and EZL' ligands include R* and R 1 -R 7 groups;

[0083] In structure (VII), R 1 and R 2 are independently: divalent bridging groups selected from alkylene, arylene, heteroatom-containing alkylene, heteroatom-containing arylene, substituted alkylene, substituted arylene, and substituted heteroatom-containing alkylene, where the heteroatom is selected from silicon, oxygen, nitrogen, germanium, phosphorus, boron, and sulfur; or selected from C1 to C 20 alkylene, C6 to C 12 arylene, heteroatom-containing C1 to C 20 alkylene, and heteroatom-containing C6 to C 12 arylene; or selected from -CH2-, -C(CH3)2-, -C(C6H5)2-, -CH2CH2-, -CH2CH2CH2-, -Si(CH3)2-, -Si(C6H5)2-, -C6H 10 -, -C6H4-, and their substituted derivatives, where the substitution includes C1 to C4 alkyl, phenyl, and halogen radicals.

[0084] In structure (VIII), R 3may be absent; or may be a group selected from a hydrocarbyl group, a hydrogen radical, a halogen radical, and a heteroatom-containing group; or may be selected from a straight-chain alkyl group, a cyclic alkyl group, and a branched-chain alkyl group having 1 to 20 carbon atoms.

[0085] In structure (VIII), *R may be absent; or may be a group selected from a hydrogen radical, a group containing a Group 14 atom, a halogen radical, and a heteroatom-containing group.

[0086] In structures (VII) and (VIII), R 4 and R 5 are independently: a group selected from an alkyl group, an aryl group, a substituted aryl group, a cycloalkyl group, a substituted cycloalkyl group, a cycloarylalkyl group, a polycyclic system, and a substituted cycloarylalkyl group, wherein each group has at most 20 carbon atoms, or 3 to 10 carbon atoms; or a group selected from C1 to C 20 alkyl, C1 to C 20 aryl, C1 to C 20 arylalkyl, and a heteroatom-containing group (e.g., PR3, where R is an alkyl group).

[0087] In structures (VII) and (VIII), R 6 and R 7 are independently: absent; or a group selected from a hydrogen radical, a halogen radical, a hydrocarbyl group, and a heteroatom-containing group; or a group selected from a straight-chain, cyclic, and branched-chain alkyl group having 1 to 20 carbon atoms; wherein R 1 and R 2 may associate with each other, and / or R 4 and R 5 may be associated with each other by a chemical bond.

[0088] More specifically described, the Group 15-containing catalyst component can be described as the embodiments shown in structures (IX), (X), and (XI) (where "N" is nitrogen):

[0089]

[0090] wherein structure (IX) represents a pyridyl-amide structure, structure (X) represents an imino-phenol structure, and structure (XI) represents a bis(amide) structure. In these structures, w is an integer from 1 to 3, or 1 or 2, or in some embodiments is 1. In some embodiments, M is an element of Group 3 to Group 13, or an element of Group 3 to Group 6, or an element of Group 4. Each X is independently selected from a hydrogen radical, a halogen ion (desirably, an anion of fluorine, chlorine, and bromine); a C1 to C6 alkyl; a C1 to C6 fluoroalkyl, a C6 to C 12 aryl; a C6 to C 12 fluoroalkyl, a C1 to C6 alkoxy, a C6 to C12 Aryloxy and C7 to C 18 Alkylaryloxy. n is an integer in the range of 0 to 4, or 1 to 3, or 2 to 3, or 2 in some embodiments.

[0091] In addition, in structures (IX), (X), and (XI), R 1 ' may be selected from alkylene and heteroatom-containing alkylene, or may be selected from -SiR2-, alkylene, arylene, alkenylene, and substituted alkylene, substituted alkenylene, and substituted arylene; or may be selected from -SiR2-, C1 to C6 alkylene, C6 to C 12 Arylene, C1 to C6 substituted alkylene, and C6 to C 12 Substituted arylene, wherein R is selected from C1 to C6 alkyl and C6 to C 12 Aryl.

[0092] In addition, in structures (IX), (X), and (XI), R 1 'R 2 ', R 3 ', R 4 ', R 5 ', R 6 ' and R * Are independently selected from hydride, C1 to C 10 Alkyl, C6 to C 12 Aryl, C6 to C 18 Alkylaryl, C4 to C 12 Heterocyclic hydrocarbon group, substituted C1 to C 10 Alkyl, substituted C6 to C 12 Aryl, substituted C6 to C 18 Alkylaryl, and substituted C4 to C 12 Heterocyclic hydrocarbon group, and their chemically bonded combinations. In some embodiments, R* is absent. In some embodiments, R*-N represents a nitrogen-containing group or ring, such as a pyridine group or a substituted pyridine group bridged by the R 1 ' group. In some embodiments, R*-N is absent, and the R 1 ' groups form a chemical bond with each other.

[0093] In some embodiments of structures (IX), (X), and (XI), R 1 ' is selected from methylene, ethylene, 1-propylene, 2-propylene, =Si(CH3)2, =Si(phenyl)2, -CH=, -C(CH3)=, -C(phenyl)2-, -C(phenyl)= (where "=" represents two chemical bonds), etc.

[0094] In a specific embodiment of structure (X), R 2' and R 4 ' is selected from 2-methylphenyl, 2-n-propylphenyl, 2-isopropylphenyl, 2-isobutylphenyl, 2-tert-butylphenyl, 2-fluorophenyl, 2-chlorophenyl, 2-bromophenyl, 2-methyl-4-chlorophenyl, 2-n-propyl-4-chlorophenyl, 2-isopropyl-4-chlorophenyl, 2-isobutyl-4-chlorophenyl, 2-tert-butyl-4-chlorophenyl, 2-methyl-4-fluorophenyl, 2-n-propyl-4-fluorophenyl, 2-isopropyl-4-fluorophenyl, 2-isobutyl-4-fluorophenyl, 2-tert-butyl-4-fluorophenyl, 2-methyl-4-bromophenyl, 2-n-propyl-4-bromophenyl, 2-isopropyl-4-bromophenyl, 2-isobutyl-4-bromophenyl, 2-tert-butyl-4-bromophenyl, etc.

[0095] In some embodiments of structures (IX) and (XI), R 2 ' and R 3 ' is selected from 2-methylphenyl, 2-n-propylphenyl, 2-isopropylphenyl, 2-isobutylphenyl, 2-tert-butylphenyl, 2-fluorophenyl, 2-chlorophenyl, 2-bromophenyl, 4-methylphenyl, 4-n-propylphenyl, 4-isopropylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 6-methylphenyl, 6-n-propylphenyl, 6-isopropylphenyl, 6-isobutylphenyl, 6-tert-butylphenyl, 6-fluorophenyl, 6-chlorophenyl, 6-bromophenyl, 2,6-dimethylphenyl, 2,6-di-n-propylphenyl, 2,6-diisopropylphenyl, 2,6-diisobutylphenyl, 2,6-di-tert-butylphenyl, 2,6-difluorophenyl, 2,6-dichlorophenyl, 2,6-dibromophenyl, 2,4,6-trimethylphenyl, 2,4,6-tri-n-propylphenyl, 2,4,6-triisopropylphenyl, 2,4,6-triisobutylphenyl, 2,4,6-tri-tert-butylphenyl, 2,4,6-trifluorophenyl, 2,4,6-trichlorophenyl, 2,4,6-tribromophenyl, 2,3,4,5,6-pentafluorophenyl, 2,3,4,5,6-pentachlorophenyl, 2,3,4,5,6-pentabromophenyl, etc.

[0096] In some embodiments of structures (IX), (X) and (XI), X is independently selected from fluorine, chlorine, bromine, methyl, ethyl, phenyl, benzyl, phenoxy, benzyloxy, 2-phenyl-2-propoxy, 1-phenyl-2-propoxy, 1-phenyl-2-butoxy, 2-phenyl-2-butoxy, etc.

[0097] Non-limiting examples of catalyst components containing Group 15 are represented by structures (XIIa) to (XIIf) (where "N" is nitrogen):

[0098]

[0099] In structures (XIIa) to (XIIf), M is selected from Group 4 atoms or from Zr and Hf; and wherein R in structures (XIIa) to (XIIf) 1 to R 11 are selected from hydride, fluorine radical, chlorine radical, bromine radical, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl and phenyl; and X is selected from fluoride ion, chloride ion, bromide ion, methyl, phenyl, benzyl, phenoxy and benzyloxy; and n is an integer in the range of 0 to 4, or 2 to 3.

[0100] The catalyst can be a mixed catalyst and can comprise 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 comprising two or more different catalyst components, each of which has a different metal group. The terms "multi-catalyst composition" and "multi-catalyst" include any composition, mixture or system comprising two or more different catalyst components, regardless of metal. Thus, unless otherwise specifically stated, the terms "bimetallic catalyst composition", "bimetallic catalyst", "multi-catalyst composition" and "multi-catalyst" are collectively referred to herein as "mixed catalyst". In one example, the mixed catalyst comprises at least one metallocene catalyst component and at least one non-metallocene component.

[0101] The catalyst can be or include a mixed catalyst containing at least one metallocene component. The catalyst can be a mixed catalyst system comprising at least one metallocene component and at least one Group 15-containing component. The metallocene component and the Group 15-containing component can be as described above. For example, the mixed catalyst can comprise [(2,4,6-Me3C6H2)NCH2CH2]2NHHfBz2 or [(2,4,6-Me3C6H2)NCH2CH2]2NHZrBz2 or [(2,3,4,5,6-Me5C6)NCH2CH2]2NHZrBz2, where Bz is a benzyl group, and the benzyl group is combined with bis(indenyl)zirconium dichloride, (pentamethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride or (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride.

[0102] One or more embodiments provide a catalyst that includes a combination of a metallocene catalyst, a post-metallocene catalyst, a first post-metallocene catalyst and a second post-metallocene catalyst, a Ziegler-Natta catalyst, a combination of a post-metallocene catalyst and a Ziegler-Natta catalyst, a chromium-based catalyst, a combination of two different metallocene catalysts, or a combination of a metallocene catalyst and a post-metallocene catalyst.

[0103] An example of a mixed catalyst system suitable for the present invention is PRODIGY available from Univation Technologies TM A bimodal catalyst.

[0104] A polymerization process can be carried out such that the catalyst composition is heterogeneous and the catalyst composition comprises at least one support material. The support material can be any material known in the art for supporting a catalyst composition, such as inorganic oxides, preferably silica, alumina, silica-alumina, magnesium chloride, graphite, magnesite, titanium dioxide, zirconium oxide, and montmorillonite, any of which can be chemically / physically modified, such as by a fluorination process, calcination, or other methods known in the art. In one embodiment, the support material can be a silica material having an average particle size of 0.1 μm to 100 μm or 10 μm to 50 μm as determined by Malvern analysis.

[0105] An activator can be used in conjunction with the catalyst compound. As used herein, the term "activator" refers to any supported or unsupported compound or combination of compounds that can activate a catalyst compound or component, such as by generating a cationic species of the catalyst component. Exemplary activators include, but are not limited to, aluminoxanes (e.g., methylaluminoxane "MAO"), modified aluminoxanes (e.g., modified methylaluminoxane "MMAO" and / or tetra-isobutyl dialuminoxane "TIBAO"), and alkylaluminum compounds. Ionizing activators (neutral or ionic) such as tris(n-butyl)ammonium tetrakis(pentafluorophenyl)borate can also be used, as well as combinations thereof. The molar ratio of the metal in the activator to the metal in the catalyst composition can be in the range of 1000:0.1 to 0.5:1, 300:1 to 0.5:1, 150:1 to 1:1, 50:1 to 1:1, 10:1 to 0.5:1, or 3:1 to 0.3:1.

[0106] The catalyst composition can include a support material or carrier. As used herein, the terms "support" and "carrier" are used interchangeably and refer to any support material, including porous support materials, such as talc, inorganic oxides, and inorganic chlorides. The catalyst component and / or activator can be deposited on, in contact with, vaporized with, bonded to, or incorporated into one or more supports or carriers, adsorbed or absorbed onto or into them. Other support materials include resin support materials (such as polystyrene), functionalized or crosslinked organic supports (such as polystyrene divinylbenzene polyolefins or polymeric compounds), zeolites, clays, or any other organic or inorganic support materials, etc., or mixtures thereof. Relatively small non-porous supports can be beneficial. For example, silica particles having a particle size of about 15 nm to about 200 nm are suitable for forming spray-dried catalyst particles having a particle size of about 20 μm to about 40 μm.

[0107] The catalyst may be selected from the group consisting of: [(2,4,6-Me3C6H2)NCH2CH2]2NHHfBz2, [(2,4,6-Me3C6H2)NCH2CH2]2NHZrBz2, or [(2,3,4,5,6-Me5C6)NCH2CH2]2NHZrBz2, where Bz is a benzyl group and bis(n-propylcyclopentadienyl)hafnium dichloride. The catalyst composition may further include a catalyst selected from the group consisting of: bis(indenyl)zirconium dichloride, (pentamethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride, or (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride.

[0108] The catalyst composition may comprise a bimodal catalyst composition. Thus, the catalyst composition may include a catalyst selected from the group consisting of: [(2,4,6-Me3C6H2)NCH2CH2]2NHHfBz2, [(2,4,6-Me3C6H2)NCH2CH2]2NHZrBz2, or [(2,3,4,5,6-Me5C6)NCH2CH2]2NHZrBz2, where Bz is a benzyl group and bis(n-propylcyclopentadienyl)hafnium dichloride. The catalyst composition may further include another metallocene catalyst selected from the group consisting of: bis(indenyl)zirconium dichloride, (pentamethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride, or (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dichloride.

[0109] The catalyst composition can be introduced into the catalyst delivery system or reactor at a flow rate as low as about 0.001 kg / hr, about 0.005 kg / hr, about 0.02 kg / hr, 0.1 kg / hr, about 0.5 kg / hr, about 1 kg / hr, about 1.5 kg / hr, about 2 kg / hr, or about 3 kg / hr up to as high as about 5 kg / hr, about 10 kg / hr, about 15 kg / hr, about 20 kg / hr, or about 25 kg / hr, where suitable ranges include combinations of any two values. For example, the catalyst can be introduced at a flow rate of about 0.4 kg / hr to about 23 kg / hr, about 1.4 kg / hr to about 14 kg / hr, or about 2.3 kg / hr to about 4.5 kg / hr. The catalyst can be or include fully formed catalyst particles suspended in one or more inert liquids (e.g., in the form of a catalyst slurry or suspension). For example, the concentration of catalyst particles in the catalyst slurry can range from as low as about 1 wt%, about 5 wt%, about 12 wt%, or about 15 wt% up to as high as about 20 wt%, about 23 wt%, about 25 wt%, or about 30 wt%, where suitable ranges include combinations of any two values. The catalyst can be slurried in any suitable liquid or combination of liquids. Suitable liquids for forming the catalyst slurry can include, but are not limited to, toluene, ethylbenzene, xylene, pentane, hexane, heptane, octane, other hydrocarbons, or any combination thereof. One or more mineral oils or other non-reactive liquid hydrocarbons can also be used to form the catalyst slurry. The catalyst system can also be in the form of a powder (e.g., spray-dried catalyst), liquid, or slurry.

[0110] The reactor can be operated in a condensation mode using ICA. The amount of ICA that can be introduced into the reactor can provide an ICA concentration in the polymerization reactor in the range of as low as about 1 mol%, about 5 mol%, or about 10 mol% up to as high as about 25 mol%, about 35 mol%, or about 45 mol%, where suitable ranges include combinations of any two values. For example, if present, the concentration of ICA can range from about 14 mol%, about 16 mol%, or about 18 mol% up to as high as about 20 mol%, about 22 mol%, or about 24 mol%, where suitable ranges include combinations of any two values. Suitable ICAs are known in the art.

[0111] Continuous additive

[0112] As used herein, a continuity aid is a chemical composition that, when introduced into a fluidized bed reactor, can affect or drive the static charge in the fluidized bed (making it negative, positive, or zero). The specific continuity aid used can depend on the nature of the static charge, and the choice of continuity aid can vary depending on the polyolefin produced and the catalyst compound used.

[0113] Continuity aids such as aluminum stearate can be used. The continuity aids used can be selected based on their ability to receive static charge in the fluidized bed without adversely affecting the production rate. Suitable continuity aids can include aluminum distearate, ethoxylated amines, and antistatic compositions such as those provided by Innospec Inc. under the trade name OCTASTAT. For example, OCTASTAT 2000 is a mixture of polysulfone copolymer, polymeric polyamine, and oil-soluble sulfonic acid.

[0114] Any of the foregoing continuity aids, as well as those described, for example, in WO 01 / 44322 (listed under the heading "Metal salts of carboxylic esters" and including chemicals and compositions listed as antistatic agents), can be used alone or in combination as regulators. For example, a metal salt of a carboxylic ester can be combined with an amine-containing regulator (e.g., a metal salt of a carboxylic ester is combined with any family member belonging to the KEMAMINE (purchased from Crompton Corporation) or ATMER (purchased from ICI Americas Inc.) product families).

[0115] Other useful continuity additives include, for example, ethyleneimine additives that can be used in the embodiments disclosed herein. The polyethyleneimine can include polyethyleneimine having the following general formula:

[0116] -(CH2-CH2-NH) n -

[0117] where n is from about 10 to about 10,000. Commercially available polyethyleneimine can be a compound having a branched chain of ethyleneimine polymer. Suitable polyethyleneimine is available from BASF Corporation under the trade name Lupasol. Another useful continuity additive can include a mixture of aluminum distearate and ethoxylated amine compounds, such as IRGASTAT AS-990 purchased from Huntsman (formerly Ciba Specialty Chemicals). The mixture of aluminum distearate and ethoxylated amine compounds can be slurried in a mineral oil such as Hydrobrite 380. For example, the mixture of aluminum distearate and ethoxylated amine compounds can be slurried in a mineral oil to a total slurry concentration in the range of about 5 wt% to about 50 wt%, or about 10 wt% to about 40 wt%, or about 15 wt% to about 30 wt%.

[0118] Based on the weight of all feeds entering the reactor (excluding recycle materials), the continuous additive can be added to the reactor in an amount of ≥ 0.05 ppm (e.g., ≥ 0.10 ppm, ≥ 1.0 ppm, ≥ 2.0 ppm, ≥ 4.0 ppm, ≥ 10.0 ppm, ≥ 20.0 ppm, ≥ 30.0 ppm, ≥ 40.0 ppm, ≥ 50.0 ppm, ≥ 60.0 ppm, ≥ 70.0 ppm, ≥ 80.0 ppm, ≥ 90.0 ppm, ≥ 100.0 ppm, ≥ 125.0 ppm, ≥ 150.0 ppm, or ≥ 175.0 ppm). Additionally or alternatively, the amount of the continuous additive can be ≤ 200.0 ppm, e.g., ≤ 175.0 ppm, ≤ 150.0 ppm, ≤ 125.0 ppm, ≤ 100.0 ppm, ≤ 90.0 ppm, ≤ 80.0 ppm, ≤ 70.0 ppm, ≤ 60.0 ppm, ≤ 50.0 ppm, ≤ 40.0 ppm, ≤ 30.0 ppm, ≤ 20.0 ppm, ≤ 10.0 ppm, ≤ 4.0 ppm, ≤ 2.0 ppm, ≤ 1.0 ppm, or ≤ 0.10 ppm. The explicitly disclosed concentration ranges of the continuous aids include the ranges formed by any pair of the above values, e.g., 2.0 ppm to 100.0 ppm, 4.0 ppm to 50.0 ppm, 10.0 ppm to 40.0 ppm, etc.

[0119] Polyolefin product

[0120] The polyolefin product (e.g., polyolefin particles) can be or include various types of polyolefins. Examples of polyolefins include, but are not limited to, polyolefins containing one or more linear, branched, or cyclic C2 to C 40 olefins, preferably polymers containing propylene, which propylene copolymerizes with one or more C3 to C 40 olefins, preferably C3 to C 20 alpha-olefins, or C3 to C 10 alpha-olefins. Preferred polyolefins include, but are not limited to, polymers containing ethylene, including, but not limited to, ethylene copolymerized with C3 to C 40 olefins, preferably C3 to C 20 alpha-olefins, such as propylene and / or butene.

[0121] Preferred polyolefin products include C2 to C 40 olefins, preferably C2 to C 20Homopolymers or copolymers of olefins, such as copolymers of α-olefins and another olefin or α-olefins (ethylene can be defined as an α-olefin). In one or more embodiments, the polyolefin product is or includes homopolyethylene, homopolypropylene, propylene copolymerized with ethylene and / or butene, ethylene copolymerized with one or more of propylene, butene or hexene, and optionally diene. 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 copolymers of propylene with 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. One or more embodiments provide that the polyolefin particles include low density polyethylene; or linear low density polyethylene or high density polyethylene; or very low linear density polyethylene. One or more embodiments provide that the polyolefin particles include polyethylene particles (e.g., polyethylene homopolymer), polypropylene particles or ethylene / (C4-C12) α-olefin copolymer particles (e.g., ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer or ethylene / 1-octene copolymer). One or more embodiments provide that one or more olefin monomers include ethylene, propylene, (C4-C12) α-olefin or combinations of any two or more thereof.

[0122] Polyolefin products can be characterized by their density. The density can be determined according to ASTM D-792. Unless otherwise specified, the density is expressed in grams per cubic centimeter (g / cm 3 ). The polyolefin composition can have a density of ≥ about 0.870 g / cm 3 (e.g., ≥ about 0.880 g / cm 3 , ≥ about 0.890 g / cm 3 , ≥ about 0.900 g / cm 3 , ≥ about 0.910 g / cm 3 , ≥ about 0.920 g / cm 3 , ≥ about 0.930 g / cm 3 , ≥ about 0.940 g / cm 3 , ≥ about 0.950 g / cm 3 or ≥ about 0.960 g / cm 3 ). Additionally or alternatively, the density of the polyolefin composition can be ≤ about 0.970 g / cm 3 , e.g., ≤ about 0.970 g / cm 3 , ≤ about 0.970 g / cm 3 , ≤ about 0.970 g / cm 3, ≤ about 0.960 g / cm 3 , ≤ about 0.950 g / cm 3 , ≤ about 0.940 g / cm 3 , ≤ about 0.930 g / cm 3 , ≤ about 0.920 g / cm 3 , ≤ about 0.910 g / cm 3 , ≤ about 0.900 g / cm 3 , ≤ about 0.890 g / cm 3 or ≤ about 0.880 g / cm 3 .

[0123] The polyolefin product is characterized by a melt flow index, also known as I 21 or I 21.6 . The melt flow index can be ≥ about 1.0, for example, ≥ about 2.0, ≥ about 2.5, ≥ about 4.0, ≥ about 5.0, ≥ about 7.0, ≥ about 10.0, ≥ about 25.0, ≥ about 50.0, ≥ about 100.0, ≥ about 125.0, ≥ about 250.0, ≥ about 500.0 or ≥ about 750.0. Additionally or alternatively, the melt flow index can be ≤ about 1000.0 g / 10 min, for example, ≤ about 750.0 g / 10 min, ≤ about 500.0 g / 10 min, ≤ about 250.0 g / 10 min, ≤ about 125.0 g / 10 min, ≤ about 100.0 g / 10 min, ≤ about 50.0 g / 10 min, ≤ about 25.0 g / 10 min, ≤ about 10.0 g / 10 min, ≤ about 7.0 g / 10 min, ≤ about 5.0 g / 10 min, ≤ about 4.0 g / 10 min, ≤ about 2.5 g / 10 min or ≤ about 2.0 g / 10 min. The melt flow index range of the polyolefin composition prepared by the method herein includes ranges formed by any combination of the explicitly disclosed values, for example, about 1.0 g / 10 min to about 1000.0 g / 10 min, about 2.0 g / 10 min to about 750.0 g / 10 min, about 2.5 g / 10 min to about 500.0 g / 10 min, about 4.0 g / 10 min to about 250.0 g / 10 min, about 5.0 g / 10 min to about 125.0 g / 10 min, about 7.0 g / 10 min to about 100.0 g / 10 min, about 10.0 g / 10 min to about 50.0 g / 10 min, etc.

[0124] Various aspects of the present disclosure are provided as follows.

[0125] Aspect 1 provides a method for reducing triboelectrification and / or reactor fouling of polyolefin particles in a fluidized bed type gas phase polymerization reactor (FBT-GPP reactor), the fluidized bed type gas phase polymerization reactor comprising a distributor plate and a wall defining a reaction zone, wherein the polyolefin particles are located in the reaction zone and the reaction zone is located above the distributor plate and in fluid communication with the distributor plate, the method comprising: feeding an argon / nitrogen mixture upward through the distributor plate into the reaction zone to fluidize the polyolefin particles in the reaction zone, wherein the argon / nitrogen mixture consists of 5 volume % (vol%) to not more than 65 volume % of argon, 95 volume % to not less than 10 volume % of nitrogen, and 0 volume % to not more than 5 volume % of helium, wherein the sum of all these volume % is equal to 100 volume % of the argon / nitrogen mixture.

[0126] Aspect 2 provides the method according to aspect 1, wherein reducing triboelectrification means that the charge of the polyolefin particles is lower than the charge of the polyolefin particles in a comparative method using an inert gas of 100 volume % of nitrogen instead of the argon / nitrogen mixture; and wherein the triboelectric charge of the polyolefin particles is measured on a sample of polyolefin particles taken from the FBT-GPP reactor, wherein the measurement is carried out according to the charge measurement test method described herein; or wherein the FBT-GPP reactor comprises an electrostatic probe, and the triboelectric charge of the polyolefin particles is measured by the electrostatic probe; and / or wherein reducing reactor fouling means that the amount of adherent polyolefin material in the FBT-GPP reactor is lower, if any, than the amount of adherent polyolefin material in the FBT-GPP reactor of a comparative method using an inert gas of 100 volume % of nitrogen instead of the argon / nitrogen mixture.

[0127] Aspect 3 provides a method according to Aspect 1 or Aspect 2, wherein the argon / nitrogen mixture has any one of the limitations (i) to (v): (i) the amount of argon is: (a) 9 vol% to not more than 65 vol% of argon, (b) 10 vol% to not more than 60 vol% of argon, (c) 10 vol% to not more than 55 vol% of argon, (d) 10 vol% to not more than 50 vol% of argon, (e) 10 vol% to not more than 45 vol% of argon, or (f) 10 vol% to not more than 35 vol% of argon; (ii) the amount of nitrogen is: (a) 90 vol% to not less than 35 vol% of nitrogen, (b) 90 vol% to not less than 40 vol% of nitrogen, (c) 90 vol% to not less than 45 vol% of nitrogen, (d) 90 vol% to not less than 50 vol% of nitrogen, (e) 90 vol% to not less than 55 vol% of nitrogen, or (f) 90 vol% to not less than 65 vol% of nitrogen; (iii) the amount of argon and the amount of nitrogen are selected from the group consisting of: limitation (i)(a) and (ii)(a), limitation (i)(b) and (ii)(b), limitation (i)(c) and (ii)(c), limitation (i)(d) and (ii)(d), limitation (i)(e) and (ii)(e), or limitation (i)(f) and (ii)(f); (iv) the argon / nitrogen mixture does not contain helium (i.e., 0 vol% of helium); or (v) limitation (iv) and any one of limitations (i) to (iii).

[0128] Aspect 4 provides a method according to Aspect 1, Aspect 2, or Aspect 3, the method having any one of the limitations (i) to (iii): (i) wherein the reduction of triboelectrification means that, relative to the triboelectric charge of the comparative polyolefin particles fluidized for 10 hours in a comparative method using an inert gas of 100 vol% of nitrogen instead of the argon / nitrogen mixture, after fluidizing for 10 hours with the argon / nitrogen mixture, the triboelectric charge of the polyolefin particles is reduced by at least 10%, alternatively at least 20%, alternatively at least 30%; (ii) wherein the reduction of reactor fouling means that, relative to the amount of polyolefin material adhered in the FBT - GPP reactor after 10 hours in a comparative method using an inert gas of 100 vol% of nitrogen instead of the argon / nitrogen mixture, the amount of polyolefin material adhered in the FBT - GPP reactor after 10 hours is reduced by at least 10%, alternatively at least 20%, alternatively at least 30%, if any, and wherein the amount of the adhered polyolefin material is equal to any one of amounts (a) to (d): (a) the weight of the polyolefin particles adhered to the distributor plate, (b) the weight of the polyolefin particles adhered to the reactor wall, or (c) the sum of weights (a) to (b); or (iii) both limitations (i) and (ii).

[0129] Aspect 5 provides a method according to Aspect 1, Aspect 2, Aspect 3 or Aspect 4, wherein the FBT-GPP reactor comprises a bottom region, the distributor plate, the wall defining the reaction zone, the wall defining the deceleration zone, a recycle line and a compressor, a line for introducing a feed and an outlet for removing polyolefin particles, which are in fluid communication in sequence; wherein the recycle line fluidly connects the deceleration zone to the compressor and fluidly connects the compressor to the bottom zone.

[0130] Aspect 6 provides a method according to Aspect 5, the method comprising contacting a feed of an olefin polymerization catalyst and a feed of one or more olefin monomers in the reaction zone to polymerize the one or more olefin monomers and prepare the polyolefin particles, wherein the feed of the argon / nitrogen mixture and the contacting step are carried out simultaneously; wherein the one or more feeds of the one or more olefin monomers include injecting the one or more olefin monomers into the bottom region, the reaction zone, the recycle line, or any combination of two or more of them; wherein the feed of the polymerization catalyst includes injecting the olefin polymerization catalyst into the reaction zone, the deceleration zone or both; and wherein the feed of the argon / nitrogen mixture includes injecting the argon / nitrogen mixture into the bottom region, the recycle line or both; wherein a recycle gas mixture comprising one or more process gases has been removed from the deceleration zone, compressed by the compressor and fed to the bottom region, all via the recycle line.

[0131] Aspect 7 provides a method according to Aspect 6, wherein the olefin polymerization catalyst is fed in the form of a dry solid or a slurry, the slurry comprising a solid olefin polymerization catalyst dispersed in a saturated hydrocarbon (such as mineral oil or isopentane).

[0132] Aspect 8 provides a method according to Aspect 6 or Aspect 7, wherein the one or more olefin monomers include ethylene, propylene, (C4-C12) α-olefins, or any combination of two or more of them; wherein the olefin polymerization catalyst includes a metallocene catalyst, a post-metallocene catalyst, a combination of a first post-metallocene catalyst and a second post-metallocene catalyst, a Ziegler-Natta catalyst, a combination of a post-metallocene catalyst and a Ziegler-Natta catalyst, a chromium-based catalyst, a combination of two different metallocene catalysts, or a combination of a metallocene catalyst and a post-metallocene catalyst; and wherein the polyolefin particles include polyethylene particles (such as polyethylene homopolymers), polypropylene particles or ethylene / (C4-C12) α-olefin copolymer particles (such as ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer or ethylene / 1-octene copolymer).

[0133] Aspect 9 provides a method according to Aspect 1, Aspect 2, Aspect 3, Aspect 4, Aspect 5, Aspect 6, Aspect 7 or Aspect 8, wherein the polyolefin particles comprise low density polyethylene; or wherein the polyolefin particles comprise linear low density polyethylene or high density polyethylene; or wherein the polyolefin particles comprise very low linear density polyethylene.

[0134] Aspect 10 provides a method according to Aspect 1, Aspect 2, Aspect 3, Aspect 4, Aspect 5, Aspect 6, Aspect 7, Aspect 8 or Aspect 9, wherein the method comprises operating an olefin polymerization process in the FBT-GPP reactor at an operating temperature of 70 °C to 120 °C and an operating total pressure of 1,500 kilopascals (kPa) to 3,000 kPa.

[0135] Aspect 11 provides a method according to Aspect 1, Aspect 2, Aspect 3, Aspect 4, Aspect 5, Aspect 6, Aspect 7, Aspect 8 or Aspect 9, wherein the method comprises starting the FBT-GPP reactor, wherein during the start-up, the temperature of the polyolefin particles in the reaction zone is 20 °C to less than 80 °C, and the total pressure in the reaction zone is 100 kilopascals (kPa) to less than 1,500 kPa.

[0136] Aspect 12 provides a method according to Aspect 1, Aspect 2, Aspect 3, Aspect 4, Aspect 5, Aspect 6, Aspect 7, Aspect 8, Aspect 9, Aspect 10 or Aspect 11, wherein the polyolefin particles are also fluidized by one or more process gases selected from the group consisting of hydrogen, one or more olefin monomer gases and one or more alkane gases, wherein the one or more process gases can be independently fed fresh into the reaction zone of the FBT-GPP reactor, or fed into the reaction zone of the FBT-GPP reactor as an upflow recycle gas mixture through the distributor plate, or a combination thereof.

[0137] Aspect 13 provides a method according to Aspect 1, Aspect 2, Aspect 3, Aspect 4, Aspect 5, Aspect 6, Aspect 7, Aspect 8, Aspect 9, Aspect 10, Aspect 11 or Aspect 12, the method comprising feeding the argon / nitrogen mixture as an upflow through the distributor plate into the reaction zone, including for a continuous fixed time interval.

[0138] Aspect 14 provides a method according to Aspect 1, Aspect 2, Aspect 3, Aspect 4, Aspect 5, Aspect 6, Aspect 7, Aspect 8, Aspect 9, Aspect 10, Aspect 11, Aspect 12 or Aspect 13, wherein feeding the argon / nitrogen mixture as an upflow through the distributor plate into the reaction zone includes in response to a deviation from steady-state polymerization process conditions.

[0139] Aspect 15 provides a method for reducing static charge in a fluidized bed type gas phase polymerization reactor (FBT-GPP reactor), the method comprising: feeding a starting gas into the FBT-GPP reactor to provide a starting gas environment, wherein the starting gas consists of 80 volume % (vol%) to 100 volume % of argon and 0 volume % to 20 volume % of nitrogen, wherein the sum of all these volume % is equal to 100 volume % of the starting gas.

[0140] Aspect 16 provides the method according to aspect 15, wherein when feeding the starting gas, no polymerization catalyst is fed into the FBT-GPP reactor.

[0141] Aspect 17 provides the method according to aspect 15 or aspect 16, wherein the starting gas environment is maintained for 5 minutes to 12 hours.

[0142] Examples

[0143] Example 1 was carried out as follows.

[0144] Figure 2 A schematic diagram of an example system 230 according to various embodiments described herein is depicted. A stainless steel column 231 (inner diameter 10 cm; column height 1.2 m) is equipped with a Faraday cage 232 at the top of the column and a Faraday cage 233 at the bottom of the column; a valve 234 (a knife gate valve with a perforated stainless steel door) is located right above the lower Faraday cage; a mass flow controller 235 (MKS model 1559) is used to measure and regulate the gas flow into the column. A gas correction factor is used for argon, and the mass flow controller is calibrated for air / nitrogen. A first hygrometer is used to measure the relative humidity and temperature of the gas; a second hygrometer is used to measure the ambient relative humidity and temperature. The static charge of the particles is measured using two Faraday cages, each connected to a digital electrometer 236 (Keithley 6514). LabVIEW software is used to control and record parameters.

[0145] The valve was closed, and polyolefin particles (1 kg; LLDPE; particle size distribution 20 μm to 2000 μm; particle Sauter mean diameter 947 μm; particle density 917 kg / m 3; purchased from UNIVATION TECHNOLOGIES, LLC) was poured into the column. After loading the polyolefin particles, the filter bag 237 was attached to the column, inside the top Faraday cage. The top Faraday cage was open to the atmosphere to allow the fluidization gas to be discharged into a duct attached to a fume hood. The fluidization gas was fed to the bottom of the column, below both the lower Faraday cage and the valve. The fluidization gas for the gas mixture tests was fed at a predetermined flow rate through two different flow meters. Continuous fluidization was also carried out, where the particles were fluidized with a pure nitrogen gas flow for 50 minutes, after which the nitrogen gas flow was reduced while the argon gas flow was increased until it reached the desired flow rate. The particles were then fluidized again with pure argon gas for 10 minutes. In all tests, the gas velocity of the fluidization gas was adjusted to U-U mf to be maintained at 0.1 m / s to fluidize the polyolefin particles for approximately 60 minutes. During the fluidization process, the charge of the entrained fines was cumulatively measured using the top Faraday cage. After fluidization, the flow of the fluidization gas was stopped and the filter bag was removed to measure the mass of the fines collected therein. The mass (m) and the static charge (Q) of the collected fines (entrained fine particles) were recorded. Then, the valve was opened and most of the fluidized particles were collected in the bottom Faraday cage; these particles were used to determine the charge-to-mass ratio (Q / m) (bulk particles). Then, the bottom Faraday cage was cleaned and reattached. Then, the inner surface of the column was inspected for particles (scaling particles) adhering to the column due to triboelectrification. Two regions were identified along the column wall, including: region 1238, located between the distributor plate and the static bed height; and region 2 239, located between the static bed height and the column outlet (i.e., consisting of the expanded bed height section and the free space section). The particles adhering to the column in each of region 1 and region 2 were discharged separately using a jet of compressed dry air, collected in the bottom Faraday cage, to measure the mass and charge for net Q / m determination. Then the column was cleaned and purged for subsequent runs. Examples 2 to 5 and Comparative Example A were carried out as in Example 1, using the different fluidization gases shown in Tables 1 to 2.

[0146] Table 1

[0147]

[0148]

[0149] The data in Table 1 show that, compared with Comparative Example A, the particle charge in Region 1 is improved, e.g., reduced, for each of Examples 1 to 3. The data in Table 1 also show that, compared with Comparative Example A, the total mass of fouling particles is improved, e.g., reduced, for each of Examples 1 to 3. Reducing fouling (i.e., the total mass of fouling particles) is desirable for many applications. The data in Table 1 also show that, as expected, there is no significant difference in the mass of fouling particles and the mass of entrained fine particles in Region 2 due to less particle contact and less charge dissipation.

[0150] Table 2

[0151]

[0152] The data in Table 2 show that, compared with Comparative Example A (see Table 1), the particle charge in Region 1 is improved, e.g., reduced, for each of Examples 4 to 5. The data in Table 2 also show that, compared with Comparative Example A (see Table 1), the total mass of fouling particles is improved, e.g., reduced, for each of Examples 4 to 5. Examples 4 to 5 provide various conditions that can be observed during the startup procedure, e.g., the case where argon is regarded as the startup gas.

Claims

1. A method for reducing triboelectrification and / or reactor fouling of polyolefin particles in a fluidized bed type gas phase polymerization reactor (FBT - GPP reactor), the fluidized bed type gas phase polymerization reactor comprising a distributor plate and a wall defining a reaction zone, wherein the polyolefin particles are located in the reaction zone and the reaction zone is located above the distributor plate and is in fluid communication with the distributor plate, the method comprising: Feeding an argon / nitrogen mixture upward through the distributor plate into the reaction zone to fluidize the polyolefin particles in the reaction zone, wherein the argon / nitrogen mixture consists of 5 volume % (vol%) to not more than 65 volume % of argon, 95 volume % to not less than 10 volume % of nitrogen, and 0 volume % to not more than 5 volume % of helium, wherein the sum of all these volume % is equal to 100 volume % of the argon / nitrogen mixture.

2. The method according to claim 1: wherein reducing triboelectrification means that the static charge of the polyolefin particles is lower than the static charge of the polyolefin particles in a comparative method using an inert gas of 100 volume % of nitrogen instead of the argon / nitrogen mixture; and wherein the triboelectric charge of the polyolefin particles is measured on a sample of the polyolefin particles taken out from the FBT - GPP reactor, wherein the measurement is carried out according to the charge measurement test method described herein; or wherein the FBT - GPP reactor comprises an electrostatic probe, and the triboelectric charge of the polyolefin particles is measured by the electrostatic probe; and / or wherein reducing reactor fouling means that the amount of adhered polyolefin material in the FBT - GPP reactor is lower, if any, than the amount of adhered polyolefin material in the FBT - GPP reactor of a comparative method using an inert gas of 100 volume % of nitrogen instead of the argon / nitrogen mixture.

3. The method according to claim 1 or claim 2, wherein the argon / nitrogen mixture has any one of the limitations (i) to (v): (i) The amount of argon is: (a) 9 volume % to not more than 65 volume % of argon, (b) 10 volume % to not more than 60 volume % of argon, (c) 10 volume % to not more than 55 volume % of argon, (d) 10 volume % to not more than 50 volume % of argon, (e) 10 volume % to not more than 45 volume % of argon, or (f) 10 volume % to not more than 35 volume % of argon; (ii) The amount of nitrogen is: (a) 90 volume % to not less than 35 volume % of nitrogen, (b) 90 volume % to not less than 40 volume % of nitrogen, (c) 90 volume % to not less than 45 volume % of nitrogen, (d) 90 volume % to not less than 50 volume % of nitrogen, (e) 90 volume % to not less than 55 volume % of nitrogen, or (f) 90 volume % to not less than 65 volume % of nitrogen; (iii) The amount of the argon and the amount of the nitrogen are selected from the group consisting of: limitation (i)(a) and (ii)(a), limitation (i)(b) and (ii)(b), limitation (i)(c) and (ii)(c), limitation (i)(d) and (ii)(d), limitation (i)(e) and (ii)(e), or limitation (i)(f) and (ii)(f); (iv) The argon / nitrogen mixture does not contain helium (i.e., 0 volume % of helium); or (v) Limitation (iv) and any one of limitations (i) to (iii).

4. The method according to any one of claims 1 to 3, the method having any one of limitations (i) to (iii): (i) Wherein the reduction of triboelectrification means that, relative to the triboelectric charge of the comparative polyolefin particles fluidized for 10 hours in a comparative method using an inert gas of 100 volume % of nitrogen in place of the argon / nitrogen mixture, after fluidizing for 10 hours with the argon / nitrogen mixture, the triboelectric charge of the polyolefin particles is reduced by at least 10%, alternatively at least 20%, alternatively at least 30%; (ii) Wherein the reduction of reactor fouling means that, relative to the amount of polyolefin material adhered in the FBT-GPP reactor after 10 hours in a comparative method using an inert gas of 100 volume % of nitrogen in place of the argon / nitrogen mixture, the amount of polyolefin material adhered in the FBT-GPP reactor after 10 hours is reduced by at least 10%, alternatively at least 20%, alternatively at least 30%, if any, and wherein the amount of the adhered polyolefin material is equal to any one of amounts (a) to (d): (a) the weight of the polyolefin particles adhered to the distributor plate, (b) the weight of the polyolefin particles adhered to the reactor wall, or (c) the sum of weights (a) to (b); or (iii) Both of limitations (i) and (ii).

5. The method according to any one of claims 1 to 4, wherein the FBT-GPP reactor comprises a bottom region, the distributor plate, the wall defining the reaction zone, the wall defining the deceleration zone, a recycle line and a compressor, a line for introducing a feed, and an outlet for removing polyolefin particles, and optionally an electrostatic probe, which are in fluid communication in sequence; wherein the recycle line fluidly connects the deceleration zone to the compressor and fluidly connects the compressor to the bottom zone.

6. The method according to claim 5, the method comprising contacting a feed of an olefin polymerization catalyst and a feed of one or more olefin monomers in the reaction zone to polymerize the one or more olefin monomers and produce the polyolefin particles, wherein the feed of the argon / nitrogen mixture and the contacting step are carried out simultaneously; wherein the one or more feeds of the one or more olefin monomers include injecting the one or more olefin monomers into the bottom region, the reaction zone, the recycle line, or any combination of two or more thereof; wherein the feed of the polymerization catalyst includes injecting the olefin polymerization catalyst into the reaction zone, the deceleration zone, or both; and wherein the feed of the argon / nitrogen mixture includes injecting the argon / nitrogen mixture into the bottom region, the recycle line, or both; wherein a recycle gas mixture comprising one or more process gases has been removed from the deceleration zone, compressed by the compressor, and fed to the bottom region, all via the recycle line.

7. The method according to claim 6, wherein the olefin polymerization catalyst is fed in dry solid or slurry form, the slurry comprising a solid olefin polymerization catalyst dispersed in a saturated hydrocarbon (e.g., mineral oil or isopentane).

8. The method according to claim 6 or claim 7, wherein the one or more olefin monomers include ethylene, propylene, (C4-C12) α-olefins, or any combination of two or more thereof; wherein the olefin polymerization catalyst includes a metallocene catalyst, a post-metallocene catalyst, a combination of a first post-metallocene catalyst and a second post-metallocene catalyst, a Ziegler-Natta catalyst, a combination of a post-metallocene catalyst and a Ziegler-Natta catalyst, a chromium-based catalyst, a combination of two different metallocene catalysts, or a combination of a metallocene catalyst and a post-metallocene catalyst; and wherein the polyolefin particles include polyethylene particles (e.g., polyethylene homopolymer), polypropylene particles, or ethylene / (C4-C12) α-olefin copolymer particles (e.g., ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, or ethylene / 1-octene copolymer).

9. The method according to any one of claims 1 to 8, wherein the polyolefin particles include low density polyethylene; or wherein the polyolefin particles include linear low density polyethylene or high density polyethylene; or wherein the polyolefin particles include very low linear density polyethylene.

10. The method according to any one of claims 1 to 9, wherein the method comprises operating an olefin polymerization process in the FBT-GPP reactor at an operating temperature of 70 °C to 120 °C and an operating total pressure of 1,500 kPa to 3,000 kPa.

11. The method according to any one of claims 1 to 9, wherein the method comprises starting the FBT-GPP reactor, wherein during the start-up, the temperature of the polyolefin particles in the reaction zone is from 20 °C to less than 80 °C, and the total pressure in the reaction zone is from 100 kilopascals (kPa) to less than 1,500 kPa.

12. The method according to any one of claims 1 to 11, wherein the polyolefin particles are further fluidized by one or more process gases selected from the group consisting of hydrogen, one or more olefin monomer gases, and one or more alkane gases, wherein the one or more process gases can be independently fed fresh to the reaction zone of the FBT-GPP reactor, or fed as a recycle gas mixture upward through the distributor plate to the reaction zone of the FBT-GPP reactor, or a combination thereof.

13. The method according to any one of claims 1 to 12, the method comprising feeding the argon / nitrogen mixture upward through the distributor plate to the reaction zone, including for a continuous fixed time interval.

14. The method according to any one of claims 1 to 13, wherein feeding the argon / nitrogen mixture upward through the distributor plate to the reaction zone includes in response to a deviation from steady-state polymerization process conditions.

15. A method for reducing static charge in a fluidized bed type gas phase polymerization reactor (FBT-GPP reactor), the method comprising: feeding a start-up gas to the FBT-GPP reactor to provide a start-up gas environment, wherein the start-up gas consists of 80 volume percent (vol%) to 100 volume percent of argon and 0 volume percent to 20 volume percent of nitrogen, wherein the sum of all these volume percents equals 100 volume percent of the start-up gas.

16. The method according to claim 15, wherein no polymerization catalyst is fed to the FBT-GPP reactor when feeding the start-up gas.

17. The method according to any one of claims 15 to 16, wherein the start-up gas environment is maintained for 5 minutes to 12 hours.

Images