WO2024069248A1

WO2024069248A1 - Polyolefin catalyst activity aid

Info

Publication number: WO2024069248A1
Application number: PCT/IB2023/053586
Authority: WO
Inventors: Liang XIONG
Original assignee: Cestoil Chemical Inc.
Priority date: 2022-09-27
Filing date: 2023-04-07
Publication date: 2024-04-04

Abstract

A catalyst activity aid for improving the productivity of a catalyst in polymerization processes is disclosed. The catalyst activity aid comprises a mixture of (a) a polysulfone copolymer; (b) a polyquaternary ammonium salt; and (c) a carrier fluid. The catalyst activity aid is particularly suitable for improving the catalyst productivity of metallocene catalysts used in polymerization processes such as those for the production of ethylene-based and propylene-based polymers.

Description

POLYOLEFIN CATALYST ACTIVITY AID

FIELD OF THE INVENTION

[0001] The present technology relates to an additive system for use in polymerization processes. In particular, the present technology relates to an additive system that can mitigate or eliminate the static charge buildup and fouling that can occur during polymerization, while also increasing catalyst activity. The additive system comprises a polysulfone, a polyquaternary ammonium salt, and a carrier fluid, and is particularly suitable for use in the manufacture of polymers for food grade applications.

BACKGROUND

[0002] The expansion of the polyolefin industry is driven by factors such as a new generation of catalysts, the lightweight material requirements in the auto industry, and consumption growth in India, Brazil, and other countries. Metallocene catalysts allow the production of polyolefins with unique structural properties, such as narrow molecular weight distribution and more uniform comonomer distribution, which can provide improved physical properties, such as tensile strength and puncture resistance. Processes for preparing metallocene-catalyzed polyolefins include gasphase fluidized bed and gas-phase stirred bed processes.

[0003] Metallocene catalysts also present challenges to traditional polymerization systems, such as gas-phase reactors. These challenges include static induced polymer agglomeration within the reactor chambers, which can produce “sheeting” or large accumulations of polyolefin on the reactor walls. The polymer agglomerates may become dislodged from the walls and fall into the reaction section, where they could interfere with fluidization and block the product discharge port. Significant sheeting or fouling typically requires shut down of the reactor for cleaning.

[0004]As a result of the risks associated with reactor discontinuity problems when using metallocene catalysts, various techniques have been developed in an attempt to minimize such problems. These techniques include modifying the support systems for metallocene catalysts, coating the polymerization equipment, controlling the polymerization rate, modifying the reactor design, and injecting various agents into the reactor, such as antistatic agents and process “continuity additives”.

[0005] Antistatic agents that have been developed are intended to control reactor static and mitigate sheeting and fouling, thereby improving gas phase reactor operability and continuity. For example, antistatic agents can be introduced into a fluidized bed reactor to influence or drive the static charge in the fluidized bed in a desired direction. Depending upon the static control agent used, the resulting static charge in the fluidized bed may be negative, positive, or neutral charge. Examples of antistatic agents that have been used to control static levels in a reactor include aluminum stearate, aluminum distearate, ethoxylated amines, a mixture of carboxylated metal salts with amine-containing compounds, and a mixture containing a polysulfone, a polymeric polyamine, a sulfonic acid, and a liquid carrier.

[0006] Although antistatic agents may be effective for controlling static, they also may result in reduced catalytic productivity. The reduced productivity may be the result of interaction between the polymerization catalyst and the antistatic agent, such as reaction or complexation with hydroxyl groups in the antistatic agent compounds. Depending on the type of antistatic agent used and the amount required to limit sheeting, catalyst activity could be decreased by as much as 40%. Ensuring that the amount of antistatic agent present in the reactor is sufficient to avoid adhesion of the polymer to the walls of the reactor, yet is not so much that the catalyst is poisoned can be difficult to accomplish.

[0007]A further difficulty with antistatic agents and continuity additives is that they often do not meet regulatory requirements for use in products that come into contact with food. For example, liquid carriers for the mixture of a polysulfone, a polymeric polyamine, and a sulfonic acid are often solvents such as toluene, naphtha, naphthalene, or short chain alcohols, such as methanol and isopropanol. These liquid carriers do not meet food-grade regulatory approval requirements.

[0008] There is therefore a need for an additive system that can maintain catalyst activity, eliminate the static charge and fouling in gas-phase or low pressure liquid slurry reactors, efficiently mitigate fouling, and be suitable for contact with food. It would also be of great benefit if the additive system could increase the activity of the metallocene catalyst, as well as the activity of other known catalysts, such as chromium-based catalysts, Ziegler-Natta catalysts, and metathesis catalysts.

BRIEF SUMMARY OF THE INVENTION

[0009] The present technology relates to an additive system comprising a polysufone, a polyquaternary ammonium salt, and a carrier fluid, for use in polymerization processes. Surprisingly, it has been found that the additive system not only controls static and eliminates reactor fouling, but also increases catalyst activity of a metallocene catalyst during gas-phase polymerization compared to the catalyst activity of a gas-phase polymerization conducted without the additive system.

[0010] In one aspect, the present technology provides a catalyst activity aid comprising about 1 wt% to about 25 wt% polysulfone copolymer; about 1 wt% to about 50 wt% polyquaternary ammonium salt comprising a polycationic polyamine and an oil-soluble organic counterion; and about 25 wt% to about 95 wt% of a carrier fluid comprising at least one of pentane, hexane, heptane, dodecane, and a food grade oil.

[0011 ] In a related aspect, the present technology provides a process for polymerizing one or more olefins comprising the steps of feeding one or more olefins to a polymerization reactor in the presence of at least one catalyst; and feeding a catalyst activity aid to the polymerization reactor during polymerization of the one or more olefins, wherein the catalyst activity aid comprises 1 wt% to 25 wt% polysulfone copolymer; 1 wt% to 50 wt% polyquaternary ammonium salt comprising a polycationic polyamine and an oil-soluble organic counterion; and 25 wt% to 95 wt% of a carrier fluid comprising at least one of pentane, hexane, heptane, dodecane, and a food grade oil.

DETAILED DESCRIPTION OF THE INVENTION

[0012] As used herein, the term “food grade oil” refers to any industrial oil that is considered safe for incidental contact with items that may be consumed by humans or animals, as long as it does not exceed a certain concentration. Food grade oils include FDA-approved white mineral oil and food grade heptane.

[0013] “Alkyl” refers to a monovalent, substituted or unsubstituted, saturated or unsaturated, straight, branched or cyclic hydrocarbon chain. Examples of unsubstituted alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, tertbutyl, sec-butyl, cyclobutyl, pentyl, cyclopentyl, hexyl, and cyclohexyl. Unsaturated alkyl refers to alkyl groups containing one or more double and/or triple bonds.

[0014]“Alkylaryl” refers to at least one alkyl group covalently bonded to an aryl group.

[0015] “Aryl” refers to a monovalent aromatic carbocyclic or heteroaromatic group.

[0016] “Alkylene” refers to a divalent, substituted or unsubstituted, saturated or unsaturated, straight, branched or cyclic hydrocarbon chain. Examples of unsubstituted alkylene groups include methylene, ethylene, propylene, isopropylene, cyclopropylene, butylene, iso-butylene, tert-butylene, sec-butylene, cyclobutylene, pentylene, cyclopentylene, hexylene, and cyclohexylene.

[0017] “Substituted” means that the moiety contains at least one, alternatively 1 -3, substituent(s). Examples of substituents include hydroxyl ( — OH), amino ( — NH2), oxy ( — O — ), carbonyl ( — CO — ), thiol, alkyl, alkoxy, halo, nitrile, nitro, aryl and heterocyclic groups.

[0018] A “catalyst activity aid” refers to a composition that increases or does not decrease the productivity of a polymerization catalyst during a polymerization reaction compared to the catalyst productivity during a polymerization reaction conducted without the composition under similar reaction conditions.

[0019] The catalyst activity aid of the present technology comprises a mixture of (a) a polysulfone; (b) a polyquaternary ammonium salt; and (c) a carrier fluid. The catalyst activity aid is used in polymerization processes, such as those for the production of ethylene-based and propylene-based polymers, or other olefin-based polymers or copolymers.

[0020]The polysulfone component of the catalyst activity aid is a polymer, preferably a linear polymer, having a structure considered to be that of alternating copolymers of olefins and sulfur dioxide, having a one-to-one molar ratio of the comonomers with the olefins in head to tail arrangement. Preferably, the polysulfone copolymer comprises about 50 mole percent of units of sulfur dioxide, about 40 to 50 mole percent of units derived from one or more 1 -alkenes each having from 6 to 24 carbon atoms, and from 0 to about 10 mole percent of units derived from an olefinic compound having the formula ACH=CHB where A is a group having the formula -(CxH2x) — COOH, wherein x is from 0 to about 17, and B is hydrogen or carboxyl, provided that, when B is a carboxyl, x is 0, and wherein A and B together can be a dicarboxylic anhydride group. The units of the one or more 1 -alkenes can be derived from straight chain alkenes having 6 to 18 carbon atoms, such as, for example, 1 -hexene, 1 -heptene, 1 -octene, 1 -decene, 1 -dodecene, 1 -hexadecene, and 1 -octadecene. Examples of units derived from the one or more compounds having the formula ACH=CHB are units derived from maleic acid, acrylic acid, and 5-hexenoic acid. The polysulfone copolymer can have a weight average molecular weight in the range of 5,000 to 1 ,000,000, and a polydispersity of 1 .5 to 15.

[0021] The polysulfone copolymer can be prepared by adding at least one alphaolefin and toluene to a pressure-resistant reactor equipped with mechanical stirring, condensing coil, and thermometer. The air in the reactor is replaced with nitrogen, and the mixture is cooled to a temperature of 5-10 ^eC. SO2 followed by a dodecanoyl peroxide initiator is added to the reactor, and the mixture is stirred and reacted at room temperature. Unreacted SO2 is removed by blowing nitrogen gas. The resulting polysulfone copolymer can be separated from the reaction mixture by extraction.

[0022] The polyquaternary ammonium salt component comprises a polycationic polyamine and an oil soluble organic acid counterion. In some embodiments, the polyquaternary ammonium salt has the following chemical structure:

Where R is an alkyl having from 8 to 28 carbon atoms, R’ is an alkyl having from 6 to 24 carbon atoms, n is an integer from 1 -30, and m is an integer from 0 to 30. Preferably R is a linear carbon chain having 10-12 carbon atoms, and R’ is a linear carbon chain having 8 to 18 carbon atoms. When m is 1 or more, the polyquaternary ammonium salt has chemical structure II. In some embodiments, 5 < m+n < 50, preferably 10 < m+n < 20.

[0023]The oil soluble organic acid counterion is preferably derived from any oil soluble sulfonic acid such as an alkanesulfonic acid or an alkylarylsulfonic acid. In some embodiments, the oil soluble organic acid counterion is derived from a linear alkyl benzene sulfonic acid, for example dodecylbenzene sulfonic acid. The polyquaternary ammonium salt has a weight average molecular weight in the range of about 5,000 to about 500,000, alternatively about 5,000 to about 400,000, alternatively about 5,000 to about 300,000, alternatively about 5,000 to about 250,000, alternatively about 5,000 to about 200,000, alternatively about 5,000 to about 100,000, alternatively about 5,000 to about 50,000, alternatively about 5,000 to about 20,000, and a polydispersity of about 1 to about 10, alternatively about 1 .5 to about 10, alternatively about 1 to about 5, alternatively about 1 to about 3.

[0024] The polyquaternary ammonium salt may be prepared by reacting an alkyl amine or N-aliphatic hydrocarbyl alkylenediamine and epichlorohydrin in a molar ratio of about 1 :1 to about 1 :1 .5, at a temperature in the range of about 50^eC to 100^eC, in the presence of a solvent, to form a polyamine chlorohydrin. Suitable alkyl amines or N-aliphatic hydrocarbyl alkylene diamines for use in preparing the polyquaternary ammonium salt are those having at least 8 carbon atoms and include, but are not limited to, dodecylamine, tetradecylamine, octadecylamine, or N-tallow alkyltrimethylenediamines. Suitable solvents include, but are not limited to toluene or xylene. An excess of an inorganic strong base, such as sodium hydroxide, is added to the polyamine chlorohydrin, and the mixture is heated to a temperature in the range of about 60^eC to about 90^eC to displace the chlorine and obtain a polyamine. The polyquaternary ammonium salt is formed by mixing the polyamine with an oil-soluble sulfonic acid in a weight ratio of about 1 :1 to 5:1 to form a reaction mixture. Oil-soluble sulfonic acids used for forming the polyquaternary ammonium salt can be any alkanesulfonic acid or alkylarylsulfonic acid. The reaction mixture is heated at a temperature in the range of about 25^eC to about 80^eC for a time sufficient to react the polyamine with the oil-soluble sulfonic acid, followed by extraction with a supercritical fluid, preferably carbon dioxide, to obtain the polyquaternary ammonium salt. Supercritical fluid extraction removes any unreacted monomer, organic acid, catalyst and impurities remaining from the reaction. Such impurities can include water, benzene, toluene, and xylene. Without being bound by theory, the presence of such impurities may contribute to a reduction in metallocene catalyst activity. Removal of the impurities by supercritical fluid extraction results in a purer polymeric component that may contribute to enhanced catalyst activity. [0025] The carrier fluid of the catalyst activity aid can be one or more hydrocarbons having from 5 to 12 carbon atoms, such as pentane, hexane, heptane, dodecane, or an isomer thereof. Mixtures of such hydrocarbons are also contemplated. Other compounds that can be used as the carrier fluid include oils, particularly food grade oils such as white mineral oil and heptane approved for food use. Mixtures of at least one hydrocarbon and at least one food grade oil are also contemplated. In some embodiments, a food grade oil may be the only carrier fluid.

[0026] The catalyst activity aid comprises from 1 wt% to 25 wt%, alternatively 2 wt% to 20 wt%, alternatively 5 wt% to 15 wt% of the polysulfone copolymer, from 1 wt% to 50 wt%, alternatively 2 wt% to 40 wt%, alternatively 2 wt% to 30 wt%, alternatively 3 wt% to 20 wt%, alternatively 5 wt% to 15 wt% of the polyquaternary ammonium salt, and from 25 wt% to 95 wt%, alternatively 30 wt% to 95 wt%, alternatively 40 wt% to 95 wt%, alternatively 50 wt% to 95 wt%, alternatively 60 wt% to 90 wt%, alternatively 70 wt% to 90 wt% of the carrier fluid, with the total of these three components preferably being 100% of the weight of the catalyst activity aid. The catalyst activity aid may be prepared by mixing the polysulfone copolymer, the polyquaternary ammonium salt, and the fluid carrier together at room temperature until combined. Alternatively, prior to extraction from their respective reaction mixtures, the polysulfone and polyquaternary ammonium salt can be combined and extracted together using supercritical fluid, and then mixed with the fluid carrier.

[0027] One feature of the catalyst activity aid is that it is free of added oil soluble sulfonic acid. Without wishing to be bound by theory, it is believed that the presence of oil soluble sulfonic acid in prior art antistatic aids may contribute to the reduction of catalytic activity during polymerization. Surprisingly, the catalyst activity aid of the present technology, which is substantially free of or does not contain oil soluble sulfonic acid as a component, not only mitigates static charge build-up and reactor fouling, but also increases catalyst activity during polymerization, compared to the catalyst activity without the catalyst activity aid. The term “substantially free of” means less than 0.5 wt%, or less than 0.1 wt% or less than 0.01 wt% based on the weight of the catalyst activity aid. The catalyst activity aid is also storage stable over prolonged storage periods, such as, for example, 10 days, 20 days, or 1 year, with no precipitation of the polymeric components. With prior art formulations containing oilsoluble sulfonic acid, the polymeric components can precipitate after a prolonged storage period or when stored at low temperatures.

[0028] The amount of the catalyst activity aid added during olefin polymerization can be in the range of about 0.1 ppm to about 100 ppm, alternatively about 1 ppm to about 50 ppm, alternatively about 10 ppm to about 30 ppm (parts per million by weight of polymer being produced). The specific amount added may depend on such factors as the type of reactor used, the type of catalyst used, and the polymerization reaction conditions, as well as other factors known to one skilled in the art. Since the catalyst activity aid can increase catalyst activity, it is not merely an antifoulant for the polyolefin process. Therefore, it may not be necessary to limit the catalyst activity aid to concentrations of 20 ppmw or less in the manufacture of ethylene-based and propylene-based food contact applications, or 4 ppmw or less for infant formula contact applications.

Use of the Catalyst Activity Aid

[0029] The catalyst activity aid can be used in polymerization processes employing different catalysts. The catalyst activity aid is particularly suitable for polymerization reactions employing metallocene catalysts, since the catalyst activity aid increases the productivity of such catalysts. Metallocene catalysts are known in the art, and examples of such catalysts are described, for example, in U.S. Patent No. 7,476,715 and U.S. Patent No. 6,894,131 . The catalyst activity aid may also be used with other polymerization catalysts, such as chromium-based catalysts, Ziegler-Natta catalysts, metathesis catalysts, and copper complex catalysts. Suitable chromium-based catalysts are described, for example, in U.S. Patent No. 4,077,904. Ziegler-Natta catalysts are known in the art and are typically magnesium/titanium electron donor complexes used in conjunction with an organoaluminum co-catalyst. Suitable metathesis catalysts can be first generation, second generation or third generation Grubbs catalysts, particularly ruthenium complex catalysts. The catalyst used can be in liquid form, solid form, and can be heterogeneous or a supported catalyst. The catalyst may be used with one or more co-catalysts, activators, and/or promoters. [0030] The catalyst activity aid may be employed in suspension, solution, slurry, or gas phase polyolefin polymerization processes, using known equipment and reaction conditions. A gas phase polymerization process may utilize a fluid bed reactor, in which a gaseous stream containing one or more monomers is passed continuously through a fluidized bed reactor under reaction conditions in the presence of a polymerization catalyst. Product is withdrawn from the reactor. A gaseous stream of unreacted monomer is withdrawn from the reactor and recycled to the reactor. Makeup of the gaseous monomer to the recirculating gas stream is at a rate equal to the rate at which particulate polymer product and monomer associated therewith is withdrawn from the reactor, and the composition of the gas passing through the reactor is adjusted to maintain essentially a steady state gaseous composition within the reaction zone.

[0031] A liquid phase polymerization process comprises adding one or more monomers and the catalyst to a reactor containing a liquid reaction medium that may dissolve or suspend the polymer product. The liquid reaction medium may comprise one or more organic solvents that are non-reactive with the monomers and catalyst under conditions employed for the reaction. Inert organic solvents that could be used in a liquid phase polymerization include, but are not limited to, isobutane, isopentane, hexane, cyclohexane, heptane, octane, benzene, or toluene. The liquid reaction medium, containing the polymer product and unreacted monomer, is withdrawn from the reactor intermittently or continuously, and the polymer product is separated. The liquid reaction medium and unreacted monomer may be recycled and fed back to the reactor.

[0032] The catalyst activity aid may be added directly to the reactor through a dedicated feed line, and/or added to any convenient feed stream, including the monomer feed stream, the co-monomer feed stream, the catalyst feed line, or the recycle line. In some embodiments, the catalyst activity aid may be added directly into the fluidized bed of a fluidized reactor and/or the seed bed may be pretreated with the catalyst activity aid. In other embodiments, the catalyst activity aid may be combined with the catalyst before feeding into the reactor. The catalyst activity aid can be added continuously or intermittently to the reactor. In a continuous gas phase polymerization process, preferably the catalyst activity aid is added continuously to the reactor. The catalyst activity aid may be diluted in a light hydrocarbon, such as isopentane, prior to being added to the reactor.

[0033] The catalyst activity aid may be used in polymerization processes for preparing a variety of polyolefin polymer products. Such polyolefins may be prepared from monomers of ethylene and/or propylene and/or butene, or in combination with one or more olefins, such as those having from 4 to 8 carbon atoms. Examples of such olefins include 1 -butene, 1 -pentene, 1 -hexene, and 1 -octene. Other monomers that could be used in the polymerization processes include ethylenically unsaturated monomers, diolefins having 4 to 18 carbon atoms, conjugated or non-conjugated dienes, polyenes, vinyl monomers, and cyclic olefins. Examples of such other monomers include norbornene, norbornadiene, isobutylene, isoprene, vinylbenzocyclobutane, styrenes, dicyclopentadiene, and cyclopentane.

[0034] One skilled in the art will recognize that modifications may be made in the present technology without deviating from the spirit or scope of the invention. The invention is further illustrated by the following examples, which are not to be construed as limiting the invention in spirit or scope to the specific procedures or compositions described therein.

EXAMPLES

[0035] The polymerization reactions described in the following examples were conducted in a continuous pilot-scale gas phase fluidized bed reactor having a fluidized bed made up of polymer granules. The gaseous feed streams of ethylene and hydrogen together with liquid comonomer were introduced below the reactor bed into the recycle gas line. Hexene was used as a comonomer. The individual flow rates of ethylene, hydrogen, and comonomer were controlled to maintain fixed composition targets. The ethylene concentration was controlled to maintain a constant ethylene partial pressure. The hydrogen was controlled to maintain a constant hydrogen to ethylene mole ratio.

[0036] In the examples where a solid metallocene catalyst was used, the catalyst was injected directly into the fluidized bed using purified nitrogen as a carrier, and the rate was adjusted to maintain a constant production rate. In examples where a bimodal catalyst was used, the catalyst was injected directly into the reactor as a slurry in purified mineral oil and the rate of the slurry catalyst feed rate was adjusted to maintain a constant production rate of polymer. The reacting bed of growing polymer particles was maintained in a fluidized state by the continuous flow of the make up feed and recycle gas through the reaction zone. The reactor was operated at a total pressure of 2240 kPa, and a constant reaction temperature of 85°C or 105^eC, depending on the end product.

[0037] The fluidized bed was maintained at a constant height by withdrawing a portion of the bed at a rate equal to the rate of formation of particulate product. The rate of product formation (the polymer production rate) was in the range of 15-25 kg/hour.

[0038]The catalyst activity aid used in each of the following Examples comprised 8 wt% polysulfone copolymer, 12 wt% polyquaternary ammonium salt, and 80 wt% carrier fluid.

Example 1

[0039] The above-mentioned polymerization reactor was used to evaluate the effect of the catalyst activity aid of the present technology as a catalyst productivity improver. The reactor was operated at a reaction temperature of 85°C, a hexene-to- ethylene molar ratio of 0.009, and H2 concentration of 835 ppm, using a metallocene catalyst, to produce a film product of about 1.2 to 3.4 melt index and 0.925 density. Initially, a commercially available antistatic agent was used in the reactor at a feed rate of about 23 ppmw based on production rate. The reactor was then transitioned to using the catalyst activity aid of the present technology diluted in isopentane, at a feed rate of 19.2 ppmw. Table 1 shows the effect of the catalyst activity aid compared to the commercial antistatic agent and operation with no additive on metallocene catalyst productivity. Table 1

The results in Table 1 show the catalyst activity aid of the present technology can increase the productivity of a metallocene catalyst compared to polymerization without the catalyst activity aid. The results also show that use of the commercial antistatic agent decreased the productivity of the catalyst.

Example 2

[0040] In this Example, an open reactor start-up was carried out where the polymerization reactor mentioned above was charged with a fresh metallocene catalyst catalyzed seed bed and following standard drying to a residual moisture level of 6 ppmv purging with nitrogen. The seed bed was pretreated with 12 ppmw catalyst activity aid based on bed weight while building monomer and comonomer concentration. The reactor was operated at a reaction temperature of 85°C, a hexene- to-ethylene molar ratio of 0.009 and a H2 concentration of 935 ppm to produce a film product of about 1 .2 to 2.4 melt index and 0.923-0.925 density. The catalyst activity aid of the present technology was fed into the reactor as a solution in isopentane at a continuous feed rate of 16 ppmw based on production rate. The reactor was then transitioned to operation without any catalyst activity aid for 12 hours before initiating catalyst activity aid feed again at approximately 20 ppmw based on production rate. Based on analysis, the effect of the catalyst activity aid on catalyst productivity is higher than at operation with no additive at the same reaction conditions and product conditions, as shown in Table 2. Table 2

Example 3

[0041 ] In this Example, different feed rates of the catalyst activity aid of the present technology were evaluated in a single gas phase reactor using a metallocene catalyst for the polymerization. The different feed rates tested were 10 ppmw, 20 ppmw and 30 ppmw based on production rate. The catalyst activity aid was diluted in isopentane. The reactor operated smoothly and the results showed that the catalyst activity aid increased catalyst productivity.

Example 4

[0042] In this Example, a spray-dried bimodal catalyst was fed to the reactor using purified nitrogen as a carrier, and the catalyst feed rate was adjusted to maintain a constant production rate. The reactor was operated at a reaction temperature of 85°C, an ethylene partial pressure of 210 psia, a hexene-to-ethylene molar ratio of 0.003, and a H2-to-ethylene molar ratio of 0.0019 to produce a bimodal type product with 0.9 to 2.5 Fl and a density of 0.945-0.946 gm/cc. Initially, a commercial antistatic agent was fed into the reactor at a feed rate of approximately 26.6 ppmw based on production rate. A switch was then made to the catalyst activity aid of the present technology, initially at a feed rate of 27.5 ppmw based on production rate, and then subsequently reduced to a feed rate of 18.8 ppmw. An increase in catalyst productivity was observed with the catalyst activity aid as compared with the commercial antistatic agent, as shown in Table 3. Table 3

*Residual Zirconium measured with Inductively Coupled Plasma Emission Spectrometry.

Example 5

[0043] A test was conducted to assess the effect of the catalyst activity aid on slurry fed bimodal catalyst activity and operability. The reactor was operated at a reaction temperature of 100°C, an ethylene partial pressure of 220 psia, a hexene-to-ethylene molar ratio of 0.0055 and a H2-to-ethylene molar ratio of 0.0020 to produce a bimodal pipe type product with 6 to 7 Fl and a density of 0.949gm/cc. Initially, the reactor was operated without any catalyst activity aid used, and then the catalyst activity aid diluted in isopentane feed was introduced into the reactor at a feed rate to give approximately 40 ppmw based on production rate. The catalyst activity aid feed rate was subsequently decreased to give an approximate concentration of 20 ppmw. The catalyst activity aid feed rate was then decreased further to give an approximate concentration of 10 ppmw. Based on mass balance, the catalyst productivity increased as shown in Table 4 with a catalyst activity aid concentration of 10 ppmw and 20 ppmw. The results in Table 4 also show that the catalyst productivity was much higher than with a commercial antistatic agent used under the same reactor operating conditions. Table 4

Example 6

[0044] This Example was conducted to assess the effect of pre-contacting a bimodal catalyst with the catalyst activity aid of the present technology before feeding to the reactor. In this test, the catalyst activity aid diluted in isopentane was fed to the reactor through the same bimodal catalyst slurry feed line, allowing for mixing of the catalyst activity aid with the slurry catalyst prior to feeding to the reactor. The reactor was initially operated in a steady state, without using the catalyst activity aid, at a reaction temperature of 100°C, an ethylene partial pressure of 220 psia, a hexene-to- ethylene molar ratio of 0.0045 and a H2 to ethylene molar ratio of 0.0020 to produce a bimodal pipe type product with 5 to 6 dg/min glow index and a density of 0.949 gm/cc. Subsequently, the catalyst activity aid diluted in isopentane was initiated to the catalyst injection line at a feed rate to give approximately 24 ppmw based on production rate. The static level remained low and the band narrow and no sheeting was experienced. There was an increase of catalyst productivity with pre-contacting the catalyst activity aid with the catalyst. The results are shown in Table 5. Table 5

**The catalyst productivity as measured using Zr ICP is corrected to account for the total of catalyst species present in the catalyst, not just those containing Zr.

[0045] In each example above, the catalyst activity aid of the present technology improved the productivity of the catalyst. Table 6 shows the productivity increase for Examples 1 , 2, and 4-6, which ranged between 3% and 23%.

Table 6: Productivity

The largest catalyst productivity gain, 23%, was made when replacing the commercial antistatic agent feed rate of approximately the same concentration, 27 ppmw, with the catalyst activity aid of the present technology, initially at a feed rate of 27.5 ppmw based on production rate. In all Examples, when the catalyst activity aid of the present technology was applied, the static level remained low and no sheeting was experienced.

[0046] The embodiments and examples described here are illustrative, and do not limit the presently described technology in any way. The scope of the present technology described in this specification is the full scope defined or implied by the claims. Additionally, any references noted in the detailed description section of the instant application are hereby incorporated by reference in their entireties, unless otherwise noted.

[0047] The present technology is now described in such full, clear and concise terms as to enable a person skilled in the art to which it pertains, to practice the same. It is to be understood that the foregoing describes preferred embodiments of the present technology and that modifications may be made therein without departing from the spirit or scope of the present technology as set forth in the appended claims. Further, the examples are provided to not be exhaustive but illustrative of several embodiments that fall within the scope of the claims.

Claims

CLAIMS A catalyst activity aid comprising:

(a) about 1 wt% to about 25 wt% polysulfone copolymer;

(b) about 1 wt% to about 50 wt% polyquaternary ammonium salt comprising a polycationic polyamine and an oil-soluble organic counterion; and

(c) about 25 wt% to about 95 wt% of a carrier fluid comprising at least one of pentane, hexane, heptane, dodecane, and a food grade oil. The catalyst activity aid of claim 1 , wherein the oil-soluble organic counterion is derived from an oil soluble sulfonic acid. The catalyst activity aid of claim 1 or 2, wherein the polyquaternary ammonium salt has one of the following chemical structures:

where R is a linear or branched, alkyl or alkene chain having from 8 to 28 carbon atoms; R’ is a linear or branched, alkyl or alkene chain having from 6 to 24 carbon atoms; n is an integer from 1 to 30; m is an integer from 0 to 30.

4. The catalyst activity aid of claim 3, wherein 5 < m+n < 50, preferably 10 < m+n < 20.

5. The catalyst activity aid of claim 3 or 4, wherein R is a linear alkyl chain having from 10 to 12 carbon atoms.

6. The catalyst activity aid of any one of claims 3-5, wherein R’ is a linear alkyl chain having from 8 to 18 carbon atoms.

7. The catalyst activity aid of any one of claims 1 -6, wherein the polyquaternary ammonium salt has an average molecular weight in the range of 5,000 to 500,000.

8. The catalyst activity aid of any one of claims 1 -7, wherein the polyquaternary ammonium salt has a polydispersity of 1 .5 to 10.

9. The catalyst activity aid of any one of claims 1 -8, wherein the polysulfone copolymer is a copolymer comprising one or more olefins and sulfur dioxide.

10. The catalyst activity aid of any one of claims 1 -9, wherein the carrier comprises a combination of food grade oil and at least one of pentane, hexane, heptane, and dodecane.

11 .The catalyst activity aid of any one of claims 1 -9, wherein the carrier is a food grade oil.

12. The catalyst activity aid of any one of claims 1 -11 , wherein the catalyst activity aid is free of added sulfonic acid.

13. The catalyst activity aid of any one of claims 1 -12, wherein the catalyst activity aid comprises 5 wt% to 15 wt% of polyquaternary ammonium salt.

14. The catalyst activity aid of any one of claims 1 -13, wherein the catalyst activity aid comprises 5 wt% to 15 wt% polysulfone copolymer.

15. The catalyst activity aid of any one of claims 1 -14, wherein the catalyst activity aid comprises 70 wt% to 90 wt% carrier fluid.

16. The catalyst activity aid of any one of claims 1 -15, wherein the catalyst activity aid increases productivity of a polymerization catalyst during a polymerization reaction compared to the productivity of the polymerization catalyst during a polymerization reaction conducted under similar reaction conditions but without the catalyst activity aid.

17. A polymerization process comprising the steps of: polymerizing at least one olefin in the presence of at least one catalyst in a polymerization reactor to form an olefin-based polymer; and feeding the catalyst activity aid of any one of claims 1 -15 to the polymerization reactor during polymerization of the at least one olefin.

18. A process for polymerizing one or more olefins to form a polyolefin, comprising the steps of: feeding the one or more olefins to a polymerization reactor in the presence of at least one catalyst; and feeding a catalyst activity aid to the polymerization reactor during polymerization of the one or more olefins, wherein the catalyst activity aid comprises:

(a) 1 to 25 wt% polysulfone copolymer;

(b) 1 to 50 wt% polyquaternary ammonium salt comprising a polycationic polyamine and an oil-soluble organic counterion; and

(c) 25 to 95 wt% of a carrier fluid comprising at least one of pentane, hexane, heptane, dodecane, and a food grade oil. The process of claim 17 or 18, wherein the catalyst comprises a metallocene catalyst. The process of claim 17 or 18, wherein the catalyst comprises a chromium- based catalyst, a Ziegler-Natta catalyst, or a metathesis catalyst. The process of any one of claims 17-20, wherein the catalyst activity aid is fed to the polymerization reactor in an amount of 0.1 ppm to 100 ppm. The process of any one of claims 17-21 , wherein the one or more olefins comprise ethylene. The process of any one of claims 17-22, wherein the catalyst activity aid is fed to the polymerization reactor at a feed rate of 0.1 to 100 ppmw. The process of any one of claims 17-23, wherein the polymerization reactor is a gas phase polymerization reactor. The process of any one of claims 17-23, wherein the polymerization reactor is a liquid phase polymerization reactor.