Ethylene/alpha-olefin copolymer having excellent processibility

Abstract

The present disclosure relates to an ethylene/alpha-olefin copolymer having excellent processibility. The ethylene/alpha-olefin copolymer according to the present disclosure is excellent in both mechanical properties and processibility.

Claims

1. An ethylene/alpha-olefin copolymer having: a weight average molecular weight of 180,000 to 250,000 g/mol, a molecular weight distribution (Mw/Mn) of 5 to 20, a density of 0.950 to 0.965 g/cm.sup.3, a melt flow rate ratio MFR.sub.5/MFR.sub.2.16, measured at 190 C. according to ASTM 1238 of 5 to 10, and a spiral flow length of 15 to 25 cm, wherein the spiral flow length is evaluated by using a mold having a thickness of 1.5 mm, an injection temperature of 190 C., a mold temperature of 50 C., and an injection pressure of 90 bar, wherein the ethylene/alpha-olefin copolymer is prepared by polymerizing ethylene and alpha-olefin in the presence of a supported single metallocene catalyst including a metallocene compound of the following Chemical Formula 1; an aluminum-containing first cocatalyst; a borate-based second cocatalyst; and a support:
(Cp.sup.1R.sup.1).sub.n(Cp.sup.2R.sup.2)MX.sub.3-n[Chemical Formula 1] in Chemical Formula 1, M is a Group 4 transition metal; Cp.sup.1 and Cp.sup.2 are 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 radical, provided that both Cp.sup.1 and Cp.sup.2 are not cyclopentadienyl, and they are optionally substituted with a C1 to C20 hydrocarbon; R.sup.1 and R.sup.2 are 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; X 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, a C2 to C20 alkylalkoxy, or a C7 to C40 arylalkoxy; and n is 1 or 0.

2. The ethylene/alpha-olefin copolymer of claim 1, wherein the weight average molecular weight is 180,000 to 220,000 g/mol.

3. The ethylene/alpha-olefin copolymer of claim 1, wherein the molecular weight distribution (Mw/Mn) is 10 to 15.

4. The ethylene/alpha-olefin copolymer of claim 1, wherein the melt flow rate ratio is 5 to 8.

5. The ethylene/alpha-olefin copolymer of claim 1, wherein a C.sub.2 value of Equation 1 is 1.0 to 0.4, when a graph of complex viscosity (*[Pa.Math.s]) versus frequency ([rad/s]) of the ethylene/alpha-olefin copolymer is fitted to Power Law of the following Equation 1:
y=c.sub.1x.sup.c.sup.2[Equation 1] wherein x means frequency, y means complex viscosity, and c1 refers to a consistency index.

6. The ethylene/alpha-olefin copolymer of claim 1, wherein a plateau delta value in a Van Gurp Palmen plot of the ethylene/alpha-olefin copolymer is 0.1 to 1.0 rad, wherein in the Van Gurp-Palmen plot, the x-axis represents complex modulus (G, dyne/cm.sup.2) and the y-axis represents phase angle (d(delta)).

7. The ethylene/alpha-olefin copolymer of claim 1, wherein the alpha-olefin is at least one selected from the group consisting of 1-propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a graph of complex viscosity versus frequency of the copolymer prepared in Examples and Comparative Examples.

(2) FIG. 2 shows a vGP plot of the copolymer prepared in Examples and Comparative Examples.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) The present invention will be described in more detail with reference to the following Examples. However, the following Examples are for illustrative purposes only, and the present invention is not intended to be limited by the following Examples.

Preparation Example

(4) ##STR00004##

(5) 11.6 mL (100 mmol) of indene was added to a well-dried 250 mL schlenk flask, diluted with 80 mL of THF and stirred. 48 mL of 2.5M nBuLi hexane solution was slowly added thereto, and after 3 hours, 18.3 g (95 mmol) of 6-chloro hexyl tert-butyl ether was added and reacted for 12 hours. As the reaction proceeded, the reaction mixture turned into a bright pink suspension. After the reaction was completed, 100 mL of water was added to the mixture and extracted more than three times with 100 mL of ether. The obtained organic layer was dried with MgSO.sub.4, and the solvent was removed by filtration and reduced pressure. Thereafter, vacuum distillation at 100 C. and 20 mmHg was carried out to obtain a pure tether-indene ligand with a yield of 90%.

(6) .sup.1H NMR (500 MHz, CDCl.sub.3): 1.22 (9H, s), 1.62 (2H, m), 1.77 (2H, m), 2.58 (2H, m), 3.36 (2H, s), 3.42 (2H, m), 6.28 (1H, s), 7.19 (1H, m), 7.24 (1H, m), 7.40 (1H, m), 7.48 (1H, m)

(7) 10 mmol of the ligand obtained above was dissolved in 45 mL of ether, and then 5 mL (1.25 eq.) of nBuLi hexane solution was added thereto. After 6 hours, 20 g (0.95 eq.) of nBuCpZrCl.sub.3 toluene solution (0.273 g/mmol) was slowly added thereto at 78 C., and then the mixture was heated and further stirred for one day. The reaction mixture was passed through a filter, and the filtrate was concentrated, extracted with 100 mL of hexane and then concentrated again to obtain 90% or more of the desired compound.

(8) .sup.1H NMR (500 MHz, CDCl.sub.3): 0.93 (3H, t), 1.15 (9H, s), 1.241.55 (10H, m), 1.581.64 (2H, m), 3.34 (2H, m), 5.77 (0.5H, s), 5.82 (1H, m), 6.02 (0.5H, s), 6.40 (1H, s), 6.62 (1H, s), 7.26 (2H, m), 7.42 (2H, m)

Example 1

(9) Step 1) Preparation of a Supported Catalyst

(10) 49.7 mL of a 10 wt % methylaluminoxane (MAO)/toluene solution was added to a glass reactor, and 9.1 g of silica (Grace 952, particle size: 30 m, surface area: 300 m.sup.2/g, pore volume: 1.6 mL/g, pore diameter: 20 nm) was added thereto at 40 C. Thereafter, the mixture was stirred at 200 rpm for 16 hours while raising the temperature of the reactor to 60 C. And then, the temperature was lowered again to 40 C. Thereafter, 441 mg of the metallocene compound of Synthesis Example 1 was added thereto in a solution state after being dissolved in toluene, and the mixture was stirred for 2 hours. Subsequently, 730 mg of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate was added thereto in a solution state after being dissolved in 20 mL of toluene, and the mixture was stirred at 40 C. for 2 hours. After completion of the reaction, the stirring was stopped, and the toluene layer was separated and removed. Thereafter, the remaining toluene was removed at 40 C. under reduced pressure to prepare a supported single metallocene catalyst.

(11) Step 2) Preparation of a Ethylene/1-Butene Copolymer

(12) Polymerization was carried out using the above-prepared supported catalyst and a hexane slurry stirred tank process polymerization reactor. Polymerization conditions were 10 kg/hr of ethylene, 7 kg/cm.sup.2 of pressure, 82 C. of temperature, 3 g/hr of hydrogen, and 7 cc/min of 1-butene.

Example 2

(13) An ethylene/1-butene copolymer was prepared in the same manner as in Example 1 except that the polymerization condition was changed to 3.5 g/hr of hydrogen in the step 2 of Example 1.

Example 3

(14) An ethylene/1-butene copolymer was prepared in the same manner as in Example 1 except that the polymerization condition was changed to 3.6 g/hr of hydrogen in the step 2 of Example 1.

Example 4

(15) An ethylene/1-butene copolymer was prepared in the same manner as in Example 1 except that the polymerization condition was changed to 3.7 g/hr of hydrogen in the step 2 of Example 1.

Example 5

(16) An ethylene/1-butene copolymer was prepared in the same manner as in Example 1 except that the polymerization condition was changed to 3.3 g/hr of hydrogen in the step 2 of Example 1.

Comparative Examples 1 to 3

(17) As Comparative Examples, the following were used. Comparative Example 1: CAP602 (manufactured by INEOS) Comparative Example 2: Lutene H ME1000 (manufactured by LG Chem) Comparative Example 3: Lumicene M5220 (manufactured by Total)

Experimental Examples

(18) Properties of the copolymers of Examples and Comparative Examples were evaluated by the following methods.

(19) 1) Density: ASTM D1505

(20) 2) Melt flow rate (MFR, 5 kg/2.16 kg): measured at 190 C., ASTM 1238

(21) 3) MFRR (MFR.sub.5/MFR.sub.2.16): a ratio where MFR.sub.5 melt index (MI, 5 kg of load) is divided by MFR.sub.2.16 (MI, 2.16 kg of load).

(22) 4) Mn, Mw, MWD: The sample was pretreated by dissolving in 1,2,4-trichlorobenzene containing 0.0125% of BHT at 160 C. for 10 hours using PL-SP260. The number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured at 160 C. using PL-GPC220. MWD is represented by a ratio (Mw/Mn) between the weight average molecular weight and the number average molecular weight.

(23) 5) Graph of complex viscosity versus frequency: Complex viscosity was measured with ARES (Advanced Rheometric Expansion System) of TA instruments. Samples were made using a parallel plate with a diameter of 25.0 mm at 190 C. so as to have a gap of 2.0 mm. Measurement was carried out in a dynamic strain frequency sweep mode with a strain of 5%, a frequency of 0.05 rad/s to 500 rad/s, and a total of 41 points with 10 points at each decade. Power law fitting was carried out using TA Orchestrator which is a measurement program. This graph is shown in FIG. 1.

(24) 6) Plateau Delta: The Van Gurp-Palmen plot was obtained by plotting G* and delta among variables derived from dynamic frequency sweep test. This graph is shown in FIG. 2.

(25) 7) Spiral flow length: ENGEL 150 ton injection machine was used. The mold thickness was 1.5 mm, the injection temperature was 190 C., the mold temperature was 50 C., and the injection pressure was 90 bar.

(26) The results are listed in Table 1 below.

(27) TABLE-US-00001 TABLE 1 MFRR Plateau Spiral Density MFR.sub.2.16 (MFR.sub.5/MFR.sub.2.16) Mw MWD Delta S* (C.sub.2) Flow Unit g/cm.sup.3 g/10 min g/mol rad cm Ex. 1 0.952 0.22 6.7 200k 10.6 0.48 0.61 14.5 Ex. 2 0.952 0.45 7.2 170k 12.3 0.52 0.57 16.0 Ex. 3 0.953 0.52 6.9 168k 12.2 0.52 0.58 16.2 Ex. 4 0.953 0.56 6.9 165k 12.6 0.52 0.57 16.5 Ex. 5 0.951 0.33 6.6 180k 9.8 0.53 0.59 15.8 Comp. 0.952 0.78 3.4 140k 9.8 0.35 10.1 Ex. 1 Comp. 0.953 0.84 3.9 155k 13.4 0.37 12.0 Ex. 2 Comp. 0.952 2.00 3.5 85k 4.3 0.3 13.0 Ex. 3