Polyolefin resin composition and production method of same
Disclosed are a polyolefin resin composition and a production method using same. The polyolefin resin satisfies the following conditions: (1) melt index (MI2.16, 190° C., under a load of 2.16 kg) is 0.1 to 1.5 g/10 min; (2) density is 0.91 to 0.93 g/cc; (3) polydispersity Index (Mw (weight-average molecular weight)/Mn (number-average molecular weight)) is 3 to 7; (4) Mz (Z-average molecular weight)/Mw (weight-average molecular weight) is 2.3 to 4.5; and (5) COI(Comonomer Orthogonal Index) value calculated by Equation 1 in the specification is 5 to 12. In Equation 1, “SCB number at Mz” represents average number of branches derived from comonomers per 1000 carbon atoms at Z-average molecular weight (Mz), and “SCB number at Mn” represents average number of branches derived from comonomers per 1000 carbon atoms at number-average molecular weight (Mn) based on a molecular weight-comonomer distribution graph.
1. A polyolefin resin satisfying following properties (1) to (6):
(1) melt index (MI2.16, 190° C., under a load of 2.16 kg) is 0.1 to 1.5 g/10 min;
(2) density is 0.91 to 0.93 g/cc;
(3) polydispersity Indexe (weight-average molecular weight/number-average molecular weight (Mw/Mn)) is 3 to 7;
Z-average molecular weight/weight average molecular weight (Mz/Mw) is 2.3 to 4.5;
(5) Comonomer Orthogonal Index (COI) value calculated by the following Equation 1 is 5 to 12; and
(6) when a temperature rising elution fractionation (TREF) curve of multimodal distribution is deconvoluted, an area of the TREF curve having a peak at 60 to 70° C. is 40 to 65% of a total area of the TREF curve of multimodal distribution,
Comonomer
Orthogonal
Index
(
COI
)
=
SCB
number
at
Mz
-
SCB
number
at
Mn
log
Mz
-
log
Mn
[
Equation
1
]
in Equation 1, “SCB” represents an average number of short chain branches, “SCB number at Mz” represents average number of short chain branches derived from comonomers per 1000 carbon atoms at Z-average molecular weight (Mz), and “SCB number at Mn” represents average number of short chain branches derived from comonomers per 1000 carbon atoms at number-average molecular weight (Mn) when a molecular weight-comonomer distribution graph was prepared in which log value (log Mw) of molecular weight (Mw) is marked in x-axis of the graph and the amount of polymer (dw_dlog Mw) corresponding to the log value (log Mw) and average number of short chain branches (SCB) derived from comonomer (number of branches per 1,000 carbon atoms, unit: number/1,000 C) corresponding to the log value (log Mw) are marked in y-axis of the graph, and wherein melt flow rate ratio (MFRR; MI21.6/MI2.16, the MI21.6 is a melt index measured at 190° C. and 21.6 kg load condition) is 17 to 40.
2. The polyolefin resin of claim 1 , wherein when the TREF (Temperature curve is deconvoluted, a number of deconvoluted peaks in the TREF curve is 2 to 5.
3. A method for preparing a polyolefin resin, comprising the steps of:
polymerizing a first polymer having high density and high melt index (MI) by introducing a metallocene supported catalyst, ethylene and alpha-olefin to a first reactor of two or more serially connected reactors selected from the group consisting of a slurry polymerization reactor and a gas phase polymerization reactor; and
polymerizing polyolefin resin by transferring the first polymer to a second reactor of the two or more serially connected reactors,
wherein the polyolefin resin satisfies the following physical properties: (1) melt index (MI2.16, 190° C., under a load of 2.16 kg) is 0.1 to 1.5 g/10 min; (2) density is 0.91 to 0.93 g/cc; (3) polydispersity Index (weight average molecular weight)/(number average molecular weight (Mw/Mn)) is 3 to 7; (4) Z-average molecular weight/weight-average molecular weight (Mz/Mw) is 2.3 to 4.5; (5) comonomer orthogonal index (COI) value calculated by the following Equation 1 is 5 to 12; and (6) when a temperature rising elution fractionation (TREF) curve of multimodal distribution is deconvoluted, an area of the TREF curve having a peak at 60 to 70° C. is 40 to 65% of a total area of the TREF curve of multimodal distributio,
Comonomer
Orthogonal
Index
(
COI
)
=
SCB
number
at
Mz
-
SCB
number
at
Mn
log
Mz
-
log
Mn
[
Equation
1
]
in Equation 1, “SCB” represents an average number of short chain branches, “SCB number at Mz” represents average number of short chain branches derived from comonomers per 1000 carbon atoms at Z-average molecular weight (Mz), and “SCB number at Mn” represents average number of short chain branches derived from comonomers per 1000 carbon atoms at number-average molecular weight (Mn) when a molecular weight-comonomer distribution graph was prepared in which log value (log Mw) of molecular weight (Mw) is marked in x-axis of the graph and the amount of polymer (dw_dlog Mw) corresponding to the log value (log Mw) and average number of short chain branches (SCB) derived from comonomer (number of branches per 1,000 carbon atoms, unit: number/1,000 C) corresponding to the log value (log Mw) are marked in y-axis of the graph, and wherein melt flow rate ratio (MFRR; MI21.6/MI2.16, the MI21.6 is a melt index measured at 190° C. and 21.6 kg load condition) is 17 to 40.
4. A method for preparing a polyolefin resin, comprising the steps of:
introducing a metallocene supported catalyst, ethylene and alpha-olefin into a reactor selected from the group consisting of a slurry polymerization reactor and a gas phase polymerization reactor, and then performing a polymerization process, to prepare a first polymer having a melt index (MI) of 4 to 15 and a density of 0.925 to 0.940 g/cc;
introducing a metallocene supported catalyst, ethylene and alpha-olefin into another reactor selected from the group consisting of a slurry polymerization reactor and a gas phase polymerization reactor, and then performing a polymerization process, to prepare a second polymer having MI of 0.1 to 0.5 and a density of 0.900 to 0.915 g/cc; and
melt-blending the first polymer and second polymer component to prepare the polyolefin resin,
wherein the polyolefin resin satisfies the following physical properties: (1) melt index (MI2.16, 190° C., under a load of 2.16 kg) is 0.1 to 1.5 g/10 min; (2) density is 0.91 to 0.93 g/cc;
(3) polydispersity Index (weight average molecular weight)/(number average molecular weight (Mw/Mn)) is 3 to 7; (4) Z-average molecular weight/weight-average molecular weight (Mz/Mw) is 2.3 to 4.5; (5) comonomer orthogonal index (COI) value calculated by the following Equation 1 is 5 to 12; and (6) when a temperature rising elution fractionation (TREF) curve of multimodal distribution is deconvoluted, an area of the TREF curve having a peak at 60 to 70° C. is 40 to 65% of a total area of the TREF curve of multimodal distribution,
Comonomer
Orthogonal
Index
(
COI
)
=
SCB
number
at
Mz
-
SCB
number
at
Mn
log
Mz
-
log
Mn
[
Equation
1
]
in Equation 1, “SCB” represents an average number of short chain branches, “SCB number at Mz” represents average number of short chain branches derived from comonomers per 1000 carbon atoms at Z-average molecular weight (Mz), and “SCB number at Mn” represents average number of short chain branches derived from comonomers per 1000 carbon atoms at number-average molecular weight (Mn) when a molecular weight-comonomer distribution graph was prepared in which log value (log Mw) of molecular weight (Mw) is marked in x-axis of the graph and the amount of polymer (dw_dlog Mw) corresponding to the log value (log Mw) and average number of short chain branches (SCB) derived from comonomer (number of branches per 1,000 carbon atoms, unit: number/1,000 C) corresponding to the log value (log Mw) are marked in y-axis of the graph, wherein melt flow rate ratio (MFRR; MI21.6/M12.16, the MI21.6 is a melt index measured at 190° C. and 21.6 kg load condition) is 17 to 40.
5. The method of claim 3 , wherein the metallocene supported catalyst comprises a metallocene compound in which a central metal is hafnium.
6. The method of claim 5 , wherein the metallocene compound contains one or more ligands selected from the group consisting of 1-propyl cyclopentadienyl radical and 1-butyl cyclopentadienyl radical.
7. The method of claim 4 , wherein the metallocene supported catalyst comprises a metallocene compound in which a central metal is hafnium.
8. The method of claim 7 , wherein the metallocene compound contains one or more ligands selected from the group consisting of 1-propyl cyclopentadienyl radical and 1-butyl cyclopentadienyl radical.
9. The method of claim 4 , wherein a content ratio of the first polymer and the second polymer is 50:50 to 35:65 based on total weight of the polyolefin resin.