Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Co-catalysts for metallocene complexes in olefin polymerization reactions
H2058 Co-catalysts for metallocene complexes in olefin polymerization reactions
Patent Drawings:

Inventor: Brandolini, et al.
Date Issued: January 7, 2003
Application: 09/664,137
Filed: September 18, 2000
Inventors: Brandolini; A. J. (Somerville, NJ)
Kissin; Yury Viktorovich (East Brunswick, NJ)
Mink; Robert Ivan (Warren, NJ)
Nowlin; Thomas E. (Princeton Junction, NJ)
Assignee: Mobil Oil Corporation (Fairfax, VA)
Primary Examiner: Carone; Michael J.
Assistant Examiner: Baker; Aileen J.
Attorney Or Agent: Reidy; Joseph F.Prodnuk; Stephen D.
U.S. Class: 502/115
Field Of Search:
International Class:
U.S Patent Documents:
Foreign Patent Documents:
Other References:









Abstract: The present invention provides cocatalysts for activating metallocene complexes in olefin polymerization reactions, and metallocene catalyst systems using the cocatalysts. The cocatalysts of the present invention include: (a) a halo-organoaluminum compound of the formula Al.sub.n R.sub.m X.sub.3n-m, where Al is aluminum, each R is independently a C.sub.l to C.sub.4 alkyl group, X is a halide, n is 1 or 2, and m is determined by the valency of Al; and (b) a dialkylmagnesium compound of the formula MgR'.sub.2, where Mg is magnesium and R' is a C.sub.2 to C.sub.6 alkyl group. The components (a) and (b) are used in amounts such that the molar ratio of Al:Mg is at least 2, preferably from 2:1 to 5:1.
Claim: We claim:

1. A catalyst composition comprising: (a) a metallocene; and (b) a cocatalyst comprising: (i) a halo-organoaluminum compound of the formula

2. The catalyst composition of claim 1, wherein each R is independently ethyl or methyl.

3. The catalyst composition of claim 1, wherein X is chloride or fluoride.

4. The catalyst composition of claim 1, wherein R' is butyl or hexyl.

5. The catalyst composition of claim 1, wherein the halo-organoaluminum compound is selected from the group consisting of AlEt.sub.2 Cl, AlMe.sub.2 Cl, Al.sub.2 Et.sub.3 Cl.sub.3 and AlEt.sub.2 F, where Me is methyl and Et is ethyl.

6. The catalyst composition of claim 1, wherein the halo-organoaluminum compound is AlEt.sub.2 Cl, where Et is ethyl.

7. The catalyst composition of claim 1, wherein the dialkylmagnesium compound is MgBu.sub.2, where Bu is butyl.

8. The catalyst composition of claim 1, wherein the halo-organoaluminum compound and the dialkylmagnesium compound are present in amounts such that the molar ratio of Al to Mg is at least 2.

9. The catalyst composition of claim 1, wherein the halo-organoaluminum compound and the dialkylmagnesium compound are present in amounts such that the molar ratio of Al to Mg is from 2:1 to 5:1.

10. The catalyst composition of claim 1, wherein the metallocene catalyst is a titanocene, zirconocene or a hafnocene.

11. The catalyst composition of claim 1, further comprising a support.

12. The catalyst composition of claim 11, wherein the support is silica.

13. A supported metallocene catalyst comprising: (a) a support; (b) a titanocene, zirconocene or hafnocene; and (c) a cocatalyst comprising: (i) a halo-organoaluminum compound of the formula

14. The supported metallocene catalyst of claim 13, wherein the halo-organoaluminum compound is selected from the group consisting of AlEt.sub.2 Cl, AlMe.sub.2 Cl, Al.sub.2 Et.sub.3 Cl.sub.3 and AlEt.sub.2 F, where Me is methyl and Et is ethyl.

15. The supported metallocene catalyst of claim 13, wherein the halo-organoaluminum compound and the dialkylmagnesium compound are present in amounts such that the molar ratio of Al to Mg is from 2:1 to 5:1.

16. The supported metallocene catalyst of claim 13, wherein the support is silica.

17. A method of forming a polyolefin catalyst, the method comprising: (a) providing a supported metallocene catalyst comprising a support, a metallocene and an activator, the activator comprising: (i) a halo-organoaluminum compound of theformula

18. The method of claim 17, wherein the monomer is ethylene.

19. The method of claim 17, wherein the monomer is a mixture of ethylene and at least one C.sub.3 -C.sub.20 alpha olefin.

20. The method of claim 17, wherein the monomer is a mixture of ethylene and 1 -hexene.
Description: FIELD OF THE INVENTION

The present invention is directed generally to catalyst systems for polymerizing olefins. More specifically, the present invention provides novel cocatalysts or activators suitable for activating metallocene catalysts for olefin polymerization,supported catalyst systems including the novel catalysts and metallocene catalysts, and methods of polymerizing olefins using the supported catalyst systems.

BACKGROUND

Activation of metallocene complexes for olefin polymerization requires the use of a cocatalyst or activator. Only a limited number of such cocatalysts are known. One type of cocatalyst includes dialkylaluminum chlorides and trialkylaluminumcompounds. Dialkylaluminum chlorides work well only with titanocenes (Natta, J., Pino, P., Mazzanti, G. and Giannini, U., J. Am. Chem. Soc. 79, 2975 (1957), and Breslow, D.S. and Newburg, N.R., J. Am. Chem. Soc. 79, 5072 (1957)). Sometrialkylaluminum compounds are known to activate zirconocenes, but are very poor cocatalysts for metallocene complexes (U.S. Pat. No. 2,924,593). Another type of cocatalyst includes alkylalumoxanes. These cocatalysts are described in Andersen et al.,Angew. Chem., Int. Ed. Engl. 15, 630 (1976); Sinn, H. and Kaminsky, W., Adv. Organomet. Chem. 18, 99 (1980); and Sinn, H., Kaminsky, W., Vollmer, H.J. and Woldt, R., Angew. Chem., Int. Ed. Engl. 19, 390 (1980). A combination oftrimethylaluminum and dimethylaluminum fluoride is also known (Zambelli, A., Longo, P., and Grassi, A., Macromolecules 22, 2186 (1989)). Additional cocatalysts include compounds or salts which generate non-coordinative anions such as [R.sub.3 NH].sup.+[B(C.sub.6 F.sub.5).sub.4 ].sup.- ; see, Ewen, J.A. et al., Makromol. Chem. Macromol. Symp. 4849, 253 (1991); Taube, R. and Krukowka, L., J. Organomet. Chem. 347, C9 (1988); Bochman, M. and Jaggar, A.J., J. Organomet. Chem. 424, C5-C7 (1992); andHerfert, N. and Fink, G., Makromol Chem. Rapid Commun. 14, 91-96 (1993).

Certain zirconium complexes containing pi-bonded organic ligands, such as bis(cyclopentadienyl)zirconium complexes, activated with an alumoxane, are particularly effective catalysts; see, e.g., U.S. Pat. Nos. 4,542,199 and 4,404,344. However,although such zirconium-based catalysts are very effective olefin polymerization catalysts, the alumoxane cocatalysts are expensive and can be utilized efficiently only if the olefin polymerization reaction can be carried out in aromatic solvents(generally in toluene).

Thus, there is a need in the art for cocatalysts capable of efficiently activating metallocene complexes, particularly zirconium, titanium and hafnium complexes. In addition, there is a need for alternative, less expensive cocatalysts effectivefor activating metallocene complexes.

SUMMARY OF THE INVENTION

The present invention provides a new type of cocatalyst which is capable of activating metallocene complexes in olefin polymerization reactions. The cocatalyst of the present invention in general includes: (a) a halo-organoaluminum compound ofthe formula:

where Al is aluminum, each R is independently a C.sub.1 to C.sub.4 alkyl group, X is a halide, n is 1 or 2, and m is determined by the valency of Al; and (b) a dialkylmagnesium compound of the formula:

where Mg is magnesium and R' is a C.sub.2 to C.sub.6 alkyl group. The components (a) and (b) are used in amounts such that the molar ratio of Al:Mg is at least 2, preferably from 2:1 to 5:1.

Cocatalysts of the present invention can be used in combination with metallocene catalysts to form active metallocene catalyst systems, preferably supported metallocene catalyst systems. Thus, the present invention also provides novel supportedmetallocene catalyst systems including a cocatalystactivator as described above, a metallocene catalyst, and a support. In the case of zirconocene complexes, each component, if used alone, does not produce an olefin polymerization catalyst, but when thecomponents are used together, they readily activate metallocene complexes for polymerization reactions. The present invention is further directed to methods of polymerizing olefins, particularly ethylene or ethylene and an alpha olefin comonomer, usingthe supported metallocene catalyst systems.

DETAILED DESCRIPTION OF THE INVENTION

Cocatalysts or activators of the present invention include a halo-organoaluminum compound and a dialkylmagnesium compound. The halo-organoaluminum compound is a compound represented by the formula:

where Al is aluminum, each R is independently a C.sub.1 to C.sub.4 alkyl group, X is a halide, n is 1 or 2, and m is determined by the valency of Al. Preferred examples of suitable halo-organoaluminum compounds include those in which R is methylor ethyl and X is chlorine or fluorine. In particular, preferred halo-organoaluminum compounds include AlEt.sub.2 Cl, AlMe.sub.2 Cl, Al.sub.2 Et.sub.3 Cl.sub.3 and AlEt.sub.2 F, where Me is methyl and Et is ethyl. These compounds are generallycommercially available or can be synthesized by methods well known in the art; the compounds used in the Examples herein were obtained commercially from Akzo Nobel Co.

The dialkylmagnesium compound is a compound of the formula:

where Mg is magnesium and each R' is independently a C.sub.2 to C.sub.6 alkyl group. Preferred dialkylmagnesium compounds include those in which each R' is butyl or hexyl. These dialkylmagnesium compounds are generally commercially available orcan be synthesized by methods well known in the art; dibutyl magnesium ("MgBu.sub.2 ") and dihexyl magnesium ("MgHex.sub.2 ") used in the Examples herein were obtained from FMC and from Akzo Nobel Co., respectively.

The halo-organoaluminum compound and the dialkylmagnesium compound are used in amounts such that the molar ratio of Al:Mg is at least 2, and generally in the range of from 2:1 to 5:1. It should be appreciated that Al:Mg ratios outside of thisrange may still provide some activation of the metallocene catalyst, but the activation is generally poor compared to catalyst systems using the preferred molar ratios.

Chloro-organoaluminum compounds and dialkylmagnesium compounds react rapidly with the formation of finely dispersed white solids. When this reaction is carried out in aliphatic solvents such as n-heptane or isohexane, the precipitation is quiterapid and produces a white voluminous mass which is soluble in water, THF, and acetone. In aromatic solvents such as toluene, the same reaction is slower and produces finely dispersed solid particles which remain in a quasi-colloidal state for longperiods of time. .sup.13 C NMR analysis of liquid products formed in the reaction of AlMe.sub.2 Cl and MgBu.sub.2 at an Al:Mg molar ratio of 2, for example, showed that both AlMe.sub.2 Cl (based on the CH.sub.3 signal at -6.5 ppm) and MgBu.sub.2 (basedon the .alpha.-CH.sub.2 signal at +9.5 ppm) are fully consumed in the reaction, and a new product, with a CH.sub.3 signal at -8.0 ppm and the .alpha.-CH.sub.2 signal at +10.8 ppm, is formed. Without wishing to be bound by theory, comparison with spectraof various organoaluminum compounds (AlMe.sub.3 and AlHex.sub.3) suggests that the most probable reaction is:

X-ray analysis of the solid product formed in this reaction confirmed formation of finely dispersed MgCl.sub.2 ; see Chien, J.C.W., Wu, J.C., and Kao, C.I., J. Polym. Sci., Chem. 21, 737 (1982). Its main broad reflections were at2.theta.=.about.16, .about.31, 51 and .about.60.degree.. However, chemical analysis of the precipitates revealed a more complex picture. The solid formed in the mixture of AlEt.sub.2 Cl and MgBu.sub.2 at an Al:Mg molar ratio of 2 (25.degree. C.,overnight) has an empirical formula MgCl.sub.2.multidot.0.4(AlR.sub.2 Cl) (R.about.C.sub.4). Analysis of the solid produced in the mixture of Al(i-Bu).sub.2 Cl and MgHex.sub.2 at an Al:Mg molar ratio of 1 (25.degree. C., overnight, reprecipitated fromethanol) also showed the presence of Al in the solid, with an Al:Mg molar ratio of 0.13. Gas chromatographic analysis of organic products generated during dissolution of the thoroughly washed solid in ethanol indicated the presence of isobutane andn-hexane in a 3:1 molar ratio. Similarly, a reaction between AlMe.sub.2 Cl and MgBu.sub.2 at an Al:Mg molar ratio of 2 produced a solid containing Al with an Al:Mg molar ratio of 0.07.

When the products of the reaction between AlR.sub.2 Cl and MgR.sub.2 ' were combined with metallocene complexes of Ti, Zr or Hf (either unsubstituted metallocenes or their ring-substituted analogues), they formed catalytically active systems forthe polymerization of ethylene and alpha-olefins. The polymerization reactions were typically carried out in aliphatic hydrocarbons with an AlR.sub.2 X:MgR.sub.2 ' molar ratio from 2 to 5 and a temperature range from 20 to 90.degree. C. The[Al]:[transition metal] molar ratio can vary from 500 to 2000. Table 1 shows several polymerization reactions using the unsubstituted zirconocene complex Cp.sub.2 ZrCl.sub.2.

TABLE 1 Polymerization with Cp.sub.2 ZrCl.sub.2 Activated with AlR.sub.2 X--MgBu.sub.2 and AlR.sub.2 X--LiBu [Al], [Mg] [Zr] T P.sub.E.sup.a C.sub.Hex.sup.b Yield Cocatalyst (mmol) (mmol) (.degree. C.) (MPa) (M) (g) MgBu.sub.2 0, 1.5 7.times. 10.sup.-3 60 1.24 0 0 AlEt.sub.2 Cl 7.5, 0 1 .times. 10.sup.-3 80 1.03 0 0 AlEt.sub.2 Cl 1.5, 0 1.4 .times. 10.sup.-2 60 0.82 3.2 .about.0.1.sup.c AlEt.sub.2 Cl/ 7.5, 2.0 1.0 .times. 10.sup.-2 80 1.03 0 56.3 MgBu.sub.2 AlEt.sub.2 Cl/ 7.5,2.0 1.0 .times. 10.sup.-2 80 1.03 2.7 45.7 MgBu.sub.2 AlEt.sub.2 Cl/ 1.5, 0.8 3.3 .times. 10.sup.-2 80 0.82 3.9 55.8 MgBu.sub.2 AlMe.sub.2 Cl/ 7.5, 2.0 7 .times. 10.sup.-3 80 1.24 3.2 23.1 MgBu.sub.2 AlEt.sub.2 F/ 4.5, 1.0 6 .times. 10.sup.-3 601.24 3.2 15.6 MgBu.sub.2 AlMe.sub.2 Cl/ 2.0, 1.0 3.4 .times. 10.sup.-3 70 1.03 1.3 12.9 sec-BuLi .sup.a partial pressure of ethylene .sup.b molar concentration of 1-hexene in solution .sup.c cationic oligomers of 1-hexene

Neither MgBu.sub.2 nor AlEt.sub.2 Cl, when used alone, activated the zirconocene complex (although AlEt.sub.2 Cl initiated cationic polymerization of 1-hexene), but combinations of AlEt.sub.2 Cl and Mg(n-Bu).sub.2 were quite effectivecocatalysts. An Al:Mg molar ratio from 2:1 to 5:1 was needed for a catalytic effect; the same combinations at an Al:Mg ratio less than 1 were virtually inactive. In the case of ethylene copolymerization reactions, polymer yields ranged from 2500 to10,000 g/mmol of Zr. Comparison with MAO as a cocatalyst showed that AlR.sub.2 Cl--MgR.sub.2 ' combinations were 5-10 times less active (per mole of the zirconocene complex).

Two other combinations of organometallic compounds are also capable of activating metallocene complexes: AlR.sub.2 F and MgR.sub.2 '; and AlR.sub.2 Cl and LiR'. However, none of the cocatalyst combinations was effective when (C.sub.5Me.sub.5).sub.2 ZrCl.sub.2 was used as a zirconocene complex, in contrast to MAO. Combinations of AlEt.sub.2 Cl and MgBu.sub.2 also readily activate metal-alkylated zirconocene complexes (Cp.sub.2 ZrMe.sub.2), zirconocenes with alkyl substitutedcyclopentadienyl rings, as well as metallocene complexes with bridged cyclopentadienyl rings (Table 2).

Table 2 also shows results of ethylene/1-hexene copolymerization reactions using supported metallocene catalysts. The catalysts can be supported on conventional supports, preferably silica, using methods well known to those skilled in the art(see, e.g., U.S. Pat. No. 5,506,184, the disclosure of which is incorporated herein by reference), and as shown in the Examples herein.

TABLE 2 Ethylene/.alpha.-olefin Copolymerization with Bridged Metallocene Complexes Activated with AlEt.sub.2 Cl--MgBu.sub.2 and with AlMe.sub.2 Cl--MgBu.sub.2 Mixtures (Al:Mg = 2.8 to 3.0) T P.sub.E.sup.a C.sub.olef.sup.b YieldC.sub.olef.sup.copol Catalyst (.degree. C.) (MPa) .alpha.-olefin (M) (g/mmol Zr) (mol %) (n-BuCp).sub.2 ZrCl.sub.2 80 1.03 1-hexene 1.38 6000 (0.5 h) 0.9 C.sub.2 H.sub.4 (Ind).sub.2 ZrCl.sub.2 80 0.41 propylene 0.23 MPa 1200 (1 h) 9.0 C.sub.2H.sub.4 (Ind).sub.2 ZrCl.sub.2 80 1.25 1-hexene 1.66 12400 (0.5 h) 5.3 C.sub.2 H.sub.4 (Ind).sub.2 ZrCl.sub.2 80 1.25 1-hexene 1.38 18000 (2 h) 2.0 C.sub.2 H.sub.4 (Ind).sub.2 ZrCl.sub.2 80 1.26 1-hexene 0.80 5200 (2 h) 0.6 C.sub.2 H.sub.4(Ind).sub.2 ZrCl.sub.2 90 1.30 1-hexene 1.75 6900 (1 h) 4.7 Me.sub.2 Si(Ind).sub.2 ZrCl.sub.2 80 1.26 1-hexene 0.90 6250 (2 h) 0.7 Me.sub.2 Si(Cp)(Flu)ZrCl.sub.2 90 1.30 1-hexene 1.75 6700 (1 h) 3.4 Silica-Supported Catalysts C.sub.2 H.sub.4(Ind).sub.2 ZrCl.sub.2 90 1.30 1-hexene 1.75 7800 (1 h) 4.4 C.sub.2 H.sub.4 (Ind).sub.2 ZrCl.sub.2.sup.c 90 1.30 1-hexene 1.75 4900 (1 h) 2.4 Me.sub.2 Si(Cp)(Flu)ZrCl.sub.2 90 1.03 1-hexene 1.75 750 (1 h) -- .sup.a partial pressure of ethylene .sup.b molar concentration of 1-hexene in solution .sup.c AlMe.sub.2 Cl--Mg(n-Bu).sub.2 combination was used as a cocatalyst

The AlR.sub.2 Cl--MgR.sub.2 ' combinations can also activate bridged metallocene complexes in stereospecific polymerization of .alpha.-olefins. Polymerization of propylene with C.sub.2 H.sub.4 (Ind).sub.2 ZrCl.sub.2 activated by AlEt.sub.2Cl--MgBu.sub.2 cocatalyst at an Al:Mg molar ratio of 2.8 at 50.degree. C. and a propylene partial pressure of 0.48 MPa produced polypropylene (2 h yield 200 g/mmol Zr) with a moderate degree of isotacticity; its melting point was 136-140.degree. C.Polymerization of 4-methyl-1-pentene with the same catalyst at 55.degree. C. also produced crystalline isotactic poly-(4-methyl-1-pentene) with a low yield.

Based on gas phase chromatography data, polymers prepared with metallocene catalysts activated with AlR.sub.2 Cl and MgR.sub.2 ' have relatively broad molecular weight distributions, with M.sub.w /M.sub.n values in the range of 10-15. However,ethylenealpha-olefin copolymers prepared with these catalysts have relatively narrow compositional distributions, an important indicator of single-site catalysis. Differential scanning calorimetry (DSC) and compositional analysis were carried out asdescribed in U.S. Pat. No. 5,086,135 and in Nowlin et al., Journal of Polymer Science, Part A: Polymer Chemistry, 26, 755-764 (1988). DSC melting curves of several ethylene/1-hexene copolymers prepared with unsubstituted and ring-substitutedzirconocene complexes, activated with AlEt.sub.2 Cl-MgBu.sub.2 at relatively high [Al]:[Zr] ratios (over 1500), showed two indicators of single-site catalysis. The copolymers containing from 3 to 5 mol % of 1-hexene had quite narrow melting peaks, andtheir melting points were relatively low (100-125.degree. C.), depending on composition. For example, as shown by DSC, a copolymer with a 1-hexene content of 2.0 mol %, prepared with a Cp.sub.2 ZrCl.sub.2 /AlEt.sub.2 Cl-MgBu.sub.2 catalyst, had aT.sub.m =118.7.degree. C. (crystallinity 67%) and a copolymer with 1-hexene content of 5.2 mol %, prepared with a C.sub.2 H.sub.4 (Ind).sub.2 ZrCl.sub.2 /AlEt.sub.2 Cl-MgBu.sub.2 catalyst, had a T.sub.m =99.6.degree. C. (crystallinity 26%). Supportedcatalysts activated with AlR.sub.2 Cl-MgR.sub.2 ' cocatalysts also produced ethylene copolymers with uniform compositional distributions. Their melting points are uniformly low, as shown in Table 3.

TABLE 3 C.sub.Hex.sup.copol 2.4 3.4 4.7 4.4 Tm (.degree. C.) 114.7 106.9 106.6 105.1

Although not wishing to be bound by theory, a possible active site formation mechanism probably includes alkylation of zirconocene complexes with AlR.sub.2 R' formed in the reaction between AlR.sub.2 Cl and MgR.sub.2 ' and the formation ofcationic metallocene species Cp.sub.2 Zr.sup.+ --R via interaction between alkylated zirconocenes and MgCl.sub.2. Chain growth reactions with AlR.sub.2 Cl-MgR.sub.2 ' activated metallocene complexes proceed in the same manner as with MAO-activatedmetallocene complexes. The principal chain termination reaction is .beta.-hydride elimination. In the case of an ethylene/1-hexene copolymer (prepared with Cp.sub.2 ZrCl.sub.2 -AlEt.sub.2 Cl-MgBu.sub.2 cocatalyst in toluene at 85.degree. C.) itproduces two chain-end double bonds:

when the last monomer unit in the chain is ethylene, and

when the last monomer unit in the chain is a 1-hexene unit. Comparison of chain-end composition with the overall copolymer composition (by IR) shows that the probability of the second reaction is about 20 times higher.

Additional features of the present invention are illustrated in the following non-limiting examples.

EXAMPLES

.sup.13 C NMR spectra of organometallic compounds were recorded at 100.4 MHz on a JEOL Eclipse 400 NMR spectrometer at 20.degree. C. .sup.13 C NMR spectra of polymers were recorded using the same instrument at 130.degree. C. under experimentalconditions appropriate for acquiring quantitative spectra of polyolefins (pulse angle was 90.degree. and the pulse delay was 15 s). Continuous .sup.1 H decoupling was applied throughout. The samples were prepared as solutions in a 3:1 mixture of1,3,5-trichlorobenzene and 1,2-dichlorobenzene-d.sub.4. Copolymer compositions were measured by IR; they are reported as mol % of an .alpha.-olefin in the copolymers, C.sub.olef.sup.copol. Infrared spectra were recorded with a Perkin-Elmer Paragon 1000spectrophotometer. X-ray diffraction patterns were recorded with a Phillips PW 1877 automated powder diffractometer.

Catalyst Preparation

EXAMPLE 1

Under an inert atmosphere and at room temperature, 0.056 g of ethylenebis(1-indenyl)zirconium dichloride was added to a 50 mL serum bottle followed by 40 mL of anhydrous toluene. The contents of the serum bottle were heated to 55.degree. C. inan oil bath for 30 minutes to produce a yellow solution. Finally, the serum bottle was removed from the oil bath and the contents were allowed to cool to room temperature.

EXAMPLE 2

Under an inert atmosphere and at room temperature, 0.0418 g of ethylenebis(1-indenyl)zirconium dichloride was added to a 100 mL round-bottom flask. Next, 3.0 mmol diethylaluminum chloride solution in toluene was added, followed by 1.0 mmol ofdibutylmagnesium (DBM) solution in toluene. then, 5 mL of anhydrous toluene was added. Finally, 1.0 g of Davison grade 955 silica, previously calcined at 600.degree. C. for about 12 hours, was added. The round-bottom flask was placed in an oil bathat 55.degree. C., and after about 10 minutes, the solvent was removed from the flask using a nitrogen purge, to produce 1.32 g of a peach-colored free-flowing powder.

EXAMPLE 3

Under an inert atmosphere and at room temperature, 0.056 g of ethylenebis(1-indenyl)zirconium dichloride was added to a 50 mL serum bottle, followed by 0.922 g of a 14.9 wt % solution of trimethylaluminum in heptane and 40.0 g of anhydroustoluene. The contents of the bottle were well shaken, to form a yellow solution.

EXAMPLE 4

Under an inert atmosphere and at room temperature, 0.196 g of dimethylsilyl(cyclopentadienyl)(9-fluorenyl)zirconium dichloride was added to a 50 mL serum bottle. Then, 5 mL of toluene, 5 mL of a 1.43 M solution of trimethylaluminum in heptane,10 mL of a 1.07M solution of dimethylaluminum chloride in toluene, and 5 mL of a 0.65M solution of dibutylmagnesium in toluene were added sequentially. A dark purple gel (viscous) solution formed immediately after the addition of the dibutylmagnesium. The contents of the serum bottle were well shaken to provide a dark purple viscous solution.

EXAMPLE 5

Under an inert atmosphere and at room temperature, 0.222 g of dimethylsilyl(cyclopentadienyl)(9-fluorenyl)zirconium dichloride was added to a 30 mL serum bottle. Then, 10 mL of a 1.07 M solution of dimethylaluminum chloride in toluene, and 4 mLof a 0.65M solution of dibutylmagnesium in toluene were added sequentially. The contents of the bottle were well shaken to provide a dark purple viscous solution. Next, 3.026 g of Davison grade 955 silica, previously calcined at 600.degree. C, wasadded to a 100 mL round-bottom flask containing a large magnetic stir bar. The entire contents of the serum bottle were added to the round-bottom flask, and the serum bottle was rinsed with 15 mL of anhydrous toluene, with the rinse solution also addedto the round bottom flask. The round bottom flask was placed in an oil bath at 53.degree. C. and stirred using the magnetic stir bar for 60 minutes. After this time, the solvents were removed with a nitrogen purge to yield 4.205 g of a free-flowingpowder.

Polymerizations (ethylene1-hexene copolymerization)

EXAMPLE 6

A 2.5 L stainless steel autoclave under a slow nitrogen purge at 50.degree. C. was filled sequentially with 450 mL of anhydrous heptane, 200 mL of anhydrous 1-hexene, 150 mL of heptane, 6.3 mL of a 25 wt % solution of diethylaluminum chloride inheptane, 3.9 mL of a solution of dibutylmagnesium (2.43 wt % Mg) in heptane and 200 mL of heptane. The reactor was closed, the stirring rate adjusted to 1050 rpm, and the internal temperature was increased to 85.degree. C. Ethylene was introduced tomaintain the internal pressure at about 202 psi. Next, 5.0 mL of the yellow solution of EXAMPLE 1 was added to the autoclave and the reactor temperature was adjusted to 90.degree. C. The polymerization was continued for 60 minutes, and then theethylene supply was stopped and the reactor allowed to cool to room temperature. The polyethylene was collected and air dried. The yield was 115 g. The polymer melt index (MI) was determined to be 108, the polymer contained 4.7 mol % 1-hexene, and thepolymer exhibited a melting point peak of 106.65.degree. C. Catalyst activity expressed as kg of polyethylene per gram zirconium under the polymerization conditions described above was 75.6kg/g Zr.

EXAMPLE 7

A 2.5 L stainless steel autoclave under a slow nitrogen purge at 50.degree. C. was filled sequentially with 450 mL of anhydrous heptane, 200 mL of anhydrous 1-hexene, 150 mL of heptane, 6.3 mL of a 25 wt % solution of diethylaluminum chloride inheptane, 3.9 mL of a solution of dibutylmagnesium (2.43 wt % Mg) in heptane and 200 mL of heptane. The reactor was closed, the stirring rate adjusted to 1050 rpm, and the internal temperature was increased to 85.degree. C. Ethylene was introduced tomaintain the internal pressure at about 202 psi. Next, 0.2246 g of the solid catalyst of EXAMPLE 2 was added to the autoclave and the reactor temperature was adjusted to 90.degree. C. The polymerization was continued for 60 minutes, and then theethylene supply was stopped and the reactor allowed to cool to room temperature. The polyethylene was collected and air dried. The yield was 113 g. The polymer melt index (MI) was determined to be 113, the polymer contained 4.35 mol % 1-hexene, and thepolymer exhibited a melting point peak of 105.09.degree. C. Catalyst activity expressed as kg of polyethylene per g zirconium under the polymerization conditions described above was 85.6 kg/g Zr.

EXAMPLE 8

A 2.5 L stainless steel autoclave under a slow nitrogen purge at 50.degree. C. was filled sequentially with 450 niL of anhydrous heptane, 100 mL of anhydrous 1-hexene, 150 mL of heptane, 6.3 mL of a 25 wt % solution of diethylaluminum chloridein heptane, 3.9 mL of a solution of dibutylmagnesium (2.43 wt % Mg) in heptane and 200 mL of heptane. The reactor was closed, the stirring rate adjusted to 1050 rpm, and the internal temperature was increased to 85.degree. C. Ethylene was introduced tomaintain the internal pressure at about 202 psi. Next, 4.7 mL of the solution of EXAMPLE 3 was added to the autoclave and the reactor temperature was adjusted to 90.degree. C. The polymerization was continued for 60 minutes, and then the ethylenesupply was stopped and the reactor allowed to cool to room temperature. The polyethylene was collected and air dried. The yield was 91.2 g. The polymer melt index (MI) was determined to be 51, the polymer contained 2.65 mol % 1-hexene, and the polymerexhibited a melting point peak of 114.9.degree. C. Catalyst activity expressed as kg of polyethylene per g Zr under the polymerization conditions described above was 75.1 kg/g Zr.

EXAMPLE 9

A 2.5 L stainless steel autoclave under a slow nitrogen purge at 50.degree. C. was filled sequentially with 450 mL of anhydrous heptane, 100 mL of anhydrous 1-hexene, 150 mL of heptane, 5.4 mL of a 25 wt % solution of diethylaluminum chloride inheptane, 3.5 mL of a solution of dibutylmagnesium (2.43 wt % Mg) in heptane and 200 mL of heptane. The reactor was closed, the stirring rate adjusted to 1050 rpm, and the internal temperature was increased to 85.degree. C. Ethylene was introduced tomaintain the internal pressure at about 202 psi. Next, 1.0 mL of the solution of EXAMPLE 4 was added to the autoclave and the reactor temperature was adjusted to 90.degree. C. The polymerization was continued for 60 minutes, and then the ethylenesupply was stopped and the reactor allowed to cool to room temperature. The polyethylene was collected and air dried. The yield was 122 g. The polymer melt index (MI) was determined to be 4.8, the polymer contained 3.43 mol % 1-hexene, and the polymerexhibited a melting point peak of 106.88.degree. C. Catalyst activity expressed as kg of polyethylene per g Zr under the polymerization conditions described above was 73.5 kg/g Zr.

EXAMPLE 10

A 2.5 L stainless steel autoclave under a slow nitrogen purge at 50.degree. C. was filled sequentially with 450 mL of anhydrous heptane, 50 mL of anhydrous 1-hexene, 150 mL of heptane, 5.4 mL of a 25 wt % solution of diethylaluminum chloride inheptane, 3.5 mL of a solution of dibutylmagnesium (2.43 wt % Mg) in heptane and 200 niL of heptane. The reactor was closed, the stirring rate adjusted to 1050 rpm, and the internal temperature was increased to 85.degree. C. Ethylene was introduced tomaintain the internal pressure at about 202 psi. Next, 0.2348 g of the catalyst of Example 5 was added to the autoclave and the reactor temperature was adjusted to 90.degree. C. The polymerization was continued for 60 minutes, and then the ethylenesupply was stopped and the reactor allowed to cool to room temperature. The polyethylene was collected and air dried. The yield was 18.5 g. The polymer melt index (MI) was determined to be 3.7, and the high load melt index (HLMI) was 66.6, with theratio HLMIMI =18, indicating a very narrow molecular weight distribution as provided by a single-site catalyst. Catalyst activity expressed as kg of polyethylene per g Zr under the polymerization conditions described above was 8.2 kg/g Zr.

EXAMPLE 11

A 2.5 L stainless steel autoclave under a slow nitrogen purge at 50.degree. C. was filled sequentially with 450 mL of anhydrous heptane, 100 mL of anhydrous 1-hexene, 150 mL of heptane, 8.0 mL of a solution containing 6.16 mmol ofdiethylaluminum chloride and 2.6 mmol of trimethylaluminum in heptane, 2.9 mL of a solution of dibutylmagnesium (2.43 wt % Mg) in heptane and 200 mL of heptane. The reactor was closed, the stirring rate adjusted to 1050 rpm, and the internal temperaturewas increased to 85.degree. C. Ethylene was introduced to maintain the internal pressure at about 202 psi. Next, 0.2280 g of the catalyst of Example 2 was added to the autoclave and the reactor temperature was adjusted to 90.degree. C. Thepolymerization was continued for 60 minutes, and then the ethylene supply was stopped and the reactor allowed to cool to room temperature. The polyethylene was collected and air dried. The yield was 71.3 g of polyethylene containing 2.45 mol % of1-hexene and exhibiting a melting point peak at 114.66.degree. C. The polymer melt index (MI) was determined to be 30.9, and the high load melt index (HLMI) was 571, with the ratio HLMIMI=18.4, indicating a very narrow molecular weight distribution asprovided by a single-site catalyst. Catalyst activity expressed as kg of polyethylene per g Zr under the polymerization conditions described above was 54.0 kg/g Zr.

Examples 1-11 are summarized in Table 4.

TABLE 4 Summary of Examples Catalyst From Polymer From Activity Example No. Example No. (kg PE/g Zr) Activator.sup.(a) 1 6 75.6 DEAC/DBM 2.sup.(b) 7 85.6 DEAC/DBM 3 8 75.1 DEAC/DBM 4 9 73.5 DEAC/DBM 5.sup.(b) 10 8.2 DEAC/DBM 2.sup.(b)11 54.0 DMAC/TMA/DBM .sup.(a) DEAC = diethylaluminum chloride; DBM = dibutylmagnesium; DMAC = dimethylaluminum chloride; TMA = trimethylaluminum .sup.(b) catalyst was supported on silica

These catalyst preparation and olefin polymerization examples clearly illustrate that metallocene compounds may be activated with mixtures of a dialkylaluminum chloride (DEAC or DMAC) and a magnesium alkyl (DBM) to produce olefin polymerizationcatalysts with high activity. Examples 2 and 5 illustrate further than these catalysts can be supported on silica. The characterization of the polymer samples prepared with these olefin polymerization catalysts indicates that the polymer has a uniformcomonomer distribution as indicated by the relatively low melting point of the polymer and a narrow MWD as provided from single-site olefin polymerization catalysts.

The various patents and publications cited in this disclosure are incorporated herein by reference in their entirety. Other publications not specifically addressed above but providing useful information for the appreciation and practice of thepresent invention include U.S. Pat. No. 5,086,135 and Kissin et al., Macromolecules 33, 4599-4601 (2000), the disclosures of which are also incorporated herein by reference.

* * * * *
 
 
  Recently Added Patents
Extension of physical downlink control channel coverage
Reaction medium for detecting and/or identifying bacteria of the Legionella genus
Electrifying roller
Communication terminal device, and recording medium
Method of predicting a motion vector for a current block in a current picture
Calcium carbonate granulation
Image capture apparatus and program
  Randomly Featured Patents
Piezoelectric ink jet recording head formed by press working
Aqueous water-repellent coatings
Proxy-based reservation of network resources
Programmable controller having automatic contact line solving
System and method for reducing surge
Gene construct and its use
System and method for identifying a television program
Colored investment data display system and method
Application platform and application
Combating nematodes with alkanesulfonic acid 2-bromoethyl esters