KR20210080973A - Polyethylene copolymer and blown film comprising the same - Google Patents

Abstract

The present invention relates to polyethylene, capable of producing a blown film having excellent heat shrinkage packaging performance as a shrinkage rate in a transverse direction (TD) of resin flow is large even at a low temperature without raising temperature to a high temperature. A polyethylene copolymer has density of 0.925 to 0.940 g/cm^3, melt index (MI2.16, 190℃, 2.16 kg load) of 0.2 to 1.0 g/10min, and a content of a branched polymer structure is 25 to 35 wt% based on the total weight of the copolymer.

Description

Polyethylene copolymer and blown film containing the same {POLYETHYLENE COPOLYMER AND BLOWN FILM COMPRISING THE SAME}

The present invention relates to a polyethylene copolymer capable of producing a blown film having excellent heat shrinkage packaging performance due to a large shrinkage in the transverse direction (TD) of the resin flow even at a low temperature without raising the temperature to a high temperature. will be.

Low density polyethylene (LDPE) is produced by copolymerizing ethylene and alpha olefin at high pressure using an initiator, and is used in shrink films.

In general, shrink films have been used for many years in the packaging industry for packaging articles. The process is applied to Collation Shrink Film such as general consumer products and beverages by packing the article, passing it through an oven tunnel, and heating and cooling it to shrink the film. It is known to use linear low density polyethylene (LLDPE) mixed with low density polyethylene (LDPE) in the shrink film composition. Typically, compositions comprising from 20% to 40% by weight of LLDPE are used with 80% to 60% by weight of LDPE. However, when LLDPE is mixed with LDPE to improve mechanical properties, there is a problem in that shrinkage properties are deteriorated.

On the other hand, in the case of collation shrink film, medium density polyethylene is used to increase stiffness for stability during movement and storage by loading the product. Among them, heat shrink film is being applied to industrial packaging, food, beverage, and general product packaging. Most of these films are formed with a blown extruder, and the shrinkage rate in the transverse direction (TD) of the resin flow determines the packaging performance.

Accordingly, it is necessary to develop a medium-density polyethylene resin with improved shrinkage characteristics in the transverse direction (TD) of the resin flow even in a heat shrink process at a low temperature.

An object of the present invention is to provide polyethylene capable of producing a blown film having excellent heat shrinkage packaging performance and a blown film including the same.

In one embodiment of the present invention, the density is 0.925 g/cm ³ to 0.940 g/cm ³ , and the melt index (MI _2.16 , 190 ^o C, 2.16 kg load) is 0.2 g/10min to 1.0 g/10min, branched The content of the polymer structure is 25 wt% to 35 wt%, based on the total weight of the polyethylene copolymer, to provide a polyethylene copolymer.

Further, in another embodiment of the present invention, it provides a blown film comprising the polyethylene copolymer of the embodiment.

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 this specification, terms such as "comprises", "comprises" or "have" are intended to describe embodied features, numbers, steps, components, or combinations thereof, and include one or more other features, numbers, or steps. , components, combinations or additions thereof are not excluded.

Also, the terms "about," "substantially," and the like, to the extent used throughout this specification are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented. It is used to prevent an unscrupulous infringer from using the disclosure in which exact or absolute figures are mentioned for better understanding.

In addition, in the present invention, the (co)polymer is meant to include both a homo-polymer and a copolymer (co-polymer).

Unless otherwise defined herein, "copolymerization" may mean block copolymerization, random copolymerization, graft copolymerization or alternating copolymerization, and "copolymer" means block copolymer, random copolymer, graft copolymer or alternating copolymer. It can mean amalgamation.

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, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Hereinafter, the present invention will be described in detail.

According to an aspect of the present invention, the density is 0.925 g/cm ³ to 0.940 g/cm ³ , and the melt index (MI _2.16 , 190 ^o C, 2.16 kg load) is 0.2 g/10min to 0.5 g/10min, min A polyethylene copolymer is provided, wherein the content of the topographic polymer structure is 25 wt% to 35 wt% based on the total weight of the polyethylene copolymer.

For reference, in the present specification, "part by weight" means a relative concept in which the weight of the other material is expressed as a ratio based on the weight of a certain material. For example, in a mixture in which the weight of material A is 50 g, material B is 20 g, and material C is 30 g, the amounts of material B and material C are each 40 parts by weight based on 100 parts by weight of material A parts by weight and 60 parts by weight.

On the other hand, "wt% (% by weight)" means an absolute concept in which the weight of a certain material is expressed as a percentage among the total weight. In the mixture exemplified above, the content of material A, material B, and material C in 100% of the total weight of the mixture is 50% by weight, 20% by weight, and 30% by weight, respectively.

In the present invention, the polyethylene copolymer is a mixture of polymers having different shapes, such as linear or branched, by physical force. For example, the branched polymer has a weight average molecular weight ratio of the side chain to the main chain of 40 % or less, or may be a polymer having a weight average molecular weight of only the side chain of 3,000 g/mol or more. In addition, the branched (branched) polymer is also referred to as a comb polymer (comb polymer).

In addition, in the present invention, the content of the branched polymer structure contained in the polyethylene copolymer and the weight average molecular weight of the main chain in the structure may be analyzed using a general method using GPC column analysis and NMR analysis, but the present invention In , the rheological properties and/or molecular weight distribution of an arbitrarily selected polymer is measured, an arbitrary value is set for the selected polymer, and the rheological property and/or molecular weight distribution of the polymer is predicted from the arbitrary value, and the measured value and predicted value It can be performed by a quantitative analysis method of a polymer structure comprising the step of determining the value of the structural parameter of the polymer by comparing the . More specifically, the quantitative analysis method of the polymer structure comprises the steps of (A) measuring the rheological properties of the polymer; (B) selecting one or more parameters among the structural parameters that the polymer may have, and assigning a random value to the selected structural parameters; And (C) predicting the rheological property of the polymer to which an arbitrary value is given, and determining the value of the structural parameter of the polymer by comparing the predicted value of the rheological property of the polymer with the measured value of the rheological property of the polymer, , The step (A) may further include the step of actually measuring the molecular weight distribution of the polymer using GPC.

In the quantitative analysis method of the polymer structure, the rheological properties of the polymer can be measured using a rheometer, and more specifically, the shear storage modulus (G') using a rotational rheometer. , shear loss modulus (G"), shear composite viscosity (η*), and the like can be measured.

In addition, in the step (B), the selected structural parameter is a polymer shape; the weight average molecular weight (Mw) of the main chain or long side chain in the branched polymer structure; polydispersity index (PDI) of the main chain or long side chain; And it may be one or more selected from the group consisting of the number of long side chains. The polymer shape parameter is a parameter that can distinguish whether the polymer to be analyzed is a linear or branched polymer, specifically, a comb-like, star, or H-shape depending on the side chain bound to the branched polymer. It represents a parameter that can qualitatively classify branched polymers that can appear as .

The structural parameter may further include a mixed interpolymer mass fraction. For example, the weight average molecular weight and polydispersity index parameter of each polymer in the polymer mixture may be calculated by multiplying the mass fraction parameter and applied to predicting rheology and/or molecular weight distribution in step (c).

In addition, in step (c), the rheological properties of the polymer are subjected to a step strain of shear flow to the polymer to which an arbitrary value is assigned, and the stress relaxation of the polymer induced by the step strain is applied. ) can be predicted from the behavior. The stress relaxation behavior may vary depending on the length, molecular weight distribution, and hierarchical structure of the main chain and side chains of the polymer. The stress change behavior is different depending on the structure of the polymer. For example, when a step deformation of shear flow is applied to the polymer, the shape of the polymer is also deformed, and the length, molecular weight distribution and side chains of the main and side chains of the polymer in the process of relaxation of the polymer through stress relaxation behavior over time hierarchical structure of In one example, in the case of a general linear polymer without side chains, as the length of the main chain is longer, the time required for relaxation may be increased because it is greatly affected by the surrounding polymer. In addition, in the case of a polymer having a side chain, the relaxation time may be longer than that of a linear polymer because the main chain cannot be relaxed unless the side chain is relaxed.

In addition, prediction of rheological properties from the stress relaxation behavior can be made using a Doi-Edwards numerical analysis model.

In addition, the comparison of the predicted rheological property value of the polymer and the measured rheological property value of the polymer made in step (C) is an error value (ε) between the predicted polymer rheological property value and the measured rheological property value of the polymer , and confirming that the error value is less than a predetermined error reference value (εs), and the determination of the structural parameter value of the polymer in step (c) is, when the error value is less than the predetermined error reference value , the arbitrary value assigned in the step (B) may be a definite value of the polymer structure parameter. In addition, the determined value may have a range expressed by the minimum and maximum values of a plurality of determined values derived by repeating steps (B) and (C) two or more times, and the steps (B) and (C) It is also possible to have an average value for a plurality of determined values derived by repeating the step two or more times.

In addition, the step (C) is a step of predicting the molecular weight distribution of the polymer to which an arbitrary value is given, and determining the value of the structural parameter of the polymer by comparing the predicted molecular weight distribution value of the polymer with the measured molecular weight distribution value of the polymer may further include, and the molecular weight distribution prediction of the polymer may be made by assuming a log normal distribution to the polymer to which an arbitrary value is assigned.

In the polyethylene copolymer according to an embodiment of the present invention, the content of the branched polymer structure measured according to the above method under the conditions satisfying the above-mentioned density and melt index ranges is 25% by weight based on the total weight of the polyethylene copolymer. to 35% by weight. When the content of the branched polymer structure is too small to be less than 25% by weight, the shrinkage rate in the TD direction is reduced in the heat shrinkage process at a low temperature, the heat shrinkage packaging performance is lowered, and there is a problem in the processability packaging performance. can On the other hand, when the content of the branched polymer structure exceeds 35% by weight and is too large, the shrinkage rate may be high, but the drop impact strength or mechanical strength is lowered, and it may be difficult to use in actual industrial packaging. Specifically, the content of the branched polymer structure in the polyethylene copolymer may be 26 wt% to 34 wt%, more specifically 28 wt% to 32 wt%.

The polyethylene copolymer according to an embodiment of the present invention simultaneously satisfies the content of the branched polymer structure as described above under the conditions that meet the above-described ranges of density and melt index, thereby providing a blow-up ratio ( The shrinkage behavior according to the blow up ratio (BUR) is greatly increased, and the shrinkage rate is large even at a low temperature of ^{about 140 o C or less without raising the temperature to a high temperature, so it can exhibit excellent heat shrinkage packaging processability.} .

In addition, in the polyethylene copolymer, the weight average molecular weight of the main chain in the branched polymer structure is 180,000 g/mol to 200,000 g/mol, more specifically 180,000 g/mol to 195,000 g/mol, more More specifically, it may be 185,000 g/mol to 190,000 g/mol.

When comparing polyethylene copolymers having an equivalent weight average molecular weight, by optimizing the content of the branched polymer structure in the polyethylene copolymer, that is, the comb-type polymer structure, and optimizing the molecular weight or number of long side chains in the structure, the BUR Accordingly, the shrinkage rate in the TD direction is increased, so that processing performance as a heat shrinkage film can be significantly improved.

For example, in the polyethylene copolymer, the number of long chain branches (LCB) may be 0.03 to 0.06 per 1,000 carbon atoms in the polyethylene copolymer, and the weight average molecular weight of the long chain branch (LCB, Long chain branch) may be 20,000 g/mol to 30,000 g/mol.

In addition, the polyethylene copolymer satisfying the characteristics of the structural parameters described above may exhibit melt index and molecular weight characteristics equivalent to these in terms of maintaining excellent mechanical properties like conventional linear low-density polyethylene.

The polyethylene copolymer corresponds to a medium-density polyethylene resin having improved shrinkage properties in the TD direction in a low-temperature heat shrinkage process, and specifically, the density measured according to ASTM D 1505 of the American Society for Testing and Materials, 0.926 g/ cm ³ to 0.938 g/cm ³ , more specifically 0.928 g/cm ³ to 0.935 g/cm ³ .

In addition, the polyethylene copolymer has a melt index (MI) of 0.23 g/10min to 0.45 g/10min, measured at a temperature of ^{190 o} C and a load of 2.16 kg in accordance with the ASTM D 1238 standard of the American Society for Testing and Materials. , specifically 0.25 g/10min to 0.4 g/10min, more specifically 0.28 g/10min to 0.4 g/10min.

And, the polyethylene copolymer may have a weight average molecular weight (Mw) of 90,000 g/mol to 120,000 g/mol, specifically 92,000 to 110,000 g/mol, more specifically 95,000 g/mol to 110,000 g/mol or 95,000 g/mol to 100,000 g/mol. In addition, the molecular weight distribution (Mw/Mn) determined by the ratio (Mw/Mn) of the number average molecular weight (Mn) to the weight average molecular weight (Mw) of the polyethylene copolymer may be 3.0 to 3.5, specifically 3.3 to 3.5, more specifically 3.4 to 3.5.

In the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are converted values with respect to standard polystyrene measured using gel permeation chromatography (GPC, manufactured by Water Corporation). However, the weight average molecular weight is not limited thereto and may be measured by other methods known in the art to which the present invention pertains.

The polyethylene copolymer may have at least one of the above-described physical properties, and may have all of the above-described physical properties to exhibit excellent mechanical strength. As such, when the content, density, and melt index conditions of the branched polymer structure are satisfied, and the molecular weight of the branched polymer structure and the ranges of the weight average molecular weight and molecular weight distribution of the polyethylene copolymer are further satisfied, blown Increases the shrinkage behavior according to BUR during film processing, and without raising the temperature to a high temperature about 140 ^o C or less, or about 120 ^o C to about 140 ^o C, or about 135 ^o C or less, or about 125 ^o C to about 135 ^o C, or ^{even at a low temperature of about 130 o} C, the shrinkage rate in the transverse direction (TD) of the resin flow can be improved, thereby further improving the heat shrinkage packaging performance.

The polyethylene copolymer exhibiting such physical properties may be, for example, a copolymer of ethylene and alpha olefin.

In this case, the alpha olefin is propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, It may include 1-tetradecene, 1-hexadecene, and mixtures thereof. Among them, the polyethylene copolymer may be a copolymer of ethylene and 1-hexene.

When the polyethylene copolymer is the above-mentioned copolymer, the above-described physical properties may be more easily implemented. However, the type of the polyethylene copolymer is not limited to the above type, and various types known in the art to which the present invention pertains may be provided as long as the above-described physical properties can be exhibited.

Meanwhile, the polyethylene copolymer having the above physical properties may be prepared in the presence of a metallocene catalyst.

Specifically, the metallocene catalyst may include at least one first metallocene compound selected from compounds represented by the following Chemical Formula 1; at least one second metallocene compound selected from compounds represented by the following formula (2); and a carrier supporting the first and second metallocene compounds. It may be a hybrid supported metallocene catalyst comprising a.

[Formula 1]

In Formula 1,

M ¹ is a Group 4 transition metal;

A is carbon (C), silicon (Si), or germanium (Ge);

X ¹ and X ² are the same as or different from each other, and each independently a halogen, a nitro group, an amido group, a phosphine group, a phosphide group, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyloxy group having 1 to 30 carbon atoms, a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms, —SiH ₃ , a hydrocarbyl (oxy)silyl group having 1 to 30 carbon atoms, a sulfonate group having 1 to 30 carbon atoms, or a sulfone group having 1 to 30 carbon atoms;

R ¹ and R ³ to R ¹⁰ are the same as or different from each other, and each independently hydrogen, a C 1 to C 30 hydrocarbyl group, a C 1 to C 30 hydrocarbyloxy group, or a C 2 to C 30 hydrocarbyl oxyhydrocar begging;

R ² is hydrogen, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyloxy group having 1 to 30 carbon atoms and a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms, a hydrocarbyl (oxy)silyl group having 1 to 20 carbon atoms, or a carbon number 1 to 20 silylhydrocarbyl groups;

Q ¹ and Q ² are the same as or different from each other, and each independently represent a hydrocarbyl group having 1 to 30 carbon atoms or a hydrocarbyloxy group having 1 to 30 carbon atoms;

[Formula 2]

In Formula 2,

M ² is a Group 4 transition metal;

X ³ and X ⁴ are the same as or different from each other, and each independently a halogen, a nitro group, an amido group, a phosphine group, a phosphide group, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyloxy group having 1 to 30 carbon atoms, a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms, —SiH ₃ , a hydrocarbyl (oxy)silyl group having 1 to 30 carbon atoms, a sulfonate group having 1 to 30 carbon atoms, or a sulfone group having 1 to 30 carbon atoms;

Z is -O-, -S-, -NR _a -, or -PR _a -,

R _a is hydrogen, a hydrocarbyl group having 1 to 20 carbon atoms, a hydrocarbyl (oxy)silyl group having 1 to 20 carbon atoms, and a silylhydrocarbyl group having 1 to 20 carbon atoms;

또는

이고,T is

or

ego,

T ¹ is C, Si, Ge, Sn or Pb,

Q ³ is hydrogen, a hydrocarbyl group having 1 to 30 carbon atoms, a hydrocarbyloxy group having 1 to 30 carbon atoms, a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms, -SiH ₃ , hydrocarbyl (oxy) having 1 to 30 carbon atoms Any one of a silyl group, a hydrocarbyl group having 1 to 30 carbon atoms substituted with a halogen, and -NR _b R _c ;

Q ⁴ is any one of a hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms,

R _b and R _c are each independently any one of hydrogen and a hydrocarbyl group having 1 to 30 carbon atoms, or are connected to each other to form an aliphatic or aromatic ring;

C ¹ is any one of the ligands represented by the following formulas 2a to 2d,

[Formula 2a]

[Formula 2b]

[Formula 2c]

[Formula 2d]

In Formulas 2a to 2d,

Y is O or S;

R ¹¹ to R ¹⁶ are the same as or different from each other, and each independently represents any one of hydrogen, a C 1 to C 30 hydrocarbyl group, or a C 1 to C 30 hydrocarbyloxy group.

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

The hydrocarbyl group is a monovalent functional group in which a hydrogen atom is removed from hydrocarbon, and is 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 alkenylaryl group, and an alkyl group. It may include a nylaryl group and the like. 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. More specifically, a 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, and methylnaphthyl, and may be an arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, and naphthylmethyl. In addition, it may be an alkenyl such as allyl, allyl, ethenyl, propenyl, butenyl, pentenyl.

A hydrocarbyloxy group is a functional group in which a hydrocarbyl group is bonded to oxygen. Specifically, the hydrocarbyloxy group having 1 to 30 carbon atoms may be a hydrocarbyloxy group having 1 to 20 carbon atoms or 1 to 10 carbon atoms. For example, the hydrocarbyloxy group may be a straight chain, branched chain or cyclic alkyl. More specifically, the hydrocarbyloxy group having 1 to 30 carbon atoms is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, tert-butoxy group, n-pentoxy group , a straight-chain, branched-chain or cyclic alkoxy group such as n-hexoxy group, n-heptoxy group, cyclohexoxy group; Or it may be an aryloxy group such as a phenoxy group or a naphthalenoxy group.

A hydrocarbyloxyhydrocarbyl group is a functional group in which one or more hydrogens of a hydrocarbyl group are substituted with one or more hydrocarbyloxy groups. Specifically, the hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms may be a hydrocarbyloxyhydrocarbyl group having 2 to 20 carbon atoms or 2 to 15 carbon atoms. For example, the hydrocarbyloxyhydrocarbyl group may be a straight chain, branched chain or cyclic alkyl group. More specifically, the hydrocarbyloxyhydrocarbyl group having 2 to 30 carbon atoms is a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhexyl group, a tert- part alkoxyalkyl groups such as a oxymethyl group, a tert-butoxyethyl group, and a tert-butoxyhexyl group; or an aryloxyalkyl group such as a phenoxyhexyl group.

The hydrocarbyl(oxy)silyl group _{is a functional group in which 1 to 3 hydrogens of -SiH 3} are substituted with 1 to 3 hydrocarbyl groups or hydrocarbyloxy groups. Specifically, the hydrocarbyl (oxy)silyl group having 1 to 30 carbon atoms may be a hydrocarbyl (oxy)silyl group having 1 to 20 carbon atoms, 1 to 15 carbon atoms, 1 to 10 carbon atoms, or 1 to 5 carbon atoms. More specifically, the hydrocarbyl (oxy)silyl group having 1 to 30 carbon atoms is an alkyl group such as a methylsilyl group, a dimethylsilyl group, a trimethylsilyl group, a dimethylethylsilyl group, a diethylmethylsilyl group or a dimethylpropylsilyl group. silyl group; Alkoxysilyl groups, such as a methoxysilyl group, a dimethoxysilyl group, a trimethoxysilyl group, or a dimethoxyethoxysilyl group; It may be an alkoxyalkylsilyl group such as a methoxydimethylsilyl group, a diethoxymethylsilyl group, or a dimethoxypropylsilyl group.

The silylhydrocarbyl group having 1 to 20 carbon atoms is a functional group in which at least one hydrogen of the hydrocarbyl group is substituted with a silyl group. The silyl group _{may be -SiH 3} or a hydrocarbyl (oxy)silyl group. Specifically, the silylhydrocarbyl group having 1 to 20 carbon atoms may be a silylhydrocarbyl group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. More specifically, the silylhydrocarbyl group having 1 to 20 carbon atoms is a silylalkyl group such as _{-CH 2 -SiH 3 ;} alkylsilylalkyl groups such as a methylsilylmethyl group, a methylsilylethyl group, a dimethylsilylmethyl group, a trimethylsilylmethyl group, a dimethylethylsilylmethyl group, a diethylmethylsilylmethyl group, or a dimethylpropylsilylmethyl group; Or it may be an alkoxysilylalkyl group, such as a dimethylethoxysilylpropyl group.

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

The sulfonate group has ^a _{structure of -O-SO 2} -R a , and R ^a may be a hydrocarbyl group having 1 to 30 carbon atoms. Specifically, the sulfonate group having 1 to 30 carbon atoms may be a methanesulfonate group or a phenylsulfonate group.

A sulfone group having 1 to 30 carbon atoms has a structure of ^{-R c'} -SO ₂ -R ^{c" , wherein R c'} and R ^c" are the same or different from each other, and each independently any one of a hydrocarbyl group having 1 to 30 carbon atoms. can Specifically, the sulfone group having 1 to 30 carbon atoms may be a methylsulfonylmethyl group, a methylsulfonylpropyl group, a methylsulfonylbutyl group, or a phenylsulfonylpropyl group.

In the present specification, that two substituents adjacent to each other are connected to each other to form an aliphatic or aromatic ring means that the atom(s) of the two substituents and the valences (atoms) to which the two substituents are bonded are connected to each other to form a ring do. Specifically, an example in which R _a and R _b or R _a' and R _{b' of -NR a} R _b or -NR _a' R _{b '} are connected to each other to form an aliphatic ring is a piperidinyl group, etc. and R _a and R _b or R _a' and R _b' of -NR _a R _b or -NR _a' R _b' are linked to each other to form an aromatic ring, for example, a pyrrolyl group can be exemplified.

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; hydrocarbyl group; hydrocarbyloxy group; a hydrocarbyl group or a hydrocarbyloxy group containing at least one hetero atom among the hetero atoms of Groups 14 to 16; silyl group; hydrocarbyl (oxy) silyl group; 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.

는 다른 치환기에 연결되는 결합을 의미한다. In this specification,

means a bond connected to another substituent.

On the other hand, the hybrid supported catalyst is a first metallocene compound having a long chain branch (LCB, Long chain branch) content increase characteristic during ethylene polymerization and a second metal having a short chain branch (SCB, short chain branch) content increase characteristic By hybrid supporting a strong compound, it exhibits high activity with excellent process stability for ethylene polymerization, and has excellent mechanical properties through improvement of molecular structure and distribution change, and has useful characteristics for preparing polyethylene copolymers with excellent shrinkage and processability.

In particular, in the hybrid supported metallocene catalyst according to the embodiment, the first metallocene compound represented by Formula 1 increases the long chain branch (LCB) content through improvement of molecular structure and distribution change. Contributes to improving mechanical properties, and the second metallocene compound represented by Chemical Formula 2 may contribute to improving shrinkage and processability by increasing the short chain branch (SCB) content. The hybrid supported metallocene catalyst is prepared by using a low-copolymerizable first metallocene compound and a high-copolymerizable second metallocene compound together as a hybrid catalyst, thereby providing excellent supported performance, catalytic activity and high airspace. synthesis can be shown.

Specifically, the first metallocene compound may be represented by the following Chemical Formula 1-1.

[Formula 1-1]

In Formula 1-1, M ¹ , X ¹ , X ² , R ² , R ⁷ to R ¹⁰ , Q ¹ , and Q ² are the same as defined in Formula 1 above.

And, in Formula 1, M ¹ may be titanium (Ti), zirconium (Zr), or hafnium (Hf), preferably zirconium (Zr).

And, in Formula 1, A may be silicon (Si).

And, in Formula 1, X ¹ and X ² may each be a halogen, specifically chlorine.

And, in Formula 1, R ¹ and R ³ to R ⁶ are each hydrogen, R ² is hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, 6 carbon atoms A to 12 aryl group, an arylalkyl group having 7 to 14 carbon atoms, and an alkylaryl group having 7 to 14 carbon atoms, an alkylsilyl group having 1 to 10 carbon atoms, a silylalkyl group having 1 to 10 carbon atoms, or an alkylsilylalkyl group having 2 to 12 carbon atoms. It could be a rengi. Specifically, R ¹ and R ³ to R ⁶ may each be hydrogen, and R ² may be hydrogen, methyl, ethyl, propyl, butyl, butenyl, trimethylsilylmethyl, or phenyl.

And, in Formula 1, R ⁷ to R ¹⁰ may each be an alkyl group having 1 to 20 carbon atoms, specifically, may be an alkyl group having 1 to 3 carbon atoms, and more specifically, methyl.

And, in Formula 1, Q ¹ and Q ² may each be an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 12 carbon atoms, specifically, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms. , more specifically methyl, ethyl, or phenyl.

In addition, the first metallocene compound may be represented by one of the following structural formulas.

The first metallocene compound represented by the above structural formulas may be synthesized by applying known reactions, and more detailed synthesis methods may refer to Examples.

On the other hand, in the method for preparing the metallocene compound, the hybrid supported catalyst, or the catalyst composition of the present invention, the equivalent (eq) means a molar equivalent (eq/mol).

In the present invention, the first metallocene compound may be a meso isomer, a racemic isomer, or a mixture thereof.

As used herein, "racemic form" or "racemic form" or "racemic isomer" means that the same substituent on two cyclopentadienyl moieties is M ₁ or M _{2 in Formula 1 or Formula 2} A transition metal represented by , for example, a plane including a transition metal such as zirconium (Zr) or hafnium (Hf) and a form on the opposite side to the center of the cyclopentadienyl moiety.

And, as used herein, the term "meso isomer" or "meso isomer" is a stereoisomer of the above-mentioned racemic isomer, and the same substituent on two cyclopentadienyl moieties is, in Formula 1 or Formula 2, A transition metal represented by M ₁ or M ₂ , for example, a plane including a transition metal such as zirconium (Zr) or hafnium (Hf), and a shape in the same phase with respect to the center of the cyclopentadienyl moiety.

On the other hand, the supported hybrid catalyst is characterized in that it includes the second metallocene compound represented by Formula 2 together with the above-described first metallocene compound.

Specifically, in Formula 2, Z is -NR _a -, wherein R _a may be a hydrocarbyl group having 1 to 10 carbon atoms, and specifically, R _a is a linear or branched alkyl group having 1 to 6 carbon atoms. and, more specifically, may be a tert-butyl group.

이고, T¹은 탄소(C) 또는 실리콘(Si)이며, Q³은 탄소수 1 내지 30의 하이드로카빌기, 또는 탄소수 1 내지 30의 하이드로카빌옥시기이고, Q⁴는 탄소수 2 내지 30의 하이드로카빌옥시하이드로카빌기일 수 있다. 구체적으로, Q³은 탄소수 1 내지 10의 하이드로카빌기이고, Q⁴는 탄소수 2 내지 12의 하이드로카빌옥시하이드로카빌기일 수 있으며, 좀더 구체적으로 Q³은 탄소수 1 내지 6의 알킬기이고, Q⁴는 탄소수 1 내지 6의 알콕시 치환된 탄소수 1 내지 6의 알킬기일 수 있다. 보다 구체적으로, T¹은 실리콘(Si)이며, Q³은 메틸이고, Q⁴는 tert-부톡시 치환된 헥실일 수 있다.And, in Formula 2, T is

and T ¹ is carbon (C) or silicon (Si), Q ³ is a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbyloxy group having 1 to 30 carbon atoms, and Q ⁴ is a hydrocarbyl group having 2 to 30 carbon atoms. It may be an oxyhydrocarbyl group. Specifically, Q ³ is a hydrocarbyl group having 1 to 10 carbon atoms, Q ⁴ may be a hydrocarbyloxyhydrocarbyl group having 2 to 12 carbon atoms, and more specifically, Q ³ is an alkyl group having 1 to 6 carbon atoms, Q ⁴ may be an alkoxy-substituted C1-C6 alkyl group having 1 to 6 carbon atoms. More specifically, T ¹ may be silicon (Si), Q ³ may be methyl, and Q ⁴ may be tert-butoxy substituted hexyl.

Specifically, the second metallocene compound may be represented by any one of the following Chemical Formulas 2-1 to 2-4.

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-4]

In Formulas 2-1 to 2-4, M ² , X ³ , X ⁴ , R _a , T ¹ , Q ³ , Q ⁴ , and R ¹¹ to R ¹⁶ are as defined in Formula 2 above.

And, in Formula 2, R ¹¹ to R ¹⁴ may each be hydrogen or a hydrocarbyl group having 1 to 10 carbon atoms, and R ¹⁵ and R ¹⁶ may be a hydrocarbyl group having 1 to 10 carbon atoms, respectively. Specifically, R ¹¹ to R ¹⁴ are each hydrogen or alkyl having 1 to 10 carbon atoms;

R ¹⁵ and R ¹⁶ may each be an alkyl having 1 to 10 carbon atoms. More specifically, R ¹¹ to R ¹⁴ may each be hydrogen or methyl, and R ¹⁵ and R ¹⁶ may be methyl.

And, in Formula 2, M ² may be titanium (Ti), zirconium (Zr), or hafnium (Hf), preferably titanium (Ti).

And, in Formula 2, X ¹ and X ² may each be a halogen, an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 6 carbon atoms, specifically chlorine or methyl.

And, in Formula 2, the second metallocene compound may be represented by one of the following structural formulas.

The second metallocene compound represented by the above structural formulas may be synthesized by applying known reactions, and for more detailed synthesis methods, refer to Examples and Synthesis Examples to be described later.

Meanwhile, in the hybrid supported metallocene catalyst of the present invention, the first metallocene compound and the second metallocene compound may be supported in a molar ratio of 1:2 to 5:1. By including the first and second metallocene compounds in the above-described mixing molar ratio, excellent supporting performance, catalytic activity, and high copolymerizability may be exhibited. In particular, when the supporting ratio is less than 1:2, only the first metallocene compound plays a dominant role, making it difficult to reproduce the desired molecular structure of the polymer, and mechanical properties may be reduced. In addition, when the loading ratio exceeds 5:1, only the second metallocene compound plays a dominant role, and processability and shrinkage may decrease.

Specifically, the hybrid supported metallocene catalyst in which the first metallocene compound and the second metallocene compound are supported in a molar ratio of 1:1.5 to 3:1, or in a molar ratio of 1:1 to 2:1 is ethylene It is preferable to produce polyethylene, which exhibits high polymerization activity, excellent copolymerizability, excellent mechanical properties, and improved processability and shrinkage.

That is, in the case of the hybrid supported metallocene catalyst of the present invention in which the first metallocene compound and the second metallocene compound are supported in the molar ratio, due to the interaction of two or more catalysts, the mechanical properties of the polyethylene copolymer In addition to physical properties, both processability and shrinkage rate can be further improved.

In the hybrid supported metallocene catalyst of the present invention, as a carrier for supporting the first metallocene compound and the second metallocene compound, a carrier containing a hydroxyl group on the surface may be used, and is preferably dried It may be one containing a hydroxyl group and a siloxane group having high reactivity on the surface from which moisture has been removed from the surface.

For example, silica dried at high temperature, silica-alumina, and silica-magnesia may be used, and these are typically oxides, carbonates, such _{as Na 2} O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) _{2 ;} It may contain sulfate, and nitrate components.

The drying temperature of the carrier ^{is preferably from about 200 o} C to about 800 ^o C, more preferably from about 300 ^o C to about 600 ^o C, and most preferably from ^{about 300 o} C to about 400 ^{o C.} When the drying temperature of the carrier is ^{less than 200 o} C, there is too much moisture, so that the moisture on the surface reacts with the cocatalyst to be described later, and ^{when it exceeds 800 o} C, the pores on the surface of the carrier are merged and the surface area is reduced, and also on the surface Since many hydroxyl groups are lost and only siloxane remains, the reaction site with the promoter is reduced, which is not preferable.

The amount of hydroxyl groups on the surface of the carrier is preferably about 0.1 mmol/g to about 10 mmol/g, more preferably about 0.5 mmol/g to about 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 about 0.1 mmol/g, there are few reaction sites with the co-catalyst, and if it exceeds about 10 mmol/g, there is a possibility that it is due to moisture other than the hydroxyl group present on the surface of the carrier particle. Not desirable.

For example, the total amount of the first and second metallocene compounds supported on a carrier such as silica, that is, the amount of the metallocene compound supported may be 0.01 mmol/g to 1 mmol/g based on 1 g of the carrier. That is, it is preferable to control so as to fall within the above-described supported amount range in consideration of the contribution effect of the catalyst by the metallocene compound.

Meanwhile, the hybrid supported metallocene catalyst may be one in which one or more of the first metallocene compound and one or more of the second metallocene compound are supported on a support together with a promoter compound. 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 is present only on the surface of the carrier, it can contribute to securing the unique properties 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 hybrid supported metallocene catalyst of the present invention may further include one or more cocatalysts selected from the group consisting of compounds represented by the following Chemical Formulas 3 to 5.

[Formula 3]

-[Al(R ³¹ )-O] _c -

In Formula 3,

R ³¹ is each independently halogen, C _1-20 alkyl or C _1-20 haloalkyl,

c is an integer greater than or equal to 2,

[Formula 4]

D(R ⁴¹ ) ₃

In Formula 4,

D is aluminum or boron,

R ⁴¹ is each independently hydrogen, halogen, C _1-20 hydrocarbyl or halogen-substituted C _1-20 hydrocarbyl;

[Formula 5]

[LH] ⁺ [Q(E) ₄ ] ^- or [L] ⁺ [Q(E) ₄ ] ^-

In Formula 5,

L is a neutral or cationic Lewis base,

[LH] ⁺ is a Bronsted acid,

Q is Br ³⁺ or Al ³⁺ ,

E is each independently C _6-40 aryl or C _1-20 alkyl, wherein said C _6-40 aryl or C _1-20 alkyl is unsubstituted or halogen, C _1-20 alkyl, C _1-20 alkoxy; and C _6-40 aryloxy, substituted with one or more substituents selected from the group consisting of.

The compound represented by Formula 3 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 (4) 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 the formula (5) is, for example, triethylammonium tetraphenyl boron, tributylammonium tetraphenyl boron, trimethylammonium tetraphenyl boron, tripropylammonium tetraphenyl boron, trimethylammonium 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 tetrapentafluorophenylaluminum, N,N-diethylaniliniumtetraphenylaluminum, N,N-diethylaniliniumtetraphenylaluminum, N,N-diethylaniliniumtetrapentafluoro Rophenylaluminum, diethylammonium tetrapentafluorophenylaluminum, triphenylphosphoniumtetraphenylaluminum, trimethylphosphoniumtetraphenylaluminum, triphenylcarboniumtetraphenylboron, triphenylcarboniumtetraphenylaluminum, triphenyl Carbonium tetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetrapentafluorophenylboron, and the like may be used.

In addition, the hybrid supported metallocene catalyst may include the cocatalyst and the first metallocene compound in a molar ratio of about 1:1 to about 1:10000, preferably about 1:1 to about 1:1000 It may be included in a molar ratio of, more preferably, it may be included in a molar ratio of about 1:10 to about 1:100.

In addition, the hybrid supported metallocene catalyst may also include the cocatalyst and the second metallocene compound in a molar ratio of about 1:1 to about 1:10000, preferably about 1:1 to about 1:1000 It may be included in a molar ratio of, more preferably, it 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, so the activity may be lowered. have.

The supported amount of such a cocatalyst may be about 5 mmol to about 20 mmol based on 1 g of the carrier.

On the other hand, the hybrid supported metallocene catalyst comprises the steps of supporting a cocatalyst on a support; supporting the first metallocene compound on the support on which the promoter is supported; and supporting the second metallocene compound on the support on which the cocatalyst and the first metallocene compound are supported.

Alternatively, the hybrid supported metallocene catalyst may include: supporting a cocatalyst on a support; supporting a second metallocene compound on the support on which the promoter is supported; and supporting the first metallocene compound on a carrier on which the cocatalyst and the second metallocene compound are supported.

Also alternatively, the hybrid supported metallocene catalyst may include: supporting a first metallocene compound on a support; supporting a cocatalyst on the carrier on which the first metallocene compound is supported; and supporting the second metallocene compound on the support on which the cocatalyst and the first metallocene compound are 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.

In addition, 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.

Meanwhile, in the presence of the hybrid supported metallocene catalyst, the polyethylene copolymer as described above may be prepared through a method comprising the step of copolymerizing ethylene and alpha-olefin.

The above-mentioned hybrid supported catalyst can exhibit excellent supporting performance, catalytic activity and high co-polymerizability, and prepare a polyethylene copolymer capable of producing a blown film having excellent heat shrinkage packaging performance in the TD direction even at low temperatures can do.

The method for preparing the polyethylene copolymer may be performed by slurry polymerization by applying a conventional apparatus and contacting technique using ethylene and alpha-olefin as raw materials in the presence of the above-described hybrid supported catalyst.

The method for preparing the polyethylene copolymer may copolymerize ethylene and alpha-olefin using a continuous slurry polymerization reactor, a loop slurry reactor, or the like, but is not limited thereto.

Here, the alpha-olefin is the same as described above, and for example, 1-hexene may be used as the alpha-olefin. Accordingly, in the slurry polymerization, a polyethylene copolymer capable of producing a blown film having excellent heat shrinkage packaging performance in the TD direction even at a low temperature can be prepared by polymerizing the ethylene and 1-hexene.

And, the polymerization temperature is about 25 ^o C to about 500 ^o C, or about 25 ^o C to about 300 ^o C, or about 30 ^o C to about 200 ^o C, or about 50 ^o C to about 150 ^o C, or It may be about 60 ^o C to about 120 ^{o C.} In addition, the polymerization pressure may be from about 1 kgf/cm 2 to about 100 kgf/cm 2 , or from about 1 kgf/cm 2 to about 50 kgf/cm 2 , or from about 5 kgf/cm 2 to about 45 kgf/cm 2 , or from about 10 kgf/cm 2 to about 10 kgf/cm 2 about 40 kgf/cm 2 , or about 15 kgf/cm 2 to about 35 kgf/cm 2 .

In the copolymerization step, the above-described supported metallocene catalyst is mixed with an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, for example, pentane, hexane, heptane, nonane, decane, and isomers thereof with an aromatic hydrocarbon solvent such as toluene and benzene, dichloro It can be injected by dissolving or diluting in a hydrocarbon solvent substituted with a chlorine atom, such as methane or chlorobenzene. The solvent used here is preferably used by treating a small amount of alkyl aluminum to remove a small amount of water or air that acts as a catalyst poison, and it is also possible to further use a cocatalyst.

As described above, the polyethylene copolymer according to the present invention may be prepared by copolymerizing ethylene and alpha-olefin using the above-described supported metallocene catalyst.

By the above-described manufacturing method, a polyethylene copolymer having the above-described physical properties can be prepared.

The polyethylene copolymer having the above-described physical properties has processing load characteristics and thus exhibits excellent processability during film production, as well as excellent transparency. Accordingly, it can be usefully applied to various fields requiring excellent transparency and processability. In particular, the polyethylene copolymer may stably form a blown film by a melt blown method or the like.

Meanwhile, the blown film may be prepared by a conventional film manufacturing method except for using the above-described polyethylene copolymer.

For example, when processing the blown film, the polyethylene copolymer may be manufactured by inflation molding to a predetermined thickness, specifically, 30 micrometers (㎛) to 90 micrometers (㎛) using an extruder. At this time, the extrusion temperature of the extruder may be ^{160 o} C to 200 ^{o C.} In addition, the blow up ratio (BUR) may be 3.4 or less, more specifically, 2.3 to 3.4.

In addition, the polyethylene blown film according to the present invention may further include additives well known in the art in addition to the above-described polyethylene copolymer. Specifically, such additives include solvents, heat stabilizers, antioxidants, UV absorbers, light stabilizers, metal deactivators, fillers, reinforcing agents, plasticizers, lubricants, emulsifiers, pigments, optical bleaches, flame retardants, antistatic agents, foaming agents, and the like. . The type of the additive is not particularly limited, and general additives known in the art may be used.

The polyethylene blown film according to an embodiment of the present invention prepared by the above method greatly increases the shrinkage behavior according to BUR and improves the shrinkage rate in the TD direction, thereby improving the heat shrinkage packaging performance. can

As an example, the blown film is a film formed into a film with a film thickness of 60 micrometers (㎛) at a blow up ratio (BUR) of 2.3 at 130 ^o C under a condition of 130 ° C. The resin flow in the vertical direction (Transverse direction, TD) ) of 10% to 15% or 11% to 15%, or 11.5% to 15%, and a film formed with a film thickness of 60 micrometers (㎛) at a blow up ratio (BUR) 3.0 of 130 ^o The shrinkage in the transverse direction (TD) of the resin flow measured under C condition is 20% or more, or 20% to 25%, or 21% or more, or 21% to 25%, or 23% or more, or 23% to 25% can be

The blown film has excellent film processability and transparency, and is a product with excellent mechanical properties such as tensile strength, elongation, and impact strength, and can be effectively used for manufacturing heavy-duty film, lamination film and general industrial blown film. Among these films, a heat shrinkable film is being applied to industrial packaging, food, beverage, and general merchandise packaging. In particular, the blown film according to the present invention has excellent packaging performance with a shrinkage rate in the TD direction, and it is possible to obtain a downgauging effect according to _{recent environmental issues (CO 2 reduction) and cost reduction.}

The polyethylene according to the present invention has a high shrinkage rate in the transverse direction (TD) of the resin flow even at a low temperature without raising the temperature to a high temperature, so that a blown film having excellent heat shrinkage packaging performance can be manufactured. It works.

Hereinafter, embodiments of the present invention will be described in more detail in the following examples. However, the following examples are only illustrative of embodiments of the present invention, and the content of the present invention is not limited by the following examples.

[Example]

<Preparation of the first metallocene compound>

Synthesis Example 1

Tetramethylcyclopentadiene (TMCP) is filtered after lithiation with n-butyllithium (n-BuLi, 1 equivalent) in tetrahydrofuran (THF, tetrahydrofuran, 0.4 M) to TMCP-Li salts (salts). was used. 3-Phenylindene (3-Ph-Ind) is lithiated with n-BuLi (1 equivalent) in hexane (Hexane, 0.5 M), filtered, and used as 3-Ph-Ind-Li salts (salts) did. 50 mmol of TMCP-Li salts and 100 mL of THF were placed in a 250 mL Schlenk flask under Ar. 1 equivalent of (CH ₃ ) ₂ SiCl ₂ was added at -20 ^{o C.} After 6 hours, CuCN 3 mol% and 3-Ph-Ind-Li salts (50 mmol, MTBE 1M solution) were ^{added at -20°} C and reacted for 12 hours. The organic layer was separated with water and hexane to obtain a ligand.

The synthesized ligand (50 mmol) was dissolved in 100 mL of methyl tert-butyl ether (MTBE) under Ar, and 2 equivalents of n-BuLi was added dropwise at -20°C. After 16 hours of reaction _{, a ligand-Li solution was added to ZrCl 4} (THF) ₂ (50 mmol, MTBE 1 M solution). After the reaction for 16 hours, the solvent was removed, dissolved in methylene chloride (MC, methylene chloride) and filtered to remove LiCl. After removing the solvent of the filtrate , 80 mL of tert -Butyl methyl ether (MTBE) was added, stirred for 2 hours, and filtered to obtain a solid catalyst precursor (Yield 40%).

¹ H NMR (500 MHz, C ₆ D ₆ ): 0.78 (3H, s), 0.97 (3H, s), 1.64 (3H, s), 1.84 (3H, s), 1.88 (6H, 2s), 5.91 ( 1H, s), 6.89 (1H, t), 7.19 (1H, t), 7.25 (1H, t), 7.30 (2H, t), 7.37 (1H, d), 7.74 (2H, d), 7.93 (1H) , d).

Comparative Synthesis Example 1

TMCP-Li (1.3 g, 10 mmol), CuCN (45 mg, 5 mol%), and THF (10 mL) were added to a dried 250 mL schlenk flask. Then, the temperature of the flask ^{was cooled to -20 o} C or less, and then dichlorodiphenylsilane (2.5 g, 10 mmol) was added dropwise, and the resulting mixture was ^{stirred at room temperature (RT, about 22-25 o} C) for 16 hours. Then, the temperature of the flask ^{was cooled to -20 o} C or less, an indene-lithiation solution (1.2 g, 10 mmol in THF 10 mL) was added dropwise, and the resulting mixture was stirred at room temperature for 24 hours. Thereafter, the resulting solution was dried under reduced pressure to remove the solvent from the solution. Then, the obtained solid was dissolved in hexane, filtered to remove the remaining LiCl, and the filtrate was dried under reduced pressure to remove hexane from the filtrate to obtain diphenyl (indenyl) (tetramethylcyclopentadienyl) silane. In a 100 mL schlenk flask, the previously synthesized diphenyl(indenyl)(tetramethylcyclopentadienyl)silane (4.2 g, 10 mmol) was dissolved in THF (15 mL). Then, the solution was cooled to -20°C or less, n-BuLi (2.5 M in hexane, 8.4 mL, 21 mmol) was slowly added dropwise to the solution, and the resulting solution was stirred at room temperature for 6 hours.

_{On the other hand, after dispersing ZrCl 4} (THF) ₂ (3.8 g, 10 mmol) in toluene (15 mL) in a 250 mL schlenk flask prepared separately, the resulting mixture was stirred at ^{-20 o C.} Then, the previously prepared lithiated ligand solution was slowly injected into the mixture. Then, the resulting mixture was stirred at room temperature for 48 hours. Thereafter, the resulting solution was dried under reduced pressure to remove the solvent from the solution. Then, the obtained solid was dissolved in dichloromethane (DCM), filtered to remove the remaining LiCl, and the filtrate was dried under reduced pressure to remove DCM. Then, the obtained solid was added to 30 mL of toluene, stirred for 16 hours, and filtered, followed by filtration. Diphenylsilylene (tetramethylcyclopentadienyl) (indenyl) zirconium dichloride (2.1 g, 3.6 mmol) in the form of a lemon-colored solid. was obtained (36% yield).

¹ H NMR (500 MHz, CDCl ₃ ): 8.08-8.12 (2H, m), 7.98-8.05 (2H, m), 7.77 (1H, d), 7.47-7.53 (3H, m), 7.42-7.46 (3H) , m), 7.37-7.41 (2H, m), 6.94 (1H, t), 6.23 (1H, d), 1.98 (3H, s), 1.95 (3H, s), 1.68 (3H, s), 1.52 ( 3H, s).

The previously synthesized diphenylsilylene (tetramethylcyclopentadienyl) (indenyl)-zirconium dichloride (1.0 g, 1.7 mmol), Pd/C (10 mol%), DCM (40 mL) was mixed with 100 mL of high pressure The reactor was injected and filled with hydrogen to a pressure of about 60 bar. Then, the mixture contained in the high pressure reactor ^{was stirred at about 80 o} C for about 24 hours. Upon completion of the reaction, the reaction product was passed through a celite pad to remove solids from the reaction product, and diphenylsilylene (tetramethylcyclopentadienyl) (tetrahydroindenyl) zirconium dichloride was obtained (0.65 g, 1.1 mmol). , 65% yield).

¹ H NMR (500 MHz, CDCl ₃ ): 7.90-8.00 (4H, m), 7.38-7.45 (6H, m), 6.80 (1H, s), 5.71 (1H, s), 3.15-3.50 (1H, m) ), 2.75-2.85 (1H, m), 2.50-2.60 (1H, m), 2.12 (3H, s), 2.03 (3H, s), 1.97-2.07 (1H, m), 1.76 (3H, s), 1.53-1.70 (4H, m), 1.48 (3H, s).

Comparative Synthesis Example 2

_{Using 6-chlorohexanol, t-butyl-O-(CH 2} ) ₆ -Cl was prepared by the method described in the literature (Tetrahedron Lett. 2951 (1988)), and NaCp was reacted with t-butyl-O -(CH ₂ ) ₆ -C ₅ H ₅ was obtained (yield 60%, bp 80 ^o C/0.1 mmHg).

In addition, t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ ^{was dissolved in THF at -78 o} C, n-BuLi was slowly added thereto, and then the temperature was raised to room temperature, followed by reaction for 8 hours. The solution was again _{slowly added to a suspension solution of ZrCl 4} (THF) ₂ ^{(170 g, 4.50 mmol)/THF (30 mL) at -78 o} C, and the resulting lithium salt solution was further reacted at room temperature for 6 hours. did it All volatiles were removed by vacuum drying, and hexane was added to the obtained oily liquid material and filtered. After vacuum drying the filter solution, hexane was added to induce a precipitate at ^{low temperature (-20 o C).} The obtained precipitate was filtered at low temperature to obtain [tBu-O-(CH ₂ ) ₆ -C ₅ H ₄ ] ₂ ZrCl ₂ ] in the form of a white solid (yield 92%).

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

¹³ C-NMR (CDCl ₃ ): 135.09, 116.66, 112.28, 72.42, 61.52, 30.66, 30.31, 30.14, 29.18, 27.58, 26.00

<Preparation of the second metallocene compound>

Synthesis Example 2

(1) Synthesis of (E)-1-(4,5-dimethylthiophen-2-yl)-2-methylbut-2-en-1-one

After quantifying 9.99 g (89.1 mmol) of 2,3-dimethylthiophene in a Schlenk flask, 90 mL of THF was added and dissolved. After dropwise addition ^{of n-BuLi (1.05 eq, 37.4 mL) at -78 o} C, the reaction was carried out at room temperature (RT) overnight. After quantifying CuCN (0.5eq, 4g) in another Schlenk flask, 30 mL of THF was added ^{, lowered to -78 o} C, and the reaction solution was transferred. After 2 hours of reaction at RT, tigloyl chloride (1eq, 9.8 mL) was added dropwise at ^{-78 o C.} After overnight reaction at RT, _{the organic layer was concentrated after work up with Na 2} CO ₃ aqueous solution and ethyl acetate (EA), and a brown liquid product, 15.48 g, was obtained in a yield of 89.5%.

¹ H-NMR (in CDCl ₃ , 500 MHz): 7.94 (s, 1H), 7.17-7.16 (m, 1H), 3.04 (s,3H), 2.81 (s, 3H), 2.59 (s, 3H), 2.53 (d, 3H)

(2) Synthesis of 2,3,4,5-tetramethyl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one

15.48 g (79.7 mmol) of (E)-1-(4,5-dimethylthiophen-2-yl)-2-methylbut-2-en-1-one obtained above was quantified in a 1L round-bottom flask (one neck). After that, 15 mL of chlorobenzene was added and stirred. After pouring 100 mL of sulfuric acid, the reaction was carried out overnight at RT, 800 mL of deionized water (DIW) was added, stirred, and then transferred to a separate pannel and extracted with EA. The organic layer was washed with an _{aqueous solution of Na 2} CO ₃ , and the organic layer was concentrated to obtain an oil product of auburn color, 10.66 g in a yield of 68.9%.

¹ H-NMR (in CDCl ₃ , 500 MHz): 6.28 (s, 2H), 6.35 (s, 1H), 3.33-3.32 (m, 4H), 2.48 (s, 6H), 2.36 (s, 6H), 1.97 (d, 6H), 1.51 (s, 18H), 1.46-1.26 (m, 20H), 1.18 (m, 18H), 0.49 (s, 3H), 0.46 (s, 3H), 0.31 (s, 6H) , 0.00 (s, 3H), -0.20 ( s, 3H)

(3) Synthesis of 2,3,4,5-tetramethyl-6H-cyclopenta[b]thiophene

After quantifying 3 g (15.4 mmol) of 2,3,4,5-tetramethyl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one obtained above in a vial, 18 mL of THF and 12 mL of methanol (MeOH) was added and dissolved. The vial ^{was immersed in ice water at 0 o} C, and with stirring, NaBH ₄ (1.5eq, 876 mg) was added little by little to the spatula. After the overnight reaction at RT, DIW was added, the organic layer was separated and concentrated, 60 mL of THF and DIW were mixed 1:1, and 12 mL of 3N HCl was added to dissolve, followed by ^{heating at 80 o} C for 3 hours. Hexane and DIW were added, the organic layer was separated _{, neutralized with Na 2} CO ₃ aqueous solution, and the organic layer was concentrated to obtain a brown liquid product, 2.3 g, in 83.5% yield.

¹ H-NMR (in CDCl ₃ , 500 MHz): 6.28 (s, 2H), 3.15 (m, 1H), 3.05 (m, 1H), 2.37 (s, 6H), 2.16 (s, 6H), 2.16 ( s, 6H), 2.03 (s, 6H), 1.28 (d, 6H)

(4) 1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-methyl-1-(2,3,4,5-tetramethyl-6H-cyclopenta[b]thiophen-6 Synthesis of -yl)silanamine

In a Schlenk flask, quantify 2.3 g (12.9 mmol) of 2,3,4,5-tetramethyl-6H-cyclopenta[b]thiophene obtained above, add 65 mL of THF to dissolve it, and then dissolve it at -78 ^o C. -BuLi (1.05 eq, 5.4 mL) was added dropwise. After overnight reaction at RT, quantify the silane compound (6-(tert-butoxy)hexyl)methyl silane (tether silane, 1.05 eq, 3.7 mL) in another Schlenk flask, add 30 mL of THF, and 0 ^o C lowered to After transfer to the reaction solution, overnight at RT. The solvent was dried through distillation under reduced pressure, filtered with hexane, concentrated, and _{30 mL of t-BuNH 2} was added, followed by reaction at RT overnight. After distillation under reduced pressure, the solvent was dried, filtered with hexane, and concentrated to obtain a brown oil product, 5 g, in a yield of 86.2%.

¹ H-NMR (in CDCl ₃ , 500 MHz): 3.32 (m, 4H), 2.35 (s, 6H), 2.25 (s, 6H), 2.11 (s, 6H), 2.07 (s, 3H), 2.05 ( s, 3H), 1.51-1.27 (m, 20H), 1.19 (s, 36H), 0.15 (s, 3H), 0.0 (s, 3H)

(5) Synthesis of Silane bridged dimethyl titanium compound

1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-methyl-1-(2,3,4,5-tetramethyl-6H-cyclopenta[b]thiophen-6- obtained above After quantifying 2.97 g (6.6 mmol) of yl)silanamine in a Schlenk flask, 33 mL of MTBE was added and dissolved. n-BuLi (2.05 eq, 5.4 mL) was added dropwise at -78 ^{o C, followed by reaction at RT overnight.} At -78 ^o C, MMB (2.5eq, 5.5 mL) and TiCl ₄ (1 eq, 6.6 mL) were added dropwise, followed by reaction overnight at RT. After vacuum drying, hexane was filtered, and DME (3 eq, 2.1 mL) was added dropwise. . After overnight reaction at RT, the solvent was vacuum dried, filtered with hexane, and concentrated to obtain 2.8 g of a transition metal compound (silane bridged dimethyl titanium compound) in a yield of 81.3%.

¹ H-NMR (in CDCl ₃ , 500 MHz): 3.32 (m, 4H), 2.47 (s, 3H), 2.34 (s, 6H), 2.30 (s, 6H), 1.95 (s, 3H), 1.50 ( s, 18H), 1.40 (s, 6H), 1.31-1.26 (m, 20H), 1.18 (s, 18H), 0.49 (s, 3H), 0.48 (s, 3H), 0.46 (s, 3H), 0.34 (s, 3H), -0.09 ( s, 3H) -0.23 (s, 3H)

Comparative Synthesis Example 3

In a dried 250 mL schlenk flask, 1.622 g (10 mmol) of fluorene was added, and 200 mL of THF was injected under argon. Then, after the resulting solution ^{was cooled to 0 o} C, n-BuLi (2.5 M in hexane, 4.8 mL, 12 mmol) was slowly added dropwise. Then, the temperature of the reaction mixture was slowly raised to room temperature, and then the reaction mixture was stirred at room temperature overnight.

Meanwhile, in a separate 250 mL schlenk flask, dichlorodimethylsilane (1.2 mL, 10 mmol, Fw 129.06, d 1.07 g/mL) was dissolved in 30 mL of hexane, and the solution was cooled to ^{-78 o C.} Then, the previously prepared lithiated solution was slowly injected into this solution. And the resulting solution was stirred at room temperature for one day.

Meanwhile, after dissolving 10 mmol of TMCP in THF, the solution was cooled to ^{0 o C.} Then, n-BuLi (2.5 M in hexane, 4.8 mL, 12 mmol) was slowly added dropwise to the solution, and the resulting solution was stirred at room temperature for one day. Thereafter, the chloro(9H-fluoren-9-yl)dimethylsilane solution and the lithiated-TMCP solution were mixed with cannula, which were stirred for one day. At this time, even if any of the two solutions was transferred to the cannula, it did not affect the experimental results. The mixture of the two solutions was stirred for one day, and then 50 mL of water was added to the flask to terminate the reaction, and the organic layer was separated. _{MgSO 4} was added to the organic layer to remove moisture and dried under reduced pressure to form (9H-fluoren-9-yl) (2,3,4,5-tetramethylcyclopenta-2,4-dien-1 in yellow powder form) -yl) silane was obtained (3.53 g, 10.25 mmol, 100% yield, purity 100% based on NMR, Mw 344.56 g/mol).

¹ H NMR (500 MHz, CDCl ₃ ): -0.36 (6H, s), 1.80 (6H, s), 1.94 (6H, s), 3.20 (1H, s), 4.09 (1H, s), 7.28~7.33 (4H, m), 7.52 (2H, d), 7.83 (2H, d).

In an oven-dried 250 mL schlenk flask, the intermediate prepared above was added, dissolved in diethyl ether, and then 2.1 equivalents of n-BuLi (8.6 mL, 21.5 mmol) was added dropwise and stirred overnight. Thereafter, the resulting product was dried under vacuum and the resulting slurry was filtered through a schlenk filter to obtain a yellow solid. The yellow solid was placed in a new 250 mL schlenk flask, and 50 mL toluene was added to prepare a suspension.

_{On the other hand, 1 equivalent of ZrCl 4} (THF) ₂ was put in a 250 mL schlenk flask prepared separately in a glove box, and toluene was added and dispersed. Then, the Zr solution and the previously prepared lithiation ligand solution were cooled to ^{-78 o C.} Then, the previously prepared lithiated ligand solution was slowly injected into the mixture. Then, after slowly raising the temperature of the resulting mixture to room temperature, the mixture was stirred for one day.

The reaction product thus obtained was filtered with a schlenk filter under argon to remove LiCl, but the solubility of the product was poor, so dimethylsilylene (tetramethylcyclopentadienyl) (9H-fluoren-9-yl) in the form of a filtercake Zirconium dichloride was obtained (3.551 g, 6.024 mmol, 61.35% yield, purity 85.6 wt% based on NMR (the remainder is LiCl), Mw 504.68 g/mol).

¹ H NMR (500 MHz, CDCl ₃ ): 1.30 (6H, s), 1.86 (6H, s), 1.95 (6H, s), 7.21 (2H, m), 7.53 (2H, m), 7.65 (2H, m), 8.06 (2H, m).

Comparative Synthesis Example 4

0.14 mol of a _{Grignard reagent tBu-O-(CH 2} ) ₆ MgCl solution from the reaction between tBu-O-(CH ₂ ) ₆ Cl compound and Mg(0) in diethyl ether (Et _{2 O) solvent} got it _{MeSiCl 3} compound (24.7 mL, 0.21 mol) was added thereto at -100 ^o C, stirred at room temperature for at least 3 hours, and the filtered solution was vacuum dried to obtain tBu-O-(CH ₂ ) ₆ SiMeCl ₂ The compound was obtained (yield 84%). In a solution _{of tBu-O-(CH 2} ) ₆ SiMeCl ₂ (7.7 g, 0.028 mol) in hexane (50 mL) at ^{-78 o} C, fluorenyllithium (4.82 g, 0.028 mol)/hexane (150 mL) solution was added slowly over 2 hours. The white precipitate (LiCl) was filtered, the desired product was extracted with hexane, and all volatiles were vacuum dried to obtain the compound of (tBu-O-(CH ₂ ) ₆ )SiMe(9-C ₁₃ H ₁₀ ) in the form of a pale yellow oil. obtained (yield 99%).

A THF solvent (50 mL) was added thereto, _{and after reacting with a C 5} H ₅ Li (2.0 g, 0.028 mol)/THF (50 mL) solution at room temperature for 3 hours or more, all volatile substances were vacuum dried and extracted with hexane. Thus, the final ligand, (tBu-O-(CH ₂ ) ₆ )(CH ₃ )Si(C ₅ H ₅ )(9-C ₁₃ H ₁₀ ) in the form of orange oil, was obtained (yield 95%). The structure of the ligand was confirmed through 1H NMR.

Also, at -78 ^o C (tBu-O-(CH ₂ ) ₆ )(CH ₃ )Si(C ₅ H ₅ )(9-C ₁₃ H ₁₀ )(12 g, 0.028 mol)/THF (100 mL) 2 equivalents of n-BuLi was added to the solution, and the mixture was heated to room temperature and reacted for at least 4 hours to form (tBu-O-(CH ₂ ) ₆ )(CH ₃ )Si(C ₅ H ₅ Li)(9-C ₁₃ H ₁₀ Li) was obtained (yield 81%). In addition, dilithium salt (2.0 g, 4.5 mmol)/ether (30 mL) in a suspension solution of ZrCl ₄ ^{(1.05 g, 4.50 mmol)/ether (30 mL) at -78 o C} The solution was slowly added and the reaction was further carried out at room temperature for 3 hours. All volatile substances were vacuum dried, and dichloromethane solvent was added to the obtained oily liquid substance and filtered off. After the filtered solution was vacuum-dried, hexane was added to induce a precipitate. The resulting precipitate was washed with hexane several times to form a red solid racemic-(t Bu-O-(CH ₂ ) ₆ )(CH ₃ )Si(C ₅ H ₄ )(9-C ₁₃ H ₉ )ZrCl ₂ compound. was obtained (yield 54%).

<Preparation of supported catalyst>

Preparation Example 1: Preparation of Hybrid Supported Metallocene Catalyst

First, silica (SP952 manufactured by Grace Davison) was dehydrated and dried under vacuum at a temperature ^{of 200 o C for 12 hours to prepare a carrier.}

Then, 3.0 kg of toluene solution was put into a high-pressure reactor made of stainless steel (sus) with a capacity of 20 L, 800 g of silica (Grace Davison, SP952) prepared earlier was added, and the reactor temperature ^{was raised to 40 o} C while stirring. did. After the silica was sufficiently dispersed for 60 minutes, 6 kg of a 10 wt% methylaluminoxane (MAO)/toluene solution was added, and the ^{reaction was slowly stirred at 70 o} C at 200 rpm for 1 hour. After completion of the reaction, the reaction solution was decanted and washed several times with a sufficient amount of toluene until the unreacted aluminum compound was completely removed.

After raising the reactor temperature to 50 ^o C, 0.2 mmol of the first metallocene compound prepared in Synthesis Example 1 was dissolved in toluene in a solution state, added, and ^{stirred at 40 o} C at 200 rpm to react for 2 hours.

After completion of the reaction, 0.1 mmol of the second metallocene compound prepared in Synthesis Example 2 was dissolved in toluene, ^{and stirred at 40 o} C at 200 rpm and reacted for 2 hours.

After the reaction was completed, the stirring was stopped and the reaction solution was decantation after settling for 30 minutes. Thereafter, after washing with a sufficient amount of toluene, 50 mL of toluene was added again, stirring was stopped for 10 minutes, and washed with a sufficient amount of toluene to remove compounds not participating in the reaction. Thereafter, 3.0 kg of hexane was added to the reactor and stirred, and the hexane slurry was transferred to a filter and filtered.

A hybrid supported catalyst was obtained by primary drying at room temperature under reduced pressure for 5 hours, and secondary drying at 50 ^{o C under reduced pressure for 4 hours.}

Comparative Preparation Example 1: Preparation of Hybrid Supported Metallocene Catalyst

100 mL of toluene was put into a 300 mL glass reactor, and 10 g of silica (SP2410 manufactured by Grace Davison) was added, followed by stirring while raising ^{the temperature of the reactor to 40 o C.} Here, 30 mL of a 30 wt% methylaluminoxane (MAO)/toluene solution (Albemarle) was added, and the temperature ^{was raised to 70 o} C and stirred at 200 rpm for 12 hours.

Meanwhile, in a schlenk flask, 0.30 g (0.15 mmol) of the metallocene compound prepared in Comparative Synthesis Example 1, 0.26 g (0.225 mmol) of the metallocene compound prepared in Comparative Synthesis Example 3, 30 mL of toluene, and triisobutyl 0.5 g of aluminum was added, and the mixture was stirred at room temperature for 15 minutes. Then, the resulting mixture was put into the organic reactor, and the temperature of the glass reactor ^{was raised to 70 o} C, followed by stirring for 2 hours.

Thereafter, after lowering the temperature of the reactor to room temperature, stirring was stopped, and the reaction product was allowed to stand for 10 minutes, followed by decantation. Then, 100 mL of hexane was added to the reactor to obtain a slurry, and then transferred to a schlenk flask for decantation. The obtained reaction product was dried under reduced pressure at room temperature for 3 hours to obtain a supported catalyst.

Comparative Preparation Example 2: Preparation of Hybrid Supported Metallocene Catalyst

Prepared in the same manner as in Preparation Example 1, but instead of the metallocene compound of Synthesis Example 1 and Synthesis Example 2, the first metallocene compound of Comparative Synthesis Example 2 and the second metallocene compound of Comparative Synthesis Example 4 were respectively prepared A hybrid supported catalyst was prepared in a ratio of the first metallocene compound of Comparative Synthesis Example 2 to the second metallocene compound of Comparative Synthesis Example 4 using 50:50 by weight.

<Production of polyethylene copolymer>

Example 1

Ethylene-1-hexene was slurry-polymerized in the presence of the supported hybrid catalyst prepared in Preparation Example 1.

At this time, the polymerization reactor was a continuous polymerization reactor that is an iso-butane (i-C4) slurry loop process, the reactor volume was 140 L, and the reaction flow rate was about 7 m/s. Gases (ethylene, hydrogen) required for polymerization and 1-hexene as a comonomer were constantly and continuously input, and the individual flow rates were adjusted to suit the target product. At this time, the amount of hydrogen input was adjusted to 1.5 ppm compared to ethylene. In addition, all the gases of Example 1 and the concentration of 1-hexene as a comonomer were confirmed by on-line gas chromatograph. The supported catalyst was prepared as an isobutane slurry having a concentration as shown in Table 1 below, and the reactor pressure was maintained at about 40 bar, and the polymerization temperature was carried out at ^{about 85 o C.}

Comparative Example 1

It was prepared in the same manner as in Example 1, except that the supported catalyst prepared in Comparative Preparation Example 1 was used instead of the supported catalyst prepared in Preparation Example 1, and ethylene-1-hexene was slurry-polymerized.

Comparative Example 2

Ethylene-1-hexene was slurry-polymerized in the same manner as in Comparative Example 1, except that the amount of hydrogen was changed to 1.7 ppm and using the supported catalyst prepared in Comparative Preparation Example 1.

Comparative Example 3

It was prepared in the same manner as in Example 1, except that the supported catalyst prepared in Comparative Preparation Example 2 was used instead of the supported catalyst prepared in Preparation Example 1, and ethylene-1-hexene was slurry-polymerized.

In the hybrid supported catalyst using ethylene-1-hexene according to Example 1 and Comparative Examples 1 to 3 for slurry polymerization, precursor types and specific polymerization reaction conditions are as shown in Table 1 below.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 metallocene catalyst first precursor Synthesis example
One Comparative Synthesis Example
One Comparative Synthesis Example
One Comparative Synthesis Example
2 Metallocene Catalyst Second Precursor Synthesis example
2 Comparative Synthesis Example
3 Comparative Synthesis Example
3 Comparative Synthesis Example
4 polymerization temperature ( ^o C) 80 80 80 80 Ethylene input (kg/hr) 25 25 25 25 Hydrogen input ^a (ppm) 1.5 1.5 1.7 5.0 1-hexene dose ^b (wt%) 2.6 2.7 2.0 8.0 catalytic activity
(kg PE/g·cat·hr) 5.5 4.0 4.2 6.0

In Table 1, a and b are the hydrogen input amount expressed in ppm and the 1-hexene input amount expressed in weight % based on the total weight of ethylene supplied to the continuous polymerization reactor. In addition, the catalyst activity (Activity, kg PE/g·cat·hr) is a value calculated by the ratio of the weight (kg PE) of the polyethylene copolymer produced per content of the supported catalyst used (g·Cat) per unit time (h) to be.

<Evaluation of physical properties of polyethylene copolymer and blown film>

Test Example 1: Evaluation of the physical properties of the polyethylene copolymer

The physical properties of the polyethylene copolymers prepared in Example 1 and Comparative Examples 1 to 3 were measured by the method described below and shown in Table 2.

(1) melt index (MI) _2.16 )

_{The melt index (MI 2.16} ^{) was measured at 190 o} C under the load of 2.16 kg according to the American Society for Testing and Materials standard ASTM D 1238 (Condition E, 190 ^o C, 2.16 kg), and the weight of the polymer melted for 10 minutes ( g).

(2) Density (g/cm ³ )

The density of the polyethylene copolymer was measured according to the ASTM D 1505 standard of the American Society for Testing and Materials.

(3) weight average molecular weight (Mw, g/mol) and molecular weight distribution (Mw/Mn, PDI)

For the ethylene-1-hexene copolymers of Examples and Comparative Examples, the weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured using gel permeation chromatography (GPC, gel permeation chromatography, manufactured by Water), and the weight The molecular weight distribution (Mw/Mn, PDI, polydispersity index) was calculated by dividing the average molecular weight by the number average molecular weight.

Specifically, as a gel permeation chromatography (GPC) apparatus, a Waters PL-GPC220 instrument was used, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. At this time, the measurement temperature was 160 °C, 1,2,4-trichlorobenzene (1,2,4-Trichlorobenzene) was used as a solvent, and the flow rate was 1 mL/min. Each sample of ethylene-1-hexene copolymer was pretreated by dissolving it in trichlorobenzene (1,2,4-Trichlorobenzene) containing 0.0125% BHT at 160 ^{o C for 10 hours using a GPC analysis device (PL-GP220).} , prepared to a concentration of 10 mg/10 mL, and then supplied in an amount of 200 μL. The values of Mw and Mn were derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weight of the polystyrene standard specimen is 2000 g/mol, 10000 g/mol, 30000 g/mol, 70000 g/mol, 200000 g/mol, 700000 g/mol, 2000000 g/mol, 4000000 g/mol, 1000000 g Nine types of /mol were used.

(4) Content of comb polymer and weight average molecular weight of main chain in comb polymer (comb main chain Mw)

For the ethylene-1-hexene copolymer samples of Examples and Comparative Examples, rheological properties and molecular weight distribution were measured using a rotational rheometer and GPC. And, as the structural parameters of the sample, the comb polymer content (Comb, wt%) in the polyethylene copolymer and the weight average molecular weight (comb main chain Mw) of the main chain in the comb polymer are selected, and an arbitrary value of the selected structural parameter is selected. was set. Then, rheology and molecular weight distribution were predicted from the above random values. A random value having an error value of less than 5% between the predicted value and the measured value is derived as a definite value, and again, from the process of setting the random value, the rheological property predicted value and the actual value are compared with the measured value, and the process of deriving a definite value is repeated, 70 confirmed values were derived. The average value of the derived definite values is described.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 MI _2.16 [g/10min] 0.28 0.3 0.5 1.0 Density [g/cm ³ ] 0.930 0.927 0.935 0.920 Mw [X10 ³ g/mol] 95,000 92,000 101,000 120,000 PDI (Mw/Mn) 3.4 3.4 3.4 2.4 Comb [wt%] 30 20 21 none Comb main chain Mw
[X10 ³ g/mol] 189.4 187.1 193.9 none

Test Example 2: Evaluation of properties of blown films

After preparing a blown film by the following method using the polyethylene copolymer prepared in Example 1 and Comparative Examples 1 to 3, the shrinkage ratio according to BUR was measured and shown in Table 3.

(5) Shrinkage according to BUR

Using the ethylene-1-hexene copolymer of Examples and Comparative Examples, a film having a thickness of 60 μm was prepared by a film forming machine at various blow up ratios (BUR) under the following conditions. , The shrinkage rate was measured in the machine direction (MD) and transverse direction (TD) at the shrinkage ^{temperature of 130 o} C, 140 ^o C, and 150 ^o C by the method of ASTM D 2732 of the American Society for Testing and Materials. . Among them, TD shrinkage according to BUR is shown in Table 3 below.

Film making conditions

Blowup Ratio (BUR): 2.3, 2.5, 3.0

Screw rpm: 40 rpm

Processing temperature: 180 ^o C

Die gap: 2.0 mm

Dies: 100mm

shrinkage temperature ( ^o C) TD shrinkage according to BUR (%) 2.3 2.5 3.0 Example 1 130 11.5 16.5 23.3 140 13.3 16.6 26.5 150 16.8 20.2 27.0 Comparative Example 1 130 7.0 10.2 11.4 140 8.0 10.5 13.5 150 12.0 13.0 15.0 Comparative Example 2 130 6.3 10.2 10.5 140 8.1 10.2 12.5 150 11.1 13.5 14.2 Comparative Example 3 130 2.5 3.0 3.0 140 2.0 2.7 1.7 150 1.0 1.0 2.0

As shown in Tables 2 and 3, the embodiment according to the present invention optimizes the content of the comb polymer (Comb) structure as a branched polymer along with the density and melt index to increase the shrinkage behavior according to BUR, By improving the shrinkage in the TD direction, it was confirmed that the heat shrinkage packaging performance was significantly improved.

On the other hand, it was confirmed that Comparative Examples 1 and 2 in which the comb-type polymer content was not optimized had a problem in that the shrinkage rate in the TD direction was decreased compared to that of Example 1. In addition, it was confirmed that Comparative Example 3 without LCB had a problem in that the BUR increased and the shrinkage rate in the TD direction was small even when the shrinkage temperature was increased.

Claims (10)

a density of 0.925 g/cm ³ to 0.940 g/cm ³ ,
Melt index (MI _2.16 , 190 ^o C, 2.16 kg load) is 0.2 g/10min to 1.0 g/10min,
The content of the branched polymer structure is 25 wt% to 35 wt% based on the total weight of the polyethylene copolymer,
polyethylene copolymer.
According to claim 1,
The weight average molecular weight of the main chain in the branched polymer structure is 180,000 g / mol to 200,000 g / mol,
polyethylene copolymer.
According to claim 1,
The polyethylene copolymer has a weight average molecular weight of 90,000 g / mol to 120,000 g / mol,
polyethylene copolymer.
According to claim 1,
The polyethylene copolymer has a molecular weight distribution (Mw / Mn) of 3.0 to 3.5,
polyethylene copolymer.
According to claim 1,
The polyethylene copolymer comprises ethylene and alpha-olefin,
polyethylene copolymer.
6. The method of claim 5,
The alpha-olefin is 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1 - At least one selected from the group consisting of octadecene, 1-eicosene, and mixtures thereof,
polyethylene copolymer.
According to claim 1,
The polyethylene copolymer is an ethylene 1-hexene copolymer,
polyethylene copolymer.
According to claim 1,
The polyethylene copolymer is prepared in the presence of a metallocene catalyst,
polyethylene copolymer.
A blown film comprising the polyethylene of claim 1 .
10. The method of claim 9,
The film is a film formed into a film with a film thickness of 60 μm at a blow up ratio (BUR) of 2.3, and the shrinkage rate in the resin flow vertical direction (TD) measured under ^{130 o C conditions is 10% to 15%} ego,
A film formed with a film thickness of 60 μm at a blow up ratio (BUR) 3.0 of 130 ^o C has a shrinkage ratio of 20% or more in the transverse direction (TD) of the resin,
blown film.