Jacobsen, Grant B. (Apartment 4202 3000 Bissonnet Street Houston, TX, 77005, US)
Van Dun, Jozef J. (Pater Damiaanlaan 76 Zandhoven, B-2240, BE)
Vanvoorden, Johan (Kabergheidestraat 35 Diepenbeek, B-3590, BE)
Carnahan, Edmund M. (4619 Twin Elm Drive Fresno, TX, 77545, US)
Jacobsen, Grant B. (Apartment 4202 3000 Bissonnet Street Houston, TX, 77005, US)
Van Dun, Jozef J. (Pater Damiaanlaan 76 Zandhoven, B-2240, BE)
Vanvoorden, Johan (Kabergheidestraat 35 Diepenbeek, B-3590, BE)
Mckinney, Osborne K. (The Dow Chemical Company Intellectual Property Section, B-1211 2301 Brazosport Boulevard Freeport, TX, 77541, US)
| 1. | A polymer composition comprising an ethylene homopolymer or an interpolymer of ethylene at least one compound represented by the formula H2C = CHR wherein R is a C1C20 linear, branched or cyclic alkyl group or a C6C20 aryl group, or a C4C20 linear, branched or cyclic diene, said polymer composition characterized as having a percent swell of at least 175 percent, a monomodal molecular weight distribution, and an Mw/Mn of from 1.5 to 10. |
| 2. | The polymer composition of Claim 1, further characterized as having a density of from 0.870 to 0.980 g/cm3. |
| 3. | The polymer composition of Claim 1, further characterized as having an 12 of from 0.0001 to 10,000 g/10 minutes. |
| 4. | The polymer composition of Claim 1, further characterized as having a melt strength which is at least 10 percent greater, preferably at least 20 percent greater, more preferably at least 30 percent greater than that of a linear ethylene polymer of the same 12 and density which linear polymer has a percent swell of less than 175 percent. |
| 5. | The polymer composition of Claim 1, further characterized as having a log [zero shear viscosity (r) o) which is at least 5 percent greater than that of a linear ethylene polymer of the same Mw and density which linear polymer has a percent swell of less than 175 percent. |
| 6. | A polymer composition comprising a copolymer of ethylene with at least one comonomer selected from the group consisting of a compound represented by the formula H2C = CHR wherein R is a C1C20 linear, branched or cyclic alkyl group or a CgC20 aryl group, and a C4C20 linear, branched or cyclic diene, prepared by a process copolymerizing said ethylene with said comonomer by a slurry polymerization process in the presence of a solid catalyst system comprising the reaction product of a Group 310 metal complex with a functionalized catalyst support comprising a particulated support material having chemically bonded thereto a plurality of aluminumcontaining groups derived from a nonionic Lewis acid, said aluminumcontaining groups: containing at least one fluorosubstituted hydrocarbyl ligand containing from 1 to 20 carbons, said hydrocarbyl ligand being bonded to aluminum, and being bonded to said support material, optionally through a bridging moiety. |
| 7. | A polymer of Claim 6, wherein the functionalized catalyst support has a chemical structure of the following formula: So Me (K\i) (Dd) s wherein: So is a particulated solid support material; Me is aluminum; m1 is a number from 120, preferably from 1 to 3, more preferably 1; Ki independently each occurrence is a ligand group bonded to Me having from 1 to 30 atoms other than hydrogen, with the proviso that in at least one occurrence, K'is a fluoro substituted hydrocarbyl group of from 1 to 20 carbons, preferably a fluorosubstituted aryl group of from 6 to 20 carbons, more preferably a perfluoroaryl group of from 6 to 20 carbons, most preferably pentafluorophenyl; and optionally two or more K'groups may be bonded together thereby forming a bridging group linking two or more Me atoms or forming a fused ring system; k1 is a number from 1 to 5 selected to provide charge neutrality to the complex; D is an oxygencontaining bridging moiety chemically bonded to So by means of which the group, Mem (K1kl) (Dd), is attached to the particulated solid support; d is a positive number from 0 to 5, preferably 1 to 3, more preferably 1, and less than or equal to m, said d equaling the average number of chemical bonds to the substrate per group, Memi (K\i) (Dd) ; s is a number greater than or equal to 2 and is equal to the number of Mem1 (K'ki) (Dd) groups attached to the substrate, So. |
| 8. | A continuous slurry polymerization process comprising contacting one or more addition polymerizable monomers under slurry polymerization conditions with a solid catalyst system comprising a Group 310 metal complex supported on a functionalized catalyst support comprising with a particulated support material having chemically bonded thereto a plurality of aluminumcontaining groups derived from a nonionic Lewis acid, said aluminumcontaining groups: containing at least one fluorosubstituted hydrocarbyl ligand containing from 1 to 20 carbons, said hydrocarbyl ligand being bonded to aluminum, and being bonded to said support material, optionally through a bridging moiety. |
| 9. | A polymer composition obtainable by the polymerization process of Claim 8. |
With the advent of single site metallocene and constrained geometry catalysts, as well as other advanced single site catalysts, have come polymers having a beneficial range of properties. in particular, such catalyst systems have made possible narrow molecular weight- distribution polymers and/or narrow composition distribution polymers, optionally and further preferably in conjunction with improved rheological properties, such as attainable through controlled long chain branching. However, the continued need for new product offerings remains.
It is well known that narrow molecular weight distribution polymers (particularly linear polymers) disadvantageously have low shear sensitivity or low 110/12 values, which limits the extrudability of such polymers. Additionally, such polymers possess low melt elasticity, causing problems in melt fabrication such as film forming processes or blow molding processes (e. g., sustaining a bubble in the blown film process, or sag in the blow molding process etc.). Finally, such resins also experience surface melt fracture properties at relatively low extrusion rates thereby processing unacceptably and causing surface irregularities in the finished product. However, it is also known that narrow molecular weight distribution linear polymers advantageously have mechanical properties.
Those in industry would find great advantage in slurry polymerized polymers which have a relatively high molecular weight, a narrow and monomodal molecular weight distribution, and good processability in blow molded applications, e. g., as evidenced by a high swell and a relatively high 110/12- US-A-5763547 discloses a slurry polymerization process using a supported catalyst formed by slurrying a silica/alumoxane support with a solution of a monocyclopentadienyl Group IV metal complex in ISOPAR E, and subsequently briefly contacting with a borane activator.
WO 97/43323 discloses slurry polymerization processes utlizing a supported catalyst formed by depositing am monocyclopentadienyl Group IV metal complex and a perfluorophenyl borate onto a dried and/or calcine silica support which has been passivated with a trialkylaluminum compound. Representative polymer compositions demonstrated a rising comonomer distribution.
WO 97/44371 discloses a gas phase polymerization process using a supported catalyst formed by contacting a dried or calcine silica support (optionally pretreated with water) with triethylaluminum, slurrying the support with toluene and contacting with a solution of a borane, and subsequently contacting with a solution of a monocyclopentadienyl Group IV
metal complex in toluene. Representative polymer compositions disclosed demonstrated improved rheological performance, and a rising comonomer distribution.
EP 824112A1 discloses a supported composition wherein a Group IIIA metal- containing compound is directly (or through a spacer) covalently bonded to a moiety on the support, which compound may be of neutral or ionic construction, aand which forms a catalyst system with a transition metal compound, such as a metallocene. Although aluminum- containing compounds are broadly disclosed as suitable Group IIIA metal-containing compounds, no example describes their use; nor do any teachings recognize any unexpected utility of aluminum-containing species.
US-A-5643847 discloses a catalyst composition comprising a metal oxide support having a counter anion dreived from a Lewis acid not having readily hydrolyzable ligand (such as a tri-perfluorophenyl borane) covalently bound to the surface of the support directly through the oxygen atom of the metal oxide, wherein the anion is also ionically bound to a catalytically active transition metal compound. Although aluminum-containing Lewis acids are broadly disclosed, no example describes their use; nor do any teachings recognize any unexpected utility of aluminum-containing species.
It would be desirable if there were provided slurry polymerization processes which yield polymers having novel physical properties, such as a high swell property coupled with a monomodal molecular weight distribution.
Accordingly, the subject invention provides polymer composition comprising an ethylene homopolymer or an interpolymer of ethylene at least one compound represented by the formula H2C = CHR wherein R is a C1-C20 linear, branched or cyclic alkyl group or a C6 -C20 aryl group, or a C4-C20 linear, branched or cyclic diene, said polymer composition characterized as having a percent swell of at least 175 percent, a monomodal molecular weight distribution, and an Mw/Mn of from 1.5 to 10.
The subject invention further provides a polymer composition comprising a copolymer of ethylene with at least one comonomer selected from the group consisting of a compound represented by the formula H2C = CHR wherein R is a C1-C20 linear, branched or cyclic alkyl group or a Cg-C20 aryl group, and a C4-C20 linear, branched or cyclic diene, prepared by a process copolymerizing said ethylene with said comonomer by a slurry polymerization process in the presence of a solid catalyst system comprising the reaction product of a Group 3-10 metal complex with a functionalized catalyst support comprising a particulated support material having chemically bonded thereto a plurality of aluminum-containing groups derived from a non-ionic Lewis acid, said aluminum-containing groups: containing at least one fluoro-substituted hydrocarbyl ligand containing from 1 to 20 carbons, said hydrocarbyl ligand being bonded to aluminum, and being bonded to said support material, optionally through a bridging moiety.
The subject invention further provides a continuous slurry polymerization process comprising contacting one or more addition polymerizable monomers under slurry polymerization conditions with a solid catalyst system comprising a Group 3-10 metal complex supported on a functionalized catalyst support, the functionalized catalyst support in turn comprising a functionalized catalyst support comprising a particulated support material having chemically bonded thereto a plurality of aluminum-containing groups derived from a non-ionic Lewis acid, said aluminum-containing groups: containing at least one fluoro-substituted hydrocarbyl ligand containing from 1 to 20 carbons, said hydrocarbyl ligand being bonded to aluminum, and being bonded to said support material, optionally through a bridging moiety.
The subject invention further provides polymer composition obtainable by the continuous slurry polymerization process of the invention.
These and other advantages are more fully set forth in the following detailed description wherein: FIGURE 1 is a plot of the percent swell of polymers of the invention as well as of comparative polymers; FIGURE 2 is gel permeation chromatogram of a polymer of the invention; FIGURE 3 is a plot of the melt strength of a polymer of the invention, as well as of comparative polymers; and FIGURE 4 is a plot of relating the zero shear viscosity to molecular weight for a polymer of the invention, as well as for comparative polymers.
All references herein to elements belonging to a certain Group refer to the Periodic Table of the Elements published and copyrighted by CRC Press, Inc., 1995. Also any reference to the Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups.
The term"interpoiymer"is used herein to indicate a polymer wherein at least two different monomers are polymerized to make the interpolymer. This includes copolymers, terpolymers, etc.
The density of the polymer compositions for use in the present invention was measured in accordance with ASTM D-792.
The molecular weight of the polymer compositions for use in the present invention is conveniently indicated using a melt index measurement according to ASTM D-1238, Condition 190°C/2.16 kg (formally known as"Condition (E)"and also known as 12) was determined, as were conditions 190°C/5 kg, 10 kg and 21.6 kg known as Is, lio, and 121 respectively. Melt index is inversely proportional to the molecular weight of the polymer.
Thus, the higher the molecular weight, the lower the melt index, although the relationship is not linear. Melt flow ratios were taken from any pair of these values.
Other useful physical property determinations made on the novel polymer compositions described herein include the melt flow ratio (MFR): measured by determining "11o" (according to ASTM D-1238, Condition 190°C/10 kg (formerly known as"Condition (N)") and dividing the obtained 11o by the 12. The ratio of these two melt index terms is the melt flow ratio and is designated as 11J12. Other melt flow ratios measured include 121. e/ts, and 121.6/12.
The molecular weight (Mw) and distribution (Mw/Mn) of the polymers of the present invention were determined by gel permeation chromatography (GPC) on a Waters 150C high temperature chromatographic unit equipped with mixed porosity columns, operating at a system temperature of 140°C. The solvent was 1,2,4-trichlorobenzene, from which 0.3 percent by weight solutions of the samples were prepared for injection. The flow rate was 1.0 milliliters/minute and the injection size was 100 microliters.
The molecular weight determination was deduced by using narrow molecular weight distribution polystyrene standards (from Polymer Laboratories) in conjunction with their elution volumes. The equivalent polyethylene molecular weights were determined by using appropriate Mark-Houwink coefficients for polyethylene and polystyrene (as described by Williams and Ward in Journal of Polvmer Science, Polymer Letters, Vol. 6, (621) 1968) to derive the following equation: Mpolyethylene = a * (Mpolystyrene) b In this equation, a = 0.4316 and b = 1.0. Weight average molecular weight, Mw, and number average molecular weight, Mn, was calculated in the usual manner according to the following formula: Mj = (E wi (Mi where wi is the weight fraction of the molecules with molecular weight Mi eluting from the GPC column in fraction i and j = 1 when calculating Mw and j =-1 when calculating Mn.
Melt properties are evaluated using a Goettfert Rheotens extruder equipped with a 30/2.5 mm L/D die. The temperature profile is 190°C flat. The output rate is kept constant at 600 g/h. The Rheotens roller acceleration is 12 cm/s2. The distance between the die of the extruder and the center of the rolls is kept constant at 10 cm. With this technique, melt strength is reported as the maximum tensile force in CN, extensibility is reported as the difference between the maximum pull-off speed of the gear wheel pair and the speed of the strand, and melt elongation is reported as v-vdvo.
Die swell is measured using a laser swell detector, and is calculated by dividing the strand diameter by the die diameter (2.5 mm) and multiplying by 100.
The ethylene copolymer of the present invention is a copolymer of ethylene with at least one comonomer selected from the group consisting of a compound represented by the formula H2C = CHR wherein R is a C1-C20 linear, branched or cyclic alkyl group or a C6- C20 aryl group, and a C4-C20 linear, branched or cyclic diene.
<BR> <P> The ethylene copolymer of the present invention has a density (g/cm³) of from 0.870<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> to 0.980. Ethylene copolymers having a density of lower than 0.870 g/cm³ cannot be produced very well by slurry polymerization. On the other hand, when an ethylene copolymer has a density of higher than 0.980, the comonomer content of such a copolymer is too low, so that it is likely that the copolymer has substantially the same properties as those of an ethylene homopolymer, but does not have various excellent properties characteristic of a copolymer having a density within the above-defined range. In the present invention, it is preferred that the ethylene copolymer have a density of from 0.87 to 0.980, more preferably from 0.890 to 0.965, even more preferably from 0.905 to 0.975, and most preferably from 0.915 to 0.955 g/cm3.
The ethylene polymer of the invention will preferably have a single molecular weight peak, as determined by gel permeation chromatography. Further, the ethylene polymer of the present invention will typically an Mw/Mn of at least 1.5, preferably at least 2.0, typically at least 2.5, and most typically at least 3.0; less than 10, preferably less than 8, more preferably less than 7, and most preferably less than 4, wherein Mw and Mn are, respectively, the weight average molecular weight and the number average molecular weight, both as measured by gel permeation chromatography (GPC).
The ethylene polymer of the invention will preferably have a melt index, (12), of at least 0.0001, typically at least 0.001, more typically at least 0.01; and less than 10000, typically less than 5000, more typically less than 3000 g/l0min., with melt indices of less than 50, especially less than 10, with melt indices of less than 5 g/10 minutes being especially preferred for blow molding applications.
The ethylene polymer of the present invention will preferably an 11o/12 of at least 6, preferably at least 6.5, more preferably atleast 7; less than 25, typically less than 20, and more typically less than 15.
The ethylene polymer of the present invention will preferably a percent swell of at least 175 percent, more preferably at least 200 percent, and most preferably at least 210 percent.
The ethylene polymer of the present invention will have preferably have a melt strength which is at least 10 percent greater, preferably atleast 20 percent greater, more preferably at least 30 percent greater than that of a linear ethylene polymer of the same 12 and density which linear polymer has a percent swell of less than 175 percent.
The ethylene polymer of the invention will preferably have a log [zero shear viscosity (rjO) which is at least 5 percent greater than that of a linear ethylene polymer of the same Mw and density which linear polymer has a percent swell of less than 175 percent.
The ethylene polymers of the invention may optionally be characterized as having long chain branching. In particular, the ethylene polymer of the invention may optionally be
characterized as having a polymer backbone which is substituted with about 0.01 long chain branches/1000 carbons to about 3 long chain branches/1000 carbons, more preferably from about 0.01 long chain branches/1000 carbons to about 1 long chain branches/1000 carbons, and especially from about 0.05 long chain branches/1000 carbons to about 1 long chain branches/1000 carbons. Long chain branching is defined herein as a chain length greater than that of the residue of a comonomer which has been incorporated into the polymer backbone.
The ethylene polymers of the invention may be suitably prepared using the catalyst systems described hereafter, which utilize a functionalized catalyst support.
The functionalized catalyst support of the invention in a preferred embodiment may be depicted as a chemical structure of the following formula: So Mem1 (K k1) (Dd) s wherein: So is a particulated solid support material; Me is aluminum; m1 is a number from 1-20, preferably from 1 to 3, more preferably 1; K'independently each occurrence is a ligand group bonded to Me having from 1 to 30 atoms other than hydrogen, with the proviso that in at least one occurrence, K'is a fluoro- substituted hydrocarbyl group of from 1 to 20 carbons, preferably a fluoro-substituted aryl group of from 6 to 20 carbons, more preferably a perfluoroaryl group of from 6 to 20 carbons, most preferably pentafluorophenyl; and optionally two or more K'groups may be bonded together thereby forming a bridging group linking two or more Me atoms or forming a fused ring system; k1 is a number from 1 to 5 selected to provide charge neutrality to the complex; D is a bridging moiety chemically bonded to So by means of which the group, Mem, (K'k1) (Dd)], is attached to the particulated solid support; d is a positive number from 0 to 5, preferably 1 to 3, more preferably 1, and less than or equal to m, said d equaling the average number of chemical bonds to the substrate per group, Mem, (K k1) (Dd)]; s is a number greater than or equal to 2 and is equal to the number of Mem, (K'ki) (Dd) groups attached to the substrate, So. Preferably s is chosen to provide a concentration of Mem, (K'ki) (Dd) groups on the substrate from 1 x 10-5 umole/gram to 2 mmole/gram, more preferably from 0.1 umole/gram to 500 umole/g.
The functionalized catalyst supports useful in the practice of the invention are readily prepared by combining a particulated support material having reactive functional groups on the surface thereof, with a non-ionic Lewis acid source of the aluminum-containing groups that is able to react with the functional surface groups of the support, preferably under
conditions to chemically attach the aluminum of the [Mem (K'k1) (Dd)] group and the support by means of the linking group D, optionally followed by removing byproducts formed by the reaction. Preferred supports and sources of aluminum groups are those capable of reacting by means of a ligand exchange to release a volatile hydrocarbon or substituted hydrocarbon by-product that is readily removed from the reaction environment.
Preferred sources of the ligand groups, Mem (K'k1) (Dd), are non-ionic Lewis acids of the formula [Mem (K') (K1k1), especially, tri (fluoroaryl) aluminum compounds, most preferably tris (pentafluorophenyl) aluminum, as well as mixtures or adducts of such tri (fluoroaryl) aluminum compounds with one or more trialkylatuminum, alkylaluminumoxy, fluorarylaluminoxy, or tri (fluoroaryl) boron compounds containing from 1 to 20 carbons in each alkyl group and from 6 to 20 carbons in each fluoroaryl ligand group. Such reactants are capable of reacting with a reactive functionality of the support to covalently bond thereto, thereby generating the linking group, D, in the process. Preferred reactants are those capable of bonding to a hydroxyl, hydrocarbyloxy, hydrocarbylmetal or hydrocarbyl metal loid functionality of the substrate, preferably by a ligand exchange mechanism, thereby generating an oxy, metal of metalloid containing linking group, D. It should be understood that the linking group, D, may be a component of either the substrate or the non-ionic Lewis acid used to generate the present compositions, or constitute a remnant resulting from the reaction of such components. Preferably, D will be an oxygen-containing bridging moiety, more preferably the oxygen contributed by the hydroxyl group of an optionally but preferably dried silica support.
Examples of the foregoing mixtures or adducts of non-ionic, Lewis acids for use in the preparation of the functionalized supports of the invention include compositions corresponding to the formula: (-AIQ1-O-) Z (-AlArt-O-) z (ArtzAi2Q 6-r) where; Q'independently each occurrence is selected from hydrocarbyl, hydrocarbyloxy, or dihydrocarbylamido, of from 1 to 20 atoms other than hydrogen; Art is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30 carbon atoms; z is a number from 1 to 50, preferably from 1.5 to 40, more preferably from 2 to 30, and the moiety (-AIQ'-O-) is a cyclic or linear oligomer with a repeat unit of 2-30; z'is a number from 1 to 50, preferably from 1.5 to 40, more preferably from 2 to 30, and the moiety (-AlArf-O-) is a cyclic or linear oligomer with a repeat unit of 2-30; and z"is a number from 0 to 6, and the moiety (Artz Ai2Q'6 z) is either tri (fluoroarylaluminum), trialkylaluminum, a dialkylaluminumalkoxide, a dialkylaluminum (dialkylamide) or an adduct of tri (fluoroarylaluminum) with a sub- stoichiometric to super-stoichiometric amount of a trialkylaluminum.
The moieties (Ar'rAl2Q's-z) may exist as discrete entities or dynamic exchange products. That is, such moieties may be in the form of dimeric or other multiple centered products in combination with metal complexes and other organometallic compounds, including those resulting from partial or complete ligand exchange during the process used for their manufacture. Such more complex mixture of compounds may result from a combination of the foregoing compounds, which are Lewis acid adducts, with other compounds such as metallocenes or alumoxanes. Such exchange products may be fluxional in nature, the concentration thereof being dependant on time, temperature, solution concentration and the presence of other species able to stabilize the compounds, thereby preventing or slowing further ligand exchange. Preferably z"is from 1-5, more preferably from 1-3.
The foregoing class of non-ionic Lewis acids are also suitable for use in the present invention in the absence of aluminumoxy species. Such compounds accordingly are adducts corresponding to the formula: ArfzAl2Q'6-z where Au', Q'and z are as previously defined.
Preferred non-ionic Lewis acids for use herein are those of the foregoing formula wherein: Q'independently each occurrence is selected from C120 alkyl; Arf is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30 carbon atoms; z is a number greater than 0 and less than 6, and the moiety: A/zAi2Q16 z is an adduct of tri (fluoroarylaluminum) with from a sub-stoichiometric to a super-stoichiometric amount of a trialkylaluminum having from 1 to 20 carbons in each alkyl group.
Examples of specific non-ionic aluminum Lewis acid reagents for use herein, reagent ratios, and resulting products are illustrated as follows:
The foregoing mixtures of non-ionic Lewis acids and adducts may be readily prepared by combining the tri (fluoroaryl) aluminum compound and trialkylaluminum compound. The reaction may be performed in a solvent or diluent, or neat. Intimate contacting of the neat reactants can be effectively achieved by drying a solution of the two reactants to form a solid mixture, and thereafter optionally continuing such contacting, optionally at an elevated temperature. Preferred tri (fluoroaryl) aluminum compounds are tris (perfluoroaryl) aluminum compounds, most preferably tris (pentafluorophenyl) aluminum. The latter compound may be_ readily prepared by ligand exchange of a trifluoroarylboron compound and a trialkylaluminum compound, especially trimethyl aluminum.
The foregoing mixtures of non-ionic Lewis acids and adducts may be readily prepared by reaction of a fluoroarylborane, preferably tris (pentafluorophenyl) borane with greater than a stoichiometric amount of one or more trihydrocarbylaluminum, dihydrocarbylaluminumhydrocarbyloxides, or dihydrocarbylaluminum (dihydrocarbyl) amide compounds having up to 20 atoms other than hydrogen in each hydrocarbyl, hydrocarbyloxy or dihydrocarbylamide group, or a mixture thereof with one or more aluminoxy compounds (such as an alumoxane) substantially according to the conditions disclosed in USP 5,602,269.
Generally the various reagents which form the improved activators useful in the practice of the invention, such as the trifluoroarylboron compound and the trialkylaluminum compound are merely contacted in a hydrocarbon liquid at a temperature from 0 to 75° C, for a period from one minute to 10 days. Preferably, such contacting occurs for a period from 1 minute to 1 day, preferably at least 30 minutes to permit ligand exchange to occur to an extent sufficient to yield the advantages associated with the practice of the invention.
Preferred non-ionic Lewis acid reagents for use in the practice of the present invention are those wherein Ar'is pentafluorophenyl, and Ql is Cl. 4 alkyl. Most preferred non- ionic Lewis acids used according to the present invention are those wherein Ar is pentafluorophenyl, and Q'each occurrence is methyl, isopropyl or isobutyl.
Preferred support materials are finely particulated materials that remain solids under conditions of preparation and use and that do not interfere with subsequent polymerizations or other uses of the composition of the invention. Suitable support materials especially include particulated metal oxides, oxides of silicon or germanium, polymers, and mixtures thereof.
Examples include alumina, silica, aluminosilicates, clay, and particulated polyolefins.
Suitable volume average particle sizes of the support are from 1 to 1000 u. M, preferably from 10 to 100 RM. Most desired supports are silica, which is thoroughly dried, suitably by heating to 200 to 900 °C for from 10 minutes to 2 days. The silica may be treated prior to use to further reduce surface hydroxyl groups thereon, or to introduce more reactive functionality than the available hydroxyl functionality for subsequent reaction with the Lewis acid. Suitable treatments include reaction with a tri (Cl. lo alkyl) silylhalide, hexa (C110 alkyl) disilazane, tri (C110
alkyl) aluminum, or similar reactive compound, preferably by contacting the support and a hydrocarbon solution of the reactive compound.
In a preferred embodiment, silica is reacted with a tri (alkyl) aluminum, preferably a Ci- lotri (alkyl) aluminum, most preferably, trimethylaluminum, triethylaluminum, triisopropylaluminum or triisobutylaluminum, to form a modified support. The amount of the trialkylaluminum is chosen to pacify 1-99% of the reactive surface species, more preferably 50-90%, as determined by titration with EtsAI. Titration with Et3AI is defined as the maximum amount of aluminum that chemically reacts with the particulated solid support material and which cannot be removed by washing with an inert hydrocarbon or aromatic solvent. Thereafter this modified support is contacted with the above cocatalyst composition, or a solution thereof, in a quantity sufficient to provide an functionalized catalyst support for olefin polymerization according to the invention. In the alternative, the modified support may be contacted with a non-ionic Lewis acid and, e. g., a trihydrocarbyl aluminum, dihydrocarbylaluminum hydrocarbyloxide or dihydrocarbylaluminum (dihydrocarbyl) amide, to form the cocatalyst reactant in situ.
Particulated polymeric supports, while less preferred than inorganic oxide supports, may be utilizied. Such particulated polymeric supports are preferably are also functionalized to provide hydroxyl, carboxylic acid or sulfonic acid reactive groups. The resulting substrate material formed by reaction with the non-ionic Lewis acid will accordingly bear the corresponding oxy-, carboxy-or sulfoxy-linking group, D.
The non-ionic Lewis acid and particulated support material may be combined and reacted in any aliphatic, alicyclic or aromatic liquid diluent, or solvent, or mixture thereof,.
Preferred diluents or solvents are C410 hydrocarbons and mixtures thereof, including hexane, heptane, cyclohexane, and mixed fractions such as Isopar E, available from Exxon Chemicals Inc. Preferred contacting times are at least one hour, preferably at least 90 minutes, at a temperature from 0 to 75 °C, preferably from 20 to 50 °C, most preferably from 25 to 35°C. Desirably, the contacting is also done prior to addition of a metal complex catalyst, such as a metallocene, to the mixture or either component separately, in order to avoid formation of further derivatives and multiple metal exchange products having reduced catalytic effectiveness. After contacting of the support and Lewis acid, the reaction mixture may be purified to remove byproducts, especially any trialkylboron compounds by any suitable technique. Alternatively, but less desirably, a Group 3-10 metal complex catalyst may first be combined with the reaction mixture prior to removing byproducts.
Suitable techniques for removing byproducts from the reaction mixture include degassing, optionally at reduced pressures, distillation, solvent exchange, solvent extraction, extraction with a volatile agent, and combinations of the foregoing techniques, all of which are conducted according to conventional procedures. Preferably the quantity of residual byproduct is less than 10 weight percent, more preferably less than 1.0 weight percent, most
preferably less than 0.1 weight percent, based on the weight of the functionalized catalyst support.
Highly preferred compounds according to the invention are those comprising less than one tri (alkyl) aluminum moeity per tri (fluoroaryl) aluminum moiety. Most highly desired adducts are those corresponding to the formula: ArfaAl2Q'2 and A/5AI2Q1. Such compositions possess extremely high catalyst activation properties.
The support material and cocatalyst derived from the nonionic Lewis acid are preferably reacted to chemically attach a plurality of the functional groups to the surface of the support. The reaction is also preferably conducted prior to formation of the active polymerization catalyst by addition of a metal complex.
Active supported catalyst compositions are prepared by adding a metal complex or a mixture of metal complexes to be activated to the surface of the above disclosed functionalized catalyst support. The molar ratio of metal complex to activator composition is preferably from 0.1: 1 to 3: 1, more preferably from 0.2: 1 to 2: 1, most preferably from 0.25: 1 to 1: 1, based on the metal content of the complex and aluminum content of the support due to non-ionic Lewis acid. In most polymerization reactions the molar ratio of metal complex: polymerizable compound employed is from 10-12: 1 to 10-1: 1, more preferably from 10'12: 1 to 10-5: 1. Any suitable means for incorporating the metal complex onto the surface of a support (including the interstices thereof) may be used, including dispersing or dissolving the same in a liquid and contacting the mixture or solution with the support by slurrying, impregnating, spraying, or coating and thereafter removing the liquid, or by combining the metal complex and support material in dry or paste form and intimately contacting the mixture, thereafter forming a dried, particulated product.
Suitable metal complexes for use in combination with the foregoing functionalized catalyst supports include any complex of a metal of Groups 3-10 of the Periodic Table of the Elements capable of being activated to polymerize addition polymerizable compounds, especially olefins by the present activators.
Suitable complexes include derivatives of Group 3,4, or Lanthanide metals containing from 1 to 3 s-bonded anionic or neutral ligand groups, which may be cyclic or non- cyclic delocalized 7r-bonded anionic ligand groups. Exemplary of such x-bonded anionic ligand groups are conjugated or nonconjugated, cyclic or non-cyclic dienyl groups, allyl groups, boratabenzene groups, and arene groups. By the term"c-bonded"is meant that the ligand group is bonded to the transition metal by a sharing of electrons from a partially delocalized s-bond.
Each atom in the delocalized s-bonded group may independently be substituted with a radical selected from the group consisting of hydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl-substituted metalloid radicals wherein the metalloid is selected
from Group 14 of the Periodic Table of the Elements, and such hydrocarbyl-or hydrocarbyl- substituted metalloid radicals further substituted with a Group 15 or 16 hetero atom containing moiety. Included within the term"hydrocarbyl"are C1 20 straight, branched and cyclic alkyl radicals, Cl_20 aromatic radicals, C7 20 alkyl-substituted aromatic radicals, and C7 20 aryl- substituted alkyl radicals. In addition two or more such radicals may together form a fused ring system, including partially or fully hydrogenated fused ring systems, or they may form a metallocycle with the metal. Suitable hydrocarbyl-substituted organometalloid radicals include mono-, di-and tri-substituted organometalloid radicals of Group 14 elements wherein each of the hydrocarbyl groups contains from 1 to 20 carbon atoms. Examples of suitable hydrocarbyl-substituted organometalloid radicals include trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyidiethylsilyl, triphenylgermyl, and trimethylgermyl groups. Examples of Group 15 or 16 hetero atom containing moieties include amine, phosphine, ether or thioether moieties or divalent derivatives thereof, e. g. amide, phosphide, ether or thioether groups bonded to the transition metal or Lanthanide metal, and bonded to the hydrocarbyl group or to the hydrocarbyl-substituted metalloid containing group.
Examples of suitable anionic, delocalized s-bonded groups include cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl, dihydroanthracenyl, hexahydroanthracenyl, decahydroanthracenyl groups, and boratabenzene groups, as well as C110 hydrocarbyl-substituted or C110 hydrocarbyl- substituted silyl substituted derivatives thereof. Preferred anionic delocalized in-bonde groups are cyclopentadienyl, pentamethylcyclopentadienyl, tetramethylcyclopentadienyl, tetramethylsilylcyclo-pentadienyl, indenyl, 2,3-dimethylindenyl, fluorenyl, 2-methylindenyl, 2- methyl-4-phenylindenyl, tetrahydrofluorenyl, octahydrofluorenyl, and tetrahydroindenyl.
Suitable metal complexes include Group 10 diimine derivatives corresponding to the formula: wherein M* is Ni (II) or Pd (II); X'is halo, hydrocarbyl, or hydrocarbyloxy; Ar* is an aryl group, especially 2,6-diisopropylphenyl or aniline group; CT-CT is 1,2-ethanediyl, 2,3-butanediyl, or form a fused ring system wherein the two T groups together are a 1,8-naphthanediyl group; and A-is the anionic component of the foregoing charge separated activators.
Similar complexes to the foregoing are also disclosed by M. Brookhart, et al., in J Am. Chem. Soc., 118,267-268 (1996) and J. Am. Chem. Soc., 117,6414-6415 (1995), as being active polymerization catalysts especially for polymerization of a-olefins, either alone or
in combination with polar comonomers such as vinyl chloride, alkyl acrylates and alkyl methacrylates.
The boratabenzenes are anionic ligands which are boron containing analogues to benzene. They are previously known in the art having been described by G. Herberich, et al., in Organometallics, 1995,14,1,471-480. Preferred boratabenzenes correspond to the formula: wherein R"is selected from the group consisting of hydrocarbyl, silyl, or germyl, said R"having up to 20 non-hydrogen atoms. In complexes involving divalent derivatives of such delocalized 7r-bonded groups one atom thereof is bonded by means of a covalent bond or a covalently bonded divalent group to another atom of the complex thereby forming a bridged system.
More preferred are metal complexes corresponding to the formula: LIMXmX'nX"p, or a dimer thereof wherein: L is an anionic, de) oca) ized, n-bonded group that is bound to M, containing up to 50 nonhydrogen atoms, optionally two L groups may be joined together through one or more substituents thereby forming a bridged structure, and further optionally one L may be bound to X through one or more substituents of L; M is a metal of Group 4 of the Periodic Table of the Elements in the +2, +3 or +4 formal oxidation state; X is an optional, divalent substituent of up to 50 non-hydrogen atoms that together with L forms a metallocycle with M; X'is an optional neutral Lewis base having up to 20 non-hydrogen atoms; X"each occurrence is a monovalent, anionic moiety having up to 40 non-hydrogen atoms, optionally, two X"groups may be covalently bound together forming a divalent dianionic moiety having both valences bound to M, or form a neutral, conjugated or nonconjugated diene that is m-bonded to M (whereupon M is in the +2 oxidation state), or further optionally one or more X"and one or more X'groups may be bonded together thereby forming a moiety that is both covalently bound to M and coordinated thereto by means of Lewis base functionality; I is 1 or 2; m is 0 or 1; n is a number from 0 to 3;
p is an integer from 0 to 3; and the sum, I+m+p, is equal to the formal oxidation state of M.
Such preferred complexes include those containing either one or two L groups. The latter complexes include those containing a bridging group linking the two L groups.
Preferred bridging groups are those corresponding to the formula (ER*2) X wherein E is silicon or carbon, R* independently each occurrence is hydrogen or a group selected from silyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, said R* having up to 30 carbon or silicon atoms, and x is 1 to 8. Preferably, R* independently each occurrence is methyl, benzyl, tert-butyl or phenyl.
Examples of the foregoing bis (L) containing complexes are compounds corresponding to the formula: wherein: M is titanium, zirconium or hafnium, preferably zirconium or hafnium, in the +2 or +4 formal oxidation state; R3 in each occurrence independently is selected from the group consisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof, said R3 having up to 20 non-hydrogen atoms, or adjacent R3 groups together form a divalent derivative (that is, a hydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fused ring system, and X"independently each occurrence is an anionic ligand group of up to 40 nonhydrogen atoms, or two X"groups together form a divalent anionic ligand group of up to 40 nonhydrogen atoms or together are a conjugated diene having from 4 to 30 non-hydrogen atoms forming a z-complex with M, whereupon M is in the +2 formal oxidation state, and R*, E and x are as previously defined.
The foregoing metal complexes are especially suited for the preparation of polymers having stereoregular molecular structure. In such capacity it is preferred that the complex possess C2 symmetry or possess a chiral, stereorigid structure. Examples of the first type are compounds possessing different delocalized 7C-bonded systems, such as one cyclopentadienyl group and one fluorenyl group. Similar systems based on Ti (IV) or Zr (IV) were disclosed for preparation of syndiotactic olefin polymers in Ewen, et al., J. Am. Chem. Soc. 110,6255-6256 (1980). Examples of chiral structures include bis-indenyl complexes. Similar systems based
on Ti (IV) or Zr (IV) were disclosed for preparation of isotactic olefin polymers in Wild et al., J.
Oraanomet. Chem, 232,233-47, (1982).
Exemplary bridged ligands containing two n-bonded groups are: (dimethylsilyl-bis- cyclopentadienyl), (dimethylsilyl-bis-methylcyclopentadienyl), (dimethylsilyl-bis- ethylcyclopentadienyl, (dimethylsilyl-bis-t-butylcyclopentadienyl), (dimethylsilyl-bis- tetramethylcyclopentadienyl), (dimethylsilyl-bis-indenyl), (dimethylsilyl-bis-tetrahydroindenyl), (dimethylsilyl-bis-fluorenyl), (dimethylsilyl-bis-tetrahydrofluorenyl), (dimethylsilyl-bis-2-methyl- 4-phenylindenyl), (dimethylsilyl-bis-2-methylindenyl), (dimethylsilyl-cyclopentadienyl- fluorenyl), (1,1,2,2-tetramethyl-1, 2-disilyl-bis-cyclopentadienyl), (1,2- bis (cyclopentadienyl) ethane, and (isopropylidene-cyclopentadienyl-fluorenyl).
Preferred X"groups are selected from hydride, hydrocarbyl, silyl, germyl, halohydrocarbyl, halosilyl, silylhydrocarbyl and aminohydrocarbyl groups, or two X"groups together form a divalent derivative of a conjugated diene or else together they form a neutral, 7r-bonded, conjugated diene. Most preferred X"groups are C1 20 hydrocarbyl groups.
A further class of metal complexes utilized in the present invention correspond to the formula: LIMXmX'nX"p, or a dimer thereof wherein: L is an anionic, delocalized, z-bonded group that is bound to M, containing up to 50 nonhydrogen atoms; M is a metal of Group 4 of the Periodic Table of the Elements in the +2, +3 or +4 formal oxidation state; X is a divalent substituent of up to 50 non-hydrogen atoms that together with L forms a metallocycle with M; X'is an optional neutral Lewis base ligand having up to 20 non-hydrogen atoms; X"each occurrence is a monovalent, anionic moiety having up to 20 non-hydrogen atoms, optionally two X"groups together may form a divalent anionic moiety having both valences bound to M or a neutral C5 30 conjugated diene, and further optionally X'and X" may be bonded together thereby forming a moiety that is both covalently bound to M and coordinated thereto by means of Lewis base functionality; I is 1 or 2; m is 1; n is a number from 0 to 3; p is an integer from 1 to 2; and the sum, I+m+p, is equal to the formal oxidation state of M.
Preferred divalent X substituents preferably include groups containing up to 30 nonhydrogen atoms comprising at least one atom that is oxygen, sulfur, boron or a member
of Group 14 of the Periodic Table of the Elements directly attached to the delocalized 7r- bonded group, and a different atom, selected from the group consisting of nitrogen, phosphorus, oxygen or sulfur that is covalently bonded to M.
A preferred class of such Group 4 metal coordination complexes used according to the present invention correspond to the formula: wherein: M is titanium or zirconium in the +2 or +4 formal oxidation state; R3 in each occurrence independently is selected from the group consisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halo and combinations thereof, said R3 having up to 20 non-hydrogen atoms, or adjacent R3 groups together form a divalent derivative (that is, a hydrocarbadiyl, siladiyl or germadiyl group) thereby forming a fused ring system, each X"is a halo, hydrocarbyl, hydrocarbyloxy or silyl group, said group having up to 20 nonhydrogen atoms, or two X"groups together form a C5 30 conjugated diene; Y is-O-,-S-,-NR*-,-PR*-; and <BR> <BR> Z is SiR*2, CR*2, SiR*2SiR*2, CR*2CR*2, CR*=CR*, CR*2SiR*2, or GeR*2, wherein:<BR> R* is as previously defined.
Illustrative Group 4 metal complexes that may be employed in the practice of the present invention include: cyclopentadienyltitaniumtrimethyl, cyclopentadienyltitaniumtriethyl, cyclopentadienyltitaniumtriisopropyl, cyclopentadienyltitaniumtriphenyl, cyclopentadienyltitaniumtribenzyl, cyclopentadienyltitanium-2, 4-pentadienyl, cyclopentadienyltitaniumdimethylmethoxide, cyclopentadienyltitaniumdimethylchloride, pentamethylcyclopentadienyltitaniumtrimethyl, indenyltitaniumtrimethyl, indenyltitaniumtriethyl, indenyltitaniumtripropyl, indenyltitaniumtriphenyl, tetrahydroindenyltitaniumtribenzyl,
pentamethylcyclopentadienyltitaniumtriisopropyl, pentamethylcyclopentadienyltitaniumtribenzyl, pentamethylcyclopentadienyltitaniumdimethylmethoxide, pentamethylcyclopentadienyltitaniumdimethylchloride, (n5-2, 4-dimethyl-1, 3-pentadienyl) titaniumtrimethyl, octahydrofluorenyltitaniumtrimethyl, tetrahydroindenyltitaniumtrimethyl, tetrahydrofluorenyltitaniumtrimethyl, (1,1-dimethyl-2,3, 4,9,1 0-il-1,4, 5,6,7,8-hexahydronaphthalenyl) titaniumtrimethyl, (1,1,2,3-tetramethyl-2,3, 4,9,1 0-il-1,4, 5,6,7,8-hexahydronaphthalenyl) titaniumtrimethyl, (tert-butylamido) (tetramethyl-Tl5-cyclopentadienyl) dimethylsilanetitanium dichloride, (tert-butylamido) (tetramethyl-rl5-cyclopentadienyl) dimethylsilanetitanium dimethyl, (tert-butylamido) (tetramethyl-r 5-cyclopentadienyl)-1, 2-ethanediyltitanium dimethyl, (tert-butylamido) (hexamethyl-rl5-indenyl) dimethylsilanetitanium dimethyl, (tert-butylamido) (tetramethyl-n5-cyclopentadienyl) dimethylsilane titanium (III) 2- (dimethylamino) benzyl; (tert-butylamido) (tetramethyl-n5-cyclopentadienyl) dimethylsilanetitanium (III) allyl, (tert-butylamido) (tetramethyl-n5-cyclopentadienyl) dimethylsilanetitanium (II) 1,4- diphenyl-1,3- butadiene, (tert-butylamido) (2-methylindenyl) dimethylsilanetitanium (II) (tert-butylamido) (2-methylindenyl) dimethylsilanetitanium (IV) 1, 3-butadiene, (tert-butylamido) (2,3-dimethylindenyl) dimethylsilanetitanium (II) 1,4- diphenyl-1,3-butadiene, (tert-butylamido) (2,3-dimethylindenyl) dimethylsilanetitanium (IV) 1,3-butadiene, (tert-butylamido) (2,3-dimethylindenyl) dimethylsilanetitanium (II) 1,3-pentadiene, (tert-butylamido) (2-methylindenyl) dimethylsilanetitanium (II) 1,3-pentadiene, (tert-butylamido) (2-methylindenyl) dimethylsilanetitanium (IV) dimethyl, (tert-butylamido) (2-methyl-4-phenylindenyl) dimethylsilanetitanium (II) 1,4-diphenyl- 1,3- butadiene, (tert-butylamido) (tetramethyl-rl5-cyclopentadienyl) dimethylsilanetitanium (IV) 1,3- butadiene, (tert-butylamido) (tetramethyl-n5-cyclopentadienyl) dimethylsilanetitanium (II) 1,4- dibenzyl-1,3-butadiene, (tert-butylamido) (tetramethyl-rl5-cyclopentadienyl) dimethylsilanetitanium (II) 2,4- hexadiene, (tert-butylamido) (tetramethyl-Tl5-cyclopentadienyl) dimethylsilanetitanium (II) 3-methyl 1,3- pentadiene, (tert-butylamido) (2,4-dimethyl-1, 3-pentadien-2-yl) dimethylsilanetitaniumdimethyl,
(tert-butylamido) (1,1-dimethyl-2,3, 4,9,10-n-1,4, 5,6,7,8-hexahydronaphthalen-4- yl) dimethylsilanetitaniumdimethyl, (tert-butylamido) (1,1,2,3-tetramethyl-2,3, 4,9,1 0-il-1,4, 5,6,7,8-hexahydronaphthalen- 4- yl) dimethylsilanetitaniumdimethyl, (tert-butylamido) (tetramethylcyclopentadienyl) dimethylsilanetitanium 1,3-pentadiene, (tert-butylamido) (3- (N-pyrrolidinyl) inden-1-yl) dimethylsilanetitanium1,3-pentadiene, (tert-butylamido) (2-methyl-s-indacen-1-yl) dimethylsilanetitanium 1,3-pentadiene, and (tert-butylamido) (3,4-cyclopenta (phenanthren-2-yl) dimethylsilanetitanium 1,4- diphenyl-1,3-butadiene.
Bis (L) containing complexes including bridged complexes suitable for use in the present invention include: biscyclopentadienylzirconiumdimethyl, biscyclopentadienyltitaniumdiethyl, biscyclopentadienyltitaniumdiisopropyl, biscyclopentadienyltitaniumdiphenyl, biscyclopentadienylzirconium dibenzyl, biscyclopentadienyltitanium-2, 4-pentadienyl, biscyclopentadienyltitaniummethylmethoxide, biscyclopentadienyltitaniummethylchloride, bispentamethylcyclopentadienyltitaniumdimethyl, bisindenyltitaniumdimethyl, indenylfluorenyltitaniumdiethyl, bisindenyltitaniummethyl (2-(dimethylamino) benzyl), bisindenyltitanium methyltrimethylsilyl, bistetrahydroindenyltitanium methyltrimethylsilyl, bispentamethylcyclopentadienyltitaniumdiisopropyl, bispentamethylcyclopentadienyltitaniumdibenzyl, bispentamethylcyclopentadienyltitaniummethylmethoxide, bispentamethylcyclopentadienyltitaniummethylchloride, (dimethylsilyl-bis-cyclopentadienyl) zirconiumdimethyl, (dimethylsilyl-bis-pentamethylcyclopentadienyl) titanium-2,4-pentadienyl, (dimethylsilyl-bis-t-butylcyclopentadienyl) zirconiumdichloride, (methylene-bis-pentamethylcyclopentadienyl) titanium (III) 2- (dimethylamino) benzyl, (dimethylsilyl-bis-indenyl) zirconiumdichloride, (dimethylsilyl-bis-2-methylindenyl) zirconiumdimethyl, (dimethylsilyl-bis-2-methyl-4-phenylindenyl) zirconiumdimethyl, (dimethylsilyl-bis-2-methylindenyl) zirconium-1, 4-diphenyl-1, 3-butadiene, (dimethylsilyl-bis-2-methyl-4-phenylindenyl) zirconium (II) 1,4-diphenyl-1,3-butadiene, (dimethylsilyl-bis-tetrahydroindenyl) zirconium (ll) 1,4-diphenyl-1,3-butadiene,
(dimethylsilyl-bis-fluorenyl) zirconiumdichloride, (dimethylsilyl-bis-tetrahydrofluorenyl) zirconiumdi (trimethylsilyl), (isopropylidene) (cyclopentadienyl) (fluorenyl) zirconiumdibenzyl, and (dimethylsilylpentamethylcyclopentadienylfluorenyl) zirconiumdimethyl.
Suitable polymerizable monomers include ethylenically unsaturated monomers, acetylenic compounds, conjugated or non-conjugated dienes, and polyenes. Preferred monomers include olefins, for examples alpha-olefins having from 2 to 20,000, preferably from 2 to 20, more preferably from 2 to 8 carbon atoms and combinations of two or more of such alpha-olefins. Particularly suitable alpha-olefins include, for example, ethylene, propylene, 1-butene, 1-pentene, 4-methylpentene-1,1-hexene, 1-heptene, 1-octene, 1- nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, or combinations thereof, as well as long chain vinyl terminated oligomeric or polymeric reaction products formed during the polymerization, and Cil-su a-olefins specifically added to the reaction mixture in order to produce relatively long chain branches in the resulting polymers.
Preferably, the alpha-olefins are ethylene, propene, 1-butene, 4-methyl-pentene-1,1-hexene, 1-octene, and combinations of ethylene and/or propene with one or more of such other alpha- olefins. Other preferred monomers include styrene, halo-or alkyl substituted styrenes, tetrafluoroethylene, vinylcyclobutene, 1,4-hexadiene, dicyclopentadiene, ethylidene norbornene, and 1,7-octadiene. Mixtures of the above-mentioned monomers may also be employed.
In general, the polymerization may be accomplished at conditions well known in the prior art for Ziegler-Natta or Kaminsky-Sinn type polymerization reactions conducted under slurry or gas phase polymerization conditions. Preferred polymerization temperatures are from 0-250°C. Preferred polymerization pressures are from atmospheric to 3000 atmospheres.
Molecular weight control agents can be used in combination with the present cocatalysts. Examples of such molecular weight control agents include hydrogen, silanes or other known chain transfer agents.
Supported catalysts for use in slurry polymerization may be prepared and used according to previously known techniques. Generally such catalysts are prepared by the same techniques as are employed for making supported catalysts used in gas phase polymerizations. Slurry polymerization conditions generally encompass polymerization of a C2-20olefin, diolefin, cycloolefin, or mixture thereof in an aliphatic solvent at a temperature below that at which the polymer is readily soluble in the presence of a supported catalyst.
Slurry phase processes particularly suited for the polymerization ofC2. 6olef ins, especially the homopolymerization and copolymerization of ethylene and propylene, and the copolymerization of ethylene with C3-8 a-olefins such as, for example, 1-butene, 1-hexene, 4-
methyl-1-pentene and 1-octene are well known in the art. Such processes are used commercially on a large scale for the manufacture of high density polyethylene (HDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE) and polypropylene, especially isotactic polypropylene.
Fabricated articles made from the novel olefin polymers may be prepared using all of the conventional polyolefin processing techniques. Useful articles include films (e. g., cast, blown and extrusion coated), fibers (e. g., staple fibers (include-nu use of a novel olefin polymer disclosed herein as at least one component comprising at least a portion of the fiber's surface), spunbond fibers or melt blown fibers (using, e. g., systems as disclosed in U. S. Pat.
No. 4,430,563, U. S. Pat. No. 4,663,220, U. S. Pat. No. 4,668,566, or U. S. Pat. No. 4,322,027, all of which are incorporated herein by reference), and gel spun fibers (e. g., the system disclosed in U. S. Pat. No. 4,413,110, incorporated herein by reference)), both woven and nonwoven fabrics (e. g., spunlaced fabrics disclosed in U. S. Pat. No. 3,485,706, incorporated herein by reference) or structures made from such fibers (including, e. g., blends of these fibers with other fibers, e. g., PET or cotton) and molded articles (e. g., made using an injection molding process, a blow molding process or a rotomolding process). The new polymers described herein are also useful for wire and cable coating operations, as well as in sheet extrusion for vacuum forming operations.
Useful compositions are also suitably prepared comprising the ethylene polymer of the present invention and at least one other natural or synthetic polymer. In this embodiment of this invention, the ethylene polymer is dry blended or melt blended with another polymer, and then optionally molded, blown, extruded, or cast into a desired article. Exemplary other polymers include any polymer with which the ethylene polymer is compatible, and include both olefin and non-olefin polymers, grafted and ungrafted. The ethylene polymer can also be blended with another ethylene polymer of the invention, with a substantially linear ethylene polymer (as disclosed in US 5,272,236 or US 5,278,272, incorporated herein by reference), a conventional heterogeneously branched or homogeneously branched linear ethylene polymer, a non-olefin polymer, any of which can be grafted or ungrafted, or any combination of these polymers. Examples of such polymers include high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ultra low density polyethylene (ULDPE), polypropylene, ethylene-propylene copolymers, ethylene-styrene interpolymers, polyisobutylene, ethylene-propylene-diene monomer (EPDM), polystyrene, acrylonitrile- butadiene-styrene (ABS) copolymer, ethylene/acrylic acid (EAA), ethylene/vinyl acetate (EVA), ethylene/vinyl alcohol (EVOH), polymers of ethylene and carbon monoxide (ECO, including those described in U. S. Pat. No. 4,916,208), or ethylene, propylene and carbon monoxide (EPCO) polymers, or ethylene, carbon monoxide and acrylic acid (ECOAA) polymers, and the like. Representative of the non-olefin polymers are the polyesters, polyvi-
nyl chloride (PVC), epoxies, polyurethanes, polycarbonates, polyamides, and the like. These blending polymers are characterized by a compatibility with the ethylene polymer such that the melt blend does not separate into separate polymer phases. If more than one of these polymers is blended with one or more ethylene polymers, then all usually exhibit sufficient compatibility with each other, one-to-one or at least in combination with one or more other polymers, such that the polymeric components do not separate into separate polymer phases which could lead to extrusion processing difficulties, such as extrudate surging, film band- effects, etc.
There are many types of molding operations which can be used to form useful fabricated articles or parts from the ethylene polymers and polymer blends disclosed herein, including various injection molding processes (e. g., that described in Modern Plastics Encyclopedia/89, Mid October 19881ssue, Volume 65, Number 11, pp. 264-268,"Introduction to Injection Molding"and on pp. 270-271,"Injection Molding Thermoplastics"and blow molding processes (e. g., that described in Modern Plastics Encyclopedia/89, Mid October 1988 Issue, Volume 65, Number 11, pp. 217-218,"Extrusion-Blow Molding"and profile extrusion. Some of the fabricated articles include automotive bumpers, facia, wheel covers and grilles; blow-molded bottles; household and personal articles, including, for example, freezer containers; drinking cups, ice cream tubs, deli containers and lids; and toys.
It is understood that the present invention is operable in the absence of any component which has not been specifically disclosed. The following examples are provided in order to further illustrate the invention and are not to be construed as limiting. Unless stated to the contrary, all parts and percentages are expressed on a weight basis. Where stated the term"room temperature"refers to a temperature from 20 to 25 °C, the term "overnight"refers to a time from 12 to 18 hours, and the term"mixed alkanes"refers to the aliphatic solvent, IsoparTM E, available from Exxon Chemicals Inc.
EXAMPLES Tris (perfluorophenyl) borane (FAB) was obtained as a solid from Boulder Scientific Inc. and used without further purification. Modified methalumoxane (MMAO-3A) in heptane was purchased from Akzo-Nobel. MAO and trimethylaluminum (TMA) both in toluene were purchased from Aldrich Chemical Co. Tris (perfluorophenyl) aluminum (FAAL) in toluene was prepared by exchange reaction between tris (pertluorophenyl) borane and trimethylaluminum.
DavisonTM 948 silica was purchased from Grace-Davison Incorporated. All solvents were purified using the technique disclosed by Pangborn et al, Oraanometallics, 1996,15,1518- 1520. All compounds and solutions were handled under an inert atmosphere (dry box).
Continuous Slurry Polymerization Examples In the case of Examples 1 and 2, the supported catalyst was prepared as follows. 50 g of a Davison 948 silica, which had been dehydrated by heating in air for 3 hours at 250°C, was slurried in toluene (500 mL). 50 mL Of a 1 M solution of triethylaluminum in hexane was added and the mixture agitated for 15 minutes. In a separate vessel a solution of tris (pentafluorophenyl) borane (12.8 g, 25 mmol) in toluene (300 mL) was treated with 25 mL of a 1 M solution of triethylaluminum in hexane. The mixture was agitated for 10 minutes and then added to the slurry of the treated silica. The mixture was agitated three hours and then the supernatant liquid was decanted from the solid phase. Fresh toluene (500 mL) was added, the mixture was briefly agitated, and the supernatant was decanted and replace with 500 mL hexanes. 12.5 mL Of a 0.2M solution of (C5Me4SiMe2NtBu) Ti (l14-1,3-pentadiene) in isoparTM E was added. The mixture was agitated four hours, filtered on a fritted funnel, and the green solid was washed with toluene (200 mL) and then hexane (300 mL) and then dried in vacuo.
Example 1: Unless otherwise indicated, all feed streams were fed through dip pipe legs in the liquid phase to allow intimate mixing. Ethylene was introduced into a 10L reactor at the rate of 780 grams/hour, hydrogen was introduced at the rate of 1.2 N liter/hour via hexane, which was in turn introduced at a flow of 2800 grams/hour. The reactor level was maintained at 67%. The reactor contents were agitated at 1000 rpm using a Lightnin A310 mixing blade.
The reactor temperature was maintained at 70°C. The heterogeneous catalyst composition was added at a rate selected to yield a reactor pressure of 12 bar. Butene comonomer was introduced at the rate of 9.26 grams/hour. The reactor contents were continuously transferred to a flashtank operated at a pressure of 1.3 bar and a temperature of 75°C to produce a dry powder. The powder was blended with 2000 ppm Irganox B 225 and subsequently fed into a Goettfert 20 mm (20 UD) lab extruder. The catalyst efficiency was 375500 g polyethylene/g titanium.
The inventive polymer was characterized as having a density of 0.944 g/cm3, a melt index of 2.5 g/10 minutes, and a percent swell of 225 percent. The inventive polymer exhibited a log [zero shear viscosity] which is at least 5 percent greater than that of a linear ethylene polymer of the same Mw and density which linear polymer has a percent swell of less than 175 percent. The inventive polymer further exhibited a melt strength which is at least 30 percent greater than that of a linear ethylene polymer of the same i2 and density which linear polymer has a percent swell of less than 175 percent.
Example 2 The procedure of Example 1 was substantially repeated. The inventive polymer was characterized as having a density of 0.935 g/cm3, a melt index of 0.39 g/10 minutes, and a percent swell of 196 percent.
Comparative Example A The catalyst was prepared as described in Example 12 of WO 98/27119. The catalyst efficiency was 697000 grams polyethylene/gram titanium. The procedure of Example 1 is substantially repeated. However, the reactor is operated at 80°C, the ethylene flow rate is 810 g/h, the hydrogen flow rate is 0.98 N liter/hour in a hexane flow of 2800 g/h. In order to maintain a constant pressure of 12 bar, catalyst is added. 12 g/h butene is added in order to obtain a copolymer. The polymer has a density of 0.953 g/cm3, an 12 of 1.5 g/10 minutes, and a percent swell of 145 percent.