KR20220009782A - Polyethylene - Google Patents

Abstract

The present invention relates to polyethylene, which does not decrease in density while increasing a comonomer content in a high molecular weight region. In order to solve the above problems, the present invention provides the following polyethylene which comprises 1-hexene as the comonomer, has 126.5℃ or more and 132℃ or less of a melting point (Tm), and a comonomer sequence distribution index represented by formula 1: Comonomer sequence distribution Index = SCB content - 6 * 10^(47) * Tm^(-22.52) is 0 or more.

Description

polyethylene {Polyethylene}

The present invention relates to polyethylene, which does not decrease in density while increasing the comonomer content in the high molecular weight region.

In general, polyethylene for injection requires a certain level of durability or more. The durability of polyethylene can be improved by increasing the comonomer content, and the BOCD index can be used to infer the comonomer content. Here, BOCD (Broad Orthogonal Comonomer Distribution) is a polymer-related term, and the BOCD structure is a structure in which the content of a comonomer such as alpha-olefin is concentrated in a high molecular weight main chain, that is, short chain branching (SCB). ) as a new structure with a higher molecular weight content, the higher the BOCD index, the higher the BOCD structure. In this case, the short chain branch (SCB) refers to branches having 2 to 7 carbon atoms attached to the main chain, and is usually an alpha-olefin having 4 or more carbon atoms, such as 1-butene, 1-hexene, 1-octene, etc. as a comonomer. It means side branches that are created when used. Therefore, in order to increase the BOCD index, high molecular weight polyethylene must contain a large amount of comonomer.

On the other hand, olefin polymerization catalyst systems can be classified into Ziegler-Natta and metallocene catalyst systems. Among them, the metallocene catalyst is composed of a combination of a main catalyst containing a metallocene compound as a main component and a cocatalyst containing an organometallic compound containing aluminum as a main component. Such a catalyst is a homogeneous complex catalyst, which is a single site catalyst, has a narrow molecular weight distribution according to the single site characteristic, and obtains a polymer with a uniform composition distribution of comonomers, and changes the ligand structure of the catalyst and the ability to change the stereoregularity, copolymerization characteristics, molecular weight, crystallinity, etc. of the polymer according to the change of polymerization conditions. However, the catalyst precursor compound for preparing polyethylene currently used has a limitation in that the comonomer content contained in the polyethylene is low because the conversion rate of the comonomer is low to prepare polyethylene having a high molecular weight and high co-polymerizability.

Accordingly, an object of the present invention is to provide a polyethylene prepared using a metallocene compound that has an equivalent level of density regardless of an increase in the comonomer content while increasing the comonomer content in the high molecular weight region.

An object of the present invention is to provide polyethylene with an increase in the comonomer content in the high molecular weight region and no decrease in density.

In order to solve the above problems, the present invention provides the following polyethylene:

1-hexene as a comonomer;

Melting point (Tm) is 126.5 ℃ or more and 132 ℃ or less,

Comonomer sequence distribution Index represented by the following formula 1 is 0 or more,

Polyethylene:

[Equation 1]

Comonomer sequence distribution Index = SCB content - 6 * 10 ⁴⁷ * Tm ^-22.52

In Equation 1 above,

SCB (short chain branch) content is a branch content of 2 to 7 carbon atoms per 1000 carbons (piece / 1000C),

Tm is the melting point.

According to the present invention, it is possible to provide a polyethylene having a higher content of comonomer compared to polyethylene having the same level of Tm, and maintaining the same level without lowering physical properties such as density.

1 shows the relationship between the melting point and the SCB content of Examples and Comparative Examples, with the melting point (Tm, ℃) being the x-axis and the SCB content (units/1000C) being the y-axis. Each Example and Comparative Example are shown on FIG. 1 .

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as "comprise", "comprising" or "have" are intended to designate the existence of an embodied feature, number, step, element, or a combination thereof, but one or more other features or It should be understood that the existence or addition of numbers, steps, elements, or combinations thereof, is not precluded in advance.

Since the present invention may have various changes and may have various forms, specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Hereinafter, the polyethylene of the present invention will be described in detail.

The polyethylene of the present invention is characterized in that the comonomer content in the high molecular weight region is improved by preparing it using a metallocene compound, which will be described later. In addition, the metallocene compound to be described later is used as a single or hybrid catalyst to improve the comonomer content in the high molecular weight region of polyethylene and at the same time allow the SCB to form a block and exist in swarms to reduce the density of the copolymer prevent. That is, the polyethylene according to the present invention has a large amount of SCB content compared to polyethylene having the same Tm, and maintains the same level of density regardless of the increase in the SCB content.

Polyethylene according to an embodiment of the present invention contains 1-hexene as a comonomer, has a melting point (Tm) of 126.5 ° C. or more and 132 ° C. or less, and has a Comonomer sequence distribution Index represented by the following formula 1 is 0 or more. do:

[Equation 1]

Comonomer sequence distribution Index = SCB content - 6 * 10 ⁴⁷ * Tm ^-22.52

In Equation 1 above,

SCB (short chain branch) content is a branch content of 2 to 7 carbon atoms per 1000 carbons (piece / 1000C),

Tm is the melting point.

In general, in order to improve the durability of polyethylene for injection, high molecular weight polyethylene should contain relatively more comonomers than low molecular weight polyethylene. The content of these comonomers can be known by the BOCD index (Broad Orthogonal Comonomer Distribution index), which is calculated as "(SCB content on the high molecular weight side - SCB content on the low molecular weight side)/(SCB content on the low molecular weight side)" . The SCB content can be measured using GPC-FTIR equipment, and the BOCD index is based on the weight average molecular weight (Mw) of the molecular weight distribution (MWD) left and right 30% (total 60%) of the SCB content (unit: pieces/1,000) It can be obtained from the above formula by measuring C).

Specifically, the larger the BOCD index, the greater the BOCD structure. The BOCD structure refers to a structure in which the content of a comonomer such as alpha-olefin is concentrated in the high molecular weight main chain, that is, a structure in which the content of Short Chain Branching (SCB) derived from the comonomer increases toward the high molecular weight main chain. Therefore, it can be seen that the BOCD structure has a high content of high molecular weight comonomers.

Accordingly, in the present invention, the content of the comonomer in the high molecular weight region was inferred through Equation 1 below to be compared. Equation 1 below is a formula to measure the SCB and Tm of polyethylene and formulate it to find polyethylene with a high content of SCB in the high molecular weight region compared to Tm, and the comonomer sequence derived by substituting the Tm and SCB contents of polyethylene into Equation 1 below SCB content at high molecular weight can be inferred from the distribution index value.

[Equation 1]

Comonomer sequence distribution Index = SCB content - 6 * 10 ⁴⁷ * Tm ^-22.52

Specifically, Equation 1 is a model for quantitatively predicting polyethylene in which the density does not decrease even if the SCB content of the high molecular weight region compared to Tm is high. Therefore, if the Comonomer Sequence Distribution Index is 0 or more, it can be confirmed that the SCB content in the high molecular weight region is high and the density is at the same level compared to the polyethylene having the equivalent Tm.

Preferably, the SCB (short chain branch) content may be 1.5/1000C or more, 1.7/1000C or more, or 1.9/1000C or more, and 6.5/1000C or less, 6.3/1000C or less, 6.0/1000C or less or less, or 5.9 pieces/1000C or less.

In addition, in general, when the SCB content in the high molecular weight region increases, a problem occurs in that the density of polyethylene is lowered. There is no problem of density drop.

Preferably, the density is at least 0.928 g/cm ³ , or at least 0.930 g/cm ³ , and at most 0.948 g/cm ³ , at most 0.945 g/cm ³ , at most 0.943 g/cm ³ , or at most 0.942 g/cm ^{3 .} may be below.

On the other hand, when a catalyst of low molecular weight, low copolymerization and high molecular weight are mixed and used, the BOCD index can be improved by including the precursor of the high molecular weight, high copolymerization catalyst. However, the conventional C2-symmetric, C2-asymmetric, or CGC type catalyst precursor used as a catalyst precursor for the production of polyethylene has a high comonomer conversion rate, but as the comonomer content increases, the density of polyethylene decreases and the physical properties decrease. have.

Accordingly, the metallocene compound of the present invention, which will be described later, is a precursor of a high molecular weight high copolymerization catalyst. When polyethylene is manufactured using the metallocene compound, while increasing the content of SCB in the high molecular weight region, the SCB forms a block to form a comonomer. By maintaining a constant density, a decrease in the density of polyethylene can be prevented and excellent physical properties can be maintained. Therefore, even if the compound is used as a hybrid catalyst in addition to being used as a single catalyst, polyethylene with increased durability can be produced by improving the BOCD index according to an increase in the comonomer content without deterioration in physical properties such as density.

Specifically, the polyethylene according to an embodiment of the present invention having a Comonomer sequence distribution index of 0 or more in Formula 1 is a catalytically active component in the presence of a specific metallocene compound, in a manufacturing method comprising the step of polymerizing an ethylene monomer can be manufactured by

More specifically, according to another embodiment of the present invention, the polyethylene of the present invention may be prepared by polymerizing an ethylene monomer in the presence of a catalyst composition including a metallocene compound represented by the following Chemical Formula 1:

[Formula 1]

In Formula 1,

M is any one of a Group 4 transition metal,

A is any one of the elements of group 14,

R ¹ and R ² are the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl , C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,

R ³ is methyl or isopropyl;

X ¹ , and X ² are the same as or different from each other and are each independently halogen,

Q ¹ , and Q ² are the same as or different from each other _{and are C 1-20} alkyl.

Unless otherwise limited herein, the following terms may be defined as follows.

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

Alkyl having 1 to 20 carbon atoms (C _1-20 ) may be a straight chain, branched chain or cyclic alkyl. Specifically, alkyl having 1 to 20 carbon atoms is straight-chain alkyl having 1 to 20 carbon atoms; straight-chain alkyl having 1 to 15 carbon atoms; straight-chain alkyl having 1 to 5 carbon atoms; branched or cyclic alkyl having 3 to 20 carbon atoms; branched or cyclic alkyl having 3 to 15 carbon atoms; Or it may be a branched or cyclic alkyl having 3 to 10 carbon atoms. For example, the alkyl having 1 to 20 carbon atoms (C _1-20 ) is methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopropyl, cyclobutyl, cyclopentyl , cyclohexyl, cycloheptyl, cyclooctyl, and the like, but is not limited thereto.

The alkenyl having 2 to 20 carbon atoms (C _2-20 ) includes straight-chain or branched alkenyl, and specifically includes allyl, allyl, ethenyl, propenyl, butenyl, pentenyl, and the like. but is not limited.

Examples of alkoxy having 1 to 20 carbon atoms (C _1-20 ) include, but are not limited to, a methoxy group, ethoxy, isopropoxy, n-butoxy, tert-butoxy, and cyclohexyloxy group. .

The alkoxyalkyl group having 2 to 20 (C _2-20 ) is a functional group in which one or more hydrogens of the aforementioned alkyl are substituted with alkoxy, specifically methoxymethyl, methoxyethyl, ethoxymethyl, iso-propoxymethyl, alkoxyalkyl such as iso-propoxyethyl, iso-propoxypropyl, iso-propoxyhexyl, tert-butoxymethyl, tert-butoxyethyl, tert-butoxypropyl, and tert-butoxyhexyl; The present invention is not limited thereto.

The aryloxy having 6 to 40 carbon atoms (C _6-40 ) may include, but is not limited to, phenoxy, biphenoxyl, naphthoxy, and the like.

The aryloxyalkyl group having 7 to 40 (C _7-40 ) is a functional group in which one or more hydrogens of the aforementioned alkyl are substituted with aryloxy, and specifically, phenoxymethyl, phenoxyethyl, phenoxyhexyl, etc. may be mentioned. , but is not limited thereto.

Alkylsilyl having 1 to 20 (C _1-20 ) or an alkoxysilyl group having 1 to 20 (C _1-20 ) is -SiH ₃ 1 to 3 hydrogens are 1 to 3 alkyl or alkoxy as described above. A substituted functional group, specifically, alkylsilyl, such as methylsilyl, dimethylsilyl, trimethylsilyl, dimethylethylsilyl, diethylmethylsilyl group or dimethylpropylsilyl; alkoxysilyl such as methoxysilyl, dimethoxysilyl, trimethoxysilyl or dimethoxyethoxysilyl; alkoxyalkylsilyl such as methoxydimethylsilyl, diethoxymethylsilyl, or dimethoxypropylsilyl, but is not limited thereto.

Silylalkyl having 1 to 20 (C _1-20 ) is a functional group in which one or more hydrogens of alkyl as described above are substituted with silyl, specifically -CH ₂ -SiH ₃ , methylsilylmethyl or dimethylethoxysilylpropyl, etc. can be mentioned, but is not limited thereto.

In addition, the alkylene having 1 to 20 carbon atoms (C _1-20 ) is the same as the above-mentioned alkyl except that it is a divalent substituent, specifically methylene, ethylene, propylene, butylene, pentylene, hexylene, hep. tylene, octylene, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, and the like, but is not limited thereto.

Aryl having 6 to 20 carbon atoms (C _6-20 ) may be a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. For example, the aryl having 6 to 20 carbon atoms (C _6-20 ) may include, but is not limited to, phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, and fluorenyl.

_Alkylaryl having 7 to 20 carbon atoms (C 7-20 ) may refer to a substituent in which one or more hydrogens among hydrogens of an aromatic ring are substituted by the aforementioned alkyl. For example, the alkylaryl having 7 to 20 carbon atoms (C _7-20 ) may include, but is not limited to, methylphenyl, ethylphenyl, methylbiphenyl, methylnaphthyl, and the like.

The arylalkyl having 7 to 20 carbon atoms (C _7-20 ) may mean a substituent in which one or more hydrogens of the aforementioned alkyl are substituted by the aforementioned aryl. For example, the arylalkyl having 7 to 20 carbon atoms (C _7-20 ) may include, but is not limited to, phenylmethyl, phenylethyl, biphenylmethyl, naphthylmethyl, and the like.

In addition, arylene having 6 to 20 (C _6-20 ) is the same as the above-described aryl except that it is a divalent substituent, specifically phenylene, biphenylene, naphthylene, anthracenylene, and phenanthrenylene. , fluorenylene, and the like, but are not limited thereto.

And, the Group 4 transition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf), or rutherpodium (Rf), specifically, titanium (Ti), zirconium (Zr), or hafnium (Hf) may be, and more specifically, may be zirconium (Zr) or hafnium (Hf), but is not limited thereto.

In addition, the group 13 element may be boron (B), aluminum (Al), gallium (Ga), indium (In), or thallium (Tl), specifically, boron (B), or aluminum (Al). and is not limited thereto.

The above-mentioned substituents are optionally a hydroxyl group within the range of exhibiting the same or similar effect as the desired effect; halogen; alkyl or alkenyl, aryl, alkoxy; alkyl or alkenyl, aryl, alkoxy containing one or more heteroatoms among the heteroatoms of Groups 14 to 16; silyl; alkylsilyl or alkoxysilyl; phosphine group; phosphide group; sulfonate group; And it may be substituted with one or more substituents selected from the group consisting of a sulfone group.

Preferably, the formula (1) may be represented by the following formula (1-1):

[Formula 1-1]

In Formula 1-1, A, M, R ¹ , R ² , R ³ , X ¹ , X ² , Q ¹ and Q ² are as defined in Formula 1,

R′ is the same as or different from each other, and each independently represents hydrogen or C _1-6 straight or branched chain alkyl;

a and b are each independently 0 or 1.

In Formula 1-1, when a and/or b is 0, hydrogen is substituted.

Preferably, A may be silicon.

Preferably, M may be zirconium (Zr) or hafnium (Hf), more preferably zirconium (Zr).

Preferably, R ¹ and R ² are each independently hydrogen, phenyl, _{or phenyl substituted with C 1-6} straight or branched chain alkyl, more preferably, R ¹ and R ² are each independently hydrogen , phenyl, or phenyl substituted with one or two tertbutyls.

Preferably, X ¹ and X ² may each be chloro.

Preferably, Q ¹ and Q ² may each independently be C _1-6 straight or branched chain alkyl or C _1-4 straight or branched chain alkyl. More preferably, Q ¹ and Q ² may each independently be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tert-butyl, most preferably methyl or ethyl have.

In addition, the compound represented by Formula 1 may be any one of compounds represented by the following structural formula:

.

.

The metallocene compound represented by Chemical Formula 1 can be prepared by a known method for synthesizing an organic compound, and has been described in more detail in Examples to be described later.

The compound represented by Formula 1 may be included in the catalyst composition and used as a single catalyst or a hybrid catalyst without particular limitation, but preferably, the catalyst composition according to an embodiment of the present invention comprises the compound represented by Formula 1 It may be included as a single catalyst.

In this case, the catalyst composition may include the metallocene compound as a single component, or may be in the form of a supported metallocene catalyst including the metallocene compound and a carrier. When a supported metallocene catalyst is used, the morphology and physical properties of the polyethylene to be prepared are excellent, and can be suitably used in conventional slurry polymerization, bulk polymerization, or gas phase polymerization processes.

Specifically, as the carrier, a carrier having a hydroxyl group, a silanol group, or a siloxane group having a high reactivity on the surface may be used. can be used For example, silica prepared by calcining silica gel, silica dried at high temperature, silica-alumina, and silica-magnesia may be used, and these are typically Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ). ₂ and the like oxide, carbonate, sulfate, and nitrate components.

The temperature for calcining or drying the carrier may be from about 200 °C to about 600 °C, or from about 250 °C to about 600 °C. When the calcination or drying temperature for the carrier is low, there is a risk that the surface moisture and the cocatalyst may react because there is too much moisture remaining in the carrier, and the cocatalyst loading rate is relatively low due to the excess hydroxyl groups. It can be increased, but this requires a large amount of co-catalyst. In addition, if the drying or calcination temperature is too high, the surface area decreases as the pores on the surface of the carrier coalesce, a lot of hydroxyl groups or silanol groups disappear on the surface, and only siloxane groups remain, so there is a risk of reducing the reaction site with the promoter. have.

The amount of hydroxyl groups on the surface of the carrier is preferably 0.1 mmol/g to 10 mmol/g, more preferably 0.5 mmol/g to 5 mmol/g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the method and conditions or drying conditions of the carrier, such as temperature, time, vacuum or spray drying, and the like. If the amount of the hydroxyl group is less than 0.1 mmol/g, there are few reaction sites with the co-catalyst, and if it exceeds 10 mmol/g, it is not preferable because it may be caused by moisture other than the hydroxyl group present on the surface of the carrier particle. not.

For example, the amount of hydroxyl groups on the surface of the carrier may be 0.1 mmol/g to 10 mmol/g or 0.5 mmol/g to 5 mmol/g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the method and conditions or drying conditions of the carrier, such as temperature, time, vacuum or spray drying, and the like. If the amount of the hydroxyl group is too low, there are few reaction sites with the promoter, and if it is too large, it may be due to moisture other than the hydroxyl group present on the surface of the carrier particle.

Among the above-mentioned carriers, silica, especially silica prepared by calcining silica gel, is supported by chemical bonding between the silica carrier and the functional group of the compound of Formula 1, so the catalyst released from the surface of the carrier in the propylene polymerization process is almost non-existent. As a result, when polyethylene is produced by slurry or gas phase polymerization, it is possible to minimize fouling caused by agglomeration of the reactor wall or polymer particles.

In addition, when supported on a carrier, the compound of Formula 1 is present in an amount of, for example, about 10 μmol or more, or about 30 μmol or more, and about 100 μmol or less, or about 80 μmol or less, based on the weight of the carrier, based on about 1 g of silica. It may be supported in a content range. When supported in the above content range, it may exhibit an appropriate supported catalyst activity, which may be advantageous in terms of maintaining the activity of the catalyst and economic feasibility.

In addition, the catalyst composition may further include one or more cocatalysts together with the above-described metallocene compound and the carrier.

The cocatalyst may be any cocatalyst used for polymerization of olefins under a general metallocene catalyst. This co-catalyst causes a bond to be formed between the hydroxyl group and the Group 13 transition metal on the carrier. In addition, since the cocatalyst exists only on the surface of the carrier, it can contribute to securing the unique characteristics of the specific hybrid catalyst composition of the present application without a fouling phenomenon in which the polymer particles are agglomerated with the reactor wall or each other.

In addition, the catalyst composition may further include one or more cocatalysts selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 4.

[Formula 2]

-[Al(R ²¹ )-O] _m -

In Formula 2,

R ²¹ are the same as or different from each other and are each independently halogen, C _1-20 alkyl or C _1-20 haloalkyl;

m is an integer greater than or equal to 2;

[Formula 3]

J(R ³¹ ) ₃

In Formula 3,

R ³¹ are the same as or different from each other and are each independently halogen, C _1-20 alkyl or C _1-20 haloalkyl;

J is aluminum or boron;

[Formula 4]

[EH] ⁺ [ZQ ₄ ] ^-

In Formula 4,

E is a neutral or cationic Lewis base;

H is a hydrogen atom;

Z is a group 13 element;

Q is the same as or different from each other and is each independently C _6-20 aryl or C _1-20 alkyl, wherein the C _6-20 aryl or C _1-20 alkyl is unsubstituted or halogen, C _1-20 alkyl , C _1-20 alkoxy and C _6-20 substituted with one or more substituents selected from the group consisting of phenoxy.

In addition, the catalyst composition may further include an antistatic agent represented by the following Chemical Formula 5.

[Formula 5]

R ¹³ N-(CH ₂ CH ₂ OH) ₂

In Formula 5,

R ¹³ is C _8-22 straight-chain alkyl, C _12-18 straight-chain alkyl, or C _13-15 straight-chain alkyl.

When the catalyst composition includes all of the above-described carrier, co-catalyst and antistatic agent, the catalyst composition comprises the steps of supporting the co-catalyst on a carrier; supporting the metallocene compound on the support on which the promoter is supported; and adding an antistatic agent in a solution state to the carrier on which the cocatalyst and the metallocene compound are supported. As described above, the catalyst composition having a structure in which a promoter, a metallocene compound, and an antistatic agent are supported in this order on a carrier may exhibit excellent process stability with high catalytic activity in the polypropylene manufacturing process.

In the present specification, the hydrocarbyl group is a monovalent functional group in the form of removing a hydrogen atom from hydrocarbon, and an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an aralkenyl group, an aralkynyl group, an alkylaryl group, an alkenyl group It may include an aryl group and an alkynylaryl group. The hydrocarbyl group having 1 to 30 carbon atoms may be a hydrocarbyl group having 1 to 20 carbon atoms or 1 to 10 carbon atoms. For example, the hydrocarbyl group may be a straight chain, branched chain or cyclic alkyl group. More specifically, the hydrocarbyl group having 1 to 30 carbon atoms is a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, and a n-hexyl group. straight-chain, branched-chain or cyclic alkyl groups such as a sil group, n-heptyl group, and cyclohexyl group; or an aryl group such as phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, or fluorenyl. In addition, it may be an alkylaryl such as methylphenyl, ethylphenyl, methylbiphenyl, or methylnaphthyl, and may be an arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, or naphthylmethyl. In addition, it may be an alkenyl such as allyl, allyl, ethenyl, propenyl, butenyl, pentenyl.

The compound represented by Formula 2 may be, for example, alkylaluminoxane such as modified methylaluminoxane (MMAO), methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, and the like.

The alkyl metal compound represented by the above formula (3) is, for example, trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, dimethylisobutylaluminum, dimethylethylaluminum, diethylchloro Aluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolyl aluminum, dimethylaluminummethoxide, dimethylaluminumethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, and the like.

The compound represented by Formula 4 is, for example, triethylammonium tetraphenyl boron, tributyl ammonium tetraphenyl boron, trimethyl ammonium tetraphenyl boron, tripropyl ammonium tetraphenyl boron, trimethyl ammonium tetra (p- Tolyl) boron, tripropylammonium tetra(p-tolyl) boron, triethylammonium tetra(o,p-dimethylphenyl) boron, trimethylammonium tetra(o,p-dimethylphenyl) boron, tributylammonium tetra (p-trifluoromethylphenyl) boron, trimethylammonium tetra (p-trifluoromethylphenyl) boron, tributylammonium tetrapentafluorophenyl boron, N,N-diethylanilinium tetraphenyl boron, N, N-diethylanilinium tetraphenylboron, N,N-diethylaniliniumtetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphoniumtetraphenylboron, trimethylphosphoniumtetra Phenyl boron, triethyl ammonium tetraphenyl aluminum, tributyl ammonium tetraphenyl aluminum, trimethyl ammonium tetraphenyl aluminum, tripropyl ammonium tetraphenyl aluminum, trimethyl ammonium tetra (p-tolyl) aluminum, tripropyl ammonium tetra (p-tolyl)aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum , Tributylammonium tetrapentafluorophenyl aluminum, N,N-diethylanilinium tetraphenylaluminum, N,N-diethylaniliniumtetraphenylaluminum, N,N-diethylaniliniumtetrapentafluoro Rophenylaluminum, diethylammonium tetrapentafluorophenylaluminum, triphenylphosphoniumtetraphenylaluminum, trimethylphosphoniumtetraphenylaluminum, triphenylcarboniumtetraphenylboron, triphenylcarboniumtetraphenylaluminum, triphenyl carbonium tetra (p-trifluoromethylphenyl) boron, triphenyl carbonium tetrapentafluorophenyl boron, and the like.

In addition, the catalyst composition may include the cocatalyst and the metallocene compound of Formula 1 in a molar ratio of about 1:1 to about 1:10000, preferably about 1:1 to about 1:1000, respectively. It may be included in a molar ratio of, and more preferably, may be included in a molar ratio of about 1:10 to about 1:100. At this time, if the molar ratio is less than about 1, the metal content of the cocatalyst is too small, so the catalytically active species is not well made, and the activity may be lowered. have.

The supported amount of the cocatalyst may be from about 3 mmol to about 25 mmol, or from about 5 mmol to about 20 mmol based on 1 g of the carrier.

On the other hand, the catalyst composition, the step of supporting a cocatalyst on a carrier; and supporting the metallocene compound on the support on which the cocatalyst is supported.

In the above method, the supporting conditions are not particularly limited and may be performed within a range well known to those skilled in the art. For example, it can proceed by appropriately using high-temperature loading and low-temperature loading, for example, the loading temperature is ^{possible in the range of about -30 o} C to about 150 ^o C, preferably about 50 ^o C to about 98 ^o C, or from about 55 ^o C to about 95 ^o C. The loading time may be appropriately adjusted according to the amount of the first metallocene compound to be supported. The supported catalyst reacted may be used as it is by removing the reaction solvent by filtration or distillation under reduced pressure, and if necessary, it may be used after Soxhlet filter with an aromatic hydrocarbon such as toluene.

And, the preparation of the supported catalyst may be carried out in the presence of a solvent or non-solvent. When a solvent is used, the usable solvent includes an aliphatic hydrocarbon solvent such as hexane or pentane, an aromatic hydrocarbon solvent such as toluene or benzene, a hydrocarbon solvent substituted with a chlorine atom such as dichloromethane, diethyl ether or tetrahydrofuran (THF) ) and most organic solvents such as acetone and ethyl acetate, preferably hexane, heptane, toluene, or dichloromethane.

As described above, the polyethylene according to the present invention may be prepared by polymerizing ethylene using the above-described supported metallocene catalyst, and 1-hexene may be used as a comonomer. As a result, the polyethylene has a comonomer sequence distribution index represented by Equation 1 above 0, and a polyethylene having a high comonomer content relative to the amount of the same comonomer used can be manufactured, so that durability can be improved.

When polyethylene is produced with the catalyst composition in which the metallocene compound according to the present invention is mixed with the low-molecular-weight, low-copolymerizable metallocene compound, the SCB content in the high molecular weight region increases to have a high BOCD index to produce polyethylene with excellent durability. can The polyethylene prepared as described above may be preferably applied to polyethylene of raised temperature resistance (PE-RT) or the like.

Hereinafter, it will be described in more detail to help the understanding of the present invention. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

[Preparation of metallocene compound]

Synthesis Example 1

of (ligand compound (2-isopropyl-4-phenyl-1H-inden-1-yl)dimethyl(2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacen-1-yl)silane Produce)

15.24 mmol of 2-isopropyl-4-phenyl-1H-indene was added to the reactor, and then dried under reduced pressure for 30 minutes. 70 mL of n-hexane and 10 mL of methyl tert-butyl ether (MTBE) were added and stirred to completely dissolve. After the reactor ^{was cooled to -25 o} C, 6.4 mL (16 mmol) of n-butyllithium (n-BuLi, 2.5 M n-hexane solution) was slowly added dropwise with stirring. After stirring at 25 ^o C for 12 hours, dichloro dimethyl silane (15.24 mmol) was then added thereto.

In another reactor, 2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacene (2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacene) 15.24 After adding mmol to the reactor, it was dried under reduced pressure for 30 minutes. 35 mL of MTBE was added and stirred to completely dissolve. After the reactor ^{was cooled to -25 o} C, 6.4 mL (16 mmol) of n-BuLi (2.5 M n-hexane solution) was slowly added dropwise with stirring. After stirring at 25 ^o C for 12 hours, CuCN was added and reacted for 30 minutes.

After mixing the two reactants prepared in this way, they ^{were reacted at 25 o} C for 12 hours. After adding water and stirring for 1 hour, the reactor was allowed to stand and the water layer was separated. Then, water and toluene were re-injected into the reactor, and after stirring and standing for 5 minutes, the water layer was separated and removed. The organic layer _{was dehydrated with MgSO 4} , filtered again, and put into the reactor and dried.

(Transition metal compound Dimethyl Silanediyl (2-methyl-1H-inden-1-yl) (2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacen-1-yl) Preparation of Zirconium chloride )

The ligand prepared above was dissolved in a mixed solvent (Toluene/Ether, volume ratio 10/1) of _{21 mL of toluene and 2.1 mL of diethyl ether (Et 2} O), and after cooling to ^{-25 o C,} 12.8 mL (32 mmol) of n-BuLi (2.5 M n-hexane solution) was slowly added dropwise and stirred. After ^{stirring at 25 o} C for 12 hours and cooling ^{to -20 o} _{C, a slurry prepared by mixing ZrCl 4} (15.24 mmol) with toluene (0.17 M) was added. Then, ^{after stirring at 25 o} C for 12 hours, all of the solvent was removed by drying. After filtering and drying using dichloromethane (DCM, dichloromethane), dichloromethane/hexane was added to recrystallize at room temperature. Then, the resulting solid was filtered and dried under vacuum to obtain the title metallocene compound as a yellow powder (powder, only racemic) in 20% (molar basis).

For the metallocene compound thus obtained, NMR data was measured using Bruker AVANCE III HD 500 MHz NMR/PABBO (1H/19F/Broad band) probe: 1H and solvent: CDCl _{3 .}

¹ H-NMR (500 MHz, CDCl ₃ , ppm): 0.21 (s, 6H), 0.82 (d, 6H), 1.81 (S, 3H), 1.98 (m, 2H), 2.38 (m, 1H), 2.81 (m,4H), 6.35(s, 2H), 7.18-7.49(m,13H), 8.29(d, 1H)

Synthesis Example 2

Diethyl Silanediyl (4-(4-(tert-butyl)phenyl)-2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl)(4-(4-(tert-butyl)phenyl )-2-isopropyl-1H-inden-1-yl) Zirconium chloride

In Synthesis Example 1, in place of 2-isopropyl-4-phenyl-1H-indene in Synthesis Example 1, 2-isopropyl-4-(4-tertbutylphenyl)-1H- Using indene (2-isopropyl-4- (4-tert-butylphenyl) -1H-indene) and using 2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacene (2-methyl -4-phenyl-1,5,6,7-tetrahydro-s-indacene) instead of 2-methyl-4-(4-tertbutylphenyl)-1,5,6,7-tetrahydro-s-indacene (2-methyl-4-(4-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacene) was used, and dichlorodiethylsilane instead of dichlorodimethylsilane was used. silane) was used, and the title metallocene compound was synthesized in the same manner as in Synthesis Example 1.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): 0.68 (m,4H), 0.85(d, 6H), 0.92 (t, 9H), 1.35 (s, 18H), 1.75 (s,3H), 1.98 (m,2H),2.38(m,1H), 2.83(m,4H), 7.35-7.40 (m, 11H), 8.22(d,1H)

Synthesis Example 3

Diethyl Silanediyl (4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl)(4-(3,5-di-tert) -butylphenyl)-2-isopropyl-1H-inden-1-yl) Zirconium chloride

In Synthesis Example 1 in the above, 2-isopropyl-4-phenyl-1H-indene (2-isopropyl-4-phenyl-1H-indene) instead of 2-isopropyl-4- (3,5-ditertbutylphenyl) Use -1H-indene (2-isopropyl-4- (3,5-di-t-butylphenyl) -1H-indene) and 2-methyl-4-phenyl-1,5,6,7-tetrahydro-s -Indacene (2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacene) instead of 2-methyl-4-(3,5-ditertbutylphenyl)-1,5,6 , using 7-tetrahydro-s-indacene (2-methyl-4-(3,5-di-tert-butylphenyl)-1,5,6,7-tetrahydro-s-indacene), and dichlorodimethylsilane A metallocene compound of the title was synthesized in the same manner as in Synthesis Example 1 except that dichlorodiethyl silane was used instead of (dichloro dimethyl silane).

¹ H-NMR (500 MHz, CDCl ₃ , ppm): 0.65 (m,4H),0.87(d,6H), 0.93 (t, 9H), 1.33 (s, 36H), 1.78 (s,3H), 1.95 (m,2H), 2.81(m,4H), 3.36(s, 2H), 7.35 (m, 4H), 7.70 (s,4H), 8.25(d,1H)

Synthesis Example 4

Dimethyl Silanediyl((2-methyl-4-phenyl-1,5,6,7-tetrahydro-s-indacen-1-yl)(2-methyl-4-phenyl-1H-inden-1-yl) Zirconium chloride

In Synthesis Example 1, 2-methyl-4-phenyl-1H-indene (2-emthyl-4) instead of 2-isopropyl-4-phenyl-1H-indene in Synthesis Example 1 -phenyl-1H-indene) was synthesized in the same manner as in Synthesis Example 1, except that the title metallocene compound was synthesized.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): 0.22(s,6H), 1.81(S, 6H), 1.98(m, 2H), 2.81(m,4H), 6.35(s, 2H), 7.18 -7.49(m,13H), 8.29(d, 1H)

Synthesis Example 5

Diethyl Silanediyl (4-(3,5-di-tert-butylphenyl)-2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl)(4-(3,5-di-tert) -butylphenyl)-2-methyl-1H-inden-1-yl) Zirconium chloride

In Synthesis Example 3 above, 2-isopropyl-4-(3,5-ditertbutylphenyl)-1H-indene (2-isopropyl-4-(3,5-di-tert-butylphenyl)-1H-indene) Except for using 2-methyl-4-(3,5-di-tert-butylphenyl)-1H-indene instead of 2-methyl-4-(3,5-di-tert-butylphenyl)-1H-indene The title metallocene compound was synthesized in the same manner as in Synthesis Example 3.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): 0.68 (m,4H), 0.90 (t, 9H), 1.37 (s, 36H), 1.82 (s,6H), 1.98 (m,2H), 2.81 (m,4H), 3.36(s, 2H), 7.35 (m, 4H), 7.73 (s,4H), 8.29(d,1H)

Comparative Synthesis Example 1

(Preparation of ligand compound)

0.83 g (5 mmol) of fluorene was added to a dried 250 mL schlenk flask, and 30 mL of ether was injected under reduced pressure. After the ether solution was cooled to -78°C, the inside of the flask was replaced with argon, and 2.4 mL (6 mmol) of a 2.5 M nBuLi hexane solution (hexane solution/) was slowly added dropwise. The reaction mixture was slowly raised to room temperature and stirred until the next day. Another 250 mL schlenk flask was filled with 30 mL of ether, and then 2.4 mL (20 mmol) of dichlorodimethylsilane was injected. After the flask was cooled to -78 °C, a lithiated solution of 2-hexyl-fluorene was injected thereto through a cannula. After the injection was completed, the mixture was slowly raised to room temperature, stirred for about 5 hours, and then ether used as a solvent and excess dichlorodimethylsilane remaining were removed under vacuum under reduced pressure. A dark ocher colored solid chloro(9H-fluoren-9-yl)dimethylsilane was obtained in the flask.

0.83 g (5 mmol) of fluorene was injected into a dried 100 mL schlenk flask and dissolved in 30 mL of ether. Then, 2.4 mL (6 mmol) of 2.5 M nBuLi hexane solution was slowly added dropwise at -78°C, and the mixture was stirred for one day. After dissolving the previously synthesized chloro(9H-fluoren-9-yl)dimethylsilane in 40 mL of ether, a lithiated solution of fluorene at -78°C is added dropwise. After reacting overnight (overnight), 50 mL of water was added to the flask to quench (quenching), and the organic layer was separated and dried over MgSO ₄ . The mixture obtained through filtration was recrystallized with hexane after removing all solvents under vacuum reduced pressure to obtain a ligand compound.

¹ H NMR (500 MHz, CDCl ₃ , ppm): -0.52 (6H, s), 4.26 (2H, s), 7.29 (4H, m), 7.36 (4H, m), 7.53 (4H, m), 7.89 (4H, m)

(Preparation of metallocene compound)

1.94 g (5 mmol) of the ligand compound synthesized in 2-1) was added to a dry 250 mL schlenk flask, dissolved in ether, and then 4.4 mL (11 mmol) of 2.5 M nBuLi hexane solution was added for lithiation. After one day, 1.88 g (5 mmol) of ZrCl ₄ (THF) ₂ was taken in a glove box and placed in a 250 mL schlenk flask to prepare a suspension containing ether. After both flasks were cooled to -78°C, the lithiated ligand compound was slowly added to the Zr suspension. After injection, the reaction mixture was slowly raised to room temperature. After the reaction was allowed to proceed for one day, the mixture was filtered in a filter system not in contact with external air to obtain a metallocene compound.

¹ H NMR (500 MHz, CDCl ₃ , ppm): 1.46 (6H, s), 6.99 (4H, m), 7.29 (4H, m), 7.68 (4H, m), 7.9 (4H, m).

Comparative Synthesis Example 2

(Preparation of ligand compound)

From the reaction between the tert-Bu-O-(CH ₂ ) ₆ Cl compound and Mg(0) in a _{THF solvent, 1.0 mol of a Grignard reagent tert-Bu-O-(CH 2} ) ₆ MgCl solution was obtained. The prepared Grignard compound _{was added to a flask containing MeSiCl 3} compound (176.1 mL, 1.5 mol) and THF (2.0 mL) at -30°C, stirred at room temperature for 8 hours or more, and the filtered solution was vacuum dried to obtain a compound of tert-Bu-O-(CH ₂ ) ₆ SiMeCl ₂ (yield 92%).

Put fluorene (3.33 g, 20 mmol), hexane (100 mL), and MTBE (methyl tert-butyl ether, 1.2 mL, 10 mmol) in a reactor at -20 ° C, and slowly add 8 ml of n-BuLi (2.5 M in Hexane) and stirred at room temperature for 6 hours to obtain a fluorenyl lithium solution. After the stirring was completed, the reactor temperature was cooled to -30°C, and tert-Bu-O-(CH ₂ ) ₆ SiMeCl ₂ (2.7 g, 10 mmol) dissolved in hexane (100 ml) at -30° C. was prepared above. The fluorenyl lithium solution was slowly added over 1 hour. After stirring at room temperature for 8 hours or more, water was added to extract, and evaporation was performed to obtain (tert-Bu-O-(CH ₂ ) ₆ )MeSi(9-C ₁₃ H ₁₀ ) ₂ compound (5.3 g). , yield 100%).

¹ H NMR (500 MHz, CDCl ₃ , ppm): -0.35 (MeSi, 3H, s), 0.26 (Si-CH ₂ , 2H, m), 0.58 (CH ₂ , 2H, m), 0.95 (CH ₂ , 4H, m), 1.17 (tert-BuO, 9H, s), 1.29 (CH ₂ , 2H, m), 3.21 (tert-BuO-CH ₂ , 2H, t), 4.10 (Flu-9H, 2H, s) , 7.25 (Flu-H, 4H, m), 7.35 (Flu-H, 4H, m), 7.40 (Flu-H, 4H, m), 7.85 (Flu-H, 4H, d).

(Preparation of metallocene compound)

4.8 mL of (tert-Bu-O-(CH ₂ ) ₆ )MeSi(9-C1 ₃ H ₁₀ ) ₂ (3.18 g, 6 mmol)/MTBE (20 mL) solution prepared in 1-1) above at -20 ° C. of n-BuLi (2.5M in Hexane) was slowly added and reacted for at least 8 hours while raising to room temperature to prepare a slurry solution of dilithium salts. At -20°C, the prepared dilithium salt _{slurry solution was slowly added to a slurry solution of ZrCl 4} (THF) ₂ (2.26 g, 6 mmol)/hexane (20 mL), followed by further reaction at room temperature for 8 hours. The precipitate was filtered and washed several times with hexane to obtain a red solid (tert-Bu-O-(CH ₂ ) ₆ )MeSi(9-C ₁₃ H ₉ ) ₂ ZrCl ₂ compound (4.3 g, yield 94.5%). ).

¹ H NMR (500 MHz, C ₆ D ₆ , ppm): 1.15 (tert-BuO, 9H, s), 1.26 (MeSi, 3H, s), 1.58 (Si-CH ₂ , 2H, m), 1.66 (CH ₂ , 4H, m), 1.91 (CH ₂ , 4H, m), 3.32 (tert-BuO-CH ₂ , 2H, t), 6.86 (Flu-H, 2H, t), 6.90 (Flu-H, 2H, t), 7.15 (Flu-H, 4H, m), 7.60 (Flu-H, 4H, dd), 7.64 (Flu-H, 2H, d), 7.77 (Flu-H, 2H, d).

[Preparation of supported catalyst]

Preparation Example 1

After putting 50 mL of toluene in a pico reactor, 7 g of silica gel (Silica gel, SYLOPOL 952X, calcinated under 250 ℃) was added under Ar, and 10 mmol of methylaluminoxane (MAO) was slowly injected at room temperature at 95 ℃. The reaction was stirred for 24 hours. After completion of the reaction, cool to room temperature and leave for 15 minutes to decant the solvent using a cannula. Toluene (400 mL) was added, stirred for 1 minute, and left for 15 minutes to decant the solvent using a cannula.

After dissolving 60 μmol of the metallocene compound of Synthesis Example 1 in 30 mL of toluene, it was transferred to the reactor using a cannula. The reaction was stirred at 80 °C for 2 hours. After the reaction was completed and the precipitation was completed, the solvent was decanted using a cannula, cooled to room temperature and left for 15 minutes. The upper layer solution was removed and the remaining reaction product was washed with toluene. After washing again with hexane, 2 wt% of an antistatic agent (Atmer 163) per unit weight (g) of silica was dissolved in 3 ml of hexane under hexane, followed by stirring at room temperature for 10 minutes. After completion of the reaction and the completion of precipitation, the upper layer was removed and transferred to a glass filter to remove the solvent.

The silica-supported metallocene catalyst in the form of solid particles was obtained by primary drying at room temperature under vacuum for 5 hours, and secondary drying at 45° C. under vacuum for 4 hours.

Preparation Examples 2 to 5

A silica-supported metallocene catalyst was prepared in the same manner as in Preparation Example 1, except that the metallocene compounds of Synthesis Examples 2 to 5 were used instead of the metallocene compound of Synthesis Example 1, respectively.

Comparative Preparation Examples 1 and 2

A silica-supported metallocene catalyst was prepared in the same manner as in Preparation Example 1, except that the metallocene compounds of Comparative Synthesis Examples 1 to 3 were used instead of the metallocene compound of Synthesis Example 1, respectively.

[Polyethylene Polymerization]

Example 1

An ethylene-1-hexene copolymer was prepared in the presence of the supported catalyst obtained in Preparation Example 3, and the specific method is as follows.

A 600 mL stainless steel reactor was vacuum dried at 120° C., cooled, and 1 g of trimethylaluminum (TMA) was added to 250 g of hexane at room temperature and stirred for 10 minutes. After removing all of the reacted hexane, 250 g of hexane and 0.5 g of triisobutylaluminum (TIBAL) were added and stirred for 5 minutes. Then, after adding 7 mg of the supported catalyst obtained in Preparation Example 3, the temperature was raised to ^{70 o C and stirred.} After stopping stirring at 70 ^o C, 10 mL of comonomer 1-hexene (1-hexene, C6) was added, and ethylene (ethylene, C2) was filled to 30 bar, and then stirring was started. After polymerization for 30 minutes, unreacted C2 was vented.

Examples 2 to 6

An ethylene-1-hexene copolymer was prepared in the same manner as in Example 1, except that the catalyst and 1-hexene used in Table 1 were used instead of the supported catalyst and 1-hexene used in Preparation Example 1.

Comparative Examples 1 to 4

An ethylene-1-hexene copolymer was prepared in the same manner as in Example 1, except that the catalyst and 1-hexene used in Table 1 were used instead of the supported catalyst and 1-hexene used in Preparation Example 1.

[Experimental Example: Evaluation of Physical Properties of Polyethylene]

Catalytic activity, process stability, and physical properties of the polyethylene copolymer of Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

(1) Melting point (Tm, ℃)

Tm was measured using a differential scanning calorimeter (DSC).

Specifically, as a differential scanning calorimeter (DSC), the melting temperature of the polymer was measured using a DSC 2920 (TA instrument). Specifically, the polymer ^{was heated to 150 o} C and maintained for 5 minutes, and ^{then lowered to -100 o} C and then the temperature was increased again. At this time, the rate of rise and fall of the temperature ^{was adjusted to 10 o} C/min, respectively. The melting temperature was taken as the maximum point of the endothermic peak measured in the section where the second temperature was increased.

(2) SCB (Short Chain Branch) content (branch content of 2 to 7 carbon atoms per 1,000 carbons, pcs/1,000C)

The sample was pretreated by dissolving it in 1,2,4-Trichlorobenzene containing 0.0125% BHT at 160℃ for 10 hours using PL-SP260VS, and then using PerkinElmer Spectrum 100 FT-IR connected to high-temperature GPC (PL-GPC220). and measured at 160 °C.

(3) Comonomer sequence distribution Index

For the polyethylene copolymers of Examples and Comparative Examples, the Comonomer sequence distribution index was calculated by substituting Tm and SCB in Equation 1 below.

[Equation 1]

Comonomer sequence distribution Index = SCB content - 6 * 10 ⁴⁷ * Tm ^-22.52

(4) Density (g/cm ³ )

It was measured by the ISO-1183 method using a pycnometer.

catalyst compound C6 usage
(ml) Tm (℃) SCB (pcs/C1000) Comonomer sequence distribution index Density
(g/cm ³ ) Example 1 Preparation 3 10 127 3.2 0.69 0.931 Example 2 Preparation Example 1 3 129.2 2.8 1.09 0.939 Example 3 Preparation 2 3 128.5 3.8 1.87 0.936 Example 4 Preparation 3 3 131.2 1.9 0.69 0.942 Example 5 Preparation 4 3 127.5 4.8 2.5 0.935 Example 6 Preparation 5 3 126.5 5.9 3.15 0.934 Comparative Example 1 Comparative Preparation Example 1 10 127.7 2.2 -0.02 0.939 Comparative Example 2 Comparative Preparation Example 2 10 128.4 1.9 -0.06 0.938 Comparative Example 3 Comparative Preparation Example 1 20 124.5 3.8 -0.13 0.926 Comparative Example 4 Comparative Preparation Example 2 20 125.8 3.1 -0.01 0.927

As shown in Table 1, when Example 4 and Comparative Example 2 were compared, it was confirmed that a relatively high density was maintained when the Comonomer sequence distribution Index was greater than 0 even with the same SCB. Similarly, Example 2 was confirmed to include 0.6 more SCBs while maintaining the density compared to Comparative Example 1.

Meanwhile, FIG. 1 shows the melting point and SCB content of Examples and Comparative Examples as the x-axis and the y-axis, respectively. As shown in FIG. 1 , it was confirmed that an embodiment of the present invention contained a large amount of SCB content compared to an equivalent melting point compared to the comparative example.

From Table 1 and FIG. 1, it was confirmed that the polyethylene according to an embodiment of the present invention had a high SCB content and a high density even though the polyethylene had an equivalent level of Tm, thereby confirming that the SCB was distributed in blocks.

Claims (9)

1-hexene as a comonomer;
Melting point (Tm) is 126.5 ℃ or more and 132 ℃ or less,
Comonomer sequence distribution Index represented by the following formula 1 is 0 or more,
Polyethylene:
[Equation 1]
Comonomer sequence distribution Index = SCB content - 6 * 10 ⁴⁷ * Tm ^-22.52
In Equation 1 above,
SCB (short chain branch) content is a branch content of 2 to 7 carbon atoms per 1000 carbons (piece / 1000C),
Tm is the melting point.
According to claim 1,
SCB (short chain branch) content is 1.5 / 1000C or more and 6.5 / 1000C or less,
polyethylene.
The method of claim 1,
Density of 0.928 g/cm ³ or more and 0.948 g/cm ³ or less,
polyethylene.
According to claim 1,
The polyethylene is prepared by polymerizing ethylene in the presence of a metallocene compound represented by the following Chemical Formula 1,
Polyethylene:
[Formula 1]

In Formula 1,
M is any one of a Group 4 transition metal,
A is any one of the elements of group 14,
R ¹ and R ² are the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl , C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,
R ³ is methyl or isopropyl;
X ¹ , and X ² are the same as or different from each other and are each independently halogen,
Q ¹ , and Q ² are the same as or different from each other _{and are C 1-20} alkyl.
5. The method of claim 4,
The formula 1 is represented by the following formula 1-1,
Polyethylene:
[Formula 1-1]

In Formula 1-1, A, M, R ¹ , R ² , R ³ , X ¹ , X ² , Q ¹ and Q ² are as defined in claim 3,
R′ is the same as or different from each other, and each independently represents hydrogen or C _1-6 straight or branched chain alkyl;
a and b are each independently 0 or 1.
5. The method of claim 4,
A is silicon, M is zirconium,
polyethylene.
5. The method of claim 4,
R ¹ and R ² are each hydrogen, phenyl, or phenyl substituted with 1 or 2 tertbutyl;
polyethylene.
5. The method of claim 4,
Q ¹ and Q ² are each independently methyl or ethyl;
polyethylene.
5. The method of claim 4,
The compound represented by Formula 1 is any one selected from the group consisting of
Polyethylene:

.

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