KR102580844B1 - Preparation method of ethylene-alpha olefin copolymer and manufacturing method of injection molded article - Google Patents

Abstract

The present invention relates to a method for producing an ethylene-alpha olefin copolymer that enables the production of injection molded articles with excellent mechanical and chemical properties while exhibiting excellent injection processability, and to a method for producing injection molded articles using the same. The method for producing ethylene-alpha olefin includes at least one predetermined first metallocene compound; At least one predetermined second metallocene compound; co-catalyst compound; and copolymerizing ethylene and alpha-olefin in the presence of a hybrid supported metallocene catalyst comprising a carrier.

Description

Method for manufacturing ethylene-alpha olefin and method for manufacturing injection molded products {PREPARATION METHOD OF ETHYLENE-ALPHA OLEFIN COPOLYMER AND MANUFACTURING METHOD OF INJECTION MOLDED ARTICLE}

The present invention relates to a method for producing an ethylene-alpha olefin copolymer that enables the production of injection molded articles with excellent mechanical and chemical properties while exhibiting excellent injection processability, and to a method for producing injection molded articles using the same.

Polyolefin resins used in the manufacture of injection molded products such as bottle caps generally have excellent physical and mechanical properties such as high mechanical strength and flexural modulus, as well as a high level of environmental stress crack resistance (ESCR). Excellent chemical properties such as etc. are required.

However, recently, for environmental issues and cost reduction, injection molded products such as container lids have been required to be lighter. For example, based on the CSD cap, weight reduction is in progress from the existing 2.4g to 2.05g, and ultra-lightweight reduction to less than 2.0g is also expected in the future.

However, when injection molded products such as container lids are made ultra-light, it becomes more difficult to meet the physical, mechanical, and chemical properties required for the product. Accordingly, there is a growing need to further improve the physical and chemical properties of polyolefin resin, which is the raw material for these injection molded products.

At the same time, in order to more easily and effectively process polyolefin resin into injection molded products, there is a need to further improve injection processability, such as lowering the injection pressure required during injection processing. However, it is generally known that the injection processability of polyolefin resin and the above-mentioned physical and chemical properties are difficult to improve simultaneously due to a trade-off relationship.

For this reason, the development of technology that can improve the physical and chemical properties of polyolefin resin while maintaining excellent injection processability in consideration of the above-mentioned weight reduction of injection molded products is facing limitations, and there is a limit to the development of technology that can solve this problem. , the development of its manufacturing method is continuously requested.

Accordingly, the present invention provides a method for producing an ethylene-alpha olefin copolymer that enables the production of injection molded products with excellent physical and chemical properties while exhibiting excellent injection processability.

The present invention also provides a method for manufacturing injection molded products that can more easily manufacture injection molded products such as container lids having excellent physical and chemical properties by applying the method for manufacturing the ethylene-alpha olefin copolymer.

The present invention relates to at least one first metallocene compound represented by the following formula (1); At least one second metallocene compound represented by the following formula (3); co-catalyst compound; and copolymerizing ethylene and alphaolefin in the presence of a hybrid supported metallocene catalyst comprising a carrier:

[Formula 1]

In Formula 1,

A is hydrogen, halogen, an alkyl group with 1 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, an arylalkyl group with 7 to 20 carbon atoms, and 1 to 20 carbon atoms. an alkoxy group, an alkoxyalkyl group with 2 to 20 carbon atoms, a heterocycloalkyl group with 3 to 20 carbon atoms, or a heteroaryl group with 5 to 20 carbon atoms;

D is -O-, -S-, -N(R)- or -Si(R)(R')-, where R and R' are the same or different from each other, and are each independently hydrogen, halogen, or carbon number 1 an alkyl group with 2 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, or an aryl group with 6 to 20 carbon atoms;

L is a straight or branched chain alkylene group having 1 to 10 carbon atoms;

B is carbon, silicon or germanium;

Q is hydrogen, halogen, an alkyl group with 1 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, or an arylalkyl group with 7 to 20 carbon atoms;

M is a group 4 transition metal;

X _{1 and} an alkylsilyl group, an alkoxy group having 1 to 20 carbon atoms, or a sulfonate group having 1 to 20 carbon atoms;

C ₁ and C ₂ are the same as or different from each other, and are each independently represented by one of Formula 2a, Formula 2b, or Formula 2c below, except for the case where C ₁ and C ₂ are both Formula 2c;

[Formula 2a]

[Formula 2b]

[Formula 2c]

In Formulas 2a, 2b, and 2c, R ₁ to R ₁₇ and R ₁ ' to R ₉ ' are the same or different from each other, and each independently represents hydrogen, halogen, an alkyl group with 1 to 20 carbon atoms, or an alkenyl group with 2 to 20 carbon atoms. , alkylsilyl group having 1 to 20 carbon atoms, silylalkyl group having 1 to 20 carbon atoms, alkoxysilyl group having 1 to 20 carbon atoms, It is an alkoxy group with 1 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, or an arylalkyl group with 7 to 20 carbon atoms, and two or more adjacent ones of R10 to R17 are connected to each other. may form a substituted or unsubstituted aliphatic or aromatic ring;

[Formula 3]

In Formula 3 above,

M ² is a group 4 transition metal,

At least one of R ¹⁰ to R ¹⁵ is -(CH ₂ )n-OR (where R is a straight or branched alkyl group having 1 to 6 carbon atoms, and n is an integer of 2 to 10), and the remainder are each other. The same or different and each independently hydrogen, an alkyl group with 1 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, or an arylalkyl group with 7 to 20 carbon atoms. ego,

R ¹⁶ to R ¹⁹ are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms,

X ^{3 and}

The present invention also includes the steps of producing an ethylene-alpha olefin copolymer by the method of the present invention; and

A method for manufacturing an injection molded product is provided, including the step of injection molding the ethylene-alpha olefin copolymer at an injection pressure of 1000 to 1500 bar.

Hereinafter, a method for manufacturing an ethylene-alpha olefin copolymer and a method for manufacturing an injection molded product using the same according to embodiments of the invention will be described in detail.

In the present invention, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from other components.

Additionally, the terminology used herein is only used to describe exemplary embodiments and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise,” “comprise,” or “have” are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and are intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

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

According to one embodiment of the invention, at least one first metallocene compound represented by Chemical Formula 1; At least one second metallocene compound represented by Formula 3 above; co-catalyst compound; and copolymerizing ethylene and alpha olefin in the presence of a hybrid supported metallocene catalyst comprising a carrier.

As a result of the present inventors' continuous experiments, polyolefin of ethylene-alphaolefin copolymer was obtained using a hybrid supported metallocene catalyst in which the first metallocene compound of Chemical Formula 1 and the second metallocene compound of Chemical Formula 3 were supported together. By manufacturing the resin, it was discovered that a polyolefin-based resin with improved physical and chemical properties and excellent injection processability could be produced, contrary to existing technical common sense, and the invention was completed. Its technical principle can be predicted as follows.

The first metallocene compound corresponds to a catalyst that mainly contributes to the production of high molecular weight copolymer chains, and the second metallocene compound corresponds to a catalyst that mainly contributes to the production of low molecular weight copolymer chains. By using a hybrid supported metallocene catalyst in which these first and second metallocene compounds are supported together, the ethylene-alphaolefin copolymer prepared by the method of one embodiment has physical and chemical properties and melt processability at a certain level or higher. can indicate. In particular, the second metallocene compound has relatively low comonomer insertion ability and comonomer incorporation compared to other types of low molecular weight metallocene catalysts known previously.

As a result, the ethylene-alpha olefin copolymer prepared by the method of one embodiment has the characteristic of inserting a relatively larger amount of comonomer in the high molecular weight region than in the low molecular weight region. Therefore, the ethylene-alpha olefin copolymer has the characteristic that the comonomer content is concentrated in the copolymer chain in the high molecular weight region, and the short chain branch (SCB) content increases as the molecular weight increases. It has a BOCD structure.

Due to these characteristics, the ethylene-alpha olefin copolymer prepared by the method of one embodiment has excellent physical and mechanical properties such as mechanical strength and flexural modulus, and chemical properties such as environmental stress crack resistance (ESCR). Physical properties can exhibit more improved properties.

In addition, this ethylene-alpha olefin copolymer can exhibit improved physical and chemical properties by forming a BOCD structure, so there is no need to excessively increase the ratio of copolymer chains in the high molecular weight region to improve these physical and chemical properties. . Accordingly, the copolymer prepared by the method of the above embodiment may exhibit a not very high viscosity in the processing area, and as a result, it can be easily and effectively injection molded into a shape such as a container lid without applying an excessively high injection pressure.

As a result, according to the method of one embodiment, an ethylene-alpha olefin copolymer that exhibits excellent injection processability with improved physical and chemical properties can be produced, and this copolymer is desirable for the production of lightweight injection molded products such as container lids. It can be used easily.

Meanwhile, the manufacturing method of one embodiment will be described in more detail for each step as follows.

First, the substituents of Chemical Formulas 1 and 3 are described in more detail as follows.

The alkyl having 1 to 20 carbon atoms includes straight or branched chain alkyl, and specifically includes methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, etc. However, it is not limited to this.

The alkenyl having 2 to 20 carbon atoms includes straight-chain or branched-chain alkenyl, and specifically includes allyl, ethenyl, propenyl, butenyl, pentenyl, etc., but is not limited thereto.

The aryl having 6 to 20 carbon atoms includes monocyclic or condensed aryl, and specifically includes phenyl, biphenyl, naphthyl, phenanthrenyl, fluorenyl, etc., but is not limited thereto.

Examples of the alkoxy having 1 to 20 carbon atoms include methoxy, ethoxy, phenyloxy, cyclohexyloxy, etc., but is not limited thereto.

The heteroaryl group having 5 to 20 carbon atoms includes a monocyclic or condensed ring heteroaryl group, carbazolyl group, pyridyl group, quinoline group, isoquinoline group, thiophenyl group, furanyl group, imidazole group, oxazolyl group, and thiazolyl group. group, triazine group, tetrahydropyranyl group, tetrahydrofuranyl group, etc., but is not limited thereto.

The Group 4 transition metals include titanium, zirconium, and hafnium, but are not limited thereto.

In the hybrid supported metallocene catalyst used in the method of one embodiment, the first metallocene compound represented by Formula 1 mainly contributes to producing high molecular weight copolymer chains having a high SCB (short chain branch) content, , the second metallocene compound represented by Formula 3 can mainly contribute to producing low molecular weight copolymer chains with low SCB content. As already described above, according to the characteristics of each metallocene compound, by using a hybrid supported metallocene catalyst containing the specific first and second metallocene compounds, it has a BOCD structure and excellent physical properties. An ethylene-alpha olefin copolymer representing can be prepared.

In terms of the role and characteristics of each catalyst, preferred functional groups included in Formula 1 may be as follows.

First, in Formula 1, R ₁ to R ₁₇ and R ₁ ' to R ₉ ' of Formulas 2a, 2b and 2c are each independently hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, phenyl group, halogen group, trimethylsilyl group, triethylsilyl group, tripropylsilyl group, tributylsilyl group, triisopropylsilyl group, trimethylsilylmethyl group , a methoxy group, or an ethoxy group, but it is not limited thereto.

In addition, it is more preferable that L in Formula 1 is a straight-chain or branched-chain alkylene group having 4 to 8 carbon atoms, but is not limited thereto. Additionally, the alkylene group may be substituted or unsubstituted with an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

In addition, A in Formula 1 is hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, tert-butyl group, methoxymethyl group, tert-butoxymethyl group, 1-ethoxyethyl group, 1-methyl group. -1-methoxyethyl group, tetrahydropyranyl group, or tetrahydrofuranyl group is preferred, but is not limited thereto.

In addition, B in Formula 1 is preferably silicon, but is not limited thereto.

In addition, according to one embodiment of the invention, specific examples of the divalent radical represented by Formula 2a include a functional group represented by one of the following structural formulas, but the invention is not limited thereto.

In addition, specific examples of the divalent radical represented by Formula 2b include functional groups represented by one of the following structural formulas, but the invention is not limited thereto.

In addition, specific examples of the divalent radical represented by Formula 2c include functional groups represented by one of the following structural formulas, but the invention is not limited thereto.

Meanwhile, according to a more specific embodiment of the invention, specific examples of the first metallocene compound represented by Chemical Formula 1 include compounds selected from the group consisting of compounds represented by the following structural formula, but are limited thereto: It is not:

The above-mentioned first metallocene compound can be prepared according to the method described in Korean Patent Publication No. 2015-0045369, 2015-0015789, or 2015-0015791.

Meanwhile, the second metallocene compound of Formula 3 has a structure in which an indene group and cyclopentadiene (Cp) are non-crosslinked, and at least one substituent of cyclopentadiene or indene group is -(CH ₂ )n-OR (At this time, R is a straight or branched chain alkyl group having 1 to 6 carbon atoms, and n is an integer of 2 to 10.) By introducing a substituent, it exhibits low insertion ability/copolymerization into the comonomer of alpha olefin. As already described above, by using this second metallocene compound as a low molecular weight catalyst, an ethylene-alphaolefin copolymer with a BOCD structure can be prepared, and this copolymer has improved physical and chemical properties and excellent It can show injection processability.

In terms of the role and characteristics of the second metallocene compound, preferred functional groups included in Formula 3 may be as follows.

In Formula 3, M ² may be zirconium.

Preferably, X ³ and X ⁴ may be a halogen group, more preferably Cl.

In addition, in the second metallocene compound, at least one of R ¹⁰ to R ¹⁵ of Formula 3 is -(CH ₂ )n-OR (where R is a straight or branched alkyl group having 1 to 6 carbon atoms, and n is an integer from 2 to 10).

In a more specific example, -(CH ₂ )n-OR may preferably be a tert-butoxy hexyl group. When a metallocene compound with this structure is supported on a carrier, the -(CH ₂ )n-OR group substituted by the indene group among the substituents forms a covalent bond through close interaction with the silanol group on the surface of the silica used as the carrier. This enables stable supported polymerization. In addition, the functional group may affect the copolymerization of the comonomer. The overall polymerization activity is maintained while the comonomer incorporation is lowered, making it easier to prepare a copolymer with a BOCD structure without deteriorating other physical properties. It can be advantageous.

Specific examples of the second metallocene compound represented by Formula 3 include compounds represented by the following structural formulas, but the invention is not limited thereto.

The second metallocene compound represented by the above formula (3) can be synthesized by applying known reactions, and the examples can be referred to for more detailed synthesis methods.

Meanwhile, the hybrid supported metallocene catalyst used in the method of one embodiment includes at least one first metallocene compound represented by Formula 1, and one type of second metallocene compound represented by Formula 3. The above may be supported on a carrier together with a co-catalyst compound.

In this hybrid supported metallocene catalyst, the co-catalyst compound supported on the carrier to activate the first and second metallocene compounds is an organometallic compound containing a Group 13 metal, and is a general metallocene catalyst. There is no particular limitation as long as it can be used when polymerizing olefin under the following conditions.

Specifically, the cocatalyst compound may include one or more of an aluminum-containing first cocatalyst of the following formula (4) and a borate-based second cocatalyst of the following formula (5).

[Formula 4]

-[Al(R ₁₈ )-O-] _k -

In Formula 4, R ₁₈ is each independently halogen, halogen-substituted or unsubstituted hydrocarbyl group having 1 to 20 carbon atoms, k is an integer of 2 or more,

[Formula 5]

T ⁺ [BG ₄ ] ^-

In Formula 5, T ⁺ is a +1-valent polyatomic ion, B is boron in the +3 oxidation state, and G is each independently hydride, dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, halocarbyl and halo-substituted hydrocarbyl, wherein G has up to 20 carbons, but at no more than one position G is halide.

Polymerization activity can be further improved by using these first and second cocatalysts.

The first cocatalyst of Formula 4 may be an alkylaluminoxane-based compound in which repeating units are bonded in a linear, circular, or network form. Specific examples of such first cocatalyst include methylaluminoxane (MAO), ethyl aluminoxane, Examples include oxalic acid, isobutyl aluminoxane, or butyl aluminoxane.

Additionally, the second cocatalyst of Formula 5 may be a borate-based compound in the form of a trisubstituted ammonium salt, dialkyl ammonium salt, or trisubstituted phosphonium salt. Specific examples of such second cocatalysts include trimetlammonium tetraphenylborate, methyldioctadecylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, and tri(n-butyl)ammonium tetraphenylborate. , Methyltetradecyclooctadecylammonium tetraphenylborate, N,N-dimethylaninium tetraphenylborate, N,N-diethylanilium tetraphenylborate, N,N-dimethyl (2,4,6-trimethylaninium ) Tetraphenylborate, trimethylammonium tetrakis(pentafluorophenyl)borate, methylditetradecylammonium tetrakis(pentaphenyl)borate, methyldioctadecylammonium tetrakis(pentafluorophenyl)borate, triethylammonium, tetra Kiss(pentafluorophenyl)borate, Tripropylammonium tetrakis(pentafluorophenyl)borate, Tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, Tri(sec-butyl)ammonium tetrakis (pentafluorophenyl)borate, N,N-dimethylaninium tetrakis(pentafluorophenyl)borate, N,N-diethylanylniumtetrakis(pentafluorophenyl)borate, N,N-dimethyl(2 , 4,6-trimethylaninium) tetrakis (pentafluorophenyl) borate, trimethylammonium tetrakis (2,3,4,6-tetrafluorophenyl) borate, triethylammonium tetrakis (2,3,4 ,6-tetrafluorophenyl)borate, tripropylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(2,3,4,6-, Tetrafluorophenyl)borate, dimethyl(t-butyl)ammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,N-dimethylaninium tetrakis(2,3,4,6- tetrafluorophenyl)borate, N,N-diethylanilium tetrakis(2,3,4,6-tetrafluorophenyl)borate or N,N-dimethyl-(2,4,6-trimethylaninium) Borate-based compounds in the form of trisubstituted ammonium salts such as tetrakis-(2,3,4,6-tetrafluorophenyl)borate; Borates in the form of dialkylammonium salts such as dioctadecylammonium tetrakis(pentafluorophenyl)borate, ditetradecylammonium tetrakis(pentafluorophenyl)borate, or dicyclohexylammonium tetrakis(pentafluorophenyl)borate. compound; or triphenylphosphonium tetrakis(pentafluorophenyl)borate, methyldioctadecylphosphonium tetrakis(pentafluorophenyl)borate, or tri(2,6-, dimethylphenyl)phosphonium tetrakis(pentafluorophenyl) ) Borate-based compounds in the form of trisubstituted phosphonium salts such as borate.

In the above-described hybrid supported metallocene catalyst, the mass ratio of all transition metals contained in the first metallocene compound represented by Formula 1 and/or the second metallocene compound represented by Formula 3 to the carrier is 1: It may be 10 to 1:1,000. When the carrier and metallocene compound are included in the above mass ratio, the optimal shape can be exhibited. Additionally, the mass ratio of co-catalyst compound to carrier may be 1:1 to 1:100.

In addition, in the hybrid supported metallocene catalyst, a carrier containing a hydroxy group on the surface can be used, and preferably has a highly reactive hydroxy group and a siloxane group that has been dried to remove moisture from the surface. Any carrier can be used.

For example, silica, silica-alumina, and silica-magnesia dried at high temperatures can be used, and they are usually oxides such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) ₂ , carbonates, etc. May contain sulfate and nitrate components.

The drying temperature of the carrier is preferably 200 to 800°C, more preferably 300 to 600°C, and most preferably 300 to 400°C. If the drying temperature of the carrier is less than 200°C, there is too much moisture, so the moisture on the surface reacts with the cocatalyst. If it exceeds 800°C, the pores on the surface of the carrier merge and the surface area decreases, and there are many hydroxyl groups on the surface. This is undesirable because it disappears and only siloxane residues remain, reducing the number of reaction sites with the cocatalyst.

The amount of hydroxyl groups on the surface of the carrier is preferably 0.1 to 10 mmol/g, and more preferably 0.5 to 5 mmol/g. The amount of hydroxy groups on the surface of the carrier can be adjusted by the preparation method and conditions of the carrier or drying conditions such as temperature, time, vacuum or spray drying.

If the amount of the hydroxy group is less than 0.1 mmol/g, there are few reaction sites with the cocatalyst, and if it exceeds 10 mmol/g, it is not preferable because it may be caused by moisture other than the hydroxy group present on the surface of the carrier particle. not.

Meanwhile, in the method of one embodiment, the ethylene-alpha olefin copolymer can be produced by copolymerizing ethylene and an alpha olefin having 3 or more carbon atoms in the presence of the above-described hybrid supported metallocene catalyst.

As the alpha olefin having 3 or more carbon atoms, propylene, 1-butene, 1-hexene or 1-octene can be used, and any alpha olefin previously known to be usable in the production of polyolefin resin can be used. However, in order to achieve appropriate physical properties for the production of injection molded products such as container lids, alpha olefins having 3 to 10 carbon atoms, more specifically 1-butene, can be more preferably used as the alpha olefin.

The copolymerization reaction of ethylene and alpha-olefin can be carried out using one continuous slurry polymerization reactor, loop slurry reactor, gas phase reactor, or solution reactor.

And, the copolymerization temperature may be 25 to 500°C, preferably 25 to 200°C, and more preferably 50 to 150°C. Additionally, the polymerization pressure may be 1 to 100 Kgf/cm2, preferably 1 to 50 Kgf/cm2, and more preferably 5 to 30 Kgf/cm2.

The hybrid supported metallocene catalyst is an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof, and an aromatic hydrocarbon solvent such as toluene and benzene, dichloromethane, and chlorobenzene. It can be dissolved or diluted in a hydrocarbon solvent substituted with the same chlorine atom and then injected. The solvent used here is preferably treated with a small amount of alkyl aluminum to remove a small amount of water or air, which acts as a catalyst poison, and it is also possible to use a cocatalyst.

As described above, in the method of one embodiment, as the ethylene-alphaolefin copolymer is prepared using a specific hybrid supported metallocene catalyst, the ethylene-alphaolefin copolymer has SCB at a higher content in the high molecular weight region. The included properties and BOCD structure can be indicated.

Accordingly, the ethylene-alpha olefin copolymer has a weight average molecular weight of 50,000 to 250,000, or 70,000 to 200,000, or 100,000 to 150,000, and a molecular weight distribution (Mw/Mn, PDI) of 12.8 to 15.0, or 13 to 14.5, or 13.5 to 13.5. It can display the characteristic of 14.0. In addition, the ethylene-alpha olefin copolymer may exhibit a density of 0.940 to 0.965 g/cm ³ , or 0.945 to 0.960 g/cm ³ , or 0.950 to 0.958 g/cm ³ .

As the ethylene-alpha olefin copolymer meets these molecular weight and density ranges, it can exhibit excellent physical and mechanical properties suitable for manufacturing injection molded products. Additionally, as it satisfies the molecular weight distribution range, the ethylene-alpha olefin copolymer can exhibit excellent processability.

In addition, the ethylene-alpha olefin copolymer has a melt flow rate (MFR _2.16 ) measured at 190°C and a load of _2.16 kg according to ASTM D1238 of 0.4 g/ _10min or more, or 0.5 g/10min or more, or 0.6 g. /10min or more, but may be less than 1.0 g/10min, or less than 0.9 g/10min.

As the ethylene-alpha olefin copolymer exhibits a relatively low melt index, the copolymer and injection molded products manufactured therefrom can exhibit superior chemical properties such as environmental stress crack resistance. However, if the melt index is too low, the melting and injection processability of the copolymer may deteriorate, which is not desirable.

In addition, _the ethylene-alpha olefin copolymer has a melt flow rate ratio (MFRR, MFR _21.6 / _{MFR 2.16} ) measured by ASTM1238 at 190°C _of 3 to 5, or 3.3 to 4, or 3.5 to 3.9. can indicate. By having a melt flow rate ratio in the above range, the flowability at each load can be appropriately adjusted, and processability and physical properties can be improved simultaneously.

On the other hand, as the above-described ethylene-alpha olefin copolymer is manufactured by the method of one embodiment, it may exhibit a BOCD (Broad Orthogonal Co-monomer Distribution) Index of 0.3 to 3, or 0.35 to 2, or 0.4 to 1. . In this way, the ethylene-alpha olefin copolymer may have a BOCD structure, and as a result, it may exhibit improved physical and chemical properties compared to previously known polyolefin resins for injection molding.

Here, the BOCD structure refers to a structure in which the content of alpha-olefin comonomers is concentrated in copolymer chains in the high molecular weight region, that is, a structure in which the short chain branch (SCB) content increases toward high molecular weight. it means. The BOCD Index is an indicator to quantitatively determine the degree of the BOCD structure, and can be measured using the following method.

First, the molecular weight, molecular weight distribution, and SCB content can be measured simultaneously and continuously using a GPC-FTIR device, with the logarithmic value (log M) of the molecular weight (M) as the x-axis, and the molecular weight distribution for the logarithmic value ( When a molecular weight distribution curve is drawn with dwt/dlog M) as the y-axis, the SCB (Short Chain Branch) content (carbon number 2 to 1,000 carbons per 1,000 carbons) is measured at the left and right boundaries of 60% of the center excluding 20% of the left and right ends of the total area. It can be obtained by measuring the content of 7 branches (unit: pieces/1,000C) and calculating the value using Equation 1 below. At this time, the SCB content on the high molecular weight side and the SCB content on the low molecular weight side mean the SCB content values at the right and left boundaries, respectively, in the 60% range excluding the 20% at the left and right ends.

[Equation 1]

BOCD Index =

At this time, if the BOCD Index is 0 or less, it is not a BOCD structure polymer, and if it is greater than 0, it can be considered a BOCD structure polymer. The larger the value, the better the BOCD characteristics can be evaluated.

The ethylene-alpha olefin copolymer prepared by the method of the above-described embodiment has a large BOCD Index of 0.3 or more, so even if it has the same molecular weight and content of high molecular weight copolymer chains, the flexural modulus, etc. Physical and mechanical properties and chemical properties such as environmental stress cracking resistance can be greatly improved. Therefore, the ethylene-alpha olefin copolymer can be very preferably used for manufacturing various injection molded products, for example, lightweight container lids.

In addition, according to one embodiment of the invention, the ethylene-alpha olefin copolymer has a SCB (Short Chain Branch) content, defined as the branch content of 2 to 7 carbon atoms per 1,000 carbons, of 3 to 7 branches/1000C, Or it could be 4 to 6 pieces/1000C. The copolymer can have the above-described BOCD structure without significantly increasing the overall SCB content, and thus can exhibit excellent injection processability along with excellent physical and chemical properties as described above.

In addition, the ethylene-alpha olefin copolymer is a 10% by weight solution of IGEPAL ( Octylphenoxy poly(ethyleneoxy)ethanol , branched) at a temperature of 50°C due to the above-mentioned physical properties, such as a high BOCD index due to the BOCD structure, etc. In an environmental stress crack resistance (ESCR) test measured according to the ASTM 1693 standard by exposure to, it can exhibit excellent chemical properties of more than 70 hours, or 80 to 200 hours, or 83 to 150 hours.

In addition, the ethylene-alpha olefin copolymer can exhibit excellent mechanical and physical properties due to the BOCD structure described above. These excellent mechanical and physical properties can be defined, for example, by the Flexible Modulus 1% secant at 1% deformation of the specimen. More specifically, the ethylene-alpha olefin copolymer exhibits excellent physical and mechanical properties such that the flexural modulus at 1% deformation is 10,000 kg/cm ² or more, or 10,000 to 13,000 kg/cm ² , or 10,500 to 11,000 kg/cm ² You can.

Meanwhile, in the above-described ethylene-alphaolefin copolymer and its production method, the content of the alpha-olefin comonomer and repeating units derived therefrom may be 0.5 to 10% by weight, or 1 to 5% by weight, and accordingly, It can exhibit excellent physical properties as described above.

The ethylene-alpha olefin copolymer prepared by the method of the above-described embodiment can exhibit improved mechanical, physical, and chemical properties while exhibiting excellent injection processability due to various properties due to the BOCD structure, etc. Accordingly, this ethylene-alpha olefin copolymer can be very preferably used in the production of injection molded products such as lightweight container lids.

According to another embodiment of the invention, preparing an ethylene-alpha olefin copolymer by the method of the above-described embodiment; And a method for manufacturing an injection molded product is provided, including the step of injection molding the ethylene-alpha olefin copolymer at an injection pressure of 1000 to 1500 bar.

In this method of manufacturing injection molded products, by using the copolymer prepared by the method of one embodiment, injection molded products such as container lids having excellent physical and chemical properties can be produced even when a relatively low injection pressure of 1000 to 1500 bar or 1200 to 1480 bar is applied. It can be manufactured.

In addition, injection molded products manufactured by this method can exhibit excellent physical and chemical properties along with excellent injection processability at low injection pressure.

More specifically, the injection molded product exhibits excellent ESCR properties when the copolymer prepared by the method of the above-described embodiment is manufactured into an injection molded product in the form of a bottle cap using injection and continuous compression molding (CCM) methods. It can be expressed. More specifically, these ESCR characteristics can be evaluated by exposing the container lid-shaped injection molded product to a 5% by weight solution of IGEPAL at a temperature of 42°C and then applying pressure to 5bar to measure the time for cracks to occur. As a result of the evaluation, the ESCR for the injection molded product can be excellent chemical properties of 30 hours or more, 35 hours or more, 35 to 50 hours, or 40 to 48 hours.

Typically, such injection molded products can be lightweight container caps, and can be made into various other injection molded products.

Meanwhile, in the manufacturing method of the injection molded product of the other embodiment described above, the injection molded product may be manufactured according to a general injection method except that the copolymer prepared by the method of the above embodiment is applied and a relatively low injection pressure is applied. You can. Additional explanation regarding this will be omitted.

According to the method for producing an ethylene-alpha olefin copolymer according to the present invention, an ethylene-alpha olefin copolymer showing improved physical and chemical properties and excellent injection processability can be produced, and this copolymer can be used in lightweight packaging such as container lids. It can be preferably used in the production of injection molded products.

Figure 1 is a schematic diagram schematically showing an apparatus for evaluating the ESCR characteristics of injection molded products in the following test examples.

Below, preferred embodiments are presented to aid understanding of the present invention. However, the following examples are provided only to make the present invention easier to understand, and the content of the present invention is not limited thereto.

Synthesis example One: 1st metallocene Preparation of Compounds Example

A first metallocene compound having the above chemical formula was prepared according to the method described in Preparation Example 1 of Korean Patent Publication No. 2015-0015789.

Synthesis example 2: 2nd metallocene Preparation of Compounds Example

The second metallocene compound having the above chemical formula was prepared by the following method.

After adding 10.8 g (100 mmol) of chlorohexanol to a dried 250 mL Schlenk flask, 10 g of molecular sieve and 100 mL of MTBE (methyl tert-butyl ether) were added, and 20 g of sulfuric acid was slowly added over 30 minutes. did. The reaction mixture slowly turned pink over time, and after 16 hours, it was poured into ice-cold saturated sodium bicarbonate solution. This mixture was extracted four times using 100 mL of ether each, and the collected organic layer was dried with MgSO ₄ and filtered, and the solvent was removed under reduced pressure to obtain 10 g of 1-(tert butoxy)-6-chlorohexane in the form of a yellow liquid ( 60% yield) was obtained.

1H NMR (500MHz, CDCl ₃ ): 3.53 (2H, t), 3.33 (2H, t), 1.79 (2H, m), 1.54 (2H, m), 1.45 (2H, m), 1.38 (2H, m) ), 1.21 (9H, s)

4.5 g (25 mmol) of 1-(tert butoxy)-6-chlorohexane synthesized above was added to a dried 250 mL Schlenk flask and dissolved in 40 mL of THF. 20 mL of sodium indenide THF solution was slowly added thereto and stirred for one day. This reaction mixture was quenched by adding 50 mL of water, extracted with ether (50 mL x 3), and the collected organic layer was thoroughly washed with brine. The remaining moisture was dried with MgSO ₄ and filtered, and the solvent was removed under reduced vacuum pressure to obtain 3-(6-tert-butoxy hexyl)-1H-indene, a dark brown, viscous product, in quantitative yield.

Mw = 272.21 g/mol

1H NMR (500MHz, CDCl ₃ ): 7.47 (1H, d), 7.38 (1H, d), 7.31 (1H, t), 7.21 (1H, t), 6.21 (1H, s), 3.36 (2H, m) , 2.57 (2H, m), 1.73 (2H, m), 1.57 (2H, m), 1.44 (6H, m), 1.21 (9H, s)

5.44 g (20 mmol) of 3-(6-tert-butoxy hexyl)-1H-indene prepared above was added to a dried 250 mL Schlenk flask and dissolved in 60 mL of ether. 13 mL of n-BuLi 2.0M hexane solution was added thereto and stirred for one day, and then a toluene solution of n-butyl cyclopentadiene ZrCl ₃ (concentration 0.378 mmol/g) was slowly added at -78°C. When this reaction mixture was raised to room temperature, it changed from a clear brown solution to a white suspension with floating yellow solids. After 12 hours, 100 mL of hexane was added to the reaction mixture to further produce a precipitate. Afterwards, it was filtered under argon to obtain a yellow filtrate, which was dried to produce the desired second metallocene compound, 3-(6-(tert-butoxy)hexyl)-1H-inden-1-yl)(3-butylcylcopenta-2). , 4-dien-1-yl) zirconium(IV) chloride was confirmed to be produced.

Mw=554.75 g/mol

1H NMR (500MHz, CDCl ₃ ): 7.62 (2H, m), 7.24 (2H, m), 6.65 (1H, s), 6.39 (1H, s), 6.02 (1H, s), 5.83 (1H, s) , 5.75 (1H, s), 3.29 (2H, m), 2.99 (1H, m), 2.89 (1H, m), 2.53 (1H, m), 1.68 (2H, m), 1.39-1.64 (10H, m) ), 1.14 (9H, s), 0.93 (4H, m)

Preparation of hybrid supported catalyst Example

Manufacturing example One

3.0 kg of toluene solution was added to a 20L sus high pressure reactor, and the reactor temperature was maintained at 40°C. 500 g of silica (Grace Davison, SP2212) dehydrated by applying vacuum for 12 hours at a temperature of 600°C was introduced into the reactor, and after sufficiently dispersing the silica, 2.78 kg of 10 wt% methylaluminoxane (MAO)/toluene solution was added. and stirred at 80°C and 200 rpm for more than 15 hours.

After lowering the reactor temperature to 40°C, 200 g of the 7.8 wt% metallocene compound/toluene solution of Synthesis Example 1 was added to the reactor and stirred at 200 rpm for 1 hour. Next, 250 g of the 8.7 wt% metallocene compound/toluene solution of Synthesis Example 2 was added to the reactor and stirred at 200 rpm for 1 hour.

70 g of cocatalyst (anilinium tetrakis(pentafluorophenyl)borate) was diluted in toluene and added to the reactor and stirred at 200 rpm for more than 15 hours. After lowering the reactor temperature to room temperature, stirring was stopped and the reaction solution was allowed to settle for 30 minutes and then decantated.

The toluene slurry was transferred to a filter dryer and filtered. 3.0 kg of toluene was added and stirred for 10 minutes, then stirring was stopped and filtered. 3.0 kg of hexane was added to the reactor and stirred for 10 minutes, then stirring was stopped and filtered. A 500g-SiO ₂ supported catalyst was prepared by drying under reduced pressure at 50°C for 4 hours.

comparison Manufacturing example One

The hybrid supported catalyst of Comparative Preparation Example 1 was prepared in the same manner as the supported catalyst Preparation Example 1 of Korean Patent Publication No. 2018-0060280.

ethylene/1- Butene copolymerization Example

Example 1, 2 and Comparative example 1 to 3

Ethylene-1-butene copolymer was prepared using the hybrid supported metallocene catalyst prepared in Preparation Example 1 or Comparative Preparation Example 1, using a hexane slurry stirred tank process polymerizer, and operating unimodal in one reactor.

Each of the hybrid supported metallocene catalysts used in Examples 1 and 2 and Comparative Examples 1 to 3 and the polymerization conditions using the same are summarized in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 metallocene catalyst Manufacturing Example 1 Manufacturing Example 1 Comparative Manufacturing Example 1 Comparative Manufacturing Example 1 Comparative Manufacturing Example 1 Ethylene supply (kg/hr) 10.0 10.0 10.0 10.0 10.0 Comonomer (1-butene) input amount (ml/min) 2.5 4.5 2.5 4.5 4.0 Hydrogen input amount (g/hr) 2.75 2.6 2.75 2.7 3.0

Comparative example 4

Polyethylene resin (product name: SM100) manufactured by LG Chemical was used as Comparative Example 4.

< Experiment example >

Evaluation of physical properties of copolymers and injection molded products

The physical properties of the copolymers prepared or obtained in the above Examples and Comparative Examples and injection molded products manufactured therefrom were evaluated by the following method.

1) Density: ASTM 1505

2) Melt rate (MFR, 2.16 kg/21.6 kg): Measurement temperature 190℃, ASTM 1238

3) MFRR (MFR _{21 .6} /MFR _{2 .16} ): This is the ratio of MFR _{21 .6} melt index (MI, 21.6 kg load) divided by MFR _{2 .16} (MI, 2.16 kg load).

4) Mn, Mw, molecular weight distribution:

The sample was pretreated by dissolving it in 1,2,4-Trichlorobenzene containing 0.0125% BHT at 160°C for 10 hours using PL-SP260, and the number average molecular weight and weight average molecular weight were measured at a measurement temperature of 160°C using PL-GPC220. Measured. Molecular weight distribution was expressed as the ratio of weight average molecular weight and number average molecular weight.

5) BOCD Index and SCB content:

When a molecular weight distribution curve is drawn with the log value (log M) of the weight average molecular weight (M) as the Excluding %, the SCB (Short Chain Branch) content (content of branches with 2 to 7 carbon atoms per 1,000 carbons, unit: pieces/1,000C) was measured at the left and right boundaries of 60% of the center, and the following equation 1 was calculated. Based on this, the BOCD Index was calculated.

At this time, the SCB content on the high molecular weight side and the SCB content on the low molecular weight side mean the SCB content values at the right and left boundaries of the center 60% range, respectively, and the sample was sampled using PL-SP260 and containing 0.0125% of BHT. After pretreatment by dissolving in 1, 2, 4-Trichlorobenzene at 160°C for 10 hours, it was measured at 160°C using a PerkinElmer Spectrum 100 FT-IR connected to a high-temperature GPC (PL-GPC220).

[Equation 1]

BOCD Index =

6-1) Evaluation of environmental stress cracking resistance (ESCR) of resin

The evaluation was conducted in accordance with ASTM D1693 standards. The evaluation was conducted using experimental method B within the standard.

At 190°C and 30 bar, each resin was manufactured into pellet-shaped press specimens and then cut to a size that complies with ASTM D1693 standards. After making a notch according to the standard, 10 specimens were bent to create the final specimen for measuring physical properties. Afterwards, each specimen is immersed in a 10% by weight IGEPAL solution and placed in an oven at 50°C for aging. Next, it is confirmed that cracks have formed around the notch, and when cracks appear in five specimens, the experiment is terminated and the corresponding time is recorded.

6-2) Evaluation of environmental stress crack resistance (ESCR) of injection molded products

An injection molded product in the form of a bottle cap was manufactured using the above copolymer (resin) specimen by injection and continuous compression molding (CCM) methods.

The specimen is fastened to the container lid-shaped preform at 16 lbf/in. after. Each specimen is immersed in 5% by weight IGEPAL solution and placed in an oven at 42°C. The experiment is conducted by applying a pressure of 5 bar to the opposite side of the preform so that pressure is applied to the specimen from the inside. For reference, a schematic diagram of the corresponding evaluation device is shown in FIG. 1.

The evaluation is completed by determining whether there is a crack when the 5 bar pressure on the specimen drops. The time is recorded at the end and evaluated based on the average value.

7) Injection pressure evaluation:

Set the injection machine experiment conditions. After setting the temperature to 190 to 250℃, holding pressure to 300 to 700 bar, cooling time to 1 to 3 s, and cycle time to 3 to 6 s, add each resin and proceed with injection. When injection is performed under these conditions, pressure is applied inside the injection machine and the injection pressure is measured. The injection pressure is measured using the corresponding data.

8) Flexible modulus 1% secant evaluation at 1% deformation:

After manufacturing pellet-shaped press specimens at 190℃ and 30bar conditions, the specimens were cut to a size that meets the ASTM D790 standard. Afterwards, evaluation was conducted according to the ASTM D790 standard.

Each physical property measured as above is summarized in Table 2 below:

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Density (g/cm ³ ) 0.956 0.952 0.956 0.952 0.952 0.952 MFR _2.16 ( _g /10min) 0.8 0.8 0.8 0.8 1.2 1.1 _{MFR 5} /MFR _2.16 3.7 3.7 3.6 3.8 3.8 4.1 BOCD index 0.4 0.5 - 0.12 0.07 0.10 SCB content (unit/1000C) 4 6 4 6 6 6 ESCR (copolymer; time) 85 90 42 80 70 70 Mw 130k 130 120k 130k 110k 120k Molecular weight distribution 14 13.5 13 13.2 9.8 12.5 ESCR (Injection Molding; Time) 40 >48 30 37 27 27 Injection pressure (bar) 1460 1420 1610 1520 1490 1460 Flexural modulus at 1% deformation (kg/cm ² ) 10500 10300 10300 9700 9000 9000

Referring to Table 2 above, it was confirmed that the copolymers and injection molded products of Examples 1 and 2 had a remarkable BOCD structure compared to the comparative examples, and thus exhibited superior physical and chemical properties compared to the comparative examples. At the same time, the injection molded products It was confirmed that the injection pressure required to manufacture molded products was low, showing excellent injection processability.

Claims (14)

At least one first metallocene compound represented by the following formula (1); At least one second metallocene compound represented by the following formula (3); co-catalyst compound; A method for producing an ethylene-alphaolefin copolymer comprising copolymerizing ethylene and alphaolefin in the presence of a hybrid supported metallocene catalyst comprising a carrier,
The ethylene-alpha olefin copolymer has a weight average molecular weight of 50,000 to 250,000, a molecular weight distribution (Mw/Mn, PDI) of 12.8 to 15.0, a density of 0.940 to 0.965 g/cm ³ , and BOCD (Broad Orthogonal Co-monomer). Distribution) Method for producing an ethylene-alpha olefin copolymer having an Index of 0.4 to 1:
[Formula 1]

In Formula 1,
A is hydrogen, halogen, an alkyl group with 1 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, an arylalkyl group with 7 to 20 carbon atoms, and 1 to 20 carbon atoms. an alkoxy group, an alkoxyalkyl group with 2 to 20 carbon atoms, a heterocycloalkyl group with 3 to 20 carbon atoms, or a heteroaryl group with 5 to 20 carbon atoms;
D is -O-, -S-, -N(R)- or -Si(R)(R')-, where R and R' are the same or different from each other, and are each independently hydrogen, halogen, or carbon number 1 an alkyl group with 2 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, or an aryl group with 6 to 20 carbon atoms;
L is a straight or branched chain alkylene group having 1 to 10 carbon atoms;
B is carbon, silicon or germanium;
Q is hydrogen, halogen, an alkyl group with 1 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, or an arylalkyl group with 7 to 20 carbon atoms;
M is a group 4 transition metal;
X _{1 and} an alkylsilyl group, an alkoxy group having 1 to 20 carbon atoms, or a sulfonate group having 1 to 20 carbon atoms;
C ₁ and C ₂ are the same as or different from each other, and are each independently represented by one of Formula 2a, Formula 2b, or Formula 2c below, except for the case where C ₁ and C ₂ are both Formula 2c;
[Formula 2a]

[Formula 2b]

[Formula 2c]

In Formulas 2a, 2b and 2c, R ₁ to R ₄ , R ₆ to R ₁₇ and R ₁ 'to R ₄ ', R ₆ ' to R ₉ ' are the same as or different from each other, and each independently represents hydrogen, halogen, Alkyl group of 1 to 20 carbon atoms, alkenyl group of 2 to 20 carbon atoms, alkylsilyl group of 1 to 20 carbon atoms, silylalkyl group of 1 to 20 carbon atoms, alkoxysilyl group of 1 to 20 carbon atoms, It is an alkoxy group of 1 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, an alkylaryl group of 7 to 20 carbon atoms, or an arylalkyl group of 7 to 20 carbon atoms, and R ₅ and R ₅ ' are each independently a group of 1 to 20 carbon atoms. It is an alkyl group, an alkylsilyl group having 1 to 20 carbon atoms, or a silylalkyl group having 1 to 20 carbon atoms, and two or more adjacent ones of R ₁₀ to R ₁₇ may be connected to each other to form a substituted or unsubstituted aliphatic or aromatic ring. There is;
[Formula 3]

In Formula 3 above,
M ² is a group 4 transition metal,
At least one of R ¹⁰ to R ¹⁵ is -(CH ₂ )n-OR (where R is a straight or branched alkyl group having 1 to 6 carbon atoms, and n is an integer of 2 to 10), and the remainder are each other. The same or different and each independently hydrogen, an alkyl group with 1 to 20 carbon atoms, an alkenyl group with 2 to 20 carbon atoms, an aryl group with 6 to 20 carbon atoms, an alkylaryl group with 7 to 20 carbon atoms, or an arylalkyl group with 7 to 20 carbon atoms. ego,
R ¹⁶ to R ¹⁹ are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms, and at least one of R ¹⁶ to R ¹⁹ is an alkyl group,
X ^{3 and}
The method for producing an ethylene-alphaolefin copolymer according to claim 1, wherein L in Formula 1 is a straight-chain or branched-chain alkylene group having 4 to 8 carbon atoms.
The method of claim 1, wherein A in Formula 1 is hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, tert-butyl group, methoxymethyl group, tert-butoxymethyl group, and 1-ethoxyethyl group. , a method for producing an ethylene-alphaolefin copolymer having a 1-methyl-1-methoxyethyl group, a tetrahydropyranyl group, or a tetrahydrofuranyl group.
The method of claim 1, wherein the first metallocene compound is selected from the group consisting of compounds represented by the following structural formula:









The method of claim 1, wherein the second metallocene compound is selected from the group consisting of compounds represented by the following structural formula:

delete The method of claim 1, wherein the ethylene-alphaolefin copolymer has an MFR _2.16 (melt flow rate measured at 190° C. and a load of 2.16 kg according to ASTM D1238) of 0.4 to 1.0 g/10 min,
A method for producing an ethylene-alphaolefin copolymer having a melt flow rate ratio (MFR ₅ /MFR _2.16 ) of 3 to 5 as measured by ASTM1238 at 190°C.
delete The method of claim 1, wherein the ethylene-alpha olefin copolymer exhibits environmental stress cracking measured according to the ASTM 1693 standard by exposing the specimen to a 10% by weight solution of IGEPAL ( Octylphenoxy poly(ethyleneoxy)ethanol, branched) at a temperature of 50°C. A method for producing an ethylene-alphaolefin copolymer having ESCR properties evaluated in an environmental stress crack resistance (ESCR) test of 70 hours or more.
The method of claim 1, wherein the ethylene-alpha olefin copolymer is an ethylene-alpha olefin having a short chain branch (SCB) content of 3 to 7/1000C, which is defined as a branch content of 2 to 7 carbon atoms per 1,000 carbon atoms. Method for producing copolymers.
The method for producing an ethylene-alpha olefin copolymer according to claim 1, wherein the ethylene-alpha olefin copolymer has a Flexible Modulus 1% secant of 10000 kg/cm ² or more when the resin pellet is deformed by 1%.
Preparing an ethylene-alpha olefin copolymer by the method of claim 1; And a method of manufacturing an injection molded product comprising the step of injecting and molding the ethylene-alpha olefin copolymer at an injection pressure of 1000 to 1500 bar.
The ESCR characteristics of claim 12, wherein the injection molded product is evaluated by exposing the injection molded product in the form of a container lid to a 5% by weight solution of IGEPAL at a temperature of 42°C and then applying pressure to 5 bar to measure the time for cracks to occur. This method of manufacturing injection molded products that is more than 30 hours.
The method of claim 12, wherein the injection molded product is a bottle cap.