Method of preparing polyolefin, and polyolefin prepared thereby

Abstract

A method of preparing a polyolefin, wherein the method is used to more effectively prepare a polyolefin which has a high molecular weight and multimodal molecular weight distribution, thereby being preferably used for blow-molding or the like, and a polyolefin prepared thereby, are provided.

Claims

1. A method of preparing a polyolefin, the method comprising the step of polymerizing olefin monomers in the presence of a metallocene catalyst, and a molecular weight modifier including a mixture of a cyclopentadienyl metal compound of Chemical Formula 1 and an organic aluminum compound of Chemical Formula 2 or a reaction product thereof, wherein the polymerization step is performed in a cascade reactor including a first reactor and a second reactor, and wherein the metallocene catalyst is fed into the first reactor and the molecular weight modifier is fed into the second reactor:
(R.sup.1-Cp.sup.1)(R.sup.2-Cp.sup.2)M.sup.1X.sub.2[Chemical Formula 1] wherein Cp.sup.1 and Cp.sup.2 are each independently a ligand including a cyclopentadienyl group, an indenyl group, or a fluorenyl group; R.sup.1 and R.sup.2 are substituents of Cp.sup.1 and Cp.sup.2, and are each independently an alkyl having 2 to 20 carbon atoms, an alkenyl having 2 to 20 carbon atoms, an alkylaryl having 7 to 20 carbon atoms, an arylalkyl having 7 to 20 carbon atoms, an aryl having 6 to 20 carbon atoms, a heteroalkyl having 1 to 20 carbon atoms, a heteroalkenyl having 2 to 20 carbon atoms, a heteroalkylaryl having 6 to 20 carbon atoms, a heteroarylalkyl having 6 to 20 carbon atoms, or a heteroaryl having 5 to 20 carbon atoms; M.sup.1 is a Group 4 transition metal element; and X is a halogen,
R.sup.3R.sup.4R.sup.5Al[Chemical Formula 2] wherein R.sup.3, R.sup.4, and R.sup.5 are each independently an alkyl having 4 to 20 carbon atoms or a halogen, and at least one of R.sup.3, R.sup.4, and R.sup.5 is an alkyl having 4 to 20 carbon atoms.

2. A method of preparing a polyolefin, the method comprising the step of solution-polymerizing olefin monomers in the presence of a metallocene catalyst, and a molecular weight modifier including a mixture of a cyclopentadienyl metal compound of Chemical Formula 3 and an organic aluminum compound of Chemical Formula 4 or a reaction product thereof, wherein the polymerization step is performed in a cascade reactor including a first reactor and a second reactor, and wherein the metallocene catalyst is fed into the first reactor and the molecular weight modifier is fed into the second reactor:
(R.sup.6-Cp.sup.3)(R.sup.7-Cp.sup.4)M.sup.2X.sub.2[Chemical Formula 3] wherein Cp.sup.3 and Cp.sup.4 are each independently a ligand including a cyclopentadienyl group, an indenyl group, or a fluorenyl group; R.sup.6 and R.sup.7 are substituents of Cp.sup.3 and Cp.sup.4 and are each independently hydrogen or a methyl; M.sup.2 is a Group 4 transition metal element; and X is a halogen,
R.sup.8R.sup.9R.sup.10Al[Chemical Formula 4] wherein R.sup.8, R.sup.9, and R.sup.10 are each independently an alkyl having 4 to 20 carbon atoms or a halogen, and at least one of R.sup.8, R.sup.9, and R.sup.10 is an alkyl having 4 to 20 carbon atoms.

3. The method of claim 1, wherein R.sup.1 and R.sup.2 are each independently selected from the group consisting of an ethyl, a butyl, and a t-butoxy hexyl.

4. The method of claim 1, wherein R.sup.3, R.sup.4 and R.sup.5 are each independently an isobutyl.

5. The method of claim 1, wherein M.sup.1 is selected from the group consisting of titanium, zirconium, and hafnium.

6. The method of claim 1, wherein X is selected from the group consisting of F, Cl, Br, and I.

7. The method of claim 1, wherein the olefin monomer includes one or more selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eitocene, norbornene, norbornadiene, ethylidene norbornene, phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinyl benzene, and 3-chloromethylstyrene.

8. The method of claim 1, wherein the molecular weight modifier is represented by the following Chemical Formula 5, Chemical Formula 6, or Chemical Formula 7: ##STR00029##

9. The method of claim 2, wherein the molecular weight modifier is represented by the following Chemical Formula 8: ##STR00030##

10. The method of claim 1, wherein the molecular weight modifier is used in an amount of about 10.sup.7 to 10.sup.1 parts by weight, based on a total of 100 parts by weight of the olefin monomer.

11. The method of claim 1, wherein the metallocene catalyst includes one or more metallocene compounds represented by any one of the following Chemical Formulae 9 to 12:
(Cp.sup.5R.sup.a).sub.n(Cp.sup.6R.sup.b)M.sup.3Z.sup.1.sub.3-n[Chemical Formula 9] wherein M.sup.3 is a Group 4 transition metal; Cp.sup.5 and Cp.sup.6 are the same as or different from each other, and are each independently any one selected from the group consisting of cyclopentadienyl, indenyl, 4,5,6,7-tetrahydro-1-indenyl, and fluorenyl radicals, and these are substituted with a hydrocarbon having 1 to 20 carbon atoms; R.sup.a and R.sup.b are the same as or different from each other, and are each independently hydrogen, a C1 to C20 alkyl, a C1 to C10 alkoxy, a C2 to C20 alkoxyalkyl, a C6 to C20 aryl, a C6 to C10 aryloxy, a C2 to C20 alkenyl, a C7 to C40 alkylaryl, a C7 to C40 arylalkyl, a C8 to C40 arylalkenyl, or a C2 to C10 alkynyl; Z.sup.1 is a halogen atom, a C1 to C20 alkyl, a C2 to C10 alkenyl, a C7 to C40 alkylaryl, a C7 to C40 arylalkyl, a C6 to C20 aryl, a substituted or unsubstituted C1 to C20 alkylidene, a substituted or unsubstituted amino group, a C2 to C20 alkylalkoxy, or a C7 to C40 arylalkoxy; and n is 1 or 0;
(Cp.sup.7R.sup.c).sub.mB.sup.1(Cp.sup.8R.sup.d)M.sup.4Z.sup.2.sub.3-m[Chemical Formula 10] wherein M.sup.4 is a Group 4 transition metal; Cp.sup.7 and Cp.sup.8 are the same as or different from each other, and are each independently any one selected from the group consisting of cyclopentadienyl, indenyl, 4,5,6,7-tetrahydro-1-indenyl, and fluorenyl radicals, and these are substituted with a hydrocarbon having 1 to 20 carbon atoms; R.sup.c and R.sup.d are the same as or different from each other, and are each independently hydrogen, a C1 to C20 alkyl, a C1 to C10 alkoxy, a C2 to C20 alkoxyalkyl, a C6 to C20 aryl, a C6 to C10 aryloxy, a C2 to C20 alkenyl, a C7 to C40 alkylaryl, a C7 to C40 arylalkyl, a C8 to C40 arylalkenyl, or a C2 to C10 alkynyl; Z.sup.2 is a halogen atom, a C1 to C20 alkyl, a C2 to C10 alkenyl, a C7 to C40 alkylaryl, a C7 to C40 arylalkyl, a C6 to C20 aryl, a substituted or unsubstituted C1 to C20 alkylidene, a substituted or unsubstituted amino group, a C2 to C20 alkylalkoxy, or a C7 to C40 arylalkoxy; B.sup.1 is any one or more of carbon, germanium, silicon, phosphorus, or nitrogen atom-containing radicals, which crosslink a Cp.sup.3R.sup.c ring and a Cp.sup.4R.sup.d ring or crosslinks one Cp.sup.4R.sup.d ring to M.sup.2, or a combination thereof; and m is 1 or 0;
(Cp.sup.9R.sup.e)B.sup.2(J)M.sup.5Z.sup.3.sub.2[Chemical Formula 11] wherein M.sup.5 is a Group 4 transition metal; Cp.sup.9 is any one selected from the group consisting of cyclopentadienyl, indenyl, 4,5,6,7-tetrahydro-1-indenyl, and fluorenyl radicals, and these are substituted with a hydrocarbon having 1 to 20 carbon atoms; R.sup.e is hydrogen, a C1 to C20 alkyl, a C1 to C10 alkoxy, a C2 to C20 alkoxyalkyl, a C6 to C20 aryl, a C6 to C10 aryloxy, a C2 to C20 alkenyl, a C7 to C40 alkylaryl, a C7 to C40 arylalkyl, a C8 to C40 arylalkenyl, or a C2 to C10 alkynyl; Z.sup.3 is a halogen atom, a C1 to C20 alkyl, a C2 to C10 alkenyl, a C7 to C40 alkylaryl, a C7 to C40 arylalkyl, a C6 to C20 aryl, a substituted or unsubstituted C1 to C20 alkylidene, a substituted or unsubstituted amino group, a C2 to C20 alkylalkoxy, or a C7 to C40 arylalkoxy; B.sup.2 is any one or more of carbon, germanium, silicon, phosphorus, or nitrogen atom-containing radicals, which crosslink a Cp.sup.5R.sup.e ring to J, or a combination thereof; J is any one selected from the group consisting of NR.sup.f, O, PR.sup.f, and S; and R.sup.f is a C1 to C20 alkyl, aryl, substituted alkyl, or substituted aryl, ##STR00031## wherein A is hydrogen, a halogen, a C1 to C20 alkyl, a C2 to C20 alkenyl, a C6 to C20 aryl, a C7 to C20 alkylaryl, a C7 to C20 arylalkyl, a C1 to C20 alkoxy, a C2 to C20 alkoxyalkyl, a C3 to C20 heterocycloalkyl, or a C5 to C20 heteroaryl; D is O, S, N(R), or Si(R)(R), in which R and R are the same as or different from each other, and are each independently hydrogen, a halogen, a C1 to C20 alkyl, a C2 to C20 alkenyl, or a C6 to C20 aryl; L is a C1 to C10 straight or branched alkylene; B is carbon, silicon, or germanium; Q is hydrogen, halogen, C1 to C20 alkyl, C2 to C20 alkenyl, C6 to C20 aryl, C7 to C20 alkylaryl, or C7 to C20 arylalkyl; M is a Group 4 transition metal; X.sup.1 and X.sup.2 are the same as or different from each other, and are each independently a halogen, a C1 to C20 alkyl, a C2 to C20 alkenyl, a C6 to C20 aryl, a nitro group, an amido group, a C1 to C20 alkylsilyl, a C1 to C20 alkoxy, or a C1 to C20 sulfonate; C.sup.1 and C.sup.2 are, the same or different from each other, and are each independently represented by any one of the following Chemical Formula 13a, Chemical Formula 13b, and Chemical Formula 13c, excluding that both C.sup.1 and C.sup.2 are Chemical Formula 13c; ##STR00032## wherein R1 to R17 and R1 to R9 are the same as or different from each other, and are each independently hydrogen, a halogen, a C1 to C20 alkyl, a C2 to C20 alkenyl, a C1 to C20 alkylsilyl, a C1 to C20 silylalkyl, a C1 to C20 alkoxysilyl, a C1 to C20 alkoxy, a C6 to C20 aryl, a C7 to C20 alkylaryl, or a C7 to C20 arylalkyl, and two or more neighboring groups of R10 to R17 are connected to each other to form a substituted or unsubstituted aliphatic or aromatic ring.

12. The method of claim 1, wherein the metallocene catalyst is supported on one or more supports selected from the group consisting of silica, silica-alumina, and silica-magnesia.

13. The method of claim 2, wherein R.sup.8, R.sup.9, and R.sup.10 are each independently an isobutyl.

14. The method of claim 2, wherein is selected from the group consisting of titanium, zirconium, and hafnium.

15. The method of claim 2, wherein X is selected from the group consisting of F, Cl, Br, and I.

16. The method of claim 2, wherein the olefin monomer includes one or more selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eitocene, norbornene, norbornadiene, ethylidene norbornene, phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinyl benzene, and 3-chloromethylstyrene.

17. The method of claim 2, wherein the molecular weight modifier is used in an amount of about 10.sup.7 to 10.sup.1 parts by weight, based on a total of 100 parts by weight of the olefin monomer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic illustration of a cascade-CSTR reactor, in which a method of preparing a polyolefin of an embedment is performed, and a schematic flow of a polymerization process using the same.

DETAILED DESCRIPTION OF THE EMBODIMENT

(2) Hereinafter, the preferred examples are provided for better understanding. However, these examples are for illustrative purposes only, and the invention is not intended to be limited by these examples.

EXAMPLE

Preparation Example of Metallocene Catalyst

Synthesis Example 1

(3) Synthesis of [t-Bu-O(CH.sub.2).sub.6C.sub.5H.sub.4].sub.2ZrCl.sub.2

(4) t-butyl-O(CH.sub.2).sub.6C1 was prepared using 6-chlorohexanol according to a method described in the document (Tetrahedron Lett. 2951 (1988)), and reacted with NaC.sub.5H.sub.5 to obtain t-butyl-O(CH.sub.2).sub.6C.sub.5H.sub.5 (yield: 60%, b.p. 80 C./0.1 mmHg).

(5) 2.0 g (9.0 mmol) of t-butyl-O(CH.sub.2).sub.6C.sub.5H.sub.5 was dissolved in THF at 78 C., and 1.0 equivalent weight of normal butyl lithium (n-BuLi) was slowly added thereto. The temperature was raised to room temperature, and reaction was allowed to proceed for 8 h. This reaction solution was slowly added to a suspension solution of ZrCl.sub.4(THF).sub.2 (1.70 g, 4.50 mmol)/THF (30 mL) at 78 C., and then further reacted at room temperature for 6 h to obtain a final reaction solution.

(6) The reaction solution was dried under vacuum to remove all volatile materials, and then hexane was added to the remaining oily liquid, followed by filtration using a Schlenk glass filter. The filtrate solution was dried under vacuum to remove the solvent, and then hexane was added thereto to induce precipitation at a low temperature (20 C.). The resulting precipitate was filtered at a low temperature to obtain a [t-Bu-O(CH.sub.2).sub.6C.sub.5H.sub.4].sub.2ZrCl.sub.2 compound as a white solid with a yield of 92%. .sup.1H NMR and .sup.13C NMR data of [t-Bu-O(CH.sub.2).sub.6C.sub.5H.sub.4].sub.2ZrCl.sub.2 thus obtained are as follows.

(7) .sup.1H NMR (300 MHz, CDCl.sub.3): 6.28 (t, J=2.6 Hz, 2H), 6.19 (t, J=2.6 Hz, 2H), 3.31 (t-J=6.6 Hz, 2H), 2.62 (t, J=8 Hz, 2H), 1.7-1.3 (m, 8H), 1.17 (s, 9H)

(8) .sup.13C NMR (CDCl.sub.3): 135.09, 116.66, 112.28, 72.42, 61.52, 30.66, 30.61, 30.14, 29.18, 27.58, 26.00

Synthesis Example 2

(9) ##STR00023##

(10) 2-1. Preparation of Ligand Compound

(11) 2 g of fluorene was dissolved in 5 mL of MTBE, 100 mL of hexane, and then 5.5 mL of a 2.5 M n-BuLi hexane solution was added dropwise thereto in a dry ice/acetone bath, followed by stirring at room temperature overnight. 3.6 g of (6-(tert-butoxy)hexyl)dichloro(methyl)silane was dissolved in 50 mL of hexane, and a fluorene-Li slurry was transferred in a dry ice/acetone bath for 30 min, followed by stirring at room temperature overnight. Simultaneously, 5,8-dimethyl-5,10-dihydroindeno[1,2-b]indole (12 mmol, 2.8 g) was dissolved in 60 mL of THF, and 5.5 mL of a 2.5 M n-BuLi hexane solution was added dropwise thereto in a dry ice/acetone bath, followed by stirring at room temperature overnight. NMR sampling of the reaction solution of fluorene and (6-(tert-butoxy)hexyl)dichloro(methyl)silane was performed to confirm completion of the reaction, and then a 5,8-dimethyl-5,10-dihydroindeno[1,2-b]indole-Li solution was transferred to a dry ice/acetone bath. The mixture was stirred at room temperature overnight. After reaction, extraction was performed using ether/water, and an organic layer was dried over MgSO.sub.4 to obtain a ligand compound (Mw 597.90, 12 mmol). Two isomers were observed in 1H-NMR.

(12) .sup.1H NMR (500 MHz, d6-benzene): 0.30-0.18 (3H, d), 0.40 (2H, m), 0.65-1.45 (8H, m), 1.12 (9H, d), 2.36-2.40 (3H, d), 3.17 (2H, m), 3.41-3.43 (3H, d), 4.17-4.21 (1H, d), 4.34-4.38 (1H, d), 6.90-7.80 (15H, m)

(13) 2-2. Preparation of Metallocene Compound

(14) 7.2 g (12 mmol) of the ligand compound prepared in 2-1 was dissolved in 50 mL of diethylether, and 11.5 mL of a 2.5 M n-BuLi hexane solution was added dropwise in a dry ice/acetone bath, followed by stirring at room temperature overnight. The solution was dried under vacuum to obtain a brown sticky oil, which was dissolved in toluene to obtain a slurry. ZrCl.sub.4(THF).sub.2 was prepared, and 50 mL of toluene was added thereto to prepare a slurry. The 50 mL toluene slurry of ZrCl.sub.4(THF).sub.2 was transferred in a dry ice/acetone bath, followed by stirring at room temperature overnight. The solution was changed to a violet color. This reaction solution was filtered to remove LiCl. Toluene was removed from the filtrate by drying under vacuum, and then hexane was added thereto, followed by sonication for 1 h. The slurry was filtered, and the filtered solid was 6 g of a dark violet metallocene compound (Mw 758.02, 7.92 mmol, yield 66 mol %). Two isomers were observed in 1H-NMR.

(15) .sup.1H NMR (500 MHz, CDCl.sub.3): 1.19 (9H, d), 1.71 (3H, d), 1.50-1.70 (4H, m), 1.79 (2H, m), 1.98-2.19 (4H, m), 2.58 (3H, s), 3.38 (2H, m), 3.91 (3H, d), 6.66-7.88 (15H, m)

Synthesis Example 3

(16) ##STR00024##

(17) 3-1. Preparation of Ligand Compound

(18) 2.1 g (9 mmol) of 5,8-dimethyl-5,10-dihydroindeno[1,2-b]indole was added to a 250 mL flask, in which the atmosphere was replaced by an argon atmosphere, and dissolved in 50 mL of THF. 3.9 mL (9.75 mmol) of a 2.5 M n-BuLi hexane solution was added dropwise thereto in a dry ice/acetone bath, followed by stirring at room temperature overnight. Thus, a yellow slurry was obtained. 50 ml of hexane was further injected, and 1.35 g of (6-(tert-butoxy)hexyl)dichloro(methyl)silane was added dropwise using a syringe in a dry ice/acetone bath, and the temperature was raised to room temperature, followed by stirring overnight. A small amount of the reaction product was sampled to confirm completion of the reaction by 1H-NMR. The solvent was dried under vacuum, and then the resulting solid was dissolved in 70 ml of toluene and filtered to remove LiCl. The resulting filtrate was used as is in metallation.

(19) .sup.1H NMR (500 MHz, CDCl3): 0.24 (3H, m), 0.30-1.40 (10H, m), 1.15 (9H, d), 2.33 (6H, d), 3.19 (2H, m), 4.05 (6H, d), 4.00 (2H, d), 6.95-7.72 (14H, m)

(20) 3-2. Preparation of Metallocene Compound

(21) 2 mL of MTBE was added to the toluene solution of the ligand compound prepared in 3-1, and then 3.9 mL (9.75 mmol) of a 2.5 M n-BuLi hexane solution was added dropwise in a dry ice/acetone bath, followed by stirring at room temperature overnight. In another flask, 1.7 g (4.5 mmol) of ZrCl.sub.4(THF).sub.2 was prepared, and 100 ml of toluene was added thereto to prepare a slurry. The toluene slurry of ZrCl.sub.4(THF).sub.2 was transferred to the lithiated ligand in a dry ice/acetone bath. The mixture was stirred at room temperature overnight, and the color was changed to violet. The reaction solution was filtered to remove LiCl, and the resulting filtrate was dried under vacuum, followed by sonication with hexane. The slurry was filtered, and the filtered solid was 3.44 g of a dark violet metallocene compound (yield 92.6 mol %).

(22) .sup.1H NMR (500 MHz, CDCl3): 1.20 (9H, d), 1.74 (3H, d), 1.50-2.36 (10H, m), 2.54 (6H, d), 3.40 (2H, m), 3.88 (6H, d), 6.48-7.90 (14H, m)

Synthesis Example 4: Preparation of Metallocene Supported Catalyst

(23) 4-1. Drying of Support

(24) Silica (manufactured by Grace Davison, SYLOPOL 948) was dehydrated under vacuum at a temperature of 400 C. for 15 h.

(25) 4-2. Preparation of Supported Catalyst

(26) 10 g of the dry silica was placed in a glass reactor, and then 100 mL of toluene was added thereto, followed by stirring. 50 mL of a 10 wt % methylaluminoxane(MAO)/toluene solution was added thereto, and the mixture was stirred at 40 C. and allowed to slowly react. Thereafter, the unreacted aluminum compound was removed by washing with a sufficient amount of toluene, and remaining toluene was removed under reduced pressure. 100 mL of toluene was injected again, and then 0.25 mmol of the metallocene catalyst prepared in Synthesis Example 3 was dissolved in toluene and injected. The reaction was allowed to proceed for 1 h, and then 0.25 mmol of the metallocene catalyst of Synthesis Example 2 was dissolved in toluene and injected. The reaction was further allowed to proceed for 1 h. After completion of the reaction, 0.25 mmol of the metallocene catalyst of Synthesis Example 1 was dissolved in toluene and injected. The reaction was further allowed to proceed for 1 h. After completion of the reaction, stirring was stopped, and a toluene layer was separated and removed. 1.0 mmol of anilinium borate (N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, AB) was injected and stirred for 1 h. Then, toluene was removed therefrom under reduced pressure at 50 C. to prepare a supported catalyst.

Preparation Example of Molecular Weight Modifier

Preparation Example 1: Preparation of Molecular Weight Modifier

(27) ##STR00025##

(28) 1.08 g (3 mmol) of bis(2-butylcyclopenta-2,4-dien-1-yl)titanium(IV) chloride was placed in a 250 mL round bottom flask, and 50 mL of hexane was added thereto, followed by stirring. 6 mL (6 mmol) of triisobutyl aluminum (1 M in hexane) was added thereto, followed by stirring at room temperature for 3 days(d). The solvent was removed under vacuum to obtain a blue liquid mixture. Because this mixture was under reduction of titanium, it was not oxidized or color-changed. The blue mixture was used as it is without purification, as below.

(29) .sup.1H NMR (CDCl.sub.3, 500 MHz): 6.1-6.6 (br m, 8H), 2.2 (m, 4H), 1.0-1.8 (br m, 16H), 0.4 (br s, 24H)

Preparation Example 2: Preparation of Molecular Weight Modifier

(30) ##STR00026##

(31) 0.91 g (3 mmol) of bis(2-ethylcyclopenta-2,4-dien-1-yl)titanium(IV) chloride was placed in a 250 mL round bottom flask, and 50 mL of hexane was added thereto, followed by stirring. 6 mL (6 mmol) of triisobutyl aluminum (1 M in hexane) was added thereto, followed by stirring at room temperature for 3 d. The solvent was removed under vacuum to obtain a blue liquid mixture. Because this mixture was under reduction of titanium, it was not oxidized or color-changed. The blue mixture was used as it is without purification, as below.

(32) .sup.1H NMR (CDCl.sub.3, 500 MHz): 6.2-6.6 (br m, 8H), 1.0-1.8 (br m, 7H), 0.8 (br s, 24H)

Preparation Example 3: Preparation of Molecular Weight Modifier

(33) ##STR00027##

(34) 1.68 g (3 mmol) of bis(2-(6-t-butoxy-hexyl)cyclopenta-2,4-dien-1-yl)titanium(IV) chloride was placed in a 250 mL round bottom flask, and 50 mL of hexane was added thereto, followed by stirring. 6 mL (6 mmol) of triisobutyl aluminum (1 M in hexane) was added thereto, followed by stirring at room temperature for 3 d. The solvent was removed under vacuum to obtain a blue liquid mixture. Because this mixture was under reduction of titanium, it was not oxidized or color-changed. The blue mixture was used as it is without purification, as below.

(35) .sup.1H NMR (CDCl.sub.3, 500 MHz): 6.31 (br m, 8H), 3.5 (m, 4H), 1.1-1.9 (br m, 28H), 0.9 (br s, 18H), 0.3 (br s, 18H)

Preparation Example 4: Preparation of Molecular Weight Modifier

(36) ##STR00028##

(37) 0.83 g of bis(cyclopentadienyl)-titanium dichloride and 50 mL of hexane were serially placed in a 250 mL round bottom flask, followed by stirring. 6 mL of triisobutyl aluminum (1 M in hexane) was added thereto, followed by stirring at room temperature for 3 d. The solvent was removed under vacuum to obtain a green mixture. Because this mixture was under reduction of titanium, it was not oxidized or color-changed. The green mixture was used as it is without purification, as below.

(38) .sup.1H NMR (CDCl.sub.3, 500 MHz): 6.3-6.6 (br m, 10H), 1.2-1.8 (br m, 4H), 0.8 (br s, 18H)

Comparative Preparation Example 1: Preparation of Molecular Weight Modifier (Tebbe's Reagent)

(39) 0.83 g of bis(cyclopentadienyl)titanium dichloride and 50 mL of hexane were serially placed in a 250 mL round bottom flask, followed by stirring. 6 mL of trimethyl aluminum (1 M in hexane) was added thereto, followed by stirring at room temperature for 3 d. The solvent was removed under vacuum to obtain a green mixture. Because this mixture was under reduction of titanium, it was not oxidized or color-changed. The green mixture was used as it is without purification, as below.

(40) .sup.1H NMR (CDCl.sub.3, 500 MHz): 6.4 (br m, 10H), 1.1-1.8 (m, 7H), 0.9 (br s, 18H)

Experimental Example 1

(41) First, the molecular weight modifier of Comparative Preparation Example 1 was not in a solution form but in a slurry form, apparent to the naked eye.

(42) However, the molecular weight modifiers of Preparation Examples 1 to 3 showed excellent performance in the following solubility test.

(43) In particular, the molecular weight modifier of Preparation Example 1 was tested at concentrations of 0.1 M, 0.5 M, 1 M, and 2 M. After 1 d, no precipitates were observed at all concentrations of 0.1 M, 0.5 M, 1 M, and 2 M. After 7 d, no precipitates were observed at all concentrations of 0.1 M, 0.5 M, 1 M, and 2 M. After 30 d, no precipitates were observed at all concentrations of 0.1 M, 0.5 M, 1 M, and 2 M. That is, when the butyl group in the cyclopentadienyl group of the molecular weight modifier was substituted, no precipitation occurred even after 30 d. Further, the molecular weight modifier of Preparation Example 2 was tested at concentrations of 0.1 M, 0.5 M, 1 M, and 2 M. After 1 d, no precipitates were observed at all concentrations of 0.1 M, 0.5 M, 1 M, and 2 M. However, after 7 d, no precipitates were observed at concentrations of 0.1 M and 0.5 M, but precipitates were observed at concentrations of 1 M and 2 M. The molecular weight modifier of Preparation Example 3 was tested at concentrations of 1 M, 2 M, 3 M, and 5 M. After 1 d, no precipitates were observed at all of the concentrations. Even after 7 d and 30 d, no precipitates were observed at all of the concentrations.

(44) According to the solubility test, the molecular weight modifier of Comparative Preparation Example 1 generates precipitates upon feeding to reduce uniformity in a practical plant operation, in which hexane is used as a solvent in a pressure vessel.

Example of Slurry Polymerization

Example 1

(45) A continuous cascade CSTR reactor consisting of two reactors with a volume of 0.2 m.sup.3 was used (see FIG. 1).

(46) Hexane, ethylene, hydrogen, and triethylaluminum (TEAL) were fed into a first reactor at a flow rate of 35 kg/h, 10 kg/h, 1.5 g/h, and 40 mmol/h, respectively. The metallocene supported catalyst prepared in Synthesis Example 4 was fed thereto at a flow rate of 1 g/h (180 mol/h). In this regard, the first reactor was maintained at a temperature of 84 C. and a pressure of 9 bar. A retention time of the reactants was 2.5 h, and a slurry mixture containing polymers was continuously transferred to a second reactor while the liquid in the reactor was maintained at a predetermined level.

(47) Hexane, ethylene, 1-hexene, and triethylaluminum (TEAL) were fed into a second reactor at a flow rate of 21 kg/h, 6.5 kg/h, 100 mL/h, and 20 mmol/h, respectively. The molecular weight modifier prepared in Preparation Example 1 was fed thereto at a flow rate of 80 mol/h. In this regard, the second reactor was maintained at a temperature of 80 C. and a pressure of 7 bar. A retention time of the reactants was 1.5 h, and a polymer mixture was continuously transferred to a post reactor while the liquid in the reactor was maintained at a predetermined level.

(48) The post reactor was maintained at a temperature of C., and unreacted monomers were polymerized therein. The polymer product was passed through solvent removal equipment and a dryer to prepare final polyethylene. The polyethylene thus prepared was mixed with 1000 ppm of calcium stearate (manufactured by DOOBON Inc.) and 2000 ppm of a thermal stabilizer 21B (manufactured by SONGWON Industrial Co.), and prepared as a pellet.

Comparative Example 1

(49) A slurry polymerization was performed in the same manner as in Example 1, except that no molecular weight modifier was used.

Comparative Example 2

(50) A slurry polymerization was performed in the same manner as in Example 1, except that 0.1 mol % of the molecular weight modifier of Comparative Preparation Example 1 (Tebbe's reagent) was used.

Comparative Example 3

(51) A slurry polymerization was performed in the same manner as in Example 1, except that 0.3 mol % of the molecular weight modifier of Comparative Preparation Example 1 (Tebbe's reagent) was used.

Experimental Example 2

(52) Properties of polyethylenes prepared in Example 1 and Comparative Examples 1 to 4 were measured by the following method, and the results are shown in the following Table 1.

(53) a) Molecular weight (Mw): measured as a weight average molecular weight using gel permeation chromatography (GPC).

(54) b) Molecular weight distribution (MWD): measured as a value obtained by dividing the weight average molecular weight by the number average molecular weight using gel permeation chromatography (GPC).

(55) c) Catalytic activity: 0.5 g of TMA was dried in a reactor, and then about 100 mg of a supported catalyst was added to 400 mL of hexane, together with alkyl aluminum and the molecular weight modifier (MWE). Polymerization was allowed to proceed at 80 C. under 9 bar of ethylene for 1 h to obtain a polymer. The polymer was filtered and then dried overnight, and weighed to calculate its catalytic activity per unit time (h).

(56) d) Melt index (MI): measured at a temperature of 190 C. under a load of 21.6 kg in accordance with ASTM 1238 of American Society for Testing Materials.

(57) TABLE-US-00001 TABLE 1 Feed amount of Activity MI Catalyst MWE MWE (mol %) (kgPE/gCat) M.sub.w MWD (21.6) Example 1 Synthesis Preparation 0.1 1.9 330,000 3.8 1.0 Example Example 1 4 Comparative Synthesis 2.3 190,000 3.8 4.1 Example 1 Example 4 Comparative Synthesis Comparative 0.1 1.6 220,000 3.6 3.5 Example 2 Example Preparation 4 Example 1 Comparative Synthesis Comparative 0.3 0.9 300,000 3.8 1.4 Example 3 Example Preparation 4 Example 1

(58) As shown in Table 1, according to the present invention, when the slurry polymerization process was performed, the polymer showed excellent solubility for the polymerization solvent, and the molecular weight of the polymer was also effectively increased during olefin polymerization without reduction in the activity or copolymerization.

Example of Solution Polymerization

Example 2

(59) The prepared metallocene catalyst precursor was used to perform ethylene gas polymerization in a solution according to the polymerization scale and conditions in the following Table 2.

(60) First, two Andrew bottles with 300 mL volume were prepared and assembled with impeller parts, and the atmosphere inside a glovebox was replaced by argon. 180 mL of toluene was added to each of the Andrew bottles treated in the glovebox (treated with a small amount of TMA), and 5 mL of MAO (10 wt % toluene) solution was added. 20 mol of the metallocene catalyst (13 to 18 mg) prepared in Synthesis Example 1 was added to a 100 mL-flask separately prepared, and dissolved in 20 mL of toluene. Each 5 mL of the catalyst solutions was taken and injected into two Andrew bottles. The injected catalysts were reacted with MAO in the bottles to show specific different colors (pink, yellow, green, or purple). The molecular weight modifier prepared in Preparation Example 1 was injected into one of the two Andrew bottles. The bottle was placed in an oil bath heated to 90 C., and the upper part of the bottle was fixed in a mechanical stirrer. The bottle was purged with ethylene gas three times, and the mechanical stirrer was operated by opening an ethylene valve to allow reaction at 500 rpm for 30 min. A vortex line inside the bottle was frequently examined during the reaction. When the line became flat, the reaction was early terminated. After reaction, temperature was decreased to room temperature and gas inside the bottle was vented. The content was poured in about 400 mL of ethanol, and the solution was stirred for 1 h and then filtered. The polymer thus obtained was dried in a vacuum oven at 60 C. for 20 h to obtain a final polymer.

(61) TABLE-US-00002 TABLE 2 Catalyst content (mol) 5 Solvent type Toluene content (mL) 180 Activator type MAO solution content (mL) 10 Comonomer type 1-Hexene content (mL) -/5 Temperature ( C.) 90 Pressure (psig) 50 Reaction time (min) 30

Example 3

(62) A solution polymerization was performed in the same manner as in Example 2, except that the molecular weight modifier of Preparation Example 4 was used.

Example 4

(63) A solution polymerization was performed in the same manner as in Example 3, except that 0.3 mol % of the molecular weight modifier of Preparation Example 4 was used.

Comparative Example 4

(64) A solution polymerization was performed in the same manner as in Example 2, except that no molecular weight modifier was used.

Comparative Example 5

(65) A solution polymerization was performed in the same manner as in Example 2, except that the molecular weight modifier of Comparative Preparation Example 1 was used.

Comparative Example 6

(66) A solution polymerization was performed in the same manner as in Example 2, except that 0.3 mol % of the molecular weight modifier of Comparative Preparation Example 1 was used.

Experimental Example 3

(67) Properties of polyethylenes prepared in Examples 1 to 3 and Comparative Examples 5 to 7 were measured by the following method, and the results are shown in the following Table 3.

(68) a) Molecular weight (Mw): measured as a weight average molecular weight using gel permeation chromatography (GPC).

(69) b) Molecular weight distribution (MWD): measured as a value obtained by dividing the weight average molecular weight by the number average molecular weight using gel permeation chromatography (GPC).

(70) c) Catalytic activity: 0.5 g of TMA was dried in a reactor, and then about 100 mg of a supported catalyst was added to 400 mL of hexane, together with alkyl aluminum and the molecular weight modifier (MWE). Polymerization was allowed to proceed at 80 C. under 9 bar of ethylene for 1 h to obtain a polymer. The polymer was filtered and then dried overnight, and weighed to calculate its catalytic activity per unit time (h).

(71) d) Melt index (MI): measured at a temperature of 190 C. under a load of 2.16 kg in accordance with ASTM 1238 of American Society for Testing Materials.

(72) TABLE-US-00003 TABLE 3 Feed amount of Activity MI Catalyst MWE MWE (mol %) (kgPE/gCat) Mw MWD (2.16) Example 2 Synthesis Preparation 0.1 6.4 101,000 12.9 0.3 Example 1 Example 1 Example 3 Synthesis Preparation 0.1 6.0 107,000 11.1 0.2 Example 1 Example 4 Example 4 Synthesis Preparation 0.3 5.8 123,000 12.5 1.0 Example 1 Example 4 Comparative Synthesis 6.9 63,000 6.8 2.3 Example 4 Example 1 Comparative Synthesis Comparative 0.1 5.9 69,000 8.2 2.1 Example 5 Example 1 Preparation Example 1 Comparative Synthesis Comparative 0.3 3.0 92,000 10.2 0.5 Example 6 Example 1 Preparation Example 1

(73) As shown in Table 3, according to the present invention, when the solution polymerization process was performed, the polymer showed excellent solubility for the polymerization solvent, and the molecular weight of the polymer was also effectively increased during olefin polymerization without reduction in the activity or copolymerization.