阅读说明：本技术 聚烯烃树脂组合物和使用其的拉伸膜 (Polyolefin resin composition and stretched film using same ) 是由 金大桓 崔二永 李玹燮 宣淳浩 裴锺永 于 2019-03-20 设计创作，主要内容包括：本发明提供了表现出优异的长期耐久性以及改善的物理性质的聚烯烃树脂组合物,以及使用其制备的制品。(The present invention provides a polyolefin resin composition exhibiting excellent long-term durability and improved physical properties, and an article manufactured using the same.)

1. A polyolefin resin composition comprising in a weight ratio of 3:1 to 1:3

i) An ethylene homopolymer having a melt index of less than 0.8g/10min (measured at 190 ℃ under a load of 2.16kg according to ASTM D1238); and

ii) an ethylene copolymer comprising repeat units derived from α -olefins having a carbon number of 4 or more, a melt index of 0.5g/10min or less (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg), and an average number of Short Chain Branches (SCB) per 1000 carbon atoms in a molecular weight distribution profile determined by GPC-FTIR of 6 or less;

wherein the composition satisfies the following requirements 1) to 5):

1) density (measured according to ASTM D1505): 0.930g/cc to 0.960g/cc

2) Melt index (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg): 0.1g/10min to 0.5g/10min

3) Melt flow Rate ratio (MI)₅/MI_2.16): less than 3.1

4) Molecular weight distribution: 2.5 to 4.2

5) Normalized viscosity according to equation 1 below: 20 to 30 percent

[ equation 1]

Mi: initial viscosity of polyolefin resin composition (measured at 240 ℃ C. under oxygen-free conditions)

Mf: viscosity of the polyolefin resin composition measured after the polyolefin resin composition was stored at 240 ℃ for 2000 seconds in the presence of oxygen.

2. The polyolefin resin composition according to claim 1, wherein the polyolefin resin composition has a weight average molecular weight of 50,000 to 250,000g/mol as measured by gel permeation chromatography.

3. The polyolefin resin composition of claim 1, wherein the polyolefin resin composition has a tensile strength of greater than 2.0gf/den by forming a film having a thickness of 100 μm as measured according to ASTM D1709A.

4. The polyolefin resin composition according to claim 1, wherein the resin composition has a residual stress measured according to DMA (dynamic mechanical analysis) (100s, 140 ℃) of less than 1%.

5. The polyolefin resin composition of claim 1, wherein the polyolefin resin composition has a density of 0.940g/cc to 0.950g/cc (measured according to ASTM D1505), a melt index of 0.2g/10min to 0.5g/10min (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg), a melt flow rate ratio (MI) of 2 to 3₅/MI_2.16) A molecular weight distribution of 2.5 to 4.0; 25% to 30%% normalized viscosity according to equation 1, and 0.1% to 0.4% residual stress measured according to DMA (dynamic mechanical analysis) (100s, 140 ℃).

6. The polyolefin resin composition of claim 1, wherein the ethylene homopolymer has a melt index (measured at 190 ℃, under a load of 2.16 kg) of 0.4g/10min to 0.8g/10min, and a density of 0.940g/cc to 0.960g/cc, measured according to ASTM D1505.

7. The polyolefin resin composition according to claim 1, wherein the α -olefin having 4 or more carbon atoms is 1-butene.

8. The polyolefin resin composition of claim 1, wherein the ethylene copolymer has a melt index (measured at 190 ℃, under a load of 2.16kg according to ASTM D1238) of from 0.1g/10min to 0.4g/10min, an average SCB number per 1000 carbon atoms in a molecular weight profile measured by GPC-FTIR of from 3 to 6, and a density of from 0.940g/cc to 0.950g/cc according to ASTM D1505.

9. The polyolefin resin composition according to claim 1, wherein the SCB is a short chain branch having a carbon number of 4 to 7.

10. A method of preparing a polyolefin resin composition comprising:

polymerizing ethylene monomer and α -olefin having a carbon number of 4 or more while introducing hydrogen in an amount of 0.1g/hr to 0.5g/hr in the presence of a hybrid supported catalyst in which a first transition metal compound of the following chemical formula 1 and a second transition metal compound of the following chemical formula 2 are supported together in a carrier to produce an ethylene copolymer comprising repeating units derived from α -olefin having a carbon number of 4 or more, the ethylene copolymer having a melt index of 0.5g/10min or less (measured at 190 ℃, 2.16kg load according to ASTM D1238), and an average Short Chain Branching (SCB) number per 1000 carbon atoms in a molecular weight distribution profile determined by GPC-FTIR of 6 or less, and

mixing the ethylene copolymer with an ethylene homopolymer having a melt index (measured according to ASTM D1238 at 190 ℃ under a load of 2.16 kg) of 0.8g/10min or less in a weight ratio of 3:1 to 1:3,

wherein the α -olefin is introduced in an amount of 2.0 to 3.0ml/min based on 10kg/hr of the introduction of the ethylene monomer:

[ chemical formula 1]

(Cp¹(R^a)_x)_n(Cp²(R^b)_y)M¹Z¹ _3-n

Wherein, in chemical formula 1,

M¹is a group 4 transition metal;

Cp¹and Cp²Identical or different and are each independently cyclopentadienyl, indenyl, 4,5,6, 7-tetrahydro-1-indenyl or fluorenyl, unsubstituted or substituted by a C1 to C20 hydrocarbon group;

R^aand R^bThe same or different, and each independently is hydrogen, C1 to C20 alkyl, C1 to C10 alkoxy, C2 to C20 alkoxyalkyl, C6 to C20 aryl, C6 to C10 aryloxy, C2 to C20 alkenyl, C7 to C40 alkylaryl, C7 to C40 arylalkyl, C8 to C40 arylalkenyl, or C2 to C10 alkynyl;

Z¹is a halogen atom, a C1 to C20 alkyl group, a C2 to C10 alkenyl group, a C7 to C40 alkylaryl group, a C7 to C40 arylalkyl group, a C6 to C20 aryl group, a substituted or unsubstituted C1 to C20 alkylidene group, a substituted or unsubstituted amino group, a C2 to C20 alkylalkoxy group, or a C7 to C40 arylalkoxy group;

n is a number of 0 or 1,

x and y are each independently an integer of 0 to 4,

[ chemical formula 2]

(Cp³(R^e)_z)B²(J)M²Z² ₂

Wherein, in chemical formula 2,

M²is a group 4 transition metal;

Cp³is cyclopentadiene unsubstituted or substituted by C1-C20 hydrocarbon groupsAn indenyl, 4,5,6, 7-tetrahydro-1-indenyl or fluorenyl group;

R^eis hydrogen, C1 to C20 alkyl, C1 to C10 alkoxy, C2 to C20 alkoxyalkyl, C6 to C20 aryl, C6 to C10 aryloxy, C2 to C20 alkenyl, C7 to C40 alkylaryl, C7 to C40 arylalkyl, C8 to C40 arylalkenyl, or C2 to C10 alkynyl;

Z²is a halogen atom, a C1 to C20 alkyl group, a C2 to C10 alkenyl group, a C7 to C40 alkylaryl group, a C7 to C40 arylalkyl group, a C6 to C20 aryl group, a substituted or unsubstituted C1 to C20 alkylidene group, a substituted or unsubstituted amino group, a C2 to C20 alkylalkoxy group, or a C7 to C40 arylalkoxy group;

B²is one or more groups containing carbon, germanium, silicon, phosphorus or nitrogen atoms, or combinations thereof, which are substituted with (Cp)³(R^e)_z) The ring is crosslinked with J;

j is selected from NR^f、O、PR^fAnd S, R^fIs a substituted or unsubstituted C1 to C20 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group, and

z is an integer from 0 to 4.

11. The method of preparing a polyolefin resin composition according to claim 10, further comprising the steps of: homopolymerizing an ethylene monomer while introducing hydrogen in an amount of 0.1g/hr to 1g/hr in the presence of a hybrid supported catalyst in which the first transition metal compound of the above chemical formula 1 and the second transition metal compound of the above chemical formula 2 are supported together in a carrier, after preparing the ethylene copolymer and before mixing the ethylene copolymer with an ethylene homopolymer, or before preparing the ethylene copolymer, to prepare an ethylene homopolymer having a melt index (measured at 190 ℃, under a load of 2.16kg according to ASTM D1238) of 0.8g/10min or less.

12. The method of preparing a polyolefin resin composition according to claim 10, wherein said first transition metal compound is selected from the group consisting of:

13. the method of preparing a polyolefin resin composition according to claim 10, wherein said second transition metal compound is selected from the group consisting of:

14. an article produced using the polyolefin resin composition according to claim 1.

15. The article of claim 14, wherein the article is a stretch film or a wrap.

Technical Field

Cross Reference to Related Applications

This application claims the rights of korean patent application No. 10-2018-0032576, filed on 21.3.2018 to the korean intellectual property office, and korean patent application No. 10-2019-0031058, filed on 19.3.2019 to the korean intellectual property office, the disclosures of which are incorporated herein by reference in their entirety.

The present invention relates to a polyolefin resin composition exhibiting excellent long-term durability and improved properties, and a stretched film prepared using the same.

Background

Stretch films are commonly used as packaging films for securing various items during transport and storage, while preventing damage from external moisture and contaminants. Therefore, durability, soil resistance and moisture resistance as well as a thin thickness are required for the stretched film.

Although polyethylene, polyvinyl chloride, polybutadiene or the like is generally used in the production of stretched films, they are poor in durability, and therefore, the films are easily torn during transportation or packaging, or articles within the films are damaged due to moisture permeation.

Therefore, a method of using a linear low density polyethylene resin having excellent strength and rigidity has been proposed, and recently, a linear low density polyethylene resin which is prepared using a metallocene catalyst and has more excellent strength and rigidity is increasingly used. However, although the linear low density polyethylene resin prepared using the metallocene catalyst shows excellent strength and rigidity, it may increase a motor load of an extruder due to its melting characteristics, thereby decreasing productivity.

Further, a method of using a high tenacity resin in combination with a polyethylene resin has been proposed, but when a product such as a bag net (balet) is produced, long-term durability may be reduced.

Factors affecting long-term durability are the properties of the resin itself and additives. Although conventional high-toughness resins have a narrow melt flow rate ratio (MRFF) and thus excellent initial properties, their long-term durability is low due to high internal stress and shear stress generated during Dynamic Mechanical Analysis (DMA). Also, since the resin having a narrow MFRR has hard resin crystals, even if it is improved using an additive, the additive is difficult to penetrate.

Disclosure of Invention

Technical purpose

An object of the present invention is to provide a polyolefin resin composition exhibiting excellent long-term durability and improved properties, and a method for preparing the same.

It is another object of the present invention to provide an article, such as a stretch film or a net, etc., prepared using the polyolefin resin composition.

Technical scheme

According to an embodiment of the present invention, there is provided a polyolefin resin composition comprising in a weight ratio of 3:1 to 1:3

i) An ethylene Homopolymer (HOMO) having a melt index of 0.8g/10min or less (measured at 190 ℃ under a load of 2.16kg according to ASTM D1238); and

ii) an ethylene Copolymer (COMO) comprising repeating units derived from α -olefins having a carbon number of 4 or more, a melt index of 0.5g/10min or less (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg), and an average number of Short Chain Branches (SCB) per 1000 carbon atoms in a molecular weight distribution profile determined by GPC-FTIR of 6 or less;

wherein the composition satisfies the following requirements 1) to 5):

1) density (measured according to ASTM D1505): 0.930g/cc to 0.960g/cc

2) Melt index (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg): 0.1g/10min to 0.5g/10min

3) Melt flow Rate ratio (MI)₅/MI_2.16): less than 3.1

4) Molecular weight distribution: 2.5 to 4.2

5) Normalized viscosity according to equation 1 below: 20 to 30 percent

[ equation 1]

Mi: initial viscosity of polyolefin resin composition (measured at 240 ℃ C. under oxygen-free conditions)

Mf: viscosity of the polyolefin resin composition measured after the polyolefin resin composition was stored at 240 ℃ for 2000 seconds in the presence of oxygen.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless explicitly stated or otherwise evident from the context, singular expressions also include plural expressions thereof. As used herein, the terms "comprises," "comprising," "includes" or "having," etc., are intended to indicate the presence of the stated features, quantities, steps, elements, or combinations thereof, as practiced, and they are not intended to preclude the possibility of one or more other features, numbers, steps, elements, or combinations thereof, being present or added.

While the present invention is susceptible to various modifications and alternative forms, specific examples will be described and illustrated in detail below. It should be understood, however, that these examples are not intended to limit the invention to the particular disclosure, and the invention includes all modifications, equivalents, and alternatives thereof without departing from the spirit and technical scope of the invention.

Throughout the specification, "olefin polymer" may be an ethylene homopolymer, or may refer to a copolymer of ethylene and α -olefin, comprising a plurality of blocks or segments of repeating units, which may differ from one another by physical or chemical properties, such as one or more property values (e.g., content (mole fraction), crystallinity, density or melting point, etc.) of the repeating units derived from ethylene or propylene, respectively, and α -olefin.

In addition, "polymer chain" contained in "olefin polymer" may refer to a number of polymer chains formed when the olefin polymer is polymerized and prepared. The molecular weight of such polymer chains can be confirmed by a molecular weight distribution curve using Gel Permeation Chromatography (GPC). Also, the distribution of SCB (short chain branching) in the polymer chain can be confirmed by analyzing the block copolymer using fourier transform infrared spectroscopy (FT-IR). And, can pass through¹H-nuclear magnetic resonance spectroscopy (¹H-NMR) to confirm the content of the polymer chain. Such polymer chains may be defined as "polymer chains" contained in "olefin polymers".

In addition, "SCB (short chain branching)" in the "olefin polymer" may refer to a chain in which the number of carbons bonded to the longest main chain in a branched form is 4 or more, more specifically 4 to 7, 4 to 6, or 4, among the above-mentioned polymer chains. The number of SCBs can be calculated by analyzing the molecular weight distribution profile of the olefin polymer measured by GPC-FTIR.

Hereinafter, a polyolefin resin composition, a method of preparing the same, and an article using the same according to embodiments of the present invention will be explained.

In the present invention, when a polyolefin resin composition for a stretch film is prepared, an ethylene Homopolymer (HOMO) containing no SCB and having a low MI is used, thereby improving long-term durability, and at the same time, in order to compensate for the problem of deterioration in processability due to the use of the ethylene Homopolymer (HOMO), an ethylene Copolymer (COMO) having a low MI and an optimized SCB content by controlling hydrogen input during polymerization is used in combination, thereby narrowing MRFF of the resin composition, reducing MI, thereby exhibiting excellent long-term durability, and at the same time, improving properties such as mechanical strength and processability, and the like.

Specifically, the polyolefin resin composition according to one embodiment of the present invention comprises, in a weight ratio of 3:1 to 1: 3:

i) an ethylene homopolymer having a melt index of less than 0.8g/10min (measured at 190 ℃ under a load of 2.16kg according to ASTM D1238); and

ii) an ethylene copolymer comprising repeat units derived from α -olefins having a carbon number of 4 or more, a melt index of 0.5g/10min or less (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg), and an average number of Short Chain Branches (SCB) per 1000 carbon atoms in a molecular weight distribution profile determined by GPC-FTIR of 6 or less;

thus, the composition satisfies the following requirements 1) to 5):

1) density (measured according to ASTM D1505): 0.930g/cc to 0.960g/cc

2) Melt index (measured according to ASTM D1238 at 190 ℃, under a load of 2.16 kg): 0.1g/10min to 0.5g/10min

3) Melt flow Rate ratio (MI)₅/MI_2.16): less than 3.1

4) Molecular weight distribution: 2.5 to 4.2

5) Normalized viscosity according to equation 1 below: 20 to 30 percent

[ equation 1]

Mi: initial viscosity of polyolefin resin composition (measured at 240 ℃ C. under oxygen-free conditions)

Mf: viscosity of the polyolefin resin composition measured after the polyolefin resin composition was stored at 240 ℃ for 2000 seconds in the presence of oxygen.

i) Ethylene homopolymer

In the polyolefin resin composition according to one embodiment of the present invention, the ethylene homopolymer does not contain SCB and has an MI of 0.8g/10min or less, more specifically, 0.4g/10min to 0.8g/10min, by controlling the hydrogen input during the preparation. If the MI of the ethylene homopolymer exceeds 0.8g/10min, it may be difficult to achieve long-term durability, i.e., the effect of improving the lifetime characteristics.

In the present invention, the MI of an ethylene homopolymer can be measured at 190 ℃ under a load of 2.16kg according to ASTM D1238.

Furthermore, the ethylene homopolymer has a high density and a low MI.

Specifically, the ethylene homopolymer may have a density of 0.940g/cc or greater, or from 0.940g/cc to 0.960g/cc, specifically from 0.948g/cc to 0.960g/cc, more specifically from 0.948g/cc to 0.952g/cc, as measured according to ASTM D1505. The ethylene homopolymer has a high density and thus exhibits excellent mechanical properties, and has a high draw ratio and thus exhibits high strength due to high elongation, and thus, it is very useful for preparing high tenacity fibers (e.g., ropes, fishing nets, etc.).

Although the method for preparing the ethylene homopolymer is not particularly limited, it may be prepared, for example, by polymerizing ethylene monomers using a metallocene catalyst. At this time, hydrogen may be optionally further introduced.

As an example of preparing an ethylene homopolymer, in the present invention, an ethylene homopolymer that realizes the above properties may be prepared by polymerizing ethylene monomers while introducing hydrogen in an amount of 0.1g/hr to 1.5g/hr in the presence of a hybrid supported catalyst in which a first transition metal compound of the following chemical formula 1 and a second transition metal compound of the following chemical formula 2 are supported together in a carrier:

[ chemical formula 1]

(Cp¹(R^a)_x)_n(Cp²(R^b)_y)M¹Z¹ _3-n

[ chemical formula 2]

(Cp³(R^e)_z)B²(J)M²Z² ₂

Wherein, in chemical formulas 1 and 2, M¹、M²、Cp¹、Cp²、Cp³、R^a、R^b、R^e、Z¹、Z²、B²J, n, x, y and z are as defined in ii) the ethylene Copolymer (COMO) described below.

The specific type and amount of the hybrid supported catalyst will be explained in more detail in the ii) ethylene Copolymer (COMO) below.

Further, as for the polymerization reaction, various polymerization methods known as polymerization reaction of ethylene monomer such as continuous solution polymerization, bulk polymerization, suspension polymerization, slurry polymerization, or emulsion polymerization may be used, and the polymerization reaction may be performed by homopolymerizing ethylene monomer using a continuous slurry polymerization reactor, a loop slurry reactor, a gas phase reactor, or a solution reactor.

Further, during the polymerization reaction, hydrogen can be introduced at a rate of 0.1g/hr to 1.5g/hr, more specifically, 0.1g/hr to 1.0g/hr, or 0.2g/hr to 0.7g/hr, at a reactor pressure of 1 atm. In the case where hydrogen is introduced within the above range, the density and MI of the ethylene homopolymer produced can be controlled within the above range while exhibiting sufficient catalytic activity. If the hydrogen input is not within the above range and exceeds 1.5g/hr, MI may rapidly increase, exceeding 0.8g/10min, and thus, it may be difficult to improve physical and mechanical properties of the polyethylene resin composition comprising the same.

Further, during the polymerization reaction, the temperature can be 25 ℃ to 500 ℃, specifically 25 ℃ to 200 ℃, more specifically 50 ℃ to 150 ℃. Also, the polymerization pressure may be 1Kgf/cm²To 100kgf/cm²Specifically 1Kgf/cm²To 50kgf/cm²More specifically 5Kgf/cm²To 30kgf/cm²。

The ethylene homopolymer may be included in an amount of 25 to 75 wt%, based on the total weight of the polyolefin resin composition. If the content of the ethylene homopolymer is less than 25 wt%, it may be difficult to obtain the effect of improving the aging characteristics due to the inclusion of the ethylene homopolymer, and if the content of the ethylene homopolymer is more than 75 wt%, it may be impossible to stretch the resin composition due to the reduction in processability. In view of the effect of improving the aging characteristics of the polyolefin resin composition according to the control of the ethylene homopolymer content, the ethylene homopolymer content may be 25 to 50 wt% based on the total weight of the resin composition.

ii) ethylene Copolymer (COMO)

In the polyolefin resin composition according to the present invention, an ethylene copolymer comprising repeating units derived from ethylene and a α -olefin having a carbon number of 4 or more, respectively, and having an MI of 0.5g/10min or less (measured at 190 ℃ under a load of 2.16kg according to ASTM D1238), the average number of SCBs per 1000 carbon atoms in a molecular weight distribution profile determined by GPC-FTIR being 6 or less, is prepared by polymerization of ethylene and a α -olefin having a carbon number of 4 or more by controlling hydrogen input during polymerization using a metallocene catalyst.

The ethylene copolymers conventionally used for the preparation of high tenacity fibers have a problem of long-term durability, i.e., low life characteristics. Therefore, a method of reducing MI has been proposed, but it is difficult to control MI with a conventional catalyst, and in the case of reducing MI with a reduced hydrogen input, long-term durability of the resin composition is still low because double bonds remain in the polymer.

Therefore, in the present invention, during the preparation of an ethylene copolymer using a metallocene catalyst, the hydrogen input is controlled to reduce the MI to 0.5g/10min or less, thereby preventing the deterioration of long-term durability of the resin composition with the generation of double bonds while exhibiting excellent mechanical strength and excellent processability. If the MI of the ethylene copolymer exceeds 0.5g/10min, long-term durability and mechanical properties of the resin composition may be deteriorated due to mixing with the above ethylene homopolymer. More specifically, the MI of the ethylene copolymer may be from 0.1g/10min to 0.4g/10 min.

Meanwhile, in the present invention, as described above, SCB is generated in the form of a branch chain by introducing α -olefin comonomer (e.g., 1-butene or 1-hexene) into the main carbon chain during polymerization, and more excellent processability can be exhibited due to higher copolymerizability of the comonomer during polymerization.

In addition, the polyolefin resin composition according to one embodiment of the present invention includes a polyethylene homopolymer having a low MI to improve long-term durability. However, since the ethylene homopolymer does not contain SCB, the processability of the resin composition may be deteriorated. Therefore, in the present invention, by optimizing SCB of the ethylene copolymer mixed with the ethylene homopolymer, the processability can be improved while improving the life characteristics.

By reducing the hydrogen input below a certain value when producing the ethylene copolymer, the amount of SCB affecting the lifetime characteristics can be reduced. Specifically, if the hydrogen input is reduced during the polymerization reaction, the amount of low molecular weight compounds produced can be reduced, thereby reducing the density. Thus, by reducing the comonomer input to provide the optimum density, the amount of SCB can be reduced. Specifically, in the present invention, by controlling the hydrogen input, and thus the comonomer input, during the polymerization reaction, an ethylene copolymer having an average SCB number per 1000 carbon atoms of 6 or less, more specifically 3 to 6, is used, thereby exhibiting excellent properties including processability while maintaining the effect of improving the long-term durability of the resin composition. If the average SCB number per 1000 carbon atoms exceeds 6, the effect of improving the lifetime characteristics due to the ethylene copolymer may be deteriorated.

Further, the ethylene copolymer can have a density, as measured according to ASTM D1505, of from 0.940g/cc to 0.950g/cc, more specifically from 0.945g/cc to 0.950 g/cc. While satisfying the above MI and SCB, if having a density within the above range, it is possible to improve strength and rigidity when preparing a film.

Meanwhile, as α -olefin contained in the ethylene copolymer, α -olefin having a carbon number of 4 to 20, such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 4-methyl-1-pentene and the like, may be mentioned, and a mixture thereof may be included.

However, if the content of α -olefin-derived repeating units is less than 1 mol%, it may be difficult to obtain a processability improving effect due to the inclusion of α -olefin-derived repeating units, and if it exceeds 5 mol%, the improving effect of the lifespan characteristics may be deteriorated.

The method for preparing the ethylene copolymer having the above characteristics is not particularly limited, and for example, may be prepared by a method comprising copolymerizing ethylene and α -olefin having a carbon number of 4 or more while introducing hydrogen in an amount of 0.1g/hr to 0.5g/hr in the presence of a hybrid supported catalyst in which a first transition metal compound of the following chemical formula 1 and a second transition metal compound of the following chemical formula 2 are supported together in a carrier, wherein the amount of introduction of α -olefin is 2.0ml/min to 3.0ml/min based on the introduction of 10kg/hr of ethylene monomer:

[ chemical formula 1]

(Cp¹(R^a)_x)_n(Cp²(R^b)_y)M¹Z¹ _3-n

Wherein, in chemical formula 1,

M¹is a group 4 transition metal;

Cp¹and Cp²Identical or different and are each independently cyclopentadienyl, indenyl, 4,5,6, 7-tetrahydro-1-indenyl or fluorenyl, unsubstituted or substituted by a C1 to C20 hydrocarbon group;

R^aand R^bThe same or different, and each independently is hydrogen, C1 to C20 alkyl, C1 to C10 alkoxy, C2 to C20 alkoxyalkyl, C6 to C20 aryl, C6 to C10 aryloxy, C2 to C20 alkenyl, C7 to C40 alkylaryl, C7 to C40 arylalkyl, C8 to C40 arylalkenyl, or C2 to C10 alkynyl;

Z¹is a halogen atom, a C1 to C20 alkyl group, a C2 to C10 alkenyl group, a C7 to C40 alkylaryl group, a C7 to C40 arylalkyl group, a C6 to C2 group0 aryl, substituted or unsubstituted C1 to C20 alkylidene, substituted or unsubstituted amino, C2 to C20 alkylalkoxy or C7 to C40 arylalkoxy, and, when substituted, they may be substituted with C1 to C20 hydrocarbyl;

n is a number of 0 or 1,

x and y are each independently an integer of 0 to 4,

[ chemical formula 2]

(Cp³(R^e)_z)B²(J)M²Z² ₂

Wherein, in chemical formula 2,

M²is a group 4 transition metal;

Cp³is cyclopentadienyl, indenyl, 4,5,6, 7-tetrahydro-1-indenyl or fluorenyl, unsubstituted or substituted by a C1 to C20 hydrocarbon group;

R^eis hydrogen, C1 to C20 alkyl, C1 to C10 alkoxy, C2 to C20 alkoxyalkyl, C6 to C20 aryl, C6 to C10 aryloxy, C2 to C20 alkenyl, C7 to C40 alkylaryl, C7 to C40 arylalkyl, C8 to C40 arylalkenyl, or C2 to C10 alkynyl;

Z²is a halogen atom, a C1 to C20 alkyl group, a C2 to C10 alkenyl group, a C7 to C40 alkylaryl group, a C7 to C40 arylalkyl group, a C6 to C20 aryl group, a substituted or unsubstituted C1 to C20 alkylidene group, a substituted or unsubstituted amino group, a C2 to C20 alkylalkoxy group, or a C7 to C40 arylalkoxy group, and, when substituted, they may be substituted with a C1 to C20 hydrocarbon group;

B²is one or more groups containing carbon, germanium, silicon, phosphorus or nitrogen atoms, or combinations thereof, which are substituted with (Cp)³(R^e)_z) The ring is crosslinked with J;

j is selected from NR^f、O、PR^fAnd S, R^fIs a substituted or unsubstituted C1 to C20 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group, which when substituted may be substituted with a C1 to C20 hydrocarbyl group, and

z is an integer from 0 to 4.

In the hybrid supported catalyst, the substituents in chemical formulas 1 and 2 are as follows.

The C1 to C20 alkyl group includes a straight chain or branched chain alkyl group, and specifically, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, pentyl, hexyl, heptyl, octyl and the like can be mentioned, but is not limited thereto.

The C2 to C20 alkenyl group includes a straight chain or branched alkenyl group, and specifically, allyl, vinyl, propenyl, butenyl, pentenyl and the like may be mentioned, but are not limited thereto.

The C6 to C20 aryl group includes monocyclic or fused aryl groups, and specifically, phenyl, biphenyl, naphthyl, phenanthryl, fluorenyl and the like can be mentioned, but is not limited thereto.

C7 to C40 alkylaryl refers to a substituent wherein one or more hydrogens of the aryl group is replaced with an alkyl group, wherein alkyl and aryl are as defined above. Specifically, there may be mentioned methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, tert-butylphenyl or cyclohexylphenyl groups and the like, but not limited thereto.

C7 to C40 arylalkyl refers to a substituent wherein one or more hydrogens of the alkyl group are replaced with an aryl group, wherein alkyl and aryl are as defined above. Specifically, benzyl, phenylpropyl, phenylhexyl or the like may be mentioned, but not limited thereto.

As the C1 to C20 alkoxy group, there may be mentioned methoxy, ethoxy, phenyloxy, cyclohexyloxy and the like, but not limited thereto.

C2 to C20 alkoxyalkyl refer to substituents wherein one or more hydrogens of the alkyl group are replaced with an alkoxy group, wherein alkyl and alkoxy are as defined above. Specifically, there may be mentioned methoxyethyl, t-butoxyethyl, t-butoxyhexyl and the like, but are not limited thereto.

The C1 to C20 hydrocarbyl groups can be C1 to C20 alkyl, C2 to C20 alkenyl, C3 to C20 cycloalkyl, C6 to C20 aryl, or combinations thereof, each as defined above.

Halogen may be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

As the group 4 transition metal, there may be mentioned titanium, zirconium, hafnium and the like, but not limited thereto.

The first transition metal compound of chemical formula 1 may be used to prepare a low molecular weight polymer having a low SCB content, the second transition metal compound of chemical formula 2 may be used to prepare a low molecular weight polymer having a medium SCB content, and, if the first transition metal compound and the second transition metal compound are supported together on the same carrier, the low SCB and MI may be more easily achieved.

The first transition metal compound may be a compound represented by one of the following structural formulae, but is not limited thereto.

More specifically, in the first transition metal compound, in chemical formula 1, M¹May be Zr, and Cp¹And Cp²Each may be a cyclopentadienyl group.

Further, Cp¹And Cp²Each may be substituted by 1 to 4R^aAnd R^bAnd if x and y are each an integer equal to or greater than 2, a plurality of R^aAnd R^bMay be the same or different. R^aAnd R^bMay be the same or different and are each independently hydrogen, C1-12 alkoxy or C2-12 alkoxyalkyl, more specifically R^aAnd R^bMay be a C2-12 alkoxyalkyl group such as tert-butoxyhexyl. If R is^aAnd R^bBeing the above substituent, the first transition metal compound can have more excellent load stability.

Further, in chemical formula 1, when n ═ 1, two Z s¹May be the same or different and are each independently a halogen. By reaction with a cocatalyst of a metal alkyl or methylaluminoxane, Z¹The halogen group in the first transition metal compound which is the above substituent may be easily substituted with an alkyl group. Also, through subsequent alkyl substitution, the first transition metal compound may form an ionic intermediate with the cocatalyst, thereby easily providing a cationic form as an active species for olefin polymerization.

Further, the second transition metal compound may be a compound represented by one of the following structural formulae, but is not limited thereto.

More specifically, in the second transition metal compound, in chemical formula 2, M²May be Zr, and CP³May be a cyclopentadienyl group.

Further, Cp³Can be substituted by 1 to 4R^eIs substituted, and if z is an integer equal to or greater than 2, R^eMay be the same or different and are each independently hydrogen or C1-20 alkyl. If R is^eIs the above substituent, the second transition metal compound can have more excellent load stability.

In addition, Z²Each may be a halogen atom.

In addition, B²May be a silicon-containing group, wherein the silicon-containing group may be a divalent silane substituted with hydrogen, C1-20 alkyl, C1-20 alkoxy or C2-20 alkoxyalkyl, more specifically, it may be a divalent silane substituted with C1-12 alkyl (e.g., methyl, ethyl, etc.), or C2-20 alkoxyalkyl (e.g., t-butoxyhexyl).

Further, in chemical formula 2, J may be NR^fAnd R is^fMay be a C1-20 alkyl group, more specifically, a C3-12 branched alkyl group such as a t-butyl group.

The second transition metal compound of chemical formula 2 having the above combination of substituents may be supported in a carrier together with the first transition metal compound of chemical formula 1, thereby exhibiting more excellent catalytic activity and easily achieving target properties by easily controlling the molecular weight distribution of an ethylene homopolymer.

In the hybrid supported catalyst, the molar ratio of the first transition metal compound to the second transition metal compound may be from 1:0.1 to 1:0.9, or from 1:0.2 to 1:0.8, or from 1:0.3 to 1: 0.5. If they are contained in the above-mentioned molar ratio range, the molecular weight distribution of the ethylene homopolymer can be easily controlled, thereby more easily achieving the aimed properties.

Meanwhile, as the support used for the hybrid supported catalyst, a support having a hydroxyl group or a siloxane group on the surface can be used. Specifically, a carrier containing highly reactive hydroxyl groups or siloxane groups by removing moisture on the surface by high-temperature drying can be used. More specifically, silica, alumina, magnesia or mixtures thereof may be used as the support. The support may be dried at elevated temperature and may typically be a composition comprising an oxide, carbonate, sulphate, nitrate, for example Na₂O、K₂CO₃、BaSO₄And Mg (NO)₃)₂And the like. Further, the support may be contained in a ratio of 10 to 1000 by weight, more specifically 10 to 500 by weight, based on 1 by weight of the metallocene compound including the first transition metal compound and the second transition metal compound. When the support is included in the above weight ratio range, the prepared hybrid supported catalyst may have an optimal shape, thus exhibiting more excellent catalytic activity.

In addition, in the hybrid supported catalyst, a co-catalyst may be further included to activate the procatalyst transition metal compound. As the cocatalyst, cocatalysts generally used in the art may be used without particular limitation. As a non-limiting example, the co-catalyst may be one or more compounds selected from the group consisting of compounds represented by the following chemical formulas 3 to 5.

The hybrid supported catalyst may further include one or more promoters selected from the group consisting of compounds represented by the following chemical formulas 3 to 5:

[ chemical formula 3]

-[Al(R₉)-O]_m-

Wherein, in chemical formula 3, R₉May be the same or different and are each independently halogen; c1 to C20 alkyl; or C1 to C20 alkyl substituted with halogen; and m is an integer of 2 or more;

[ chemical formula 4]

J(R₁₀)₃

Wherein, in chemical formula 4, R₁₀May be the same or different and are each independently halogen; c1 to C20 alkyl; or is coveredHalogen-substituted C1 to C20 alkyl; and J is aluminum or boron;

[ chemical formula 5]

[E-H]⁺[ZA₄]^-Or [ E]+[ZA₄]^-

Wherein, in chemical formula 5, E is a neutral or cationic lewis base; h is a hydrogen atom; z is a group 13 element; a may be the same or different, and each independently is a C6 to C20 aryl group or a C1 to C20 alkyl group in which one or more hydrogen atoms are unsubstituted or substituted with halogen, C1-20 alkyl, alkoxy, or phenoxy.

As non-limiting examples of the compound represented by chemical formula 3, there may be mentioned methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, tert-butylaluminoxane, or the like. Further, as non-limiting examples of the compound represented by chemical formula 4, trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, or the like may be mentioned. Further, as non-limiting examples of the compound represented by chemical formula 5, trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammoniumtetrakis (pentafluorophenyl) borate, N-dimethylaniliniumtetrakis (pentafluorophenyl) borate, N-dimethylaniliniumn-butyltris (pentafluorophenyl) borate, N-dimethylaniliniumbenzyltris (pentafluorophenyl) borate, N-dimethylaniliniumtetrakis (4- (tert-butyldimethylsilyl) -2,3,5, 6-tetrafluorophenyl) borate, N-dimethylaniliniumtetrakis (4- (triisopropylsilyl) -2,3,5, 6-tetrafluorophenyl) borate, N-dimethylaniliniumpentafluorophenoxytris (pentafluorophenyl) borate, N-dimethylaniliniumtris (pentafluorophenyl) borate, N-fluorophenyloxy tris (pentafluorophenyl) borate, N-dimethylaniliniumtetrakis (triisopropylsilyl) -2,3,5, 6-tetrafluorophenyl) borate, N, N-dimethyl-2, 4, 6-trimethylanilinium tetrakis (pentafluorophenyl) borate, trimethylammoniumtetra (2,3,4, 6-tetrafluorophenyl) borate, N-dimethylaniliniumtetrakis (2,3,4, 6-tetrafluorophenyl) borate, hexadecyldimethylaniliniumtetrakis (pentafluorophenyl) borate, N-methyl-N-dodecylanilinium tetrakis (pentafluorophenyl) borate, or methylbis (dodecyl) ammoniumtetra (pentafluorophenyl) borate, and the like.

The cocatalyst may be included in a molar ratio of 1 to 20 based on 1 mole of the metallocene compound including the first and second transition metal compounds. When the cocatalyst is contained in the above-mentioned molar ratio range, an effect exceeding a certain level can be obtained by the cocatalyst, and the properties of the ethylene homopolymer produced by the effective activation of the metallocene compound can be appropriately controlled.

The hybrid supported catalyst can be prepared, for example, by the following method: the cocatalyst is supported in the carrier, and the catalyst precursor first and second transition metal compounds are supported in the cocatalyst-supported carrier. For a specific preparation method of the hybrid supported catalyst, reference may be made to the following examples. However, the preparation method of the hybrid supported catalyst is not limited thereto, and it may additionally employ steps commonly used in the art, and the steps of the preparation method may be changed by generally changeable steps.

Further, the hybrid supported catalyst may be dissolved or diluted in a C5-12 aliphatic hydrocarbon solvent (e.g., pentane, hexane, heptane, nonane, decane and isomers thereof), an aromatic hydrocarbon solvent (e.g., toluene, benzene, etc.), a hydrocarbon solvent substituted with a chlorine atom (e.g., dichloromethane, chlorobenzene, etc.) to be introduced into the polymerization reaction. Among them, it is preferable to treat the used solvent with a small amount of aluminum alkyl to remove a small amount of water or air used as a catalyst poison, and a cocatalyst may be further used.

Further, the α -olefin which can be used in the preparation of the ethylene copolymer may be a C4-20 α -olefin such as 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 4-methyl-1-pentene and the like, and a mixture thereof may be used in the preparation of the ethylene copolymer.

For the polymerization of ethylene and α -olefin, various polymerization methods known as polymerization of olefin monomers, such as continuous solution polymerization, bulk polymerization, suspension polymerization, slurry polymerization, emulsion polymerization, or the like, can be employed.

Further, during the polymerization reaction, hydrogen gas may be introduced at a rate of 0.1g/hr to 0.5g/hr, more specifically 0.2g/hr to 0.5g/hr, under a reactor pressure of 1 atm. When hydrogen is introduced at the above rate, the SCB content in the produced copolymer can be easily controlled within the above range while exhibiting sufficient catalytic activity.

The hydrogen gas plays a role of activating the inactive site of the metallocene compound and causing a chain transfer reaction to control the molecular weight, and in the present invention, the MI of the produced ethylene copolymer can be controlled to be below 0.5g/10min by controlling the hydrogen gas input within the above range. If the hydrogen input exceeds 0.5g/hr during the polymerization reaction, it may be difficult to reduce the MI of the ethylene homopolymer to 0.5g/10min or less, and in this case, it may be difficult to achieve the effect of improving the long-term durability and mechanical properties of the resin composition. Also, if the hydrogen input is less than 0.1g/hr, although the MI of the ethylene copolymer can be reduced, double bonds may remain in the chain and thus may be broken at an early stage upon aging.

Thus, in the present invention, α -olefin can be introduced in such an amount as to have SCB per 1000 carbon atoms in the ethylene copolymer of 6 or less, more specifically 3 to 6, while satisfying the hydrogen input range, α -olefin can be introduced in an amount of 2.0ml/min to 3.0ml/min, specifically, based on 10kg/hr of ethylene monomer introduction, if α -olefin is introduced in the above content range, ethylene copolymer satisfying the above SCB condition can be easily prepared, however, if α -olefin monomer input is less than 2.0ml/min or more than 3.0ml/min, it may be difficult to prepare ethylene copolymer satisfying the above SCB condition.

Further, the temperature during the polymerization reaction can be from 25 ℃ to 500 ℃, specifically from 25 ℃ to 200 ℃, more specifically from 50 ℃ to 150 ℃. Also, the polymerization pressure may be from 1 bar to 100 bar, specifically from 1 bar to 50 bar, more specifically from 5 bar to 30 bar.

The ethylene copolymer may be included in a content of 25 to 75 wt% based on the total weight of the polyolefin resin composition. If the content of the ethylene copolymer is less than 25 wt%, it may be difficult to obtain a processability improving effect due to the inclusion of the ethylene copolymer, and if the content of the ethylene copolymer exceeds 75 wt%, the lifespan characteristics may be deteriorated. The content of the ethylene copolymer may be 50 to 75 wt% based on the total weight of the resin composition, in view of the effect of improving the processability and lifespan characteristics of the polyolefin resin composition according to the control of the content of the ethylene copolymer.

Polyolefin resin composition

The polyolefin resin composition according to one embodiment of the present invention may be prepared by mixing i) the ethylene homopolymer and ii) the ethylene copolymer described above by a conventional polymer mixing method.

Specifically, the polyolefin resin composition may be prepared by a method comprising polymerizing an ethylene monomer and α -olefin having a carbon number of 4 or more in the presence of a hybrid supported catalyst in which a first transition metal compound of the above chemical formula 1 and a second transition metal compound of the above chemical formula 2 are supported together in a carrier while introducing hydrogen in an amount of 0.1g/hr to 0.5g/hr to prepare an ethylene copolymer comprising repeating units derived from α -olefin having a carbon number of 4 or more, the ethylene copolymer having a melt index of 0.5g/10min or less (measured at 190 ℃ under a load of 2.16kg according to ASTM D1238) and an average Short Chain Branch (SCB) number per 1000 carbon atoms of 6 or less in a molecular weight distribution diagram measured by GPC-FTIR), and mixing the ethylene copolymer with an ethylene homopolymer having a melt index of 0.8g/10min or less in a weight ratio of 3:1 to 1:3, wherein the ethylene homopolymer is introduced at an amount of 0.26 ml to α ml based on the weight ratio of the ethylene monomer mixed at 190 ℃ under 2.16 kg.

In addition, the preparation method may further include the steps of: after the ethylene copolymer is prepared and before the ethylene copolymer is mixed with an ethylene homopolymer, or before the ethylene copolymer is prepared, an ethylene monomer is polymerized while introducing hydrogen in an amount of 0.1g/hr to 1.5g/hr in the presence of a hybrid supported catalyst in which the first transition metal compound of the above chemical formula 1 and the second transition metal compound of the above chemical formula 2 are supported together in a carrier, to prepare an ethylene homopolymer having a melt index (measured at 190 ℃, under a load of 2.16kg according to ASTM D1238) of 0.8g/10min or less.

In the preparation method of the polyolefin resin composition, the hybrid supported catalyst for preparing the ethylene copolymer and the ethylene homopolymer, and the preparation method of the copolymer and homopolymer using the same are as described above.

Further, i) the ethylene homopolymer and ii) the ethylene copolymer may be dry-mixed using, for example, a henschel mixer, a tumbler mixer or the like, or the dry-mixed mixture may be separately melt-mixed using an extruder, a roll mixer, a roll mill, a kneader, a banbury mixer or the like.

Wherein i) the ethylene homopolymer and ii) the ethylene copolymer may be mixed in a weight ratio of 3:1 to 1: 3. If the mixing ratio of the ethylene homopolymer and the ethylene copolymer does not fall within the above range and the content of the ethylene homopolymer is too high, exceeding 3:1, there is a fear of deterioration of the life characteristics, and if the content of the ethylene copolymer is too high, exceeding 1:3, there is a fear of deterioration of the processability. More preferably, it may be mixed in a weight ratio of 1:1 to 1:3 and comprises i) an ethylene homopolymer and ii) an ethylene copolymer.

In addition, when the ethylene homopolymer and the ethylene copolymer are mixed, one or more additives, such as an antioxidant, an antistatic agent, a slip agent, an antiblocking agent, a lubricant, a dye, a pigment, a plasticizer, an age resistor, or the like, may be further added. These additives may be contained at an appropriate content within a range not to impair the properties of the resin composition, and specifically, may be contained at a content of 0.1 to 1 part by weight based on 100 parts by weight of the mixture of the ethylene homopolymer and the ethylene copolymer.

The polyolefin resin composition compounded and prepared as described above, having a density of 0.930g/cc to 0.960g/cc as measured according to ASTM D1505 and an MI of 0.1g/10min to 0.5g/10min as measured at 190 ℃ under a load of 2.16kg as measured according to ASTM D1238; MI₅/MI_2.16(MFRR) is less than 3.1; a molecular weight distribution of 2.5 to 4.2; rheological properties measured using a rheometer after 2000 seconds of storage at 240 ℃ under aerobic conditions, specifically, a normalized viscosity calculated from the change in viscosity according to the above equation 1 was 20% to 30%. As described above, it can exhibit a low normalized viscosity of 20 to 30% and a low MI while maintaining excellent properties of a narrow MFRR of less than 3.1, thus exhibiting excellent effects in terms of processability and long-term life characteristics as well as basic properties.

More specifically, the polyolefin resin composition has a density of 0.940g/cc to 0.950g/cc as measured according to ASTM D1505, and an MI of 0.2g/10min to 0.5g/10min as measured at 190 ℃ under a load of 2.16kg according to ASTM D1238; MI₅/MI_2.16(MFRR) in a ratio of 2 to 3; a molecular weight distribution of 2.5 to 4.0; rheological properties measured using a rheometer after being stored for 2000 seconds at 240 ℃ under aerobic conditions, that is, a normalized viscosity calculated from a change in viscosity according to the above equation 1 is 25% to 30%, thus exhibiting further improved mechanical properties and long-term durability.

Also, since the MI is low, the resin composition exhibits reduced residual stress. Specifically, the resin composition may have a residual stress (100s, 140 ℃) of less than 1%, or 0.01% or more and less than 1%, more specifically 0.1% to 0.4%. Since the polyolefin resin composition has a reduced residual stress in the above range and satisfies the above property requirements, it can exhibit further improved long-term durability.

Meanwhile, the residual stress of the polyolefin resin composition can be measured by DMA (dynamic mechanical analysis). For example, after taking a polyolefin resin composition and applying 200% strain, the change in residual stress is measured for 100 seconds. As the measuring device, a Discovery Hybrid Rheometer (DHR) manufactured by TA Instruments and the like can be used.

And, the polyolefin resin composition may have a weight average molecular weight (Mw) measured by GPC of 50,000 to 250,000 g/mol. Since the polyolefin resin composition has a weight average molecular weight within the above range and satisfies the above property requirements, it can exhibit excellent mechanical strength while exhibiting appropriate processability.

Meanwhile, throughout the specification, the weight average molecular weight (Mw) of the resin composition means a weight average molecular weight (unit: g/mol) in terms of polystyrene measured by GPC, and the molecular weight distribution is a value obtained by measuring the weight average molecular weight and the number average molecular weight (Mn), and calculating the ratio (Mw/Mn) of the weight average molecular weight to the number average molecular weight.

Further, the polyolefin resin composition exhibits improved properties, particularly mechanical strength, particularly tensile strength greater than 2.0gf/den, particularly, greater than 2.4gf/den, more particularly, greater than 2.5gf/den, as measured by forming a film having a thickness of 100 μm according to ASTM D1709A. If the polyolefin resin composition has a tensile strength of 2.0gf/den or less, it is difficult to obtain a sufficient strength when the resin composition is used for a film, particularly a stretched film.

Therefore, according to another embodiment of the present invention, there is provided a film comprising or produced using the polyolefin resin composition, and more particularly, a stretched film.

The film may be prepared by applying various molding methods, conditions and apparatuses known in the art of polymer molding, such as a T-die method, etc., without limitation.

According to still another embodiment of the present invention, there is provided a pack comprising or prepared using the polyolefin resin composition.

The pack can be prepared using a general pack preparation method in addition to the use of the above resin composition, and can exhibit remarkably improved long-term durability while exhibiting excellent mechanical properties and processability by using the resin composition.

Advantageous effects

The polyolefin resin composition according to the present invention has excellent long-term durability and improved properties, and thus can be used for films, particularly for stretched films.

Drawings

Fig. 1 and 2 are graphs showing molecular weight distribution curves (solid line) and SCB number distribution per 1000 carbon atoms (broken line) of the ethylene copolymers prepared in preparation examples 1 and 2, respectively.

FIG. 3 is a graph showing a molecular weight distribution curve (solid line) and a SCB number distribution per 1000 carbon atoms (broken line) of the polymer in the resin composition used in comparative example 4.

Detailed Description

The present invention will be explained in more detail in the following examples. However, these examples are merely illustrative of the present invention, and the scope of the present invention is not limited thereto.

Synthesis example: preparation of hybrid supported catalysts

6.0kg of a toluene solution was introduced into a 20L stainless steel (sus) high pressure reactor, and the temperature of the reactor was maintained at 40 ℃. Then, 1000g of silicon oxide (SYLOPOL manufactured by Grace Davison) dehydrated by applying vacuum at 600 ℃ for 12 hours was introduced into the reactor^TM948) And dispersed sufficiently, then, 80g of the first metallocene compound (I) of the following structure was dissolved in toluene and introduced, and the resulting solution was stirred at 40 ℃ for 2 hours to react. After that, the stirring was stopped, followed by settling for 30 minutes, and the reaction solution was decanted.

2.5kg of toluene was introduced into the reactor, and 9.4kg of a 10 wt% Methylaluminoxane (MAO)/toluene solution was introduced, and then, the solution was stirred at 200rpm at 40 ℃ for 12 hours. After the reaction, the stirring was stopped, followed by settling for 30 minutes, and the reaction solution was decanted. And, 3.0kg of toluene was introduced and stirred for 10 minutes, and then, the stirring was stopped, followed by settling for 30 minutes, and the reaction solution was decanted.

3.0kg of toluene was introduced into the reactor, 314mL of a 29.2 wt% solution of the second metallocene compound (II)/toluene of the following structure was introduced, and the resulting solution was stirred at 200rpm at 40 ℃ for 12 hours. After the temperature of the reactor was lowered to room temperature, the stirring was stopped, followed by settling for 30 minutes, and the reaction solution was decanted.

2.0kg of toluene was introduced into the reactor, stirred for 10 minutes, then, the stirring was stopped, followed by settling for 30 minutes, and the toluene solution was decanted.

3.0kg of hexane was introduced into the reactor, and the hexane was addedThe slurry was transferred to a filter drier and the hexane solution was filtered. Drying at 40 ℃ under reduced pressure for 4 hours gives 890g of SiO₂A hybrid supported catalyst.

Preparation example 1: preparation of ethylene Copolymers (COMO)

Ethylene copolymers were prepared by a single mode (unimodal) run of one reactor in the presence of the hybrid supported catalyst prepared in the synthesis example using a hexane slurry stirred tank reactor. 1-butene was used as comonomer, and the reactor pressure was maintained at 40 bar, the polymerization temperature was maintained at 90 ℃.

Feeding ethylene: 10.0kg/hr

Hydrogen input: 0.2g/hr

1-butene input: 2.5 ml/min.

Preparation example 2: preparation of ethylene Copolymers (COMO)

An ethylene copolymer was produced by the same method as in production example 1, except that the hydrogen gas input was changed to 0.7 g/hr.

Preparation example 3: preparation of ethylene Copolymers (COMO)

An ethylene copolymer was produced by the same method as in production example 1, except that the input of 1-butene was changed to 3.5 ml/min.

Preparation example 4: preparation of ethylene Homopolymers (HOMO)

Ethylene homopolymers (MI 0.6g/10min, density 0.952g/cc, see table 1 below) were prepared by a one-reactor, single-mode run using a hexane slurry stirred tank reactor in the presence of the hybrid supported catalyst prepared in the synthesis examples. The reactor pressure was maintained at 40 bar and the polymerization temperature was maintained at 90 ℃.

Feeding ethylene: 10.0kg/hr

Hydrogen input: 0.7g/hr

Preparation example 5: preparation of ethylene Homopolymers (HOMO)

An ethylene homopolymer (MI 1.3g/10min, density 0.954g/cc, see table 1 below) was prepared by the same method as preparation example 4, except that the hydrogen input was changed to 2.0 g/hr.