Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F10/00—Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
  • C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/659—Component covered by group C08F4/64 containing a transition metal-carbon bond
  • C08F4/65916—Component covered by group C08F4/64 containing a transition metal-carbon bond supported on a carrier, e.g. silica, MgCl2, polymer
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/659—Component covered by group C08F4/64 containing a transition metal-carbon bond
  • C08F4/6592—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F4/00—Polymerisation catalysts
  • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
  • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
  • C08F4/60—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with refractory metals, iron group metals, platinum group metals, manganese, rhenium technetium or compounds thereof
  • C08F4/62—Refractory metals or compounds thereof
  • C08F4/64—Titanium, zirconium, hafnium or compounds thereof
  • C08F4/659—Component covered by group C08F4/64 containing a transition metal-carbon bond
  • C08F4/6592—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
  • C08F4/65922—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring containing at least two cyclopentadienyl rings, fused or not
  • C08F4/65925—Component covered by group C08F4/64 containing a transition metal-carbon bond containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring containing at least two cyclopentadienyl rings, fused or not two cyclopentadienyl rings being mutually non-bridged
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S526/00—Synthetic resins or natural rubbers -- part of the class 520 series
  • Y10S526/901—Monomer polymerized in vapor state in presence of transition metal containing catalyst
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S526/00—Synthetic resins or natural rubbers -- part of the class 520 series
  • Y10S526/943—Polymerization with metallocene catalysts

Definitions

• the present invention relates to a polymerization process for the production of polyolefins utilizing a metallocene catalyst and a compound containing an ether linkage in amounts sufficient to reduce the electrostatic charge in the polymerization reactor.
• the use of a compound containing an ether linkage as a catalytic agent further provides polyolefins that are suitable for molding and film applications.
• Polyolefins such as polyethylene are well known and are useful in many applications.
• linear polyethylene polymers possess properties which distinguish them from other polyethylene polymers, such as branched ethylene homopolymers commonly referred to as LDPE (low density polyethylene). Certain of these properties are described by Anderson et al, U.S. Patent No. 4,076,698.
• a particularly useful polymerization medium for producing polyethylene and polypropylene polymers is a gas phase process. Examples of such are given 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 Canadian Patent No. 991,798 and Belgian Patent No. 839,380.
• chromium oxide catalysts which polymerize ethylene to high molecular weight high density polyethylene (HDPE)
• organochromium catalysts used to polymerize ethylene 3.
• Ziegler-Natta type catalysts which typically consist of a transition metal component and a co-catalyst that is typically an organoaluminum compound,
• metallocene catalysts which typically consist of a transition metal having a cyclopentadienyl ligand and a co-catalyst
• the above catalysts are, or can be, supported on inert porous particulate carriers.
• agglomerates may be formed as a result of the presence of very fine polymer particles in the polymerization medium. These fine polymer particles may be present as a result of introducing fine catalyst particles or breakage of the catalyst within the polymerization medium.
• fine particles are believed to deposit onto and electrostatically adhere to the inner walls of the polymerization reactor and the associated equipment for recycling the gaseous stream such as, for example, the heat exchanger. If the fine particles remain active, and the polymerization reaction continues, then the particles will grow in size resulting in the formation of agglomerates. These agglomerates when formed within the polymerization reactor tend to be in the form of sheets.
• European Patent Application 0 359 444 Al describes the introduction into the polymerization reactor of small amounts of an activity retarder in order to keep substantially constant either the polymerization rate or the content of transition metal in the polymer produced. The process is said to produce a polymer without forming agglomerates.
• U.S. Patent No. 4,739,015 describes the use of gaseous oxygen containing compounds or liquid or solid active-hydrogen containing compounds to prevent the adhesion of the polymer to itself or to the inner wall of the polymerization apparatus.
• Additional processes for reducing or eliminating electrostatic charge include (1) installation of grounding devices in a fluidized bed, (2) ionization of gas or particles by electrical discharge to generate ions which neutralize the electrostatic charge on the particles and (3) the use of radioactive sources to produce radiation capable of generating ions which neutralize the electrostatic charge on the particles.
• the polymerization process of the present invention comprises the introduction into a polymerization medium comprising an olefin, particularly ethylene, and optionally at least one or more other olefin(s), a metallocene catalyst and at least one compound comprising at least one carbon-oxygen-carbon linkage (C-O-C) of the formula R'-O(-R 2 -O) m -R 3 where m ranges from 0 to 30, and R 1 , R 2 and R independently contain from 1 to 30 carbon atoms and from 0 to 30 heteroatoms of an element, or mixtures thereof, selected from Groups 13, 14, 15, 16 and 17 of the Periodic Table of Elements, and further wherein R 1 , R 2 and/or R 3 can be linked and form part of a cyclic or polycyclic structure, herein referred to as the ether, wherein the ether is present in an amount sufficient to reduce the electrostatic charge in the polymerization medium to a level lower than would occur in the same polymerization process in the absence of the
• the present invention also relates to a process for reducing the electrostatic charge in the polymerization of an olefin, particularly ethylene, and optionally at least one or more other olefin(s) in a polymerization medium, particularly gas phase, in the presence of a metallocene catalyst, and at least one ether comprising at least one carbon-oxygen-carbon linkage (C-O-C) of the formula R 1 -O(-R 2 -O) m -R J where m ranges from 0 to 30, and R 1 , R 2 and R J independently contain from 1 to 30 carbon atoms and from 0 to 30 heteroatoms of an element, or mixtures thereof, selected from Groups 13, 14, 15, 16 and 17 of the Periodic Table of Elements, and further wherein R , R and/or R can be linked and form part of a cyclic or polycyclic structure, comprising introducing the ether into the polymerization medium in an amount sufficient to reduce the electrostatic charge in the polymerization medium to a level lower
• a halogenated hydrocarbon may be added to the polymerization medium.
• the ether as defined herein and the optional halogenated hydrocarbon may be added to the polymerization medium in any manner.
• the ether as defined herein and the halogenated hydrocarbon may be added to the metallocene catalyst just prior to addition to the polymerization medium, or added separately from the catalyst to the polymerization medium in any manner known in the art.
• the ether as defined herein may optionally be premixed with the halogenated hydrocarbon prior to addition to the polymerization medium.
• ether as defined herein prior to the heat removal means, e.g., the heat exchanger, to slow the rate of fouling of said heat removal means in addition to reducing the electrostatic charge in the polymerization reactor.
• the polymerization process of the present invention comprises the introduction into a polymerization medium comprising an olefin, particularly ethylene, and optionally at least one or more other olefin(s), a metallocene catalyst and at least one compound comprising at least one carbon-oxygen-carbon linkage (C-O-C) of the formula R'-O(-R 2 -O) m -R 3 where m ranges from 0 to 30, and R 1 , R 2 and R 3 independently contain from 1 to 30 carbon atoms and from 0 to 30 heteroatoms of an element, or mixtures thereof, selected from Groups 13, 14, 15,
• R 1 , R 2 and/or R 3 can be linked and form part of a cyclic or polycyclic structure, herein referred to as the ether, wherein the ether is present in an amount sufficient to reduce the electrostatic charge in the polymerization medium to a level lower than would occur in the same polymerization process in the absence of the ether.
• the present invention also relates to a process for reducing electrostatic charge in the polymerization of an olefin, particularly ethylene, and optionally at least one or more other olefin(s) in a polymerization medium, particularly gas phase, in the presence of a metallocene catalyst, and at least one ether comprising at least one carbon-oxygen-carbon linkage (C-O-C) of the formula R 1 -O(-R 2 -O) m -R 3 where m ranges from 0 to 30, and R , R and R independently contain from 1 to 30 carbon atoms and from 0 to 30 heteroatoms of an element, or mixtures thereof, selected from Groups 13, 14, 15, 16 and 17 of the Periodic Table of Elements, and further wherein R 1 , R 2 and/or R can be linked and form part of a cyclic or polycyclic structure, comprising introducing the ether into the polymerization medium in an amount sufficient to reduce the electrostatic charge in the polymerization medium to a level lower than would
• a halogenated hydrocarbon may be added to the polymerization medium.
• the ether used herein to reduce the electrostatic charge in the polymerization medium is any compound comprising at least one carbon-oxygen-
• C-O-C carbon linkage (C-O-C) of the formula R -O(-R -O) m -R where m ranges from 0 to 30, and R 1 , R 2 and R 3 independently contain from 1 to 30 carbon atoms and from 0 to 30 heteroatoms of an element, or mixtures thereof, selected from Groups 13, 14,
• R , R and/or R 3 can be linked and form part of a cyclic or polycyclic structure.
• R 1 , R 2 and R 3 groups suitable for use herein are C ⁇ - 30 alkyl, C 2-30 alkenyl, C 4 . 30 dienyl, C 3 . 30 cycloalkyl, C 3 - 30 cycloalkenyl, C 4 - 30 cyclodienyl, C 6 - ⁇ 8 aryl, C - 30 aralkyl and C - 30 alkaryl.
• hydrocarbons containing from 1 to 30 carbon atoms and from 1 to 30 heteroatoms of an element, or mixtures thereof, from Groups 13, 14, 15, 16 and 17 of the Periodic Table of Elements such as, for example, B ⁇ - 3 o borohydrocarbons, Si ⁇ - 0 silahydrocarbons, P ⁇ - 0 phosphahydrocarbons, S ⁇ - 0 thiahydrocarbons, Cl ⁇ - 30 chlorohydrocarbons and halogenated hydrocarbons containing mixtures of halogens.
• Exemplary of compounds used herein to reduce the electrostatic charge are compounds comprising one carbon-oxygen-carbon linkage (C-O-C), such as alkyl, alkenyl, dienyl and aryl substituted compounds of the formula R ⁇ O-R 3 .
• C-O-C carbon-oxygen-carbon linkage
• dimethyl ether diethyl ether; dipropyl ether; diisopropyl ether; dibutyl ether; dipentyl ether; dihexyl ether; dioctyl ether; diisoamyl ether; di-tert- butyl ether; diphenyl ether; dibenzyl ether; divinyl ether; diallyl ether; dicyclopropyl ether; dicyclopentyl ether; dicyclohexyl ether; allyl methyl ether; allyl ethyl ether; allyl cyclohexyl ether; allyl phenyl ether; allyl benzyl ether; allyl 2-tolyl ether; allyl 3-tolyl ether; benzyl methyl ether; benzyl ethyl ether; benzyl isoamyl ether; benzyl chloromethyl ether; benzyl
• Exemplary compounds comprising more than one C-O-C linkage include alkyl, alkenyl, dienyl and aryl substituted compounds of the formula R'-O(-R 2 -O) m - R 3 where m ranges from 1 to 30.
• dimethoxymethane 1,1- dimethoxy ethane; 1,1,1-trimethoxy ethane; 1,1,2-trimethoxyethane; 1,1- dimethoxypropane; 1,2-dimethoxypropane; 2,2-dimethoxypropane; 1,3- dimethoxypropane; 1,1,3-trimethoxypropane; 1,4-dimethoxybutane; 1,2- dimethoxybenzene; 1,3-dimethoxybenzene; 1,4-dimethoxybenzene; ethylene glycol dimethyl ether; ethylene glycol diethyl ether; ethylene glycol divinyl ether; ethylene glycol diphenyl ether; ethylene glycol tert-butyl methyl ether; ethylene glycol tert-butyl ethyl ether; di(ethylene glycol) dimethyl ether; di(ethylene glycol) diethyl ether; di(ethylene glycol) dibutyl
• Preferred for use herein as compounds to reduce the electrostatic charge are dimethyl ether; diethyl ether; dipropyl ether; diisopropyl ether; dibutyl ether; diisoamyl ether; di-tert-butyl ether; diphenyl ether; dibenzyl ether; divinyl ether; butyl methyl ether; butyl ethyl ether; sec-butyl methyl ether; tert-butyl methyl ether; cyclopentyl methyl ether; cyclohexyl ethyl ether; tert-amyl methyl ether; sec- butyl ethyl ether; chloromethyl methyl ether; trimethylsilylme hyl methyl ether; bis(trirnethylsilylmethyl) ether; bis(2,2,2-trifluoroethyl) ether; methyl phenyl ether; ethylene oxide; propylene
• tetrahydrofuran diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dioctyl ether, tert-butyl methyl ether, trimethylene oxide and tetrahydropyran.
• Any halogenated hydrocarbon may be used in the process of the present invention. If desired more than one halogenated hydrocarbon can be used. Typical of such halogenated hydrocarbons are monohalogen and polyhalogen substituted saturated or unsaturated aliphatic, alicyclic, or aromatic hydrocarbons having 1 to 12 carbon atoms. Preferred for use in the process of the present invention are dichloromethane, chloroform, carbon tetrachloride, chlorofluorome hane, chlorodifluromethane, dichlorodifluoromethane, fluorodichloromethane, chlorotrifluoromethane, fluorotrichloromethane and 1,2-dichloroethane. Most preferred for use in the process of the present invention is chloroform.
• Metallocene catalysts are well known in the industry and are comprised of at least one transition metal component and at least one co-catalyst component.
• the transition metal component of the metallocene catalyst comprises a compound having at least one moiety selected from substituted or unsubstituted cyclopentadienyl, substituted or unsubstituted pentadienyl, substituted or unsubstituted pyrrole, substituted or unsubstituted phosphole, substituted or unsubstituted arsole, substituted or unsubstituted boratabenzene, and substituted or unsubstituted carborane, and at least one transition metal.
• the moiety is a substituted or unsubstituted cyclopentadienyl.
• the transition metal is selected from Groups 3, 4, 5, 6, 7, 8, 9 and 10 of the Periodic Table of the Elements. Exemplary of such transition metals are scandium, titanium, zirconium, hafnium, vanadium, chromium, manganese, iron, cobalt, nickel, and the like, and mixtures thereof. In a preferred embodiment the transition metal is selected from Groups 4, 5 or 6 such as, for example, titanium, zirconium, hafnium, vanadium and chromium, and in a still further preferred embodiment, the transition metal is titanium or zirconium or mixtures thereof.
• the co-catalyst component of the metallocene catalyst can be any compound, or mixtures thereof, that can activate the transition metal component of the metallocene catalyst in olefin polymerization.
• the co-catalyst is an alkylaluminoxane such as, for example, methylaluminoxane (MAO) and aryl substituted boron compounds such as, for example, tris(perfluorophenyl)borane and the salts of tetrakis(perfluoro ⁇ henyl)borate.
• metallocene catalyst are described in U.S. Patent Nos. 4,564,647; 4,752,597; 5,106,804; 5,132,380; 5,227,440; 5,296,565; 5,324,800; 5,331,071; 5,332,706; 5,350,723; 5,399,635; 5,466,766; 5,468,702; 5,474,962; 5,578,537 and 5,863,853.
• the above metallocene catalysts can be introduced in the process of the present invention in any manner.
• the catalyst components can be introduced directly into the polymerization medium in the form of a solution, a slurry or a dry free flowing powder.
• the catalyst and the co-catalyst can be premixed to form an activated catalyst prior to addition to the polymerization medium, or the components can be added separately to the polymerization medium, or the components can be premixed and then contacted with one or more olefins to form a prepolymer and then added to the polymerization medium in prepolymer form.
• any electron donor compound may be added to the catalyst to control the level of activity of the catalyst.
• additional organometallic compounds may be the same or different from the co-catalyst.
• the carrier can be any parti culate organic or inorganic material.
• the carrier particle size should not be larger than about 200 microns in diameter. The most preferred particle size of the carrier material can be easily established by experiment.
• the carrier should have an average particle size of 5 to 200 microns in diameter, more preferably 10 to 150 microns and most preferably 20 to 100 microns.
• suitable inorganic carriers include metal oxides, metal hydroxides, metal halogenides or other metal salts, such as sulphates, carbonates, phosphates, nitrates and silicates.
• exemplary of inorganic carriers suitable for use herein are compounds of metals from Groups 1 and 2 of the Periodic Table of the Elements, such as salts of sodium or potassium and oxides or salts of magnesium or calcium, for instance the chlorides, sulphates, carbonates, phosphates or silicates of sodium, potassium, magnesium or calcium and the oxides or hydroxides of, for instance, magnesium or calcium.
• inorganic oxides such as silica, titania, alumina, zirconia, chromia, boron oxide, silanized silica, silica hydrogels, silica xerogels, silica aerogels, and mixed oxides such as talcs, silica/chromia, silica/chromia/titania, silica/alumina, silica/titania, silica magnesia, silica/magnesia/titania, aluminum phosphate gels, silica co-gels and the like.
• inorganic oxides such as silica, titania, alumina, zirconia, chromia, boron oxide, silanized silica, silica hydrogels, silica xerogels, silica aerogels, and mixed oxides such as talcs, silica/chromia, silica/chromia/titania, silic
• the inorganic oxides may contain small amounts of carbonates, nitrates, sulfates and oxides such as Na 2 CO 3 , K 2 CO 3 , CaCO 3 , MgCO 3 , Na 2 SO 4 , Al 2 (SO 4 ) 3 , BaSO 4 , KNO 3 , Mg(NO 3 ) 2 , Al(NO 3 ) 3 , Na 2 O, K 2 O and Li 2 O.
• Carriers containing at least one component selected from the group consisting of SiO 2 , Al 2 O 3 or mixtures thereof as a main component are preferred.
• suitable organic carriers include polymers such as, for example, polyethylene, polypropylene, interpolymers of ethylene and alpha-olefms, polystyrene, and functionalized polystyrene.
• the metallocene catalyst may be prepared by any method known in the art.
• the catalyst can be in the form of a solution, a slurry or a dry free flowing powder.
• the amount of metallocene catalyst used is that which is sufficient to allow production of the desired amount of the polyolefin.
• the co- catalyst(s) is added to the transition metal component of the metallocene catalyst in any amount sufficient to effect production of the desired polyolefin. It is preferred to utilize the co-catalyst(s) in a molar ratio of co-catalyst(s) to the transition metal component ranging from about 0.5:1 to about 10000: 1. In a more preferred embodiment, the molar ratio of co-catalyst(s) to transition metal component ranges from about 0.5:1 to about 1000:1.
• the polymerization process of the present invention may be carried out using any suitable process, for example, solution, slurry and gas phase.
• a particularly desirable method for producing polyolefin polymers according to the present invention is a gas phase polymerization process preferably utilizing a fluidized bed reactor. This type reactor and means for operating the reactor are well known and completely described in U.S Patents Nos. 3,709,853; 4,003,712; 4,011,382; 4,012,573; 4,302,566; 4,543,399; 4,882,400; 5,352,749; 5,541,270;
• the polymerization process of the present invention may be effected as a continuous gas phase process such as a fluid bed process.
• a fluid bed reactor for use in the process of the present invention typically comprises a reaction zone and a so-called velocity reduction zone.
• the reaction zone comprises a bed of growing polymer particles, formed polymer particles and a minor amount of catalyst particles fluidized by the continuous flow of the gaseous monomer and diluent to remove heat of polymerization through the reaction zone.
• some of the recirculated gases may be cooled and compressed to form liquids that increase the heat removal capacity of the circulating gas stream when readmitted to the reaction zone.
• a suitable rate of gas flow may be readily determined by simple experiment.
• Make up of gaseous monomer to the circulating 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 an essentially steady state gaseous composition within the reaction zone.
• the gas leaving the reaction zone is passed to the velocity reduction zone where entrained particles are removed. Finer entrained particles and dust may be removed in a cyclone and/or fine filter.
• the gas is passed through a heat exchanger wherein the heat of polymerization is removed, compressed in a compressor and then returned to the reaction zone.
• the reactor temperature of the fluid bed process herein ranges from about 30°C to about 150°C. In general, the reactor temperature is operated at the highest temperature that is feasible taking into account the sintering temperature of the polymer product within the reactor.
• the process of the present invention is suitable for the production of homopolymers of olefins, particularly ethylene, and/or copolymers, terpolymers, and the like, of olefins, particularly ethylene, and at least one or more other olefin(s).
• the olefins are alpha-olefms.
• the olefins may contain from 2 to 16 carbon atoms.
• Particularly preferred for preparation herein by the process of the present invention are polyethylenes.
• Such polyethylenes are preferably homopolymers of ethylene and interpolymers of ethylene and at least one alpha-olefin wherein the ethylene content is at least about 50% by weight of the total monomers involved.
• Exemplary olefins that may be utilized herein are ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4- methylpent-1-ene, 1-decene, 1-dodecene, 1-hexadecene and the like.
• polyenes such as 1 ,3-hexadiene, 1 ,4-hexadiene, cyclopentadiene, dicyclopentadiene, 4-vinylcyclohex-l-ene, 1,5-cyclooctadiene, 5- vinylidene-2-norbornene and 5-vinyl-2-norbornene, and olefins formed in situ in the polymerization medium.
• olefins are formed in situ in the polymerization medium, the formation of polyolefins containing long chain branching may occur.
• the ether used to reduce the electrostatic charge in the polymerization medium is added in any manner.
• the ether may be added to the preformed catalyst, to the prepolymer during the prepolymerization step, to the preformed prepolymer and/or to the polymerization medium.
• the ether may optionally be premixed with the co- catalyst when utilized.
• the ether is added in any amount sufficient to reduce the electrostatic charge in the polymerization medium to a level lower than would occur in the same polymerization process in the absence of the ether. It is preferred to incorporate the ether in a molar ratio of compound to transition metal component of the metallocene catalyst ranging from about 0.001:1 to about 100:1. In a more preferred embodiment, the molar ratio of the ether to transition metal component ranges from about 0.01 :1 to about 50:1.
• the halogenated hydrocarbon may be added to the polymerization medium in any amount sufficient to effect production of the desired polyolefin. It is preferred to incorporate the halogenated hydrocarbon in a molar ratio of halogenated hydrocarbon to transition metal component of the metallocene catalyst ranging from about 0.001:1 to about 100:1. In a more preferred embodiment, the molar ratio of halogenated hydrocarbon to transition metal component ranges from about 0.001:1 to about 10:1.
• the molecular weight of the polyolefin produced by the present invention can be controlled in any known manner, for example, by using hydrogen.
• the molecular weight control of polyethylene may be evidenced by an increase in the melt index (I 2 ) of the polymer when the molar ratio of hydrogen to ethylene in the polymerization medium is increased.
• Any conventional additive may be added to the polyolefins obtained by the present invention.
• additives examples include nucleating agents, heat stabilizers, antioxidants of phenol type, sulfur type and phosphorus type, lubricants, antistatic agents, dispersants, copper harm inhibitors, neutralizing agents, foaming agents, plasticizers, anti-foaming agents, flame retardants, crosslinking agents, flowability improvers such as peroxides, ultraviolet light absorbers, light stabilizers, weathering stabilizers, weld strength improvers, slip agents, antiblocking agents, antifogging agents, dyes, pigments, natural oils, synthetic oils, waxes, fillers and rubber ingredients.
• nucleating agents such as peroxides, ultraviolet light absorbers, light stabilizers, weathering stabilizers, weld strength improvers, slip agents, antiblocking agents, antifogging agents, dyes, pigments, natural oils, synthetic oils, waxes, fillers and rubber ingredients.
• the polyolefins, particularly polyethylenes, of the present invention may be fabricated into films by any technique known in the art.
• films may be produced by the well known cast film, blown film and extrusion coating techniques.
• polyolefins particularly polyethylenes
• polyethylenes may be fabricated into other articles of manufacture, such as molded articles, by any of the well known techniques.
• the polymerization process utilized in Examples 1-15 herein is carried out in a fluidized-bed reactor for gas-phase polymerization, consisting of a vertical cylinder of diameter 0.74 meters and height 7 meters and surmounted by a velocity reduction chamber.
• the reactor is provided in its lower part with a fluidization grid and with an external line for recycling gas, which connects the top of the velocity reduction chamber to the lower part of the reactor, at a point below the fluidization grid.
• the recycling line is equipped with a compressor for circulating gas and a heat transfer means such as a heat exchanger.
• the reactor contains a fluidized bed consisting of a polyethylene powder made up of particles with a weight-average diameter of about 0.5 mm to about 1.4 mm.
• the gaseous reaction mixture which contains ethylene, olefin comonomer, hydrogen, nitrogen and minor amounts of other components, passes through the fluidized bed under a pressure ranging from about 280 psig to about 300 psig with an ascending fluidization speed, referred to herein as fluidization velocity, ranging from about 1.6 feet per second to about 2.0 feet per second.
• fluidization velocity ascending fluidization speed
• ESM Electrostatic Monitor
• the electrostatic probe was installed in the vertical cylindrical section of the reactor at a height such as to be within the fluidized bed of polymer particles.
• the electrostatic probe measures the current flow between the polymerization medium and the ground.
• a reduction in electrostatic charge is defined as a reduction in the absolute magnitude of the measured current and/or a reduction in the variability of the measured current.
• the polymerization process is carried out as described above.
• the olefins used herein are ethylene and 1-hexene. Hydrogen is used to control molecular weight.
• the metallocene catalyst contains bis(l-butyl-3- methylcyclopentadienyl)zirconium dichloride and methylaluminoxane supported on silica. The ether introduced to reduce the electrostatic charge is tetrahydrofuran.
• Example 1 The process of Example 1 is followed with the exception that the ether utilized to reduce the electrostatic charge is as follows:
• Example 5 tert-butyl methyl ether, Example 6 dimethoxyethane.
• Example 1 The process of Example 1 is followed with the exception that a homopolymer of ethylene is produced.
• the level of electrostatic charge in the polymerization medium is expected to be reduced as a result of incorporating the tetrahydrofuran in the polymerization medium.
• Example 8 propylene
• Example 9 1 -butene, Example 10 1-pentene, Example 11 4-methylpent-l-ene,
• Example 1 The process of Example 1 is followed with the exception that the supported metallocene catalyst is replaced with the following silica supported metallocene catalysts:
• Example 13 bis(l-butyl-3- methylcyclopentadieny 1) dimethy lzir conium and tris(perfluorophenyl)borane
• Example 14 bis(l-butyl-3- methylcyclopentadienyl)dimethylzirconium and triphenylmethylium tetrakis(perfluorophenyl)borate
• Example 15 (tert-butylamido)dimethyl(tetramethyl- ⁇ 5 - cyclopentadienyl)silanetitaniumdimethyl and triphenylmethylium tetrakis(perfluorophenyl)borate
• Example 16 (tert-butylamido)dimethyl(tetramethyl- ⁇ 5 - cyclopentadienyl)silanetitaniumdimethyl and tris(perfluorophenyl)borane
• Example 17 (tert-butylamido)dimethyl(te
• Films are prepared from the polyolefins of the present invention.
• Articles such as molded items are also prepared from the polyolefins of the present invention.

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