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US5227440A - Mono-Cp heteroatom containing Group IVB transition metal complexes with MAO: supported catalysts for olefin polymerization - Google Patents
Mono-Cp heteroatom containing Group IVB transition metal complexes with MAO: supported catalysts for olefin polymerization Download PDF
US5227440A
US5227440A US07751392 US75139291A US5227440A US 5227440 A US5227440 A US 5227440A US 07751392 US07751392 US 07751392 US 75139291 A US75139291 A US 75139291A US 5227440 A US5227440 A US 5227440A
US07751392
This is a division of application Ser. No. 581,869 filed Sep. 13, 1990, now U.S. Pat. No. 5,057,475 which is a continuation-in-part of Ser. No. 533,245 filed Jun. 4, 1990, now U.S. Pat. No. 5,055,438, which is a continuation-in-part of Ser. No. 406,945 filed Sep. 13, 1989, now abandoned.
The zirconium metallocene species, as cocatalyzed or activated with an alumoxane, are commonly more active than their hafnium or titanium analogues for the polymerization of ethylene alone or together with an α-olefin comonomer. When employed in a non-supported form--i.e., as a homogeneous or soluble catalyst system--to obtain a satisfactory rate of productivity even with the most active zirconium species of metallocene typically requires the use of a quantity of alumoxane activator sufficient to provide an aluminum atom to transition metal atom ratio (Al:TM) of at least greater than 1000:1; often greater than 5000:1, and frequently on the order of 10,000:1. Such quantities of alumoxane impart to a polymer produced with such catalyst system an undesirable content of catalyst metal residue, i.e., an undesirable "ash" content (the nonvolatile metal content). In high pressure polymerization procedures using soluble cata;yst systems wherein the reactor pressure exceeds about 500 bar only the zirconium or hafnium species of metallocenes may be used. Titanium species of metallocenes are generally unstable at such high pressures unless deposited upon a catalyst support.
Supported metallocene-alumoxane catalysts systems for olefin polymerization are described in U.S. Pat. No. 4,701,432 of Welborn. These supported metallocene-alumoxane catalysts are obtained by reacting a metallocene and an alumoxane in the presence of the solid support material. The supported catalyst may then be employed either as the sole catalyst component or may be employed in combination with an organometallic cocatalyst. The supported metallocene-alumoxane catalyst, however, still produced polymers of generally lower molecular weight and comonomer incorporation than desired for certain applications.
(C5 H5-y-x Rx) is a cyclopentadienyl ring which is substituted with from zero to five substituent groups R, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent group R is, independently, a radical selected from a group consisting of C1 -C20 hydrocarbyl radicals, substituted C1 -C20 hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, alkylborido radicals, or any other radical containing a Lewis acidic or basic functionality, C1 -C20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the Group IV A of the Periodic Table of Elements; and halogen radicals, amido radicals, phosphido radicals, alkoxy radicals, alkylborido radicals or any other radical containing a Lewis acidic or basic functionality, or (C5 H5-y-x Rx) is a cyclopentadienyl ring in which at least two adjacent R-groups are joined forming a C4 -C20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand such as indenyl, tetrahydroindenyl, fluorenyl or octahydrofluorenyl;
L is a neutral Lewis base such as diethylether, tetraethylammonium chloride, tetrahydrofuran, dimethylaniline, aniline, trimethylphosphine, n-butylamine, and the like; and "w" is a number from 0 to 3. L can also be a second transition metal compound of the same type such that the two metal centers M and M' are bridged by Q and Q', wherein M' has the same meaning as M and Q' has the same meaning as Q. Such dimeric compounds are represented by the formula: ##STR2## The alumoxane component of the catalyst may be represented by the formulas: (R3 --Al--O)m ; R4 (R5 --Al--O)m AlR6 or mixtures thereof, wherein R3 -R6 are, independently, a C1 -C5 alkyl group or halide and "m" is an integer ranging from 1 to about 50 and preferably is from about 13 to about 25.
A typical polymerization process of the invention such as for the polymerization or copolymerization of ethylene comprises the steps of contacting ethylene or C3 -C20 α-olefins alone, or with other unsaturated monomers including C3 -C20 α-olefins, C5 -C20 diolefins, and/or acetylenically unsaturated monomers either alone or in combination with other olefins and/or other unsaturated monomers, with a supported catalyst comprising, an inert support material, the Group IV B transition metal component illustrated above; and a methylalumoxane in an amount to provide a molar aluminum to transition metal ratio of from about 1:1 to about 20,000:1 or more; and reacting such monomer in the presence of such supported catalyst system at a temperature of from about -100° C. to about 300° C. for a time of from about 1 second to about 10 hours to produce a polyolefin having a weight average molecular weight of from about 1,000 or less to about 5,000,000 or more and a molecular weight distribution of from about 1.5 to about 15.0.
(C5 H5-y-x Rx) is a cyclopentadienyl ring which is substituted with from zero to five substituent groups R, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent group R is, independently, a radical selected from a group consisting of C1 -C20 hydrocarbyl radicals, substituted C1 -C20 hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, an alkylborido radical, or other radical containing a Lewis acidic or basic functionality, C1 -C20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the Group IV A of the Periodic Table of Elements; and halogen radicals, amido radicals, phosphido radicals, alkoxy radicals, alkylborido radicals, or any other radical containing a Lewis acidic or basic functionality, or (C5 H5-y-x Rx) is a cyclopentadienyl ring in which two adjacent R-groups are joined forming C4 -C20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand such as indenyl, tetrahydroindenyl, fluorenyl or octahydrofluorenyl;
(JR'z-1-y) is a heteroatom ligand in which J is an element with a coordination number of three from Group V A or an element with a coordination number of two from Group VI A of the Periodic Table of Elements, preferably nitrogen, phosphorus, oxygen or sulfur with nitrogen being preferred, and each R' is, independently a radical selected from a group consisting of C1 -C20 hydrocarbyl radicals, substituted C1 -C20 hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, an alkylborido radical or other radical containing a Lewis acidic or basic functionality, and "z" is the coordination number of the element J;
Suitable hydrocarbyl and substituted hydrocarbyl radicals, which may be substituted as an R group for at least one hydrogen atom in the cyclopentadienyl ring, will contain from 1 to about 20 carbon atoms and include straight and branched alkyl radicals, cyclic hydrocarbon radicals, alkyl-substituted cyclic hydrocarbon radicals, aromatic radicals and alkyl-substituted aromatic radicals, amido-substituted hydrocarbyl radicals, phosphido-substituted hydrocarbyl radicals, and alkoxy-substituted hydrocarbyl radicals and cyclopentadienyl rings containing one or more fused saturated or unsaturated rings. Suitable organometallic radicals, which may be substituted as an R group for at least one hydrogen atom in the cyclopentadienyl ring, include trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, triphenylgermyl, trimethylgermyl and the like. Other suitable radicals that may be substituted for one or more hydrogen atoms in the cyclopentadienyl ring include halogen radicals, amido radicals, phosphido radicals, alkoxy radicals, alkylboride radicals, and the like. Examples of cyclopentadienyl ring groups (C5 H5-y-x Rx) which are suitable as a constituent group of the Group IV B transition metal component of the catalyst system are identified in Column 2 of Table 1 under the heading (C5 H5-y-x Rx).
Suitable R' radicals of the heteroatom J ligand are independently a hydrocarbyl radical selected from a group consisting of 1 to about 20 carbon atoms and include straight and branched alkyl radicals, cyclic hydrocarbon radicals, alkyl-substituted cyclic hydrocarbon radicals, aromatic radicals and the like; substituted C1 -C20 hydrocarbyl radicals wherein one or more hydrogen atom is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, and alkylborido radical, or other radical containing a Lewis acidic or basic functionality, and the like. Examples of heteroatom ligand groups (JR'z-1-y) which are suitable as a constituent group of the Group IV B transition metal component of the catalyst system are identified in column 3 of Table 1 under the heading (JR'z-1-y).
Table 1 depicts representative constituent moieties for the "Group IV B transition metal component", the list is for illustrative purposes only and should not be construed to be limiting in any way. A number of final components may be formed by permuting all possible combinations of the constituent moieties with each other. Illustrative compounds are: dimethylsilyltetramethylcyclopentadienyl-tert-butylamido zirconium dichloride, methylphenylsilyltetramethylcyclopentadienyl-tert-butylamido titanium dichloride, and dimethylsilyltetramethylcyclopentadienylcyclododecylamido titanium dichloride, and the like.
For illustrative purposes, the above compounds and those permuted from Table 1 do not include the neutral Lewis base ligand (L). The conditions under which complexes containing neutral Lewis base ligands such as ether or those which form dimeric compounds is determined by the steric bulk of the ligands about the metal center. For example, the t-butyl group in Me2 Si(Me4 C5) (N-t-Bu)ZrCl2 has greater steric requirements than the phenyl group in Me2 Si(Me4 C5) (NPh)ZrCl2.Et2 O thereby not permitting ether coordination in the former compound. Similarly, due to the decreased steric bulk of the trimethylsilylcyclopentadienyl group in [Me2 Si(Me3 SiC5 H3) (N-t-Bu)ZrCl2 ]2 versus that of the tetramethylcyclopentadienyl group in Me2 Si(Me4 C5) (N-t-Bu)ZrCl2, the former compound is dimeric and the latter is not.
TABLE 1__________________________________________________________________________ ##STR5##T (when y = 1)         (C.sub.3 H.sub.3-y-a R.sub.a)                             (JR'.sub.a-l-y)                                         Q          R__________________________________________________________________________dimethylsilyl cyclopentadienyl     .sub.- t-butylamide                                         hydride    zirbonium.diethylsilyl  methylcyclopentadienyl                             phenylamido chloro     hafniumdi- -n-propylsilyl         1,2-dimethylcyclopentadienyl                             p- -n-butylphenylamido                                         methyl     titaniumdiisopropylsilyl         1,3-dimethylcyclopentadienyl                             cyclohexylamido                                         ethyldi- -n-butylsilyl         indenyl             perflurophenylamido                                         phenyldi- .sub.- t-butylsilyl         1,2-diethylcyclopentadienyl                              -n-butylamido                                         fluorodi- -n-hexylsilyl         tetramethylcyclopentadienyl                             methylamido bromomethylphenylsilyl         ethylcyclopentadienyl                             ethylamido  iodoethylmethylsilyl          -n-butylcyclopentadienyl                              -n-propylamido                                          -n-propyldiphenylsilyl cyclohexylmethylcyclopentadienyl                             isopropylamido                                         isopropyldi(p- .sub.- t-butylphenethylsilyl)          -n-octylcyclopentadienyl                             benzylamido  -n-butyl -n-hexylmethylsilyl         β-phenylpropylcyclopentadienyl                              .sub.- t-butylphosphido                                         amylcyclopentamethylenesilyl         tetrahydroindenyl   ethylphosphido                                         isoamylcyclotetramethylenesilyl         propylcyclopentadienyl                             phenylphosphido                                         hexylcyclotrimethylenesilyl          .sub.- t-butylcyclopentadienyl                             cyclohexylphosphido                                         isobutyldimethylgermanyl         bensylcyclopentadienyl                             oxo (when y = 1)                                         heptyldiethylgermanyl         diphenylmethylcyclopentadienyl                             sulfido (when y = 1)                                         octylphenylamido   trimethylgermylcyclopentadienyl                             methoxide (when y = 0)                                         nonyl .sub.- t-butylamido         trimethylstannylcyclopentadienyl                             ethoxide (when y = 0)                                         decylmethylamido   triethylplumbylcyclopentadienyl                             methylthic (when y = 0)                                         cetyl .sub.- t-butylphosphido         trifluromethylcyclopentadienyl                             ethylthic (when y = 0)                                         methoxyethylphosphido         trimethylsilylcyclopentadienyl  ethoxyphenylphosphido         pentamethylcycloopentadienyl (when y = 0)                                         propoxymethylene     fluorenyl                       butoxydimethylmethylene         octahydrofluoroxyl              phenoxydiethylmethylene         N,N-dimethylamidocyclopentadienyl                                         dimethylamideethylene      dimethylphosphidocyclopentadienyl                                         diethylamidedimethylethylene         methoxycyclopentadienyl         methylethylamidediethylethylene         dimethylboridocyclopentadienyl  di- .sub.- t-butylamidedipropylethylene         (N,N-dimethylamidomethyl)-      diphenylamidepropylene     cyclopentadienyl                diphenylphosphidedimethylpropylene                             dicyclophoxyl-diethylpropylene                              phosphide1,1-dimethyl-3,3-                             dimethylphosphidedimethylpropylene                             methylidene (both Q)tetramethyldisiloxane                         ethylidene (both Q)1,1,4,4-tetramethyldisilyl-                   propylidene (both Q)ethylene                                      ethyleneglycoldianion                                         (both Q)__________________________________________________________________________
The normally hydrocarbon soluble transition metal component and alumoxane are prepared as a supported catalyst by deposition on a support material. The support material for preparing the supported catalyst may be any resinous support material such as a polyolefin or any finely divided inorganic solid porous support, such as talc, silica, alumina, silica-alumina, or mixtures thereof. Other inorganic oxides that may be employed either alone or in combination with silica or silica-alumina are magnesia, titania, zirconia, and the like. The inorganic oxides may be dehydrated, as is well known in the art, to remove water. If desired, the residual surface hydroxyl groups in the inorganic solid porous support may be removed by additional heating or by reaction with chemical dehydrating agents such as lithium alkyl, silylchlorides, aluminum aklyls, or preferably with alumoxane. Preferred catalyst supports include dehydrated inorganic oxide treated with an alumoxane, more preferably with methylalumoxane. A suitable support material of this type is a dehydrated silica gel treated with methylalumoxane. When such a alumoxane-treated support is utilized in the production of the supported catalyst, it may not be necessary to include additional alumoxane in the catalyst composition. Also preferred as a catalyst support is a wet gel, more preferably a wet silica gel, containing up to approximately 20% by weight absorbed water. Wet gels may be directly mixed with trialkyl aluminums to form the alumoxane component of the catalyst system.
The specific particle size, surface area and pore volume of the inorganic support material determine the amount of inorganic support material that is desirable to employ in preparing the catalyst compositions, as well as affecting the properties of polymers formed with the aid of the catalyst compositions. These properties must frequently be taken into consideration in choosing an inorganic support material for use in a particular aspect of the invention. A suitable inorganic support such as silica would have a particle diameter in the range of 0.1-600 microns, preferably 0.3-100 microns; a surface area of 50-1000 m2 /g, preferably 100-500 m2 /g; and a pore volume of 0.5-3.5 cm3 /g. To insure its use in dehydrated form the support material may be heat treated at 100°-1000° C. for a period of 1-100 hours, preferably 3- 24 hours. The treatment may be carried out in a vacuum or while purging with a dry inert gas such as nitrogen. As an alternative, the support material may be chemically dehydrated. The chemical dehydration is accomplished by slurrying the support in an inert low boiling solvent such as, for example, heptane, in the presence of the dehydrating agent such as for example, triethylaluminum in a moisture and oxygen-free atmosphere.
Catalyst Systems-Method and Use The Supported Catalyst--Preparation Method 1
The supported catalyst of this invention can be prepared by combining in any order the Group IV B transition metal component, an alumoxane component, and the support in one or more suitable solvents or diluents. Suitable solvents and/or diluents include, but are not necessarily limited to, straight and branched-chain hydrocarbons such as isobutane, butane, pentane, hexane, heptane, octane and the like; cyclic and alicyclic hydrocarbons such as cyclohexane, cycloheptane, methylcyclohexane, methylcyclopentane and the like; and aromatic and alkyl-substituted aromatic compounds such as benzene, toluene, xylene and the like.
In a preferred method, the Group IV B transition metal component and alumoxane are combined in a first step in a suitable solvent such as an aromatic solvent to produce a solution of the reaction product. This reaction may be carried out in the temperature range of -100° C. to about 300° C., preferably about 0° C. to about 100° C. Holding times to allow for the completion of the reaction may range from about 10 seconds to about 60 minutes depending on the reaction variables.
The solution produced by combining the Group IV B transition metal component and alumoxane is then contacted with the support. The method of contact may vary, but it is preferred that the support be added to the catalyst solution with vigorous stirring. Again contact temperatures may range from about 0° C. to about 100° C. depending upon the solvents used. Contact times may vary from about 10 seconds to about 60 minutes or longer.
The Modified Supported Catalyst--Preparation Method
The modified supported catalyst of this invention can be prepared by combining in any order the Group IV B transition metal component, an alumoxane component, a modifier and the support in one or more suitable solvents or diluent. A modifier may be defined as a compound containing a Lewis acid or basic functionality, such as, for example, tetraethoxysilane, phenytriethyoxysilane bis-tert-butylhydroxytoluene (BHT), N,N-dimethylanaline and the like. Suitable solvents and/or diluents are the same as those described above.
In a preferred method, the alumoxane and the modifier are combined in a first step in a suitable solvent such as an aromatic solvent to produce a solution. The Group IV B transition metal compound is then added to this solution. These combined steps may be carried out in the temperature range of -100° C. to about 300° C., preferably about 0° C. Holding times to allow for the completion of the reaction may range from about 10 seconds to about 60 minutes depending on the reaction variables.
The solution produced by combining the Group IV B transition metal component, the alumoxane and the modifier is then contacted with the support. The method of contact may vary, but it is preferred that the support be added to the catalyst solution without vigorous stirring. Again contact temperatures may range from about 0° C. to about 100° C. depending upon the solvents used. Contact times may vary from about 10 seconds to about 60 minutes or longer.
In accordance with this invention, optimum results are generally obtained wherein the alumoxane to Group IV B transition metal compound molar ratio is from about 1:1 to about 20,000:1, preferably from about 10:1 to about 1000:1 and the alumoxane to modifier molar ratio is from about 1:1 to about 20,000:1, preferably from about 10:1 to about 1000:1. The Group IV B transition metal compound concentration on the support is typically between 0.01 wt % to about 100 wt %, preferably about 0.1 wt % to about 20 wt % based upon the weight of the support.
The Supported Catalyst--Preparation Method 3
In an alternative procedure the alumoxane component of the catalyst complex is prepared by direct reaction of a trialkyl aluminum or trialkyl aluminum mixtures with the material utilized as the catalyst support, such as an undehydrated silica gel. Silica useful as the catalyst support is that which has a surface area in the range of about 10 to about 700 m2 /g, preferably about 100-500 and desirably about 200-400 m2, a pore volume of about 3 to about 0.5 cc/g and preferably 2-1 cc/g, and an adsorbed water content of from about 6 to about 20 weight percent, preferably from about 9 to about 15 weight percent. The average particle size (APS) of the silica may be from about 0.3μ to about 100μ, and for a gas phase catalyst preferably from about 30μ to about 60μ (1μ=10-6 m). For a catalyst intended for high pressure polymerization the particle size of the silica should range from about 0.3 to no greater than about 10μ. Hereafter, silica having the above identified properties is referred to as undehydrated silica gel.
Undehydrated silica gel, as defined above, is added over time, about a few minutes, to a stirred solution of trialkyl aluminum, in an amount sufficient to provide a mole ratio of trialkyl aluminum to water of from about 3:1 to 1:2, preferably about 1.2:1 to 0.8:1. The trialkyl aluminum preferred for use in forming the alumoxane is trimethylaluminum. Next in order of preference, is triethylaluminum.
Thereafter a transition metal component is added to the stirred suspension of alumoxane silica gel product in an amount sufficient to provide a mole ratio of aluminum to transition metal of from about 1000:1 to about 1:1, preferably from about 300:1 to about 10:1 and most preferably from about 150:1 to about 30:1. The mixture is stirred for about 30 minutes to about one hour at ambient or an elevated temperature to permit the transition metal component to undergo complete reaction with the adsorbed alumoxane. Thereafter, the solvent is removed and the residual solids are dried, preferably at a temperature of 25° C. or greater, to a free flowing powder. The free flowing powder comprises a silica gel supported transition metal alumoxane catalyst complex of sufficiently high catalytic activity for use in the polymerization of olefins by conventional gas phase or liquid phase polymerization procedures.
Prepolymerization of the solid catalyst material aids in obtaining a polyolefin produced therefrom during slurry polymerization in well-defined particle form. The prepolymerized catalyst may be rinsed with a hydrocarbon to provide the good granular particle form. Prepolymerization also greatly reduces the requirement for alumoxane. For example, an Al:Transition Metal Component ratio of about 1000:1 or greater for alumoxane:Transition Metal Component is needed for high activity when the alumoxane is added to the liquid phase of the reactor, but a ratio less than 1000:1 is sufficient when the alumoxane is incorporated into the prepolymerized catalyst. For a prepolymerized catalyst the ratio of aluminum to transition metal may range from about 1:1 to 500:1, preferably from about 20:1 to 100:1, and high activities will still be obtained.
Most preferably, the prepolymerized supported catalyst is prepared in the following manner 1) forming a slurry by the addition of the alumoxane dissolved in a suitable solvent, toluene for example, to the support; 2) stirring the slurry at 60°-80° C. for 30-60 minutes; 3) removal of solvent under vacuum with heating sufficient to produce a dry powder; 4) adding a light hydrocarbon, pentane for example, to slurry the powder; 5) adding a solution of the transition metal component in pentane or a minimum amount of toluene and stirring for 15-60 minutes at 20°-60° C.; 6) prepolymerizing with ethylene or other olefin in the pentane slurry; and 7) then collecting, rinsing and drying the supported catalyst. For best particle form, it is preferred to add no alumoxane to the reactor beyond what is on the prepolymerized catalyst. Sufficient aluminum alkyl, such as triethylaluminum or triisobutylaluminum, to scavenge impurities in the feeds may be added, but not an excess.
The supported catalysts may be most usefully employed in gas or slurry phase processes, both of which are known to those of skill in the art. Thus, polymerizations using the invention supported catalysts may be conducted by either of these processes, generally at a temperature in the range of about 0°-160° C. or even higher, and under atmospheric, subatmospheric or superatmospheric pressure conditions.
A slurry polymerization process can utilize sub-or super-atmospheric pressures and temperatures in the range of -80°-250° C. In a slurry polymerization, a suspension of solid, particulate polymer is formed in a liquid polymerization medium to which ethylene, α-olefin, diolefin, cyclic olefin or acetylenically unsaturated comonomer, hydrogen and catalyst are added. Alkanes and cycloalkanes, such as butane, pentane, hexane, or cyclohexane, are preferred with C4 to C10 alkanes especially preferred. Preferred solvents also include liquid olefins which may act as monomers or comonomers including ethylene, propylene, butadiene, cyclopentene, 1-hexene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1,4-hexadiene, 1-octene, 1-decene and the like.
A gas-phase polymerization process utilizes superatmospheric pressure and temperatures in the range of about 50° C. -120° C. Gas-phase polymerization can be performed in a stirred or fluidized bed of catalyst and product particles in a pressure vessel adapted to permit the separation of product particles from unreacted gases. Thermostated ethylene, comonomer, including α-olefins, diolefins, cyclic olefins or acetylenically unsaturated comonomer, hydrogen and an inert diluent gas such as nitrogen can be introduced or recirculated so as to maintain the particles at a temperature of 50°-120° C. Polymer product can be withdrawn continuously or semicontinuously at a rate such as to maintain a constant product inventory in the reactor. After polymerization and deactivation of the catalyst, the product polymer can be recovered by any suitable means. In commercial practice, the polymer product can be recovered directly from the gas phase reactor, freed of residual monomer with a nitrogen purge, and used without further deactivation or catalyst removal. The polymer obtained can be extruded into water and cut into pellets or other suitable comminuted shapes. Pigments, antioxidants and other additives, as is know in the art, may be added to the polymer.
All procedures were performed under an inert atmosphere of nitrogen. Solvent choices are often optional, for example, in most cases either pentane or 30-60 petroleum ether can be interchanged. The lithiated amides were prepared from the corresponding amines and either n-BuLi or MeLi. Published methods for preparing LiHC5 Me4 include C. M. Fendrick et. al., Organometallics, 3:819 (1984) and F. H. Kohler and K. H. Doll, Z. Naturforich, 376:144 (1982). Other lithiated substituted cyclopentadienyl compounds are typically prepared from the corresponding cyclopentadienyl ligand and n-BuLi or MeLi, or by reaction of MeLi with the proper fulvene. TiCl4 and ZrCl4 were purchased from either Aldrich Chemical Company or Cerac. TiCl4 was typically used in its etherate form. The etherate, TiCl4.2Et2 O, can be prepared by gingerly adding TiCl4 to diethylether. Amines, silanes, and lithium reagents were purchased from Aldrich Chemical Company or Petrarch Systems. Methylalumoxane (MAO) solutions were either toluene or heptane based and were supplied by either Schering or Ethyl Corp. The silica used was Davidson 948 grade, and was dried at 800° C. Triethylalumina (TEAL), supplied by Texas Alkyls as a 1.6M solution in heptane, was used as a scavenger in the polymerizations.
Preparation of Group IV B Transition Metal Components Example A Compound A
Part 1. Me4 HC5 Li (10.0 g, 0.078 mol) was slowly added to a Me2 SiCl2 (11.5 ml, 0.095 mol, in 225 ml of tetrahydrofuran (THF) solution. The solution was stirred for 1 hour to assure complete reaction. The thf solvent was then removed via a vacuum to a cold trap held at -196° C. Pentane was added to precipitate the LiCl. The mixture was filtered through Celite. The solvent was removed from the filtrate. Me4 HC5 SiMe2 Cl (15.34 g, 0.071 mol) was recovered as a pale yellow liquid.
Part 2. Me4 HC5 SiMe2 Cl (10.0 g, 0.047 mol) was slowly added to a suspension of LiHN-t-Bu (3.68 g, 0.047 mol, ˜100 ml THF). The mixture was stirred overnight. The thf was then removed via a vacuum to a cold trap held at -196° C. Petroleum ether (˜100 ml) was added to precipitate the LiCl. The mixture was filtered through Celite. The solvent was removed from the filtrate. Me2 Si(Me4 HC5) (HN-t-Bu) (11.4 g, 0.044 mol) was isolated as a pale yellow liquid.
Part 3. Me2 Si(Me4 HC5) (HN-t-Bu) (11.14 g, 0.044 mol) was diluted with ˜100 ml of Et2 O. MeLi (1.4M, 64 ml, 0.090 mol) was slowly added. The mixture was allowed to stir for 0.5 hours after the final addition of MeLi. The ether was reduced in volume prior to filtering off the product. The product, [Me2 Si(Me4 C5) (N-t-Bu) ]Li2 was washed with several small portions of ether, then vacuum dried.
Part 4. [Me2 Si(Me4 C5) (N-t-Bu)]Li2 (3.0 g, 0.011 mol) was suspended in ˜150 ml of Et2 O. ZrCl4 (2.65 g, 0.011 mol) was slowly added and the resulting mixture was allowed to stir overnight. The ether was removed via a vacuum to a cold trap held at -196° C. Pentane was added to precipitate the LiCl. The mixture was filtered through Celite twice. The pentane was significantly reduced in volume and the pale yellow solid was filtered off and washed with solvent. Me2 Si(Me4 C5) (N-t-Bu) ZrCl2 (1.07 g, 0.0026 mole) was recovered. Additional Me2 Si(Me4 C5) (N-t-Bu) ZrCl2 was recovered from the filtrate by repeating the recrystallization procedure. Total yield, 1.94 g, 0.0047 mol.
Part 1. MePhSiCl2 (14.9 g, 0.078 mol) was diluted with 250 ml of THF. Me4 HC5 Li (10.0 g, 0.078 mol) was slowly added as a solid. The reaction solution was allowed to stir overnight. The solvent was removed via a vacuum to a cold trap held at 196° C. Petroleum ether was added to precipitate the LiCl. The mixture was filtered through Celite and the pentane was removed from the filtrate. MePhSi(Me4 C5 H)Cl (20.8 g, 0.075 mol) was isolated as a yellow viscous liquid.
Part 2. LiHN-t-Bu (4.28 g, 0.054 mol) was dissolved in ˜100 ml of THF. MePhSi(C5 Me4 H)Cl (15.0 g, 0.054 mol) was added dropwise. The yellow solution was allowed to stir overnight. The solvent was removed in vacuo. Petroleum ether was added to precipitate the LiCl. The mixture was filtered through Celite, and the filtrate was evaporated. MePhSi(C5 Me4 H) (NH-t-Bu) (16.6 g, 0.053 mol) was recovered as an extremely viscous liquid.
Part 4. Li2 [MePhSi(C5 Me4) (N-t-Bu)](8.75 g, 0.027 mol) was suspended in ˜125 ml of cold ether (-30° C.). TiCl4.2Et2 O(9.1 g, 0.027 mol) was slowly added. The reaction was allowed to stir for several hours prior to removing the ether via vacuum. A mixture of toluene and dichloromethane was then added to solubilize the product. The mixture was filtered through Celite to remove the LiCl. The solvent was largely removed via vacuum and petroleum ether was added. The mixture was cooled to maximize product precipitation. The crude product was filtered off and redissolved in toluene. The toluene insolubles were filtered off. The toluene was then reduced in volume and petroleum ether was added. The mixture was cooled to maximize precipitation prior to filtering off 3.34 g (7.76 mmol) of the yellow solid MePhSi(C5 Me4) (N-t-Bu)TiCl2.
Part 2. (C5 Me4 H)SiMe2 Cl (8.0 g, 0.037 mol) was slowly added to a suspension of LiHNC12 H23 (C12 H23 =cyclododecyl, 7.0 g, 0.037 mol, ˜80 ml THF). The mixture was stirred overnight. The THF was then removed via a vacuum to a cold trap held at -196° C. Petroleum ether and toluene were added to precipitate the LiCl. The mixture was filtered through Celite. The solvent was removed from the filtrate. Me2 Si(C5 Me4 H) (NHC12 H23) (11.8 g, 0.033 mol) was isolated as a pale yellow liquid.
Part 3. Me2 Si(C5 Me4 H) (NHC12 H23) (11.9 g, 0.033 mol) was diluted with ˜150 ml of ether. MeLi (1.4M, 47 ml, 0.066 mol) was slowly added. The mixture was allowed to stir for 2 hours after the final addition of MeLi. The ether was reduced in volume prior to filtering off the product. The product, [Me2 Si(C5 Me4) (NC12 H23)]Li2, was washed with several small portions of ether, then vacuum dried to yield 11.1 g (0.030 mol) of product.
Part 4. [Me2 Si(C5 Me4) (NC12 H23)]Li2 (3.0 g, 0.008 mol) was suspended in cold ether. TiCl4.2Et2 O (2.7 g, 0.008 mol) was slowly added and the resulting mixture was allowed to stir overnight. The ether was removed via a vacuum to a cold trap held at -196° C. Methylene chloride was added to precipitate the LiCl. The mixture was filtered through Celite. The solvent was significantly reduced in volume and petroleum ether was added to precipitate the product. This mixture was refrigerated prior to filtration in order to maximize precipitation. The solid collected was recrystallized from methylene chloride and Me2 Si(C5 Me4) (NC12 H23)TiCl2 was isolated (1.0 g, 2.1 mmol).
Supported Catalyst Preparation and Use in Polymerization Procedures Example 1
The transition metal compound, A, Me2 Si(Me4 C5) (N-t-Bu)ZrCl2 (0.063 g, 0.153 mmole) prepared as described for Example A, was combined with 35 ml of 1.0M MAO in toluene. The solution was stirred for five minutes prior to the addition of the treated silica (2.5 g). The mixture was then stirred for 5 minutes, after which time the toluene was removed via vacuum, and the prepared supported catalyst was recovered.
A typical run consisted of injecting 400 ml of hexane, 0.2 ml TEAL (1.6M in heptane), and 0.5 g of the prepared supported catalyst into the reactor. The reactor was heated to 80° C. and 65 psi of ethylene was introduced prior to the injection of the prepared supported catalyst. The polymerization reaction was limited to 30 minutes. The reaction was stopped by rapidly cooling and venting the system. A mass of 20.2 g of polyethylene was recovered, having a molecular weight (MW) of 231,200, and a molecular weight distribution (MWD)=3.26.
Dried silica (5.0 g) was slurried in 25 ml of toluene. MAO (12.5 ml, 1.0M) was added and the mixture was permitted to stir for five minutes. The transition metal compound A, Me2 Si(Me4 C5) (N-t-Bu)ZrCl2 (0.100 g, 0.243 mmole) prepared as described for Example A, was then added and the mixture was stirred for five minutes. Toluene was removed from the mixture via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure as described for Example 1, 400 ml of hexane, 0.20 ml of triethylaluminum (TEAL) (1.6M in heptane), 0.50 g of the prepared supported catalyst, and 60 psi of ethylene were added to the reactor at 80° C. and allowed to react for 20 minutes. A mass of 1.9 g of polyethylene was recovered having a molecular weight of 170,900, and a MWD of 2.992.
Dried silica was pretreated with methylalumoxane as described for Example 1. The transition metal compound B, MePhSi(Me4 C5) (N-t-Bu)TiCl2 (0.015 g, 0.035 mmol), prepared as described for Example B, was combined with 7.5 ml of 1.0M MAO in toluene and stirred for five minutes. Pretreated silica (0.5 g) was then added to this mixture with stirring for 5 minutes. The toluene was then removed via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure as described for Example 1, 400 ml of hexane, 0.20 ml of TEAL (1.6M in heptane), 0.50 g of the prepared supported catalyst and 65 psi of ethylene were added to the reactor at 80° C. and allowed to react for 10 minutes. A mass of 10.7 g of polyethylene was recovered, having a molecular weight of 189,900, and a MWD of 3.652.
The transition metal compound B, MePhSi(Me4 C5) (N-t-Bu)TiCl2 (0.015 g, 0.035 mmol), prepared as described for Example B, was combined with 5.0 ml of 1.5M MAO in heptane and stirred for five minutes. Dried silica, which had not been pretreated (0.5 g) was then added to this mixture with stirring for 5 minutes. The heptane was removed via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure as described for Example 1, 400 ml of hexane, 0.20 ml of TEAL (1.6M in heptane), 0.50 g of the prepared supported catalyst and 65 psi of ethylene were added to the reactor at 80° C. and allowed to react for 15 minutes. A mass of 0.5 g of polyethylene was recovered having a molecular weight of 175,600 and a MWD of 2.801.
The transition metal compound B, MePhSi(Me4 C5) (N-t-Bu)TiCl2 (0.015 g, 0.035 mmol), prepared as described for Example B, was combined with 7.5 ml of 1.0M MAO in toluene and stirred for five minutes. Dried silica (0.5 g), which had not been pretreated, was then added to this mixture with stirring for 5 minutes. The toluene was then removed via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure as described for Example 1, 400 ml of hexane, 0.20 ml of TEAL (1.6M in heptane), 0.50 g of the prepared supported catalyst and 65 psi of ethylene were added to the reactor at 80° C. and allowed to react for 10 minutes. A mass of 3.1 g of polyethylene was recovered having a molecular weight of 313,900 and a MWD of 3.175.
The transition metal compound B, MePhSi(Me4 C5) (N-t-Bu)TiCl2 (0.015 g, 0.035 mmol), prepared as described for Example B, was combined with 5.0 ml of 1.5M MAO in heptane and stirred for five minutes. Pretreated silica/(0.5 g) was then added to this mixture with stirring for 5 minutes. The heptane was removed via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure as described for Example 1, 400 ml of hexane, 0.20 ml of TEAL (1.6M in heptane), 0.50 g of the prepared supported catalyst and 65 psi of ethylene were added to the reactor at 80° C. and allowed to react for 10 minutes. A mass of 2.0 g of polyethylene was recovered having a molecular weight of 365,900 and a MWD of 4.845.
The transition metal compound C, Me2 Si(Me4 C5) (NC12 H23)TiCl2 (40 mg, 0.084 mmol), prepared as described for Example C, was dissolved in 12.3 ml of 1.5M MAO in heptane and was permitted to stir 0.5 hours. Pretreated silica (2.5 g) was added, and the mixture stirred for an additional 0.5 hours. Toluene was then thoroughly removed via vacuum and the prepared supported catalyst was recovered.
A solution of 1.4M trimethylaluminum (TMA) in heptane (200 ml) was placed into a 1 L flask equipped with a magnetic stirring bar. Untreated silica gel (50 g), containing 9.6% water, was slowly added to the flask. After the addition of the silica was completed, the mixture was stirred at ambient temperature for one hour. The transition metal compound B, MePhSi(Me4 C5) (N-t-Bu)TiCl2 (1.35 g, 3.1 mmol), prepared as described for Example B, was slurried in 50 ml of heptane, and then added to the flask containing the treated silica. The mixture was permitted to react for one hour, and was then heated to 65° C. while a nitrogen stream was passed through the flask to remove the solvent. The nitrogen stream was stopped when the mixture in the flask turned into a free flowing powder.
A gas phase laboratory reactor was utilized with the following reactor conditions: 74° C., 300 psi, 50 mole % ethylene, 1 mole % hexene, 400 ppm hydrogen, cycle gas velocity 0.7 feet/sec, and TEAL feed rate (1% in isopentane) of 1 ml/hr. Polyethylene was recovered, (productivity 49 g/g) having the following properties: a molecular weight of 153,000, MWD of 4.817, 9 mole % hexene (as determined by 1 H NMR), and density of 0.916.
The transition metal compound, C, Me2 Si(Me4 C5) N-C12 H23 TiCl2 (0.010 g, 0.021 mmole) prepared as described for Example C, was dissolved in 5.0 ml of 1M MAO in toluene, which contained tetraethoxysilane (TEOS) (40 mg, 0.192 mmole) as a modifier, and was permitted to stir for 5 minutes. Pretreated silica (0.50 g) was added to this mixture with stirring for 5 additional minutes. Toluene was removed from the mixture via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure described for Example 1, 400 ml of hexane, 0.50 g of the prepared supported catalyst and 65 psi of ethylene were added to the reactor at 80° C. and allowed to react for 0.50 hours. A mass of 13.2 g of polyethylene in fine particulate matter, was recovered, having a molecular weight of 221,055, and an MWD or 2.670.
The transition metal compound, C, Me2 Si(Me4 C5) N-C12 H23 TiCl2 (0.010 g, 0.021 mmole) prepared as described for Example C, was dissolved in 5.0 ml of 1M MAO in toluene, and was permitted to stir for 5 minutes. Pretreated silica (0.50 g) was added to this mixture with stirring for 5 additional minutes. Toluene was removed from the mixture via vacuum and the prepared supported catalyst was recovered.
Using the same general polymerization procedure described for Example 1, 400 ml of hexane, 0.50 g of the prepared supported catalyst and 65 psi of ethylene were added to the reactor at 80° C. and allowed to react for 0.50 hours. A mass of 7.2 g of polyethylene in clusters of fine particles was recovered, having a molecular weight of 169,340, and a MWD of 4.999.
TABLE 2__________________________________________________________________________Summary of Polyethylene Polymerization ResultsTransition  AT   Molar                 RXN    ActivityMetal (TM)  (MAO)            AL/TM                 Time                    Yield                        g/mmoleExampleType   mmole       mmole            Ratio                 (hr)                    (g) TM. hr                             MW  MWD__________________________________________________________________________1    A  0.031       7.0  230  0.50                    20.2                        1,300                             231,200                                 3.262    A  0.024       1.25  50  0.33                    1.9   240                             170,900                                 2.993    B  0.035       7.5  210  0.17                    10.7                        1,800                             189,900                                 3.654    B  0.035       7.5  210  0.25                    0.5   60 175,600                                 2.805    B  0.035       7.5  210  0.17                    3.1   520                             313,900                                 3.186    B  0.035       7.5  210  0.17                    2.0   340                             365,900                                 4.857.sup.aC  0.020       4.4  220  66.5                    5.5    4 732,900                                 2.989.sup.bB  0.021       5.0  240  0.50                    13.2                        1,260                             221,100                                 2.6710   B  0.021       5.0  240  0.50                    7.2   690                             169,300                                 5.00__________________________________________________________________________ .sup.a Gas Phase Polymerization .sup.b TEOS Modifier Used
1. A process for the polymerization of one or more olefins comprising contacting the monomer or monomers under polymerization conditions in the presence of a catalyst system comprising:
(A) an inert support;
(B) a transition metal compound represented by the formulae: ##STR7## wherein M is Zr, Hf, or Ti in its highest formal oxidation state:
(C5 --H5-y-x Rx) is a cyclopentadienyl ring which is substituted with from zero to five substituent groups R, "x" is 0, 1, 2, 3, 4 or 5 denoting the degree of substitution, and each substituent group R is, independently, a radical selected from a group consisting of C1 -C20 hydrocarbyl radicals; substituted C1 -C20 hydrocarbyl radicals wherein one or more hydrogen atoms is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, an alkylborido radical, or other radical containing a Lewis acidic or basic functionality; C1 -C20 hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected from the Group IV A of the Periodic Table of Elements; and halogen radicals, amido radicals, phosphido radicals, alkoxy radicals, alkylborido radicals, or a radical containing Lewis acidic or basic functionality; or (C5 H5-y-x Rx) is a cyclopentadienyl ring in which two adjacent R-groups are joined forming C4 -C20 ring to give a saturated or unsaturated polycyclic cyclopentadienyl ligand;
(JR'z-1-y) is a heteroatom ligand in which J is an element with a coordination number of three from Group V A or an element with a coordination number of two from Group VI A of the Periodic Table of Elements, each R' is, independently a radical selected from a group consisting of C1 -C20 hydrocarbyl radicals; substituted C1 -C20 hydrocarbyl radicals wherein one or more hydrogen atom is replaced by a halogen radical, an amido radical, a phosphido radical, an alkoxy radical, an alkylborido radical, or other radical containing a Lewis acidic or basic functionality; and "z" is the coordination number of the element J;
each Q is, independently, any univalent anionic ligand provided that where Q is a hydrocarbyl ligand such Q cannot be a substituted or unsubstituted cyclopentadienyl ring or both Q together are an alkylidene, a cyclometallated hydrocarbyl or a divalent anionic chelating ligand;
(C) an alumoxane.
2. The process of claim 1 wherein the heteroatom ligand group J element is nitrogen, phosphorous, oxygen or sulfur.
3. The process of claim 1 wherein Q is a halogen or hydrocarbyl radical.
4. The process of claim 2, wherein the heteroatom ligand group J element is nitrogen.
5. The process of claim 1 wherein M is titanium or zirconium.
6. The process of claim 1 wherein the aluminum atom to transition metal atom mole ratio is from about 10:1 to about 1,000:1.
7. The process of claim 1 wherein the support is an inorganic support selected from the group consisting of talc, silica, alumina, silica-alumina, magnesia, titania, zirconia, or mixtures thereof.
8. The process of claim 7, wherein said support is dehydrated.
9. The process of claim 1, further comprising a modifier compound containing a Lewis acidic or basic functionality.
10. The process of claim 1, wherein the aluminum atom to transition metal atom mole ratio is about 10:1 to about 20,000:1.
11. The process of claim 1, wherein the alumoxane is formed on the support by reaction of a hydrated support with a trialkylaluminum.
12. The process of claim 7, wherein the hydrated support is silica containing from about 6 to about 20 weight percent water and is reacted with trimethylaluminum.
US07751392 1989-09-13 1991-08-28 Mono-Cp heteroatom containing Group IVB transition metal complexes with MAO: supported catalysts for olefin polymerization Expired - Lifetime US5227440A (en)
US07751392 US5227440A (en) 1989-09-13 1991-08-28 Mono-Cp heteroatom containing Group IVB transition metal complexes with MAO: supported catalysts for olefin polymerization
US07581869 Division US5057475A (en) 1989-09-13 1990-09-13 Mono-Cp heteroatom containing group IVB transition metal complexes with MAO: supported catalyst for olefin polymerization
US5227440A true US5227440A (en) 1993-07-13
ID=27503532
US07751392 Expired - Lifetime US5227440A (en) 1989-09-13 1991-08-28 Mono-Cp heteroatom containing Group IVB transition metal complexes with MAO: supported catalysts for olefin polymerization
US (1) US5227440A (en)
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Okuda, Chem. Ber. 123 (1990) pp. 1649-1651.
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Shapiro et al., Organometallics, 1990, 9, pp. 867-869.
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