PROCATALYST COMPOSITION MADE WITH A COMBINATION OF INTERNAL ELECTRON DONORS

Abstract

A phthalate-free procatalyst composition is disclosed for olefin polymerization that exhibits excellent polymerization activity and response to hydrogen, and can produce a polyolefin exhibiting high stereoregularity, high melt flow rate, and desirable molecular weight distribution. The method for producing the procatalyst composition includes reaction of a magnesium support precursor with a tetravalent titanium halide and a combination of different internal electron donors. The first internal electron donor may comprise one or more substituted phenylene aromatic diester and the second internal electron donor may comprise a polyether, preferably a 1,3-diether. In one embodiment, the support precursor comprises a spherical spray crystalized MgCl.sub.2-EtOH adduct.

Claims

1. A procatalyst composition for stereoselective polymerization of propylene comprising: a combination of a magnesium moiety, a titanium moiety, and a mixed internal electron donor, the mixed internal electron donor comprising at least a first internal electron donor and a second internal electron donor, the first internal electron donor comprising a non-phthalate and non-succinate internal electron donor, the second internal electron donor comprising a polyether compound.

2. A procatalyst composition as defined in claim 1, wherein the second internal electron donor comprises a 1,3-diether.

3. A procatalyst composition as defined in claim 1, wherein the first internal electron donor and the second internal electron donor are present in the composition in a molar ratio of from about 10:1 to about 1:10.

4. A procatalyst composition as defined in claim 1, wherein the second internal electron donor has the following structure: ##STR00013## where R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are the same or different and comprise methyl, C.sub.2-C.sub.18 linear or branched alkyls, C.sub.3-C.sub.18 cycloalkyls, C.sub.4-C.sub.18 cycloalkyl-alkyls, C.sub.4-C.sub.18 alkyl-cycloalkyls, phenyls, organosilicons, C.sub.7-C.sub.18 arylalkyls, C.sub.7-C.sub.18 alkylaryl radicals; and where R.sub.1 ,R.sub.2 or both optionally are a hydrogen atom.

5. A procatalyst composition as defined in claim 1, wherein the second internal electron donor has the following structure: ##STR00014## where R.sub.1-R.sub.6 are the same or different and comprise a methyl, a C.sub.2-C.sub.18 linear or branched alkyl, a C.sub.3-C.sub.18 cycolalkyl, a C.sub.4-C.sub.18 cycolalkyl-alkyl, a C.sub.4-C.sub.18 alkyl-cycolalkyl, a phenyl, an organosilicon, a C.sub.7-C.sub.18 arylalkyl, or a C.sub.7-C.sub.18 alkylaryl radical, and where R.sub.1-R.sub.4 are optionally a hydrogen atom or are combined to form one or more C.sub.5-C.sub.7 fused aromatic or non-aromatic ring structures, optionally containing an N, O, or S heteroatom.

6. A procatalyst composition as defined in claim 1, wherein the second internal electron donor comprises a bis(methoxymethyl)alkane.

7. A procatalyst composition as defined in claim 1 wherein the second internal electron donor comprises a substituted bis(methoxymethyl) cyclopentadiene.

8. A procatalyst composition as defined in claim 1, wherein the second internal electron donor comprises 9,9-bis(methoxymethyl)fluorene.

9. A procatalyst composition as defined in claim 1, wherein the second internal electron donor comprises 4,4-bis(methoxymethyl)-2,6-dimethyl heptane.

10. A procatalyst composition as defined in claim 1, wherein the combined magnesium moiety, titanium moiety, and mixed internal electron donors form a substantially spherical shaped particle.

11. A procatalyst composition as defined in claim 1, wherein the magnesium moiety comprises a magnesium-based spherical carrier.

12. A procatalyst composition as defined in claim 1, wherein the first internal electron donor comprises a substituted phenylene aromatic diester.

13. A procatalyst composition as defined in claim 12, wherein the substituted phenylene aromatic diester has the following structure: ##STR00015## where R.sub.1-R.sub.4 are the same or different, each of R.sub.1-R.sub.4 is selected from the group consisting of hydrogen, a substituted hydrocarbyl group having 1 to 20 carbon atoms, an unsubstituted hydrocarbyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a heteroatom, and combinations thereof, and at least one of R.sub.1-R.sub.4 is not hydrogen; and at least one or two, or three, or four R groups of R.sub.1-R.sub.4 is selected from a substituted hydrocarbyl group having 1 to 20 carbon atoms, an unsubstituted hydrocarbyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a heteroatom, and combinations thereof, and where E.sub.1 and E.sub.2 are the same or different and selected from the group consisting of an alkyl having 1 to 20 carbon atoms, a substituted alkyl having 1 to 20 carbon atoms, an aryl having 1 to 20 carbon atoms, a substituted aryl having 1 to 20 carbon atoms, or a heteroatom containing functional group having 1 to 20 carbon atoms.

14. A catalyst system for the polymerization of propylene polymers comprising: the procatalyst composition as defined in claim; and a cocatalyst.

15. A catalyst system as defined in claim 14, wherein the system further comprises an external electron donor.

16. A catalyst system as defined in claim 14, further comprising an activity limiting agent.

17. A polymerization process comprising: polymerizing an olefin in the presence of a catalyst composition comprising a Ziegler-Natty procatalyst composition, a cocatalyst composition, and optionally an external electron donor compound, the procatalyst composition formed from a transition metal compound and a mixture of internal electron donors comprising at least a first internal electron donor and a second internal electron donor, the first internal electron donor comprising a non-phthalate and non-succinate internal electron donor, the first internal electron donor comprising a phenylene dicarboxylic acid ester, the second internal electron donor comprising a polyether compound.

18. A process as defined in claim 17, wherein the process produces a polypropylene polymer.

19. A process as defined in claim 17, wherein the second internal electron donor comprises the following structure: ##STR00016## where R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are the same or different and comprise a methyl, a C.sub.2-C.sub.18 linear or branched alkyls, a C.sub.3-C.sub.18 cycloalkyls, a C.sub.4-C.sub.18 cycloalkyl-alkyls, a C.sub.4-C.sub.18 alkyl-cycloalkyls. phenyl, an organosilicon, a C.sub.7-C.sub.18 arylalkyls, or a C.sub.7-C.sub.18 alkylaryl radicals and where R.sub.1, R.sub.2 or both optionally are a hydrogen atom.

20. A process as defined in claim 17, wherein the second internal electron donor comprises the following structure: ##STR00017## where R.sub.1-R.sub.6 are the same or different and comprise a methyl, a C.sub.2-C.sub.18 linear or branched alkyl, a C.sub.3-C.sub.18 cycolalkyl, a C.sub.4-C.sub.18 cycolalkyl-alkyl, a C.sub.4-C.sub.18 alkyl-cycolalkyl, a phenyl, an organosilicon, a C.sub.7-C.sub.18 arylalkyl, or a C.sub.7-C.sub.18 alkylaryl radical, and where R.sub.1-R.sub.4 are optionally a hydrogen atom or combined to form one or more C.sub.6-C.sub.7 fused aromatic or non-aromatic ring structures, optionally containing an N, O, or S heteroatom.

21. A process as defined claim 17, wherein the olefin comprises propylene and ethylene for forming a propylene and ethylene copolymer.

22. A process as defined in claim 17, wherein the second internal electron donor comprises a 1,3 diether.

23. A process as defined in claim 17, wherein the second internal electron donor comprises a bis(methoxymethyl)alkane, a substituted bis(methoxymethyl)cyclopentadiene, 9,9-bis(methoxymethyl)fluorene, and/or 4,4-bis(methoxymethyl)-2,6-dimethyl heptane.

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)

28. (canceled

29. (canceled)

30. (canceled)

Description

EXAMPLES

Example 1

[0126] Spherical MgCl.sub.2 precursor preparation has been described previously (see U.S. Pat. No. 5,468,698). A sample with average particle size of 58 micron (Malvern d50) was used for procatalyst synthesis.

[0127] Procatalyst preparation: MgCl2 precursor (20 g) and octane (70 mL) were added to a 1L jacketed glass reactor with overhead stirring and the mixture was cooled to 20 C. TiCl4 (340g pre-cooled to 20 C.) was added and the temperature was increased to 20 C. over a 1.5 h period. A solution of 4,4-bis(methoxymethyl)-2,6-dimethylheptane (DE1, 1.8g) in octane (5mL) was added by microcannual. After completing the addition, reactor temperature was increased to 100 C. at a rate of 0.89 C./min. During the temperature ramp a solution of 3-methyl-5-tert-butyl-1,2phenylene dibenzoate (CDB, 2.5 g) in toluene (25 mL) was metered by syringe pump at a rate of 0.428 mL/m in. After reaching 100 C., stirring was continued for 1 h before allowing catalyst solids to settle and decanting the supernatant. Pre-heated TiCl4 (340 g) was added and the mixture stirred for 0.5 h before repeating the settle and decant steps. TiCl4 treatment was repeated at 120 C. for 0.5 h and then the reactor was cooled to 80 C. Catalyst solids were washed with heptane at 80 C. (3200 mL) and at 25 C. (2200 mL). After final heptane wash the catalyst was dried under vacuum at 40 C. for 4 h to a free flowing powder. Yield: 7.2 g (3.5% Ti, 9.2% DE1, 10.1% CDB)

Example 2

[0128] Proctalyst composition was prepared as described in Example 1 except 2.25 g of DE1 and 1.1 g of CDB were used. Yield: 7.9 g (3.4% Ti, 14.3% DE1, 4.8% CDB)

Example 3

[0129] Procatalyst was prepared as described in Example 1 except a solution of 9,9-bis(methoxymethyl)-9H-fluorene (DE2, 2.2 g) in toluene (20 mL) was used instead of DE1 as the first donor. Yield: 9.8 g (3.8% Ti, 11.2% DE2, 9.3% CDB).

Comparative 1

[0130] Procatalyst preparation: Spray crystallized MgCl2 carrier (1.90 kg) and heptane (4.67 kg) were added to a 50 L agitated, jacketed metal reactor and the mixture was cooled to 20 C. TiCl4 (32.8 kg pre-cooled to 20 C.) was added over 480 min. The temperature was ramped to 20 C. over a 2.0 h period. Ethylbenzoate (0.143 kg) in was then added. After completing the addition, reactor temperature was increased linearly to 100 C. over 150 min. During the temperature ramp a solution of CDB (0.370 kg) in toluene (2.47 kg) was metered into the reactor at a rate of 0.0247 kg/min. After reaching 100 C., stirring was continued for 30 min before allowing catalyst solids to settle and decanting the supernatant. Pre-heated TiCl4 (100 C., 32.8 kg) was added, a solution of CDB (0.185 kg) in toluene (1.24 kg) was added, and the mixture was stirred for 30 min at 100 C. before repeating the settle and decant steps. TiCl4 treatment without addition of donor was repeated at 120 C. for 15 min and then the reactor was cooled to 95C over 15 min. The solids were then allowed to settle and the supernatant was decanted. Catalyst solids were washed with heptane at 80 C. (313.0 kg) and at 25 C. (213.0 kg). After final heptane wash the catalyst was dried under vacuum starting at 25 C. and finished at 40 C. to produce a free flowing powder. Yield: 1.25 kg (3.7 wt % Ti, 10.8 wt % CDB).

Comparative 2

[0131] Procatalyst preparation: Spray crystallized MgCl2 carrier (20 g) and octane (70 mL) were added to a 1 L jacketed glass reactor with overhead stirring and the mixture was cooled to 20 C. TiCl4 (340 g pre-cooled to 20 C.) was added and the temperature was increased to 20 C. over a 1.5 h period. A solution of DE1 (2.5 g) in octane (7 mL) was added by microcannual. After completing the addition reactor temperature was increased to 110 C. at a rate of 1.0 C./min. After reaching 110 C., stirring was continued for 1 h before allowing catalyst solids to settle and decanting the supernatant. Pre-heated TiCl4 (340 g) was added and the mixture stirred for 0.5 h before repeating the settle and decant steps. TiCl4 treatment was repeated a second time for 0.5 h and then the reactor was cooled to 80 C. Catalyst solids were washed with heptane at 80 C. (3200mL) and at 25 C. (2200mL). After final heptane wash the catalyst was dried under vacuum at 40 C. for 4 h to a free flowing powder. Yield: 9.0 g (4.1% Ti, 13.9% DE1).

Comparative 3

[0132] A commercial catalyst with diisobutylphthalate as internal donor was used.

Example 4

[0133] Procatalysts were used in liquid polypropylene polymerizations at 70 C. : A cocatalyst solution was prepared by mixing 2.23 mmol of triethylaluminum and 0.15 mmol of dicyclopentyldimethoxysilane (DCDMS) in 15 mL of heptane. To a dry 2 L stainless steel autoclave reactor at 20 C. was added 300 mL of liquid propylene. The propylene was then vented off to 5 psig reactor pressure and 188 mmol of hydrogen were added. A portion of the cocatalyst solution (6 mL) was added to the reactor with 600 mL of propylene and stirring initiated at 500 rpm. The remaining cocatalyst solution was contacted with the procatalyst for 5 minutes and charged to the reactor with 450 mL of propylene. The reactor was heated to 70 C. in 10 minutes and polymerization continued for 1 h. The stirrer was turned off; excess monomer vented while cooling to 20 C.; and the reactor was purged for 5 minutes with argon. The reactor bottom was dropped and polymer removed. Polymer was dried in a vacuum oven at 50 C. before weighing and analysis. Results are collected in Table 1.

Example 5

[0134] Procatalysts were used in propylene polymerization as described in Example 5 except 0.15 mmol of cyclohexylmethyldimethoxysilane (CMDMS) was used as external donor and the hydrogen charge was 63 mmol. Results are summarized in Table 2.

TABLE-US-00001 TABLE 1 Bulk polytests with DCDMS external donor Activity MFR XSRT Catalyst (mg) (Kg/g-cat*h) (g/10 min.) (wt %) Exp-1 (2.15) 88 58.8 1.72 Exp-2 (2.50) 81 68.9 1.44 Exp-3 (2.05) 93 73.7 0.99 C1 (2.40) 92 10.8 1.35 C2 (2.95) 77 175.2 3.34 C3 (4.50) 63 17.0 1.77 TEAI/DCDMS = 15, H.sub.2 charge = 188 mmol.

TABLE-US-00002 TABLE 2 Bulk polytests with CMDMS external donor Activity MFR XSRT PDI Catalyst (mg) (Kg/g-cat*h) (g/10 min.) (wt %) (Pa) Exp-1 (3.00) 90 3.2 1.28 4.6 Exp-2 (2.70) 89 6.4 2.54 4.6 Exp-3 (2.60) 106 6.1 0.98 C1 (2.55) 90 1.5 2.22 5.3 C2 (2.50) 77 23.5 4.00 3.8 C3 (5.20) 48 5.3 2.20 4.3 TEAI/CMDMS = 15, H.sub.2 charge = 68 mmol.

[0135] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention as further described in such appended claims.