Metal-based catalyst for producing polydienes

Abstract

To provide a beneficial method for polymerizing conjugated dienes with a metal-based catalyst system.SOLUTION: A method for preparing a polymer comprises polymerizing a conjugated diene monomer in the presence of a catalyst system including (i) a nickel-containing compound, (ii) triethyl aluminum, (iii) a hydrocarbyl aluminum hydride, and (iv) a halogen-containing compound.SELECTED DRAWING: None

Description

[Technical field]

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 002,407, filed March 31, 2020, which is incorporated herein by reference.

[0002] FIELD OF THEINVENTION One or more embodiments of the present invention relate to a process for polymerizing conjugated dienes using a metal-based catalyst system. [Background technology]

[0003] Synthetic elastomers with a linear backbone are often used in the manufacture of tire components, such as sidewalls and treads. These polymers are believed to provide advantageous tensile properties, wear resistance, low hysteresis, and fatigue resistance. For example, cis-1,4-polydienes are used in tires.

[0004] Cis-1,4-polydienes can be produced by using a lanthanide-based catalyst system or a nickel-based catalyst system. A lanthanide-based catalyst system typically includes a lanthanide-based compound, an alkylating agent, and a source of halogen to activate the system. A nickel-based catalyst system typically includes a nickel-containing compound, an alkylating agent, and a source of halogen to activate the system. Alkyl aluminum compounds, such as trialkyl aluminum compounds and alkyl aluminum hydrides, are often used as alkylating agents. The species selected for each component, their relative concentrations, and many other factors can affect the polymerization process and the resulting polydienes that are ultimately synthesized. For example, triisobutyl aluminum is known to result in higher monomer conversion and higher cis-1,4-microstructure content than when triethyl aluminum is used as the alkylating agent in the lanthanide system. Summary of the Invention

[0005] One or more embodiments of the present invention provide a method for preparing a polymer comprising polymerizing a conjugated diene monomer in the presence of a lanthanide-based catalyst system comprising a lanthanide-containing compound, triethylaluminum, aluminum hydride, and a halogen-containing compound.

[0006] Yet another embodiment of the present invention provides a polymer prepared by polymerizing a conjugated diene monomer in the presence of a lanthanide-based catalyst system comprising a lanthanide-containing compound, triethylaluminum, aluminum hydride, and a halogen-containing compound.

[0007] Another embodiment of the present invention provides a method for preparing a polymer comprising polymerizing a conjugated diene monomer in the presence of a metal-based catalyst system comprising a nickel-containing compound, triethylaluminum, aluminum hydride, and a halogen-containing compound selected from a fluorine-containing compound and a chlorine-containing compound.

[0008] Yet another embodiment of the present invention provides a polymer prepared by polymerizing a conjugated diene monomer in the presence of a metal-based catalyst system comprising a nickel-containing compound, triethylaluminum, aluminum hydride, and a halogen-containing compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention is based, at least in part, on the discovery of a process for the polymerization of conjugated dienes using a metal-based catalyst system comprising triethylaluminum and aluminum hydride as alkylating agents. The use of this particular combination of alkylating agents has unexpectedly provided beneficial results, including improved polymerization activity and beneficial polymer properties. Although the prior art teaches that the use of triethylaluminum as an alkylating agent provides lower polymerization activity than other commonly used trialkylaluminum compounds (e.g., triisobutylaluminum), the findings related to the present invention show that the combination of triethylaluminum and aluminum hydride provides particularly beneficial results compared to other alkylating agents, such as triisobutylaluminum, particularly with respect to the polymerization activity of the lanthanide-based catalyst and the resulting polymer properties. Another embodiment is based, at least in part, on the discovery of a process for the polymerization of conjugated dienes using a nickel-based catalyst system comprising triethylaluminum and aluminum hydride as alkylating agents. This particular combination of alkylating agents also provides benefits over alkylating agents traditionally used in these catalyst systems.

[0010] A first set of embodiments provides a polymerization process whereby conjugated diene monomers are polymerized in the presence of a lanthanide-based catalyst system comprising: (i) a lanthanide-containing compound; (ii) triethylaluminum; (iii) aluminum hydride; and (iv) a halogen-containing compound. In one or more embodiments, other organometallic compounds, Lewis bases, and / or catalyst modifiers may be used in addition to the above components or ingredients.

[0011] A second set of embodiments provides a polymerization process whereby a conjugated diene monomer is polymerized in the presence of a nickel-based catalyst system comprising: (i) a nickel-containing compound; (ii) triethylaluminum; (iii) an aluminum hydride; and (iv) a halogen-containing compound selected from a chlorine-containing compound and a fluorine-containing compound. In one or more embodiments, other organometallic compounds, Lewis bases, and / or catalyst modifiers may be used in addition to the above components or ingredients.

[0012] Lanthanide-Containing Compounds Lanthanide-containing compounds useful in the lanthanide-based catalyst system include compounds containing at least one atom of lanthanum, neodymium, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and didymium. In one embodiment, these compounds can include neodymium, lanthanum, samarium, or didymium. As used herein, the term "didymium" refers to a commercially available mixture of rare earth elements obtained from monazite sand. In addition, the lanthanide-containing compounds useful in the present invention can be in the form of elemental lanthanide.

[0013] The lanthanide atom in the lanthanide-containing compound may be in various oxidation states, including, but not limited to, 0, +2, +3, and +4 oxidation states. In one embodiment, a trivalent lanthanide-containing compound (wherein the lanthanide atom is in the +3 oxidation state) may be used. Suitable lanthanide-containing compounds include, but are not limited to, lanthanide carboxylates, lanthanide organophosphates, lanthanide organophosphonates, lanthanide organophosphinates, lanthanide carbamates, lanthanide dithiocarbamates, lanthanide xanthates, lanthanide β-diketonates, lanthanide oxides, lanthanide alkoxides or aryloxides, lanthanide halides, lanthanide pseudohalides, lanthanide oxyhalides, and organolanthanide compounds.

[0014] In one or more embodiments, the lanthanide-containing compound may be soluble in a hydrocarbon solvent (e.g., an aromatic hydrocarbon, an aliphatic hydrocarbon, or a cycloaliphatic hydrocarbon). However, hydrocarbon-insoluble lanthanide-containing compounds may also be useful in the present invention because they can be suspended in the polymerization medium to form the catalytically active species.

[0015] For ease of explanation, the further discussion of useful lanthanide-containing compounds will focus on neodymium compounds, although one of ordinary skill in the art would be able to select similar compounds based on other lanthanide metals.

[0016] Suitable neodymium carboxylates include, but are not limited to, neodymium formate, neodymium acetate, neodymium acrylate, neodymium methacrylate, neodymium valerate, neodymium gluconate, neodymium citrate, neodymium fumarate, neodymium lactate, neodymium maleate, neodymium oxalate, neodymium 2-ethylhexanoate, neodymium neodecanoate (also known as neodymium versatate), neodymium naphthenate, neodymium stearate, neodymium oleate, neodymium benzoate, and neodymium picolinate.

[0017] Suitable neodymium organic phosphates include, but are not limited to, neodymium dibutyl phosphate, neodymium dipentyl phosphate, neodymium dihexyl phosphate, neodymium diheptyl phosphate, neodymium dioctyl phosphate, neodymium bis(1-methylheptyl)phosphate, neodymium bis(2-ethylhexyl)phosphate, neodymium didecyl phosphate, neodymium didodecyl phosphate, neodymium dioctadecyl phosphate, neodymium dioleyl phosphate, neodymium diphenyl phosphate, neodymium bis(p-nonylphenyl)phosphate, neodymium butyl(2-ethylhexyl)phosphate, neodymium(1-methylheptyl)(2-ethylhexyl)phosphate, and neodymium(2-ethylhexyl)(p-nonylphenyl)phosphate.

[0018] Suitable neodymium organic phosphonates include neodymium butyl phosphonate, neodymium pentyl phosphonate, neodymium hexyl phosphonate, neodymium heptyl phosphonate, neodymium octyl phosphonate, neodymium (1-methylheptyl) phosphonate, neodymium (2-ethylhexyl) phosphonate, neodymium decyl phosphonate, neodymium dodecyl phosphonate, neodymium octadecyl phosphonate, neodymium oleyl phosphonate, neodymium phenyl phosphonate, neodymium (p-nonylphenyl) phosphonate, neodymium butyl butyl phosphonate, neodymium pentyl pentyl phosphonate, neodymium hexyl hexyl phosphonate, neodymium heptyl heptyl phosphonate, neodymium octyloctyl phosphonate, neodymium (1-methylheptyl) (1-methylheptyl) phosphonate, neodymium neodymium (2-ethylhexyl) (2-ethylhexyl) phosphonate, neodymium decyldecyl phosphonate, neodymium dodecyl dodecyl phosphonate, neodymium octadecyl octadecyl phosphonate, neodymium oleyl oleyl phosphonate, neodymium phenyl phenyl phosphonate, neodymium (p-nonylphenyl) (p-nonylphenyl) phosphonate, neodymium butyl (2-ethylhexyl) phosphonate, neodymium (2-ethylhexyl) butyl phosphonate, neodymium (1-methylheptyl) (2-ethylhexyl) phosphonate, neodymium (2-ethylhexyl) (1-methylheptyl) phosphonate, neodymium (2-ethylhexyl) (p-nonylphenyl) phosphonate, and neodymium (p-nonylphenyl) (2-ethylhexyl) phosphonate.

[0019] Suitable neodymium organic phosphinates include neodymium butyl phosphinate, neodymium pentyl phosphinate, neodymium hexyl phosphinate, neodymium heptyl phosphinate, neodymium octyl phosphinate, neodymium (1-methylheptyl) phosphinate, neodymium (2-ethylhexyl) phosphinate, neodymium decyl phosphinate, neodymium dodecyl phosphinate, neodymium octadecyl phosphinate, neodymium oleyl phosphinate, neodymium phenyl phosphinate, neodymium (p-nonylphenyl) phosphinate, neodymium dibutyl phosphinate, neodymium dipentyl phosphinate, neodymium dihexyl phosphinate, neodymium di neodymium dioctylphosphinate, neodymium bis(1-methylheptyl)phosphinate, neodymium bis(2-ethylhexyl)phosphinate, neodymium didecylphosphinate, neodymium didodecylphosphinate, neodymium dioctadecylphosphinate, neodymium dioleylphosphinate, neodymium diphenylphosphinate, neodymium bis(p-nonylphenyl)phosphinate, neodymium butyl(2-ethylhexyl)phosphinate, neodymium (1-methylheptyl)(2-ethylhexyl)phosphinate, and neodymium (2-ethylhexyl)(p-nonylphenyl)phosphinate.

[0020] Suitable neodymium carbamates include, but are not limited to, neodymium dimethyl carbamate, neodymium diethyl carbamate, neodymium diisopropyl carbamate, neodymium dibutyl carbamate, and neodymium dibenzyl carbamate.

[0021] Suitable neodymium dithiocarbamates include, but are not limited to, neodymium dimethyldithiocarbamate, neodymium diethyldithiocarbamate, neodymium diisopropyldithiocarbamate, neodymium dibutyldithiocarbamate, and neodymium dibenzyldithiocarbamate.

[0022] Suitable neodymium xanthates include, but are not limited to, neodymium methyl xanthate, neodymium ethyl xanthate, neodymium isopropyl xanthate, neodymium butyl xanthate, and neodymium benzyl xanthate.

[0023] Suitable neodymium β-diketonates include, but are not limited to, neodymium acetylacetonate, neodymium trifluoroacetylacetonate, neodymium hexafluoroacetylacetonate, neodymium benzoylacetonate, and neodymium 2,2,6,6-tetramethyl-3,5-heptanedionate.

[0024] Suitable neodymium alkoxides or aryloxides include, but are not limited to, neodymium methoxide, neodymium ethoxide, neodymium isopropoxide, neodymium 2-ethylhexoxide, neodymium phenoxide, neodymium nonylphenoxide, and neodymium naphthoxide.

[0025] Suitable neodymium halides include, but are not limited to, neodymium fluoride, neodymium chloride, neodymium bromide, and neodymium iodide. Suitable neodymium pseudohalides include, but are not limited to, neodymium cyanide, neodymium cyanate, neodymium thiocyanate, neodymium azide, and neodymium ferrocyanide. Suitable neodymium oxyhalides include, but are not limited to, neodymium oxyfluoride, neodymium oxychloride, and neodymium oxybromide. Neodymium oxide may also be used. A Lewis base (e.g., tetrahydrofuran ("THF")) may be used to facilitate solubilization of this class of neodymium compounds in an inert organic solvent. When using lanthanide halides, lanthanide oxyhalides, or other lanthanide-containing compounds that contain halogen atoms, the lanthanide-containing compounds may optionally provide all or part of the halogen source in the lanthanide-based catalyst system.

[0026] As used herein, the term organolanthanide compound refers to any lanthanide-containing compound that contains at least one lanthanide-carbon bond. These compounds are primarily, but not exclusively, compounds that contain cyclopentadienyl ("Cp"), substituted cyclopentadienyl, allyl, and substituted allyl ligands. Suitable organolanthanide compounds include, but are not limited to, Cp3Ln, Cp2LnR, Cp2LnCl, CpLnCl2, CpLn(cyclooctatetraene), (C5Me5)2LnR, LnR3, Ln(allyl)3, and Ln(allyl)2Cl, where Ln represents a lanthanide atom and R represents a hydrocarbyl group. In one or more embodiments, the hydrocarbyl groups useful in the present invention may contain heteroatoms, such as nitrogen, oxygen, boron, silicon, sulfur, and phosphorus atoms.

[0027] Nickel-containing compounds In the nickel-based catalyst system, various nickel-containing compounds or mixtures thereof can be used. In one or more embodiments, such nickel-containing compounds can be soluble in a hydrocarbon solvent, such as an aromatic hydrocarbon, an aliphatic hydrocarbon, or a cycloaliphatic hydrocarbon. In other embodiments, hydrocarbon-insoluble nickel-containing compounds that can be suspended in the polymerization medium to form catalytically active species can also be useful.

[0028] The nickel atom in the nickel-containing compound may be in various oxidation states, including but not limited to, 0, +2, +3, and +4 oxidation states. Nickel-containing compounds include, but are not limited to, nickel carboxylates, nickel carboxylate borates, nickel organophosphates, nickel organophosphonates, nickel organophosphinates, nickel carbamates, nickel dithiocarbamates, nickel xanthates, nickel β-diketonates, nickel alkoxides or aryloxides, nickel halides, nickel pseudohalides, nickel oxyhalides, or organonickel compounds.

[0029] Nickel carboxylates can include nickel formate, nickel acetate, nickel acrylate, nickel methacrylate, nickel valerate, nickel gluconate, nickel citrate, nickel fumarate, nickel lactate, nickel maleate, nickel oxalate, nickel 2-ethylhexanoate, nickel neodecanoate, nickel naphthenate, nickel stearate, nickel oleate, nickel benzoate, and nickel picolinate.

[0030] Nickel carboxylate borates can include compounds defined by the formula (RCOONiO)3B or (RCOONiO)2B(OR), where each R, which can be the same or different, is a hydrogen atom or a monovalent organic group. In one embodiment, each R can be a hydrocarbyl group, such as, but not limited to, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl, aryl, and alkynyl groups, each group preferably containing from 1 carbon atom (or the minimum number of carbon atoms suitable for forming a group) up to about 20 carbon atoms. These hydrocarbyl groups can contain heteroatoms, such as, but not limited to, nitrogen, oxygen, silicon, sulfur, and phosphorus atoms. Nickel carboxylate borates can include those disclosed in U.S. Pat. No. 4,522,988, which is incorporated herein by reference. Specific examples of nickel borate carboxylates include nickel(II) neodecanoate borate, nickel(II) hexanoate borate, nickel(II) naphthenate borate, nickel(II) stearate borate, nickel(II) octoate borate, 2-ethylhexanoate nickel(II) borate, and mixtures thereof.

[0031] Nickel organic phosphates can include nickel dibutyl phosphate, nickel dipentyl phosphate, nickel dihexyl phosphate, nickel diheptyl phosphate, nickel dioctyl phosphate, nickel bis(1-methylheptyl)phosphate, nickel bis(2-ethylhexyl)phosphate, nickel didecyl phosphate, nickel didodecyl phosphate, nickel dioctadecyl phosphate, nickel dioleyl phosphate, nickel diphenyl phosphate, nickel bis(p-nonylphenyl)phosphate, nickel butyl(2-ethylhexyl)phosphate, nickel(1-methylheptyl)(2-ethylhexyl)phosphate, and nickel(2-ethylhexyl)(p-nonylphenyl)phosphate.

[0032] Nickel organic phosphonates include nickel butyl phosphonate, nickel pentyl phosphonate, nickel hexyl phosphonate, nickel heptyl phosphonate, nickel octyl phosphonate, nickel (1-methylheptyl) phosphonate, nickel (2-ethylhexyl) phosphonate, nickel decyl phosphonate, nickel dodecyl phosphonate, nickel octadecyl phosphonate, nickel oleyl phosphonate, nickel phenyl phosphonate, nickel (p-nonylphenyl) phosphonate, nickel butyl butyl phosphonate, nickel pentyl pentyl phosphonate, nickel hexyl hexyl phosphonate, nickel heptyl heptyl phosphonate, nickel octyloctyl phosphonate, and nickel (1-methylheptyl) (1-methylheptyl) phosphonate. , nickel (2-ethylhexyl) (2-ethylhexyl) phosphonate, nickel decyl decyl phosphonate, nickel dodecyl dodecyl phosphonate, nickel octadecyl octadecyl phosphonate, nickel oleyl oleyl phosphonate, nickel phenyl phenyl phosphonate, nickel (p-nonylphenyl) (p-nonylphenyl) phosphonate, nickel butyl (2-ethylhexyl) phosphonate, nickel (2-ethylhexyl) butyl phosphonate, nickel (1-methylheptyl) (2-ethylhexyl) phosphonate, nickel (2-ethylhexyl) (1-methylheptyl) phosphonate, nickel (2-ethylhexyl) (p-nonylphenyl) phosphonate, and nickel (p-nonylphenyl) (2-ethylhexyl) phosphonate.

[0033] Nickel organic phosphinates include nickel butyl phosphinate, nickel pentyl phosphinate, nickel hexyl phosphinate, nickel heptyl phosphinate, nickel octyl phosphinate, nickel (1-methylheptyl) phosphinate, nickel (2-ethylhexyl) phosphinate, nickel decyl phosphinate, nickel dodecyl phosphinate, nickel octadecyl phosphinate, nickel oleyl phosphinate, nickel phenyl phosphinate, nickel (p-nonylphenyl) phosphinate, nickel dibutyl phosphinate, nickel dipentyl phosphinate, nickel dihexyl phosphinate, nickel Examples of suitable phosphinates include keldiheptylphosphinate, nickel dioctylphosphinate, nickel bis(1-methylheptyl)phosphinate, nickel bis(2-ethylhexyl)phosphinate, nickel didecylphosphinate, nickel didodecylphosphinate, nickel dioctadecylphosphinate, nickel dioleylphosphinate, nickel diphenylphosphinate, nickel bis(p-nonylphenyl)phosphinate, nickel butyl(2-ethylhexyl)phosphinate, nickel(1-methylheptyl)(2-ethylhexyl)phosphinate, and nickel(2-ethylhexyl)(p-nonylphenyl)phosphinate.

[0034] Nickel carbamates can include nickel dimethyl carbamate, nickel diethyl carbamate, nickel diisopropyl carbamate, nickel dibutyl carbamate, and nickel dibenzyl carbamate.

[0035] Nickel dithiocarbamates can include nickel dimethyldithiocarbamate, nickel diethyldithiocarbamate, nickel diisopropyldithiocarbamate, nickel dibutyldithiocarbamate, and nickel dibenzyldithiocarbamate.

[0036] Nickel xanthates include nickel methyl xanthate, nickel ethyl xanthate, nickel isopropyl xanthate, nickel butyl xanthate, and nickel benzyl xanthate.

[0037] Nickel β-diketonates can include nickel acetylacetonate, nickel trifluoroacetylacetonate, nickel hexafluoroacetylacetonate, nickel benzoylacetonate, and nickel 2,2,6,6-tetramethyl-3,5-heptanedionate.

[0038] Nickel alkoxides or aryloxides can include nickel methoxide, nickel ethoxide, nickel isopropoxide, nickel 2-ethylhexoxide, nickel phenoxide, nickel nonylphenoxide, and nickel naphthoxide.

[0039] Nickel halides can include nickel fluoride, nickel chloride, nickel bromide, and nickel iodide. Nickel pseudohalides include nickel cyanide, nickel cyanate, nickel thiocyanate, nickel azide, and nickel ferrocyanide. Nickel oxyhalides include nickel oxyfluoride, nickel oxychloride, and nickel oxybromide. If the nickel halide, nickel oxyhalide, or other nickel-containing compound contains labile fluorine or chlorine atoms, the nickel-containing compound can also function as a fluorine-containing or chlorine-containing compound. Lewis bases, such as alcohols, can be used as solubilizing agents for this class of compounds.

[0040] The term "organic nickel compound" may refer to any nickel compound that contains at least one nickel-carbon bond. Organonickel compounds include bis(cyclopentadienyl)nickel (also called nickelocene), bis(pentamethylcyclopentadienyl)nickel (also called decamethylnickelocene), bis(tetramethylcyclopentadienyl)nickel, bis(ethylcyclopentadienyl)nickel, bis(isopropylcyclopentadienyl)nickel, bis(pentadienyl)nickel, bis(2,4-dimethylpentadienyl)nickel, (cyclopentadienyl)(pentadienyl)nickel, bis(1,5-cyclooctadiene)nickel, bis(allyl)nickel, bis(methallyl)nickel, and bis(crotyl)nickel.

[0041] Alkylating Agent Blend As noted above, the lanthanide-based and nickel-based catalyst systems include an aluminum hydride compound in addition to triethylaluminum. The aluminum hydride and triethylaluminum combined may be referred to as an alkylating agent blend or alkylating agent system.

[0042] As one of ordinary skill in the art would understand, triethylaluminum can be defined by the formula Al(CH2CH3)3.

[0043] Aluminum hydride compounds, which may also be referred to as hydrocarbyl aluminum hydrides, have the general formula AlR n H 3-nwhere each R can be independently a monovalent organic group bonded to the aluminum atom through a carbon atom, and n can be an integer ranging from 1 to 3. In one or more embodiments, each R can be independently a hydrocarbyl group, such as alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl, aryl, and alkynyl groups, each group containing from 1 carbon atom (or the minimum number of carbon atoms suitable to form the group) up to about 20 carbon atoms. These hydrocarbyl groups can contain heteroatoms, such as, but not limited to, nitrogen, oxygen, boron, silicon, sulfur, and phosphorus atoms. In one or more embodiments, the aluminum hydride can be a dihydrocarbyl aluminum hydride, and in other embodiments, it can be a hydrocarbyl aluminum dihydride.

[0044] Suitable dihydrocarbylaluminum hydride compounds include diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride, phenylisobutylaluminum hydride, phenyl- Examples of aluminum hydride include, but are not limited to, n-octylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, p-tolyl-n-butylaluminum hydride, p-tolylisobutylaluminum hydride, p-tolyl-n-octylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride, benzyl-n-butylaluminum hydride, benzylisobutylaluminum hydride, and benzyl-n-octylaluminum hydride.

[0045] Suitable hydrocarbylaluminum dihydrides include, but are not limited to, ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride, and n-octylaluminum dihydride.

[0046] Halogen-Containing Compounds As noted above, the lanthanide-based and nickel-based catalyst systems include a halogen-containing compound.

[0047] Various compounds containing one or more halogen atoms, or their mixtures, can be used as halogen-containing compounds. Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine. Combinations of two or more halogen atoms can also be used. Halogen-containing compounds that are soluble in hydrocarbon solvents are suitable for use in the present invention. However, halogen-containing compounds that are insoluble in hydrocarbon solvents are also useful because they can be suspended in the polymerization system to form catalytically active species.

[0048] Useful types of halogen-containing compounds that can be used include, but are not limited to, elemental halogens, mixed halogens, hydrogen halides, organic halides, inorganic halides, metal halides, and organometallic halides.

[0049] Suitable elemental halogens include, but are not limited to, fluorine, chlorine, bromine, and iodine. Some specific examples of suitable mixed halogens include iodine monochloride, iodine monobromide, iodine trichloride, and iodine pentafluoride.

[0050] Suitable hydrogen halides include, but are not limited to, hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide.

[0051] Suitable organic halides include, but are not limited to, t-butyl chloride, t-butyl bromide, allyl chloride, allyl bromide, benzyl chloride, benzyl bromide, chloro-di-phenylmethane, bromo-di-phenylmethane, triphenylmethyl chloride, triphenylmethyl bromide, benzylidene chloride, benzylidene bromide, methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, diphenyldichlorosilane, trimethylchlorosilane, benzoyl chloride, benzoyl bromide, propionyl chloride, propionyl bromide, methyl chloroformate, and methyl bromoformate.

[0052] Suitable inorganic halides include, but are not limited to, phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride, phosphorus oxychloride, phosphorus oxybromide, boron trifluoride, boron trichloride, boron tribromide, silicon tetrafluoride, silicon tetrachloride, silicon tetrabromide, silicon tetraiodide, arsenic trichloride, arsenic tribromide, arsenic triiodide, selenium tetrachloride, selenium tetrabromide, tellurium tetrachloride, tellurium tetrabromide, and tellurium tetraiodide.

[0053] Suitable metal halides include, but are not limited to, tin tetrachloride, tin tetrabromide, aluminum trichloride, aluminum tribromide, antimony trichloride, antimony pentachloride, antimony tribromide, aluminum triiodide, aluminum trifluoride, gallium trichloride, gallium tribromide, gallium triiodide, gallium trifluoride, indium trichloride, indium tribromide, indium triiodide, indium trifluoride, titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, zinc dichloride, zinc dibromide, zinc diiodide, and zinc difluoride.

[0054] Suitable organometallic halides include dimethylaluminum chloride, diethylaluminum chloride, dimethylaluminum bromide, diethylaluminum bromide, dimethylaluminum fluoride, diethylaluminum fluoride, methylaluminum dichloride, ethylaluminum dichloride, methylaluminum dibromide, ethylaluminum dibromide, methylaluminum difluoride, ethylaluminum difluoride, methylaluminum sesquichloride, ethylaluminum sesquichloride, isobutylaluminum sesquichloride, methylmagnesium chloride, methylma. Examples of magnesium iodide include, but are not limited to, magnesium bromide, methyl magnesium iodide, ethyl magnesium chloride, ethyl magnesium bromide, butyl magnesium chloride, butyl magnesium bromide, phenyl magnesium chloride, phenyl magnesium bromide, benzyl magnesium chloride, trimethyltin chloride, trimethyltin bromide, triethyltin chloride, triethyltin bromide, di-t-butyltin dichloride, di-t-butyltin dibromide, dibutyltin dichloride, dibutyltin dibromide, tributyltin chloride, and tributyltin bromide.

[0055] In one or more embodiments, the lanthanide-based catalyst system can include a compound containing a non-coordinating anion or a non-coordinating anion precursor. In one or more embodiments, a compound containing a non-coordinating anion or a non-coordinating anion precursor can be used in place of the halogen source described above. A non-coordinating anion is a sterically bulky anion that does not form a coordinate bond with, for example, the active center of the catalyst system due to steric hindrance. Non-coordinating anions useful in the present invention include, but are not limited to, tetraarylborate anions and fluorinated tetraarylborate anions. Compounds containing a non-coordinating anion can also contain a counter cation, for example, a carbonium, ammonium, or phosphonium cation. Exemplary counter cations include, but are not limited to, triarylcarbonium cations and N,N-dialkylanilinium cations. Examples of compounds containing a noncoordinating anion and a countercation include, but are not limited to, triphenylcarbonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, triphenylcarbonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate.

[0056] Those skilled in the art will appreciate that halogen-containing compounds can include lanthanide-containing compounds or nickel-containing compounds, which contain labile halogen atoms.

[0057] In this embodiment, non-coordinating anion precursors can also be used. Non-coordinating anion precursors are compounds that can form non-coordinating anions under reaction conditions. Useful non-coordinating anion precursors include, but are not limited to, triarylboron compounds, BR3, where R is a highly electron-withdrawing aryl group, such as pentafluorophenyl or 3,5-bis(trifluoromethyl)phenyl groups.

[0058] Fluorine-containing compounds In certain embodiments, the nickel-based catalyst system may include a fluorine-containing compound. The fluorine-containing compound may include various compounds or mixtures thereof that contain one or more labile fluorine atoms. In one or more embodiments, the fluorine-containing compound may be soluble in a hydrocarbon solvent. In other embodiments, a hydrocarbon-insoluble fluorine-containing compound may be useful that can be suspended in the polymerization medium to form catalytically active species.

[0059] Types of fluorine-containing compounds include, but are not limited to, elemental fluorine, halogen fluorides, hydrogen fluoride, organic fluorides, inorganic fluorides, metal fluorides, organometallic fluorides, and mixtures thereof. In one or more embodiments, complexes of fluorine-containing compounds with Lewis bases such as ethers, alcohols, water, aldehydes, ketones, esters, nitriles, or mixtures thereof may be used. Specific examples of these complexes include complexes of boron trifluoride with Lewis bases of hydrogen fluoride.

[0060] Halofluorides can include iodine monofluoride, iodine trifluoride, and iodine pentafluoride.

[0061] Organic fluorides can include t-butyl fluoride, allyl fluoride, benzyl fluoride, fluoro-di-phenylmethane, triphenylmethyl fluoride, benzylidene fluoride, methyltrifluorosilane, phenyltrifluorosilane, dimethyldifluorosilane, diphenyldifluorosilane, trimethylfluorosilane, benzoyl fluoride, propionyl fluoride, and methylfluoroformate.

[0062] Inorganic fluorides can include phosphorus trifluoride, phosphorus pentafluoride, phosphorus oxyfluoride, boron trifluoride, silicon tetrafluoride, arsenic trifluoride, selenium tetrafluoride, and tellurium tetrafluoride.

[0063] Metal fluorides can include tin tetrafluoride, aluminum trifluoride, antimony trifluoride, antimony pentafluoride, gallium trifluoride, indium trifluoride, titanium tetrafluoride, and zinc difluoride.

[0064] Examples of organometallic fluorides include dimethylaluminum fluoride, diethylaluminum fluoride, methylaluminum difluoride, ethylaluminum difluoride, methylaluminum sesquifluoride, ethylaluminum sesquifluoride, isobutylaluminum sesquifluoride, methylmagnesium fluoride, ethylmagnesium fluoride, butylmagnesium fluoride, phenylmagnesium fluoride, benzylmagnesium fluoride, trimethyltin fluoride, triethyltin fluoride, di-t-butyltin difluoride, dibutyltin difluoride, and tributyltin fluoride.

[0065] Various compounds containing one or more labile chlorine atoms, or their mixtures, can be used as chlorine-containing compound.In one or more embodiments, chlorine-containing compound can be soluble in hydrocarbon solvent.In other embodiments, hydrocarbon-insoluble chlorine-containing compound can be useful, which can be suspended in polymerization medium to form catalytically active species.

[0066] Catalyst component ratio In a first set of embodiments, the lanthanide-based catalyst composition used in the present invention can be formed by combining or mixing the above-mentioned catalyst components. It is believed that one or more active catalytic species can be obtained from a combination of lanthanide-based catalyst components, but the degree of interaction or reaction between the various catalyst components or components is not very precisely known. Therefore, the term "catalyst composition" is used to include a simple mixture of components, a complex of various components resulting from physical or chemical attraction, a chemical reaction product of the components, or a combination of the above.

[0067] In one or more embodiments, the molar ratio of triethylaluminum hydride to the lanthanide-containing compound (alkylating agent / Ln) can vary from about 2:1 to about 15:1, in other embodiments from about 3.5:1 to about 10:1, and in other embodiments from about 4.5:1 to about 7.5:1.

[0068] In one or more embodiments, the molar ratio of the hydrocarbylaluminum hydride to the lanthanide-containing compound (alkylating agent / Ln) can vary from about 1:1 to about 10:1, in other embodiments from about 2.5:1 to about 8:1, and in other embodiments from about 4:1 to about 6:1.

[0069] In one or more embodiments, the molar ratio of the halogen-containing compound to the lanthanide-containing compound is best described in terms of the ratio of moles of halogen atoms in the halogen source to moles of lanthanide atoms in the lanthanide-containing compound (Halogen / Ln). In one or more embodiments, the Halogen / Ln molar ratio can vary from about 0.5:1 to about 20:1, in other embodiments from about 1:1 to about 10:1, and in other embodiments from about 2:1 to about 6:1.

[0070] In yet other embodiments, the molar ratio of the noncoordinating anion or noncoordinating anion precursor to the lanthanide-containing compound (An / Ln) can be from about 0.5:1 to about 20:1, from about 0.75:1 to about 10:1 in other embodiments, and from about 1:1 to about 6:1 in other embodiments.

[0071] In a second set of embodiments, the nickel-based catalyst composition used in the present invention may be formed by combining or mixing the above catalyst components. It is believed that one or more active catalytic species are obtained from the combination of nickel-based catalyst components, but the degree of interaction or reaction between the various catalyst components or components is not so precisely known. Thus, the term "catalyst composition" is used to include a simple mixture of components, a complex of various components resulting from physical or chemical attraction, a chemical reaction product of the components, or a combination of the above.

[0072] In one or more embodiments, the molar ratio of triethylaluminum to the nickel-containing compound (alkylating agent / Ni) can vary from about 1:1 to about 200:1, in other embodiments from about 2:1 to about 100:1, and in other embodiments from about 5:1 to about 50:1.

[0073] In one or more embodiments, the molar ratio of the hydrocarbylaluminum hydride to the nickel-containing compound (alkylating agent / Ni) can vary from about 1:1 to about 500:1, in other embodiments from about 2:1 to about 100:1, and in other embodiments from about 3:1 to about 50:1.

[0074] In embodiments where the nickel-containing catalyst system includes a fluorine-containing compound, the molar ratio of the fluorine-containing compound to the nickel-containing compound is best described in terms of the ratio of moles of fluorine atoms in the fluorine-containing compound to moles of nickel atoms in the nickel-containing compound (F / Ni). In one or more embodiments, the F / Ni molar ratio can vary from about 2:1 to about 500:1, in other embodiments from about 5:1 to about 300:1, and in other embodiments from about 8:1 to about 200:1.

[0075] catalyst formation A variety of procedures can be used to prepare the lanthanide-based and nickel-based catalyst systems of the present invention. In one or more embodiments, the catalyst system can be formed in situ by separately adding the catalyst components to the monomer to be polymerized, either in a stepwise or simultaneous manner. In other embodiments, the catalyst system can be preformed. That is, the catalyst components are premixed outside the polymerization system in the absence of monomer or in the presence of a small amount of monomer. The resulting preformed catalyst composition can be aged, if necessary, and then added to the monomer to be polymerized.

[0076] The catalyst system may be formed by a variety of methods.

[0077] In one embodiment, forming the catalyst composition in situ may be carried out by adding the catalyst components to a solution containing monomer and solvent or to bulk monomer in either a stepwise or simultaneous manner, In one embodiment, the alkylating agent may be added first, followed by the lanthanide-containing or nickel-containing compound, and then the halogen-containing compound or the compound containing a non-coordinating anion or a non-coordinating anion precursor.

[0078] In another embodiment, the catalyst composition may be preformed. That is, the catalyst components are premixed outside of the polymerization system at a suitable temperature, which may be from about -20°C to about 80°C, in the absence of monomer or in the presence of a small amount of at least one conjugated diene monomer. The amount of conjugated diene monomer that may be used to preform the catalyst may range from about 1 to about 500 moles, in other embodiments from about 5 to about 250 moles, and in other embodiments from about 10 to about 100 moles per mole of lanthanide-containing or nickel-containing compound. The resulting catalyst composition may be aged, if desired, before being added to the monomer to be polymerized.

[0079] In yet another embodiment, the catalyst composition may be formed by using a two-stage procedure. The first stage may involve combining an alkylating agent with a lanthanide-containing or nickel-containing compound in the absence of monomer or in the presence of a small amount of at least one conjugated diene monomer at a suitable temperature, which may be from about -20°C to about 80°C. The amount of monomer used in the first stage may be similar to that previously described for preforming the catalyst. In the second stage, the mixture formed in the first stage and the halogen-containing compound, non-coordinating anion, or non-coordinating anion precursor may be charged to the monomer to be polymerized in either a stepwise or simultaneous manner.

[0080] In one or more embodiments, a solvent may be used as a carrier to dissolve or suspend the catalyst or initiator to facilitate delivery of the catalyst to the polymerization system. In other embodiments, the monomer may be used as a carrier. In yet other embodiments, the catalyst may be used neat without any solvent.

[0081] In one or more embodiments, suitable solvents include organic compounds that do not undergo polymerization or incorporation into the propagating polymer chain during polymerization of monomers in the presence of a catalyst or initiator. In one or more embodiments, these organic species are liquid at ambient temperature and pressure. In one or more embodiments, these organic solvents are inert to the catalyst or initiator. Exemplary organic solvents include hydrocarbons with low or relatively low boiling points, such as aromatic, aliphatic, and cycloaliphatic hydrocarbons. Non-limiting examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, diethylbenzene, and mesitylene. Non-limiting examples of aliphatic hydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexane, isopentane, isooctane, 2,2-dimethylbutane, petroleum ether, kerosene, and mineral spirits. Additionally, non-limiting examples of cycloaliphatic hydrocarbons include cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane. Mixtures of the above hydrocarbons can also be used. As is known in the art, for environmental reasons, it may be desirable to use aliphatic and cycloaliphatic hydrocarbons. The low boiling hydrocarbon solvent is typically separated from the polymer when the polymerization is completed.

[0082] Other examples of organic solvents include high molecular weight, high boiling point hydrocarbons, including hydrocarbon oils that are commonly used in oil-extended polymers. Examples of these oils include paraffinic oils, aromatic oils, naphthenic oils, vegetable oils other than castor oil, and low PCA oils, such as MES, TDAE, SRAE, heavy naphthenic oils. Because these hydrocarbons are non-volatile, they typically do not need to be separated and remain entrapped within the polymer.

[0083] Polymerization Process The lanthanide-based or nickel-based catalyst compositions described above have relatively high catalytic activity for polymerizing conjugated dienes into polymers over a wide range of catalyst concentrations and catalyst component ratios. The polymers may be referred to as polydienes, and in one or more embodiments may include cis-1,4-polydienes. Several factors may affect the optimal concentration of any one of the catalyst components. For example, the catalyst components may interact to form active species, so the optimal concentration for any one catalyst component may depend on the concentration of the other catalyst components.

[0084] Examples of conjugated diene monomers include 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene.

[0085] The production of reactive polymers according to the present invention can be achieved by polymerizing a conjugated diene monomer, optionally with a monomer copolymerizable with the conjugated diene monomer, in the presence of a catalytically effective amount of a catalyst. The introduction of the catalyst, the conjugated diene monomer, optionally a comonomer, and any solvent, if used, forms a polymerization mixture in which the reactive polymer is formed. The amount of catalyst or initiator used can depend on the interaction of various factors, such as the type of catalyst or initiator used, the purity of the components, the polymerization temperature, the desired polymerization rate and conversion, the desired molecular weight, and many other factors. Thus, a specific amount of catalyst or initiator cannot be definitively stated, other than to say that a catalytically effective amount of catalyst or initiator can be used.

[0086] In one or more embodiments, the amount of coordinated metal compound (e.g., lanthanide-containing compound or nickel-containing compound) used can vary from about 0.001 to about 2 mmol, in other embodiments from about 0.005 to about 1 mmol, and in still other embodiments from about 0.01 to about 0.2 mmol, per 100 grams of monomer.

[0087] In one or more embodiments, the polymerization may be carried out in a polymerization system that includes a significant amount of solvent. In one embodiment, a solution polymerization system may be used in which both the monomer to be polymerized and the polymer formed are soluble in the solvent. In another embodiment, a precipitation polymerization system may be used by selecting a solvent in which the polymer formed is insoluble. In both cases, an amount of solvent is usually added to the polymerization system in addition to the amount of solvent that may be used in preparing the catalyst. The additional solvent may be the same or different from the solvent used in preparing the catalyst. Exemplary solvents are described above. In one or more embodiments, the solvent content of the polymerization mixture may be greater than 20 wt%, greater than 50 wt% in other embodiments, and greater than 80 wt% in still other embodiments, based on the total weight of the polymerization mixture.

[0088] In other embodiments, the polymerization system used may generally be considered to be a bulk polymerization system that is substantially solvent-free or contains minimal amounts of solvent. Those skilled in the art will appreciate the advantages of a bulk polymerization process (i.e., a process in which the monomer acts as a solvent), and therefore the polymerization system contains less solvent that would adversely affect the benefits sought by conducting a bulk polymerization. In one or more embodiments, the solvent content of the polymerization mixture may be less than about 20% by weight, in other embodiments less than about 10% by weight, and in yet other embodiments less than about 5% by weight, based on the total weight of the polymerization mixture. In another embodiment, the polymerization mixture contains no solvent other than that inherent in the raw materials used. In yet another embodiment, the polymerization mixture is substantially devoid of solvent. This refers to the absence of an amount of solvent that, if present, would have a significant effect on the polymerization process. A polymerization system that is substantially devoid of solvent may also be said to be substantially free of solvent. In certain embodiments, the polymerization mixture is devoid of solvent.

[0089] The polymerization may be carried out in any conventional polymerization vessel known in the art. In one or more embodiments, the solution polymerization may be carried out in a conventional stirred tank reactor. In other embodiments, the bulk polymerization may be carried out in a conventional stirred tank reactor, especially when the monomer conversion is less than about 60%. In still other embodiments, the bulk polymerization may be carried out in an elongated reactor, in which the polymerizing viscous cement is moved by or substantially moved by a piston, especially when the monomer conversion in the bulk polymerization process is greater than about 60%, which typically results in a highly viscous cement. For example, an extruder in which the cement is pushed by a self-cleaning single screw or twin screw agitator is suitable for this purpose. An example of a useful bulk polymerization process is disclosed in U.S. Pat. No. 7,351,776, which is incorporated herein by reference.

[0090] In one or more embodiments, the components used for the polymerization may all be mixed in a single vessel (e.g., a conventional stirred tank reactor) and all steps of the polymerization process may occur in this vessel. In other embodiments, two or more components may be precombined in one vessel and then transferred to another vessel in which polymerization of the monomer (or at least a majority of it) takes place.

[0091] The polymerization can be carried out as a batch, continuous, or semi-continuous process. In a semi-continuous process, monomer is intermittently charged as needed to replace already polymerized monomer. In one or more embodiments, the conditions under which the polymerization proceeds can be controlled to maintain the temperature of the polymerization mixture in the range of about -10°C to about 200°C, in other embodiments about 0°C to about 150°C, and in other embodiments about 20°C to about 100°C. In one or more embodiments, the heat of polymerization can be removed by external cooling through a thermally controlled reactor jacket, internal cooling by vaporization and condensation of the monomer by using a reflux condenser connected to the reactor, or a combination of the two methods. The polymerization conditions can also be controlled to carry out the polymerization under pressures of about 0.1 atm to about 50 atm, in other embodiments about 0.5 atm to about 20 atm, and in other embodiments about 1 atm to about 10 atm. In one or more embodiments, pressures under which the polymerization may be carried out include pressures that ensure that the majority of the monomer is in the liquid phase. In these or other embodiments, the polymerization mixture can be maintained under anaerobic conditions.

[0092] As described above, the catalyst system and polymerization process of the present invention provide beneficial polymerization activity. In one or more embodiments, the polymerization activity can be expressed in terms of the monomer conversion of the polymerization process. In one or more embodiments, the catalyst system and polymerization process achieve a monomer conversion of more than 80%, in other embodiments, more than 85%, and in other embodiments, more than 90%.

[0093] Reactive Polymers In one or more embodiments, the polymerization process of the present invention produces reactive polymers. The reactive polymers are believed to be prepared by a coordination polymerization mechanism. The important mechanistic features of coordination polymerization have been discussed in books (e.g., Kuran, W., Principles of Coordination Polymerization; John Wiley & Sons: New York, 2001) and reviews (e.g., Mulhaupt, R., Macromolecular Chemistry and Physics 2003, volume 204, pages 289-327). Coordination catalysts are believed to initiate polymerization of monomers by a mechanism that involves coordination or complexation of the monomer to an active metal center prior to insertion of the monomer into the growing polymer chain. A beneficial feature of coordination catalysts is their ability to provide stereochemical control over the polymerization, thereby producing stereoregular polymers. As known in the art, there are many methods for forming coordination catalysts. However, all methods ultimately generate an active intermediate that can coordinate with the monomer and insert the monomer into the covalent bond between the active metal center and the growing polymer chain. The coordination polymerization of conjugated dienes is believed to proceed via π-allyl complexes as intermediates. Coordination catalysts can be one-component, two-component, three-component, or multi-component. In one or more embodiments, coordination catalysts can be formed by combining a heavy metal compound (e.g., a lanthanide-containing compound), an alkylating agent (e.g., an organoaluminum compound), and optionally other cocatalyst components (e.g., a Lewis acid or Lewis base). In one or more embodiments, the heavy metal compound may be referred to as a coordination metal compound.

[0094] In one or more embodiments, especially when a lanthanide-based catalyst system is used, the resulting polymer chains have reactive chain ends before the polymerization mixture is quenched. Thus, when referring to a reactive polymer, it refers to a polymer with reactive chain ends resulting from the synthesis of the polymer by using a coordination catalyst, and the reactive polymer may be referred to as a pseudo-living polymer. In one or more embodiments, a polymerization mixture containing a reactive polymer may be referred to as an active polymerization mixture. The percentage of polymer chains possessing reactive ends depends on various factors, such as the type of catalyst or initiator, the type of monomer, the purity of the components, the polymerization temperature, the monomer conversion, and many other factors. In one or more embodiments, at least about 5% of the polymer chains have reactive ends, in other embodiments, at least about 10% of the polymer chains have reactive ends, and in still other embodiments, at least about 15% of the polymer chains have reactive ends. In any case, the reactive polymer may be reacted with a functionalizing agent to form the binding polymer of the present invention.

[0095] sensualization In one or more embodiments, a functionalizing agent may optionally be added to the polymerization mixture to functionalize at least a portion of the polymer chains, particularly those having reactive chain ends. Mixtures of two or more functionalizing agents may be used.

[0096] In one or more embodiments, the functionalizing agent includes a compound or reagent capable of reacting with the reactive polymer produced by the present invention, thereby imparting functional groups to the polymer that are distinct from the propagating chains that have not reacted with the functionalizing agent. The functional groups may be reactive or interactive with other polymer chains (propagating and / or non-propagating) or with other components that may be combined with the polymer, such as reinforcing fillers (e.g., carbon black). In one or more embodiments, the reaction between the functionalizing agent and the reactive polymer proceeds via an addition or substitution reaction.

[0097] Useful functionalizing agents may include compounds that simply provide a functional group at the end of the polymer chain. In one or more embodiments, functionalizing agents include compounds that will add or impart heteroatoms to the polymer chain. In certain embodiments, functionalizing agents include compounds that impart functional groups to the polymer chain to form a functionalized polymer that reduces the 50° C. hysteresis loss of a carbon black-loaded vulcanizate prepared from the functionalized polymer compared to a similar carbon black-loaded vulcanizate prepared from a non-functionalized polymer.

[0098] In other embodiments, additional binders may be used in combination with functionalizing agents. These compounds, which may be referred to as co-binders, may link two or more polymer chains together to form a single macromolecule. Some functionalizing agents may serve to link polymer chains in addition to providing the polymer chains with useful functionality, and the co-binders may be referred to herein simply as functionalizing agents.

[0099] In one or more embodiments, suitable functionalizing agents include compounds that contain groups that can react with the reactive polymers produced according to the present invention.Exemplary functionalizing agents include ketones, quinones, aldehydes, amides, esters, isocyanates, isothiocyanates, epoxides, imines, aminoketones, aminothioketones, and acid anhydrides.Examples of these compounds are described in U.S. Patent Nos. 4,906,706, 4,990,573, 5,064,910, 5,567,784, 5,844,050, 6838,526, 6977,281, and 6,992,147, U.S. Patent Application Publication No. 2006 / 0004131(A1), 2007 / 0004132, 2007 / 0004133, 2007 / 0004134, 2007 / 0004135, 2007 / 0004136, 2007 / 0004137, 2007 / 0004138, 2007 / 0004139 ... Nos. 2006 / 0025539(A1), 2006 / 0030677(A1), and 2004 / 0147694(A1), and Japanese Patent Application Nos. 05-051406(A), 05-059103(A), 10-306113(A), and 11-035633(A), all of which are incorporated herein by reference. Other examples of functionalizing agents include the azine compounds described in U.S. Patent Serial No. 11 / 640,711, the hydrobenzamide compounds disclosed in U.S. Patent Serial No. 11 / 710,713, the nitro compounds disclosed in U.S. Patent Serial No. 11 / 710,845, and the protected oxime compounds disclosed in U.S. Patent Serial No. 60 / 875,484, all of which are incorporated herein by reference.

[0100] In certain embodiments, the functionalizing agents used can be epoxides, isocyanates, metal carboxylates, hydrocarbyl metal carboxylates, and hydrocarbyl metal ester-carboxylates.

[0101] In one or more embodiments, exemplary epoxy compounds may be selected from (3-glycidyloxypropyl)trimethoxysilane, (3-glycidyloxypropyl)triethoxysilane, (3-glycidyloxypropyl)triphenoxysilane, (3-glycidyloxypropyl)methyldimethoxysilane, (3-glycidyloxypropyl)methyldiethoxysilane, (3-glycidyloxypropyl)methyldiphenoxysilane, [2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane, and [2-(3,4-epoxycyclohexyl)ethyl]triethoxysilane.

[0102] Exemplary isocyanate compounds include (3-isocyanatepropyl)trimethoxysilane, (3-isocyanatepropyl)triethoxysilane, (3-isocyanatepropyl)triphenoxysilane, (3-isocyanatepropyl)methyldimethoxysilane, (3-isocyanatepropyl)methyldiethoxysilane, (3-isocyanatepropyl)methyldiphenoxysilane, and (isocyanatemethyl)methyldimethoxysilane.

[0103] Exemplary metal carboxylate compounds include tin tetraacetate, tin bis(2-ethylhexanoate), and tin bis(neodecanoate).

[0104] Exemplary hydrocarbyl metal carboxylate compounds include triphenyltin 2-ethylhexanoate, tri-n-butyltin 2-ethylhexanoate, tri-n-butyltin neodecanoate, triisobutyltin 2-ethylhexanoate, diphenyltin bis(2-ethylhexanoate), di-n-butyltin bis(2-ethylhexanoate), di-n-butyltin bis(neodecanoate), phenyltin tris(2-ethylhexanoate), and n-butyltin tris(2-ethylhexanoate).

[0105] Exemplary hydrocarbyl metal ester-carboxylate compounds include di-n-butyltin bis(n-octylmaleate), di-n-octyltin bis(n-octylmaleate), diphenyltin bis(n-octylmaleate), di-n-butyltin bis(2-ethylhexylmaleate), di-n-octyltin bis(2-ethylhexylmaleate), and diphenyltin bis(2-ethylhexylmaleate).

[0106] Exemplary metal alkoxide compounds include dimethoxytin, diethoxytin, tetraethoxytin, tetra-n-propoxytin, tetraisopropoxytin, tetra-n-butoxytin, tetraisobutoxytin, tetra-t-butoxytin, and tetraphenoxytin.

[0107] The amount of functionalizing agent that can be added to the polymerization mixture can depend on a variety of factors, such as the type and amount of catalyst or initiator used to synthesize the reactive polymer, and the desired degree of functionalization. In one or more embodiments, the amount of functionalizing agent used can be described based on the lanthanide metal of the lanthanide-containing compound. For example, the molar ratio of functionalizing agent to lanthanide metal can be from about 1:1 to about 200:1, in other embodiments from about 5:1 to about 150:1, and in other embodiments from about 10:1 to about 100:1.

[0108] Post-polymerization work-up In one or more embodiments, after polymerization, and optionally functionalization of the reactive polymer, a quenching agent may be added to the polymerization mixture to protonate the reaction product between the reactive polymer and the functionalizing agent, to deactivate any remaining reactive polymer chains, and / or to deactivate the catalyst or catalyst components. The quenching agent may include a protic compound, including, but not limited to, an alcohol, a carboxylic acid, an inorganic acid, water, or a mixture thereof. An antioxidant, such as 2,6-di-tert-butyl-4-methylphenol, may be added along with, before, or after the addition of the quenching agent. The amount of antioxidant used may range from 0.01% to 1% by weight of the polymer product. Additionally, the polymer product may be oil extended by adding oil to the polymer, which may be in the form of a polymer cement or polymer dissolved or suspended in the monomer. The practice of the present invention does not limit the amount of oil that may be added, and thus conventional amounts may be added (e.g., 5 to 50 phr). Useful oils or spreading agents that may be used include, but are not limited to, aromatic oils, paraffinic oils, naphthenic oils, vegetable oils (other than castor oil), low PCA oils (such as, for example, MES, TDAE, and SRAE), and heavy naphthenic oils.

[0109] After the polymerization mixture is quenched, various components of the polymerization mixture may be recovered. In one or more embodiments, unreacted monomers may be recovered from the polymerization mixture. For example, the monomers may be distilled from the polymerization mixture using techniques known in the art. After the monomers are removed from the polymerization mixture, they may be purified, stored, and / or recycled back into the polymerization process.

[0110] The polymer product may be recovered from the polymerization mixture using techniques known in the art. In one or more embodiments, desolventization and drying techniques may be used. The polymer may be recovered by subjecting the polymerization mixture to steam desolventization followed by drying the resulting polymer crumbs in a hot air tunnel. Alternatively, the polymer may be recovered by passing through an expander-expeller. The polymer may also be recovered by directly drying the polymerization mixture on a drum dryer.

[0111] Polymer properties In one or more embodiments, the polymers prepared according to the present invention may contain unsaturation. In these or other embodiments, the binding polymer is vulcanizable. In one or more embodiments, the binding polymer has a glass transition temperature (T) that is less than 0° C., in other embodiments less than −40° C., and in other embodiments less than −60° C. g ).

[0112] In one or more embodiments, the binding polymers of the present invention may be cis-1,4-polydienes having a cis-1,4-linkage content of greater than 85%, in other embodiments greater than about 90%, in other embodiments greater than about 92%, and in other embodiments greater than about 94%, the percentages being based on the number of diene mer units and taking the cis-1,4 linkages versus the total number of diene mer units. Measurement of the cis-1,4-, 1,2-, and trans-1,4-linkage content may be performed by infrared spectroscopy.

[0113] In one or more embodiments, the number average molecular weight (M n), as determined by using gel permeation chromatography (GPC) calibrated with polystyrene standards, can be from about 10 to about 1,000, in other embodiments from about 50 to about 500, in other embodiments from about 100 to about 400, and in other embodiments from about 200 to about 300 kg / mol. In these or other embodiments, the molecular weight distribution or polydispersity (M w / M n ) can be from about 1.0 to about 7.0, in other embodiments from about 1.5 to about 5.0, and in other embodiments from about 2.0 to about 4.0. In these or other embodiments, the molecular weight distribution or polydispersity (M w / M n ) may be less than 7.0, in other embodiments less than 5.0, in other embodiments less than 4.0, and in other embodiments less than 3.0.

[0114] When a polymer is functionalized, it is believed that the reactive polymer and the functionalizing agent (and optionally the functionalizing agent) react to produce a functionalized or conjugated polymer, with a residue of the functionalizing agent being attached to at least one polymer chain end. It is believed that the reactive end of the polymer chain reacts with the functionalizing agent, and in some embodiments, up to three chain ends react with the functionalizing agent to form a conjugated polymer. Nevertheless, the exact chemical structure of the conjugated polymer produced in any embodiment is not very precisely known, especially as the structure relates to the functionalizing agent and optionally the residues attached to the polymer chain end by the functionalizing agent. In practice, it is speculated that the structure of the conjugated polymer may depend on various factors, such as the conditions used to prepare the reactive polymer (e.g., type and amount of catalyst or initiator) and the conditions used to react the functionalizing agent (and optionally the functionalizing agent) with the reactive polymer (e.g., type and amount of functionalizing agent and functionalizing agent). The conjugated polymer resulting from the reaction between the reactive polymer and the functionalizing agent may be protonated or further modified.

[0115] Use of polymers Rubber compositions can be prepared by using the polymers of the present invention alone or with other elastomers (i.e., polymers that can be vulcanized to form compositions having rubbery or elastomeric properties). Other elastomers that may be used include natural and synthetic rubbers. Synthetic rubbers are typically derived from the polymerization of conjugated diene monomers, the copolymerization of conjugated diene monomers with other monomers, such as vinyl substituted aromatic monomers, or the copolymerization of ethylene with one or more α-olefins and optionally one or more diene monomers.

[0116] Exemplary elastomers include natural rubber, synthetic polyisoprene, polybutadiene, polyisobutylene-co-isoprene, neoprene, poly(ethylene-co-propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), poly(styrene-co-isoprene-co-butadiene), poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, and mixtures thereof. These elastomers can have a myriad of macromolecular structures, such as linear, branched, and star structures.

[0117] The rubber composition may include fillers, such as inorganic and organic fillers. Examples of organic fillers include carbon black and starch. Examples of inorganic fillers include silica, aluminum hydroxide, magnesium hydroxide, mica, talc (hydrated magnesium silicate), and clay (hydrated aluminum silicate). Carbon black and silica are the most common fillers used in the manufacture of tires. In some embodiments, a mixture of different fillers may be used to advantage.

[0118] In one or more embodiments, carbon blacks include furnace blacks, channel blacks, and lamp blacks. More specific examples of carbon blacks include super abrasion furnace blacks, medium super abrasion furnace blacks, high abrasion furnace blacks, high speed extrusion furnace blacks, fine furnace blacks, semi-reinforced furnace blacks, medium processed channel blacks, hard processed channel blacks, conductive channel blacks, and acetylene blacks.

[0119] In certain embodiments, the carbon black has a molecular weight of at least 20 2 / g, and in other embodiments, at least 35m 2 The surface area value can be determined using the cetyltrimethylammonium bromide (CTAB) technique per ASTM standard D-1765. The carbon black can be in pelletized or non-pelletized flocculent form. The preferred form of the carbon black can depend on the type of mixing equipment used to mix the rubber compound.

[0120] The amount of carbon black used in the rubber composition may be up to about 50 parts by weight per 100 parts by weight rubber (phr), with from about 5 to about 40 phr being typical.

[0121] Some commercially available silicas that may be used include Hi-Sil™ 215, Hi-Sil™ 233, and Hi-Sil™ 190 (PPG Industries, Inc.; Pittsburgh, Pa.) Other suppliers of commercially available silica include Grace Davison (Baltimore, Md.), Degussa Corp. (Parsippany, NJ), Rhodia Silica Systems (Cranbury, NJ), and JM Huber Corp. (Edison, NJ).

[0122] In one or more embodiments, silica can be characterized by its surface area, which is a measure of its reinforcing properties. The Brunauer, Emmet and Teller (Brunauer, Emmet and Teller, "BET") method (described in J. Am. Chem. Soc., vol. 60, p. 309 et seq.) is a recognized method for determining surface area. The BET surface area of ​​silica is generally about 450 m 2 / g. A useful range of surface area is from about 32 to about 400 m 2 / g, about 100~250m 2 / g, and about 150 to about 220 m 2 / g are examples.

[0123] The pH of the silica generally ranges from about 5 to about 7, or slightly above 7, or in other embodiments, from about 5.5 to about 6.8.

[0124] In one or more embodiments, when silica is used as a filler (alone or in combination with other fillers), a silica binder and / or silica shielding agent may be added to the rubber composition during mixing to enhance the interaction of the silica with the elastomer. Useful silica binders and silica shielding agents are described in U.S. Patents 3,842,111; 3,873,489; 3,978,103; 3,997,581; 4,002,594; 5,580,919; 5,583,245; 5,663,396; 5,674,932; 5,684,171; and the like. Nos. 5,684,172, 5,696,197, 6,608,145, 6,667,362, 6,579,949, 6,590,017, 6,525,118, 6,342,552, and 6,683,135, which are incorporated herein by reference.

[0125] The amount of silica used in the rubber composition can be from about 1 to about 100 phr, or in other embodiments, from about 5 to about 80 phr. The useful upper range is limited by the high viscosity imparted by the silica. When silica is used with carbon black, the amount of silica can be as low as about 1 phr. Because the amount of silica is low, less binder and shielding agent can be used. Generally, the amount of binder and shielding agent ranges from about 4% to about 20% by weight, based on the weight of silica used.

[0126] A number of rubber curing agents (also called vulcanizing agents) may be used, including sulfur or peroxide based cure systems. Curing agents are described in Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 20, pgs. 365-468, (3 rd Ed.1982), especially Vulcanization Agents and Auxiliary Materials, pgs.390-402, and AYCoran, Vulcanization, Encyclopedia of Polymer Science and Engineering, (2 nd Ed. 1989), which are incorporated herein by reference. The vulcanizing agents may be used alone or in combination.

[0127] Other components typically used in rubber compounding may also be added to the rubber composition. These include accelerators, accelerator activators, oils, plasticizers, waxes, scorch inhibitors, processing aids, zinc oxide, tackifying resins, reinforcing resins, fatty acids such as stearic acid, peptizers, antidegradants such as antioxidants and antiozonants. In certain embodiments, the oils used include those traditionally used as extending oils, as previously described.

[0128] All components of the rubber composition can be mixed using standard mixing equipment, such as Banbury or Brabender mixers, extruders, kneaders, and two-roll mills. In one or more embodiments, the components are mixed in two or more stages. In the first stage (often also called the masterbatch mixing stage), a so-called masterbatch (typically including the rubber component and filler) is prepared. To prevent premature vulcanization (also known as scorch), vulcanizing agents may be omitted from the masterbatch. The masterbatch may be mixed at an initiation temperature of about 25°C to about 125°C and an extrusion temperature of about 135°C to about 180°C. Once the masterbatch is prepared, vulcanizing agents may be introduced and mixed into the masterbatch in a final mixing stage, which is typically performed at a relatively low temperature, thereby reducing the possibility of premature vulcanization. Optionally, an additional mixing stage, often called a re-mill, may be used between the masterbatch mixing stage and the final mixing stage. When silica is included as a filler in the rubber composition, one or more re-mill stages are often used. The addition of various ingredients, including the binding polymers of the present invention, can occur during these remills.

[0129] Mixing procedures and conditions particularly applicable to silica filled tire compounds are described in U.S. Patent Nos. 5,227,425, 5,719,207, and 5,717,022, and European Patent No. 890,606, all of which are incorporated herein by reference. In one embodiment, an initial masterbatch is prepared by incorporating the binding polymer of the present invention and silica in the substantial absence of silica binders and silica shielding agents.

[0130] Rubber compositions prepared from the polymers of the present invention are particularly useful in forming tire components such as treads, subtreads, sidewalls, body ply skims, bead fillers, and the like. For example, the polymers of the present invention are used in tread and sidewall formulations. In one or more embodiments, these tread or sidewall formulations may contain from about 10% to about 100% by weight, in other embodiments from about 35% to about 90% by weight, and in other embodiments from about 50% to about 80% by weight of the polymer of the present invention, based on the total weight of the rubber in the formulation.

[0131] When the rubber compositions are used in the manufacture of tires, they can be processed into tire components by conventional tire manufacturing techniques, such as standard rubber molding, molding, and curing techniques. Typically, vulcanization is performed by heating the vulcanizable composition in a mold, which can be heated to about 140°C to about 180°C, for example. The cured or crosslinked rubber composition can be referred to as a vulcanizate, which generally contains a thermoset three-dimensional polymer network. Other components (e.g., fillers and processing aids) can be uniformly dispersed throughout the crosslinked network. Pneumatic tires can be made as described in U.S. Pat. Nos. 5,866,171, 5,876,527, 5,931,211, and 5,971,046, which are incorporated herein by reference.

[0132] In order to demonstrate the practice of the present invention, the following examples have been prepared and tested. However, these examples should not be construed as limiting the scope of the invention. The claims shall define the invention. EXAMPLES

[0133] Examples 1 to 5 The following examples illustrate embodiments for lanthanide-based catalyst systems. Polymerizations were carried out in 750 mL N2-purged glass bottles. The bottles were individually charged with approximately 20 wt% butadiene / hexane mixture and high purity hexane, sufficient to prepare 333 g of a 14 wt% butadiene solution. Each bottle was charged with the appropriate amount of 1.0 M alkylaluminum reagent solution from Table 1, followed by 1.64 mL of neodymium versatate solution (0.054 M in hexane). The bottles were allowed to stand for 3 minutes, and then 0.13 mL of ethylaluminum dichloride solution (1.09 M in hexane) was added. The bottles were placed in an 80° C. stirring bath. After 30 minutes of stirring, the bottles were removed from the bath. The polymers were terminated by charging the polymerization mixture with 4.0 mL of a 10 wt% solution of 2,6-di-tert-butyl-4-methylphenol in isopropanol. The polymer was coagulated in 8 liters of isopropanol containing 15 g of 2,6-di-tert-butyl-4-methylphenol and then drum-dried. The polymer was analyzed by Mooney, GPC, and IR, and the values ​​are reported in Table 1.

[0134] [Table 1]

[0135] Mooney viscosity (ML) of polymer sample 1+4 The number average (M) of the polymer samples was determined by using a Monsanto Mooney Viscometer equipped with a large rotor at 100° C., with a preparatory time of 1 minute and a running time of 4 minutes. n ) and weighted average (M w ) Molecular weights were determined by gel permeation chromatography (GPC) using a Tosoh Ecosec HLC-8320 GPC system and a Tosoh TSKgel GMHxl-BS column with THF as the solvent. The system was calibrated using a series of polystyrene standards and referenced to polystyrene. The cis-1,4-, trans-1,4-, and 1,2-bond contents of the polymer samples were determined by infrared spectroscopy.

[0136] As can be seen from the data in Table 1, the use of triethylaluminum (TEAL) alone (Examples 2 and 3) results in lower conversion than the control mixture of triisobutylaluminum (TIBA) and diisobutylaluminum hydride (DIBA) (Example 1). Similarly, DIBA alone (Example 5) results in lower conversion than the control mixture of TIBA and DIBA (Example 1). In contrast, the mixture of DIBA and TEAL (Example 4) results in higher conversion than either the TIBA / DIBA mixture or TEAL alone.

[0137] Examples 6 to 12 The following example illustrates an embodiment for a nickel-based catalyst system. Polymerizations were carried out in 750 mL N2-purged glass bottles. The bottles were individually charged with approximately 20 wt% butadiene / hexane mixture and high purity hexane, enough to prepare 300 mL of 15 wt% butadiene solution. Each bottle was charged with the appropriate amount of 1.0 M alkylaluminum reagent solution from Table 2, followed by 1.36 mL of nickel 2-ethylhexanoate solution (0.012 M in hexane). Then, the appropriate amount of 4.56 M BF3 solution and hexanol was added to obtain 1.68 equivalents of B per Al (0.10-0.13 mL). The bottles were placed in a stirred bath at 80°C. After 40 minutes of stirring, the bottles were removed from the bath. The polymers were terminated by charging the polymerization mixture with 4.0 mL of a 10 wt% solution of 2,6-di-tert-butyl-4-methylphenol in isopropanol. The polymer was coagulated in 8 liters of isopropanol containing 15 g of 2,6-di-tert-butyl-4-methylphenol and then drum-dried. The polymer was analyzed by Mooney, GPC, and IR, and the values ​​are reported in Table 2.

[0138] [Table 2]

[0139] Mooney viscosity (ML) of polymer sample1+4 ), the number average of the polymer samples (M n ) and weighted average (M w ) The molecular weight, cis-1,4-linkage, trans-1,4-linkage, and 1,2-linkage content of the polymer samples were determined as provided above for Examples 1-5.

[0140] As can be seen from the data in Table 2, the use of a mixture of DIBA and TEAL results in an overall better balance of polymerization and polymer properties.

[0141] Various modifications and alterations that do not depart from the scope and spirit of the present invention will be apparent to those skilled in the art. This invention is not to be duly limited to the illustrative embodiments set forth herein. The present disclosure includes the following embodiments. <1> 1. A method for preparing a polymer comprising the steps of: (i) a lanthanide-containing compound; (ii) triethylaluminum, (iii) aluminum hydride; (iv) a halogen-containing compound; and polymerizing a conjugated diene monomer in the presence of a lanthanide-based catalyst system comprising: <2> the lanthanide-containing compound is selected from the group consisting of lanthanide carboxylates, lanthanide organophosphates, lanthanide organophosphonates, lanthanide organophosphinates, lanthanide carbamates, lanthanide dithiocarbamates, lanthanide xanthates, lanthanide β-diketonates, lanthanide alkoxides or aryloxides, lanthanide halides, lanthanide pseudohalides, lanthanide oxyhalides, and organolanthanide compounds; <1> The method according to <3> The aluminum hydride has the general formula AlR n H (3-n) wherein each R may independently be a monovalent organic group bonded to the aluminum atom through a carbon atom, and n may be an integer ranging from 1 to 3. <1> The method according to <4> The aluminum hydride is a dihydrocarbyl aluminum hydride. <1> The method according to <5> The aluminum hydride is a hydrocarbyl aluminum dihydride. <1> The method according to <6> The aluminum hydride is selected from the group consisting of diethyl aluminum hydride, di-n-propyl aluminum hydride, diisopropyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, di-n-octyl aluminum hydride, diphenyl aluminum hydride, di-p-tolyl aluminum hydride, dibenzyl aluminum hydride, phenylethyl aluminum hydride, phenyl-n-propyl aluminum hydride, phenylisopropyl aluminum hydride, phenyl-n-butyl aluminum hydride, phenylisobutyl aluminum hydride, and phenyl the aluminum hydride is selected from the group consisting of p-tolyl-n-octylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, p-tolyl-n-butylaluminum hydride, p-tolylisobutylaluminum hydride, p-tolyl-n-octylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride, benzyl-n-butylaluminum hydride, benzylisobutylaluminum hydride, and benzyl-n-octylaluminum hydride; <1> The method according to <7> the aluminum hydride is selected from the group consisting of ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride, and n-octylaluminum dihydride; <1> The method according to <8> the source of halogen is a compound selected from the group consisting of elemental halogen, mixed halogen, hydrogen halide, organic halide, inorganic halide, metal halide, and organometallic halide; <1> The method according to <9> the molar ratio of the triethylaluminum hydride to the lanthanide-containing compound (alkylating agent / Ln) is about 2:1 to about 15:1; <1> The method according to <10> the molar ratio of the hydrocarbylaluminum hydride to the lanthanide-containing compound (alkylating agent / Ln) is from about 1:1 to about 10:1; <1> The method according to <11> The halogen / Ln molar ratio is about 0.5:1 to about 20:1. <1> The method according to <12> the conjugated diene monomer is selected from the group consisting of 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene; <1> The method according to <13> In the polymerization step, about 0.001 to about 2 mmol of the lanthanide compound is used per 100 g of monomer. <1> The method according to <14> The step of polymerizing results in a polydiene, and further comprises the step of functionalizing the polydiene. <1> The method according to <15> The method further comprises the step of quenching the polymerizing step. <1> The method according to <16> the step of polymerizing results in a polydiene, the polydiene having a cis-1,4-linkage content of greater than 95%; <1> The method according to <17> The step of polymerizing results in a monomer conversion of greater than 85%. <1> The method according to <18> The step of polymerizing results in a monomer conversion of greater than 90%. <1> The method according to <19> A polymer comprising: (i) a lanthanide-containing compound; (ii) triethylaluminum, (iii) aluminum hydride; (iv) a halogen-containing compound; and a polymer prepared by polymerizing a conjugated diene monomer in the presence of a lanthanide-based catalyst system comprising: <20> The above <19> 2. A tire component prepared by using the polymer described in claim 1. <21> The above <19> 1. A vulcanizable composition comprising the polymer of claim 1, a filler, and a curing agent. <22> 1. A method for preparing a polymer comprising the steps of: (i) a nickel-containing compound; (ii) triethylaluminum, (iii) aluminum hydride; (iv) a halogen-containing compound selected from a fluorine-containing compound and a chlorine-containing compound. <23> the nickel-containing compound is selected from the group consisting of nickel carboxylates, nickel carboxylate borates, nickel organophosphates, nickel organophosphonates, nickel organophosphinates, nickel carbamates, nickel dithiocarbamates, nickel xanthates, nickel β-diketonates, nickel alkoxides or aryloxides, nickel halides, nickel pseudohalides, nickel oxyhalides, or organonickel compounds; <22> The method according to <24> The aluminum hydride has the general formula AlR n H (3-n) wherein each R may independently be a monovalent organic group bonded to the aluminum atom through a carbon atom, and n may be an integer ranging from 1 to 3. <22> or <23> The method according to <25> The aluminum hydride is a dihydrocarbyl aluminum hydride. <22> ~ <24> 2. The method according to claim 1 . <26> The aluminum hydride is a hydrocarbyl aluminum dihydride. <22> ~ <25> 2. The method according to claim 1 . <27> The aluminum hydride is diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride, phenylisobutylaluminum hydride, phenyl-n-octylaluminum hydride, the aluminum hydride is selected from the group consisting of p-tolyl ethyl aluminum hydride, p-tolyl-n-propyl aluminum hydride, p-tolyl isopropyl aluminum hydride, p-tolyl-n-butyl aluminum hydride, p-tolyl isobutyl aluminum hydride, p-tolyl-n-octylaluminum hydride, benzyl ethyl aluminum hydride, benzyl-n-propyl aluminum hydride, benzyl isopropyl aluminum hydride, benzyl-n-butyl aluminum hydride, benzyl isobutyl aluminum hydride, and benzyl-n-octylaluminum hydride; <22> ~ <26> 2. The method according to claim 1 . <28> the aluminum hydride is selected from the group consisting of ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride, and n-octylaluminum dihydride; <22> ~ <27> 2. The method according to claim 1 . <29> The halogen-containing compound is a fluorine-containing compound. <22> ~ <28> 2. The method according to claim 1 . <30> the molar ratio of the triethylaluminum to the nickel-containing compound is about 2:1 to about 100:1; <22> ~ <29> 2. The method according to claim 1 . <31> the molar ratio of the hydrocarbyl aluminum hydride to the nickel-containing compound is from about 1:1 to about 500:1; <22> ~ <30> 2. The method according to claim 1 . <32> The F / Ni molar ratio is about 2:1 to about 500:1. <22> ~ <31> 2. The method according to claim 1 . <33> The conjugated diene monomer is 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene. <22> ~ <32> 2. The method according to claim 1 . <34> In the polymerization step, about 0.001 to about 2 mmol of the nickel compound is used per 100 g of the monomer. <22> ~ <33> 2. The method according to claim 1 . <35> The step of polymerizing results in a polydiene, and further comprises the step of functionalizing the polydiene. <22> ~ <34> 2. The method according to claim 1 . <36> The method further comprises the step of quenching the polymerizing step. <22> ~ <35> 2. The method according to claim 1 . <37> the fluorine-containing compound is selected from the group consisting of elemental fluorine, halogen fluorides, hydrogen fluoride, organic fluorides, inorganic fluorides, metal fluorides, organometallic fluorides, and mixtures thereof; <22> ~ <36> 2. The method according to claim 1 . <38> The step of polymerizing results in a monomer conversion of greater than 85%. <22> ~ <37> 2. The method according to claim 1 . <39> The step of polymerizing results in a monomer conversion of greater than 90%. <22> ~ <38> 2. The method according to claim 1 . <40> A polymer comprising: (i) a nickel-containing compound; (ii) triethylaluminum, (iii) aluminum hydride; (iv) a halogen-containing compound; and a polymer prepared by polymerizing a conjugated diene monomer in the presence of a nickel-based catalyst system comprising: <41> The above <40> 2. A tire component prepared by using the polymer described in claim 1. <42> The above <41> 1. A vulcanizable composition comprising the polymer of claim 1, a filler, and a curing agent.

Claims

1. 1. A method for preparing a polymer comprising the steps of: (i) a nickel-containing compound; and (ii) triethylaluminum; and (iii) a hydrocarbylaluminum hydride; and (iv) polymerizing a conjugated diene monomer in the presence of a catalyst system comprising:

2. 2. The method of claim 1, wherein the hydrocarbyl aluminum hydride is a dihydrocarbyl aluminum hydride or a hydrocarbyl aluminum dihydride.

3. the polymerizing step results in a polydiene; The method of claim 1 further comprising the step of functionalizing the polydiene.

4. 4. The method of claim 3, wherein the polydiene has a cis-1,4-linkage content of greater than 95% and the polymerizing step has a monomer conversion of greater than 85%.

5. The method of claim 1 , wherein the halogen-containing compound is a fluorine-containing compound.

6. (i) the molar ratio of said triethylaluminum to said nickel-containing compound is from about 2:1 to about 100:1; (ii) the molar ratio of said hydrocarbylaluminum hydride to said nickel-containing compound is from about 1:1 to about 500:1; (iii) the molar ratio of the halogen of said halogen-containing compound to said nickel-containing compound is from about 2:1 to about 500:

1.

7. A tire component prepared by using a polymer, the polymer comprising: (i) a nickel-containing compound; and (ii) triethylaluminum; and (iii) a hydrocarbylaluminum hydride; and (iv) a halogen-containing compound; and a tire component prepared by polymerizing a conjugated diene monomer in the presence of a catalyst system comprising:

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