KR102775684B1 - Polyethylene and its chlorinated polyethylene - Google Patents

Abstract

The polyethylene according to the present invention implements a high-molecular-weight region in its molecular structure, thereby making it easy to perform deoxidation, dehydration and drying processes during chlorination processing by reacting it with chlorine, and enabling an increase in the chlorination temperature, thereby improving chlorination productivity.

Description

POLYETHYLENE AND ITS CHLORINATED POLYETHYLENE

The present invention relates to polyethylene and chlorinated polyethylene thereof which can increase chlorination productivity by implementing a high-molecular-weight region in the molecular structure, thereby facilitating deoxidation, dehydration and drying processes during chlorination processing and enabling an increase in chlorination temperature.

Chlorinated polyethylene (CPE), which is manufactured by reacting polyethylene and chlorine, is known to have improved physical and mechanical properties compared to polyethylene, and is used as a packing material for various containers, fibers, pipes, and as a heat-conducting material because it can withstand harsh external environments.

Chlorinated polyethylene is generally manufactured by making polyethylene into a suspension and then reacting it with chlorine, or by putting polyethylene in an HCl aqueous solution and reacting it with chlorine to replace the hydrogen in the polyethylene with chlorine. Through this process of chlorinating polyethylene, CPE acquires rubber-like properties.

In order to fully express the characteristics of chlorinated polyethylene, chlorine must be uniformly substituted in the polyethylene, which is affected by the characteristics of polyethylene that reacts with chlorine. In particular, chlorinated polyethylene such as CPE (Chlorinated Polyethylene) is widely used for purposes such as wires and cables through compounding with inorganic additives and crosslinking agents, and the strength of the compound varies depending on the properties of chlorinated polyethylene.

In addition, chlorinated polyethylene can generally be manufactured by reacting polyethylene with chlorine in a suspension state, or by reacting polyethylene with chlorine in an HCl aqueous solution. Specifically, when producing CPE, it goes through the processes of chlorination, deoxidation, dehydration, and drying. If the crystal structure of polyethylene is not stably maintained, the crystal structure may collapse and the pores of the polyethylene particles may be blocked during the high-temperature chlorination reaction. In the process after deoxidation, washing with water is required to remove residual HCl in the polyethylene particles. If the pores are blocked, the overall production time is delayed due to the delay in the deoxidation time, which reduces the chlorination productivity. In particular, as the melting phenomenon of polyethylene chains becomes more severe due to the temperature increase in the chlorination process, the particles melt together and become a single mass, causing blocking, and as they swell, water is trapped inside, which takes a long time to dry after chlorination. Due to this phenomenon, it is known that the productivity of CPE of a CPE company is better when the washing and drying time in the chlorination stage is better.

Accordingly, it is necessary to secure optimized physical properties of chlorinated polyethylene to improve strength and processability during extrusion when compounding for use in wires and cables, and in addition, there is a continuous demand for the development of technology that can manufacture polyethylene with a molecular structure with many intermediate molecular regions to improve productivity in the chlorination process.

The present invention aims to provide polyethylene and its chlorinated polyethylene, which can manufacture chlorinated polyethylene having excellent strength and improved processability during extrusion by implementing a high-molecular-weight region in the molecular structure.

In addition, the present invention seeks to provide a method for producing the polyethylene.

According to one embodiment of the invention, there is provided polyethylene having a melt index MI ₅ (measured at 190° C., 5 kg load) of 0.7 g/10 min to 1.0 g/10 min, a density of 0.953 g/cm ³ or more, a complex viscosity (η*(ω0.05), complex viscosity) measured at a frequency (ω, frequency, ω) of 0.05 rad/s of 43000 Paㆍs or more, and a complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω, frequency, ω) of 500 rad/s of 550 Paㆍs to 850 Paㆍs.

Additionally, the present invention provides a method for producing the polyethylene.

In addition, the present invention provides chlorinated polyethylene manufactured by reacting the polyethylene and chlorine.

The polyethylene according to the present invention implements a high molecular weight region in its molecular structure, and by reacting it with chlorine, chlorinated polyethylene with excellent chlorination productivity and thermal stability can be manufactured.

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

In addition, the terminology used herein is only used to describe exemplary embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. It should be understood that the terms "comprises," "includes," or "has" in this specification are intended to specify the presence of implemented features, numbers, steps, components, or combinations thereof, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, components, or combinations thereof.

In addition, the terms “about,” “substantially,” and the like used throughout this specification are used in a meaning that is at or close to the numerical value when manufacturing and material tolerances inherent in the meanings mentioned are presented, and are used to prevent unscrupulous infringers from unfairly utilizing the disclosure in which exact or absolute values are mentioned to aid the understanding of the present invention.

In addition, in this specification, "part by weight" means a relative concept that expresses the weight of a substance as a ratio based on the weight of the other substance. For example, in a mixture containing 50 g of substance A, 20 g of substance B, and 30 g of substance C, the amounts of substance B and substance C are 40 parts by weight and 60 parts by weight, respectively, based on 100 parts by weight of substance A.

In addition, "% by weight" means an absolute concept that expresses the weight of a certain substance as a percentage of the total weight. In the mixture in the example above, the contents of substance A, substance B, and substance C are 50 wt%, 20 wt%, and 30 wt%, respectively, out of 100% of the total weight of the mixture. At this time, the total sum of the contents of each component does not exceed 100 wt%.

The present invention may have various modifications and may take various forms, and thus specific embodiments are illustrated and described in detail below. However, this is not intended to limit the present invention to specific disclosed forms, but should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

Hereinafter, the present invention will be described in more detail.

According to one embodiment of the invention, there is provided polyethylene capable of producing chlorinated polyethylene having improved processability during extrusion along with excellent strength by implementing a molecular structure having a high molecular weight region.

The above polyethylene is characterized in that it has a melt index MI ₅ (measured at 190° C., 5 kg load) of 0.7 g/10 min to 1.0 g/10 min, a density of 0.953 g/cm ³ or more, a complex viscosity (η*(ω0.05), complex viscosity) measured at a frequency (ω, frequency, ω) of 0.05 rad/s of 43000 Paㆍs or more, and a complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω, frequency, ω) of 500 rad/s of 550 Paㆍs to 850 Paㆍs.

In general, chlorinated polyethylene is manufactured by reacting polyethylene with chlorine, and means that some of the hydrogens of the polyethylene are replaced with chlorine. When the hydrogen of the polyethylene is replaced with chlorine, the atomic volumes of hydrogen and chlorine are different, so that the properties of the polyethylene change, for example, the chlorination productivity and thermal stability increase. In particular, the smaller and more uniform the overall size of the chlorinated polyethylene particles, the easier it is for chlorine to penetrate to the center of the polyethylene particles, so that the degree of chlorine substitution within the particles is uniform, so that excellent physical properties can be exhibited. To this end, the polyethylene according to the present invention has a high medium-molecular weight region in its molecular structure, so that chlorinated polyethylene having excellent strength and improved processability during extrusion can be provided.

The polyethylene of the present invention is characterized by having a high medium-molecular weight region in its molecular structure, thereby optimizing the melt index MI ₅ (measured at 190°C, 5 kg load) and density, while maximizing the complex viscosity in the low-frequency region and maintaining the complex viscosity in the high-frequency region within an optimal range. As a result, the medium-molecular weight content of the polyethylene is increased, and chlorinated polyethylene having excellent chlorination productivity, thermal stability, and mechanical properties can be manufactured.

The polyethylene according to the present invention may be an ethylene homopolymer that does not include a separate copolymer.

The above polyethylene should have a melt index MI ₅ of about 0.7 g/10 min to 1.0 g/10 min as measured under the conditions of a temperature of 190 ℃ and a load of 5 kg by the method of ASTM D 1238 as described above, or can be about 0.75 g/10 min to 1.0 g/10 min, or about 0.79 g/10 min to 0.99 g/10 min. The lower the melt index MI ₅ , the higher the viscosity, and when manufacturing chlorinated polyethylene, the properties such as pattern viscosity deviate from the optimal range. In this case, when processing products such as wires and cables, a lot of processing load is applied in the extrusion process, and a problem of poor inorganic dispersion may occur. Therefore, the melt index MI ₅ should be about 0.7 g/10 min or more in order to reduce the extrusion processing load during product processing and to secure excellent appearance properties. In addition, if the melting index MI ₅ is too high, the low molecular content increases, and during the chlorination process, the low molecular weight particles melt at high temperatures and form lumps, which causes changes in particle shape and reduces thermal stability. Accordingly, the melting index MI ₅ should be about 1.0 g/10 min or less in order to realize excellent thermal stability.

In addition, the polyethylene must have a density of about 0.953 g/cm ³ or more. Specifically, the density of the polyethylene may be about 0.953 g/cm ³ or more, or about 0.953 g/cm ³ to about 0.960 g/cm ³ , or about 0.954 g/cm ³ or more, or about 0.954 g/cm ³ to about 0.9568 g/cm ³ . This means that the content of the crystal structure of the polyethylene is high and dense, which has the characteristic that the crystal structure is unlikely to change during the chlorination process. In particular, when the density of the polyethylene is less than about 0.953 g/cm ³ , the crystallinity of the particles decreases, which reduces the thermal stability, and the shape of the particles changes significantly during the chlorination process, which may cause lumps to form, thereby lowering the chlorination productivity.

In particular, the polyethylene is manufactured by optimizing a specific metallocene catalyst and hydrogen input as described below, thereby optimizing the complex viscosity according to a specific frequency together with the melting index and density, thereby increasing the number of medium and high molecular regions in the molecular structure, thereby facilitating the deoxidation, dehydration and drying processes during chlorination processing, and enabling an increase in the chlorination temperature, thereby increasing chlorination productivity, thereby improving the strength of the final product, the CPE compound.

The above polyethylene exhibits a high complex viscosity (η*(ω0.05), complex viscosity) of about 43,000 Paㆍs or more, or about 43,000 Paㆍs to about 110,000 Paㆍs when measured at a frequency (ω, frequency, ω) of 0.05 rad/s. Specifically, the complex viscosity (η*(ω0.05), complex viscosity) measured at the frequency (ω, frequency, ω) of 0.05 rad/s may be about 43,000 Paㆍs or more, or about 43,000 Paㆍs to about 65,000 Paㆍs, or about 45,000 Paㆍs or more, or about 45,000 Paㆍs to about 60,000 Paㆍs. In addition, the complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω, frequency, ω) of 500 rad/s shows an optimal range of 550 Paㆍs to 850 Paㆍs. Specifically, the complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω, frequency, ω) of 500 rad/s can be about 580 Paㆍs to about 800 Paㆍs, or about 600 Paㆍs to about 750 Paㆍs. Here, the complex viscosity (η*(ω0.05), complex viscosity) measured at a frequency (ω, frequency, ω) of 0.05 rad/s should be about 43000 Paㆍs or more in order to improve the chlorination productivity of polyethylene. In addition, the complex viscosity (η*(ω500), complex viscosity) measured at the frequency (ω, frequency, ω) of 500 rad/s should be maintained within the range described above in order to ensure that the processing load is appropriately maintained during extrusion for compound product processing after the chlorination process of polyethylene.

In general, a perfectly elastic material deforms in proportion to the elastic shear stress, which is called Hooke's law. In addition, in the case of a purely viscous liquid, deformation occurs in proportion to the viscous shear stress, which is called Newton's law. A perfectly elastic material can recover its deformation when the elastic shear stress is removed because elastic energy is accumulated, but a perfectly viscous material does not recover its deformation even when the viscous shear stress is removed because all energy is dissipated through deformation. In addition, the viscosity of the material itself does not change.

However, polymers have properties that are intermediate between perfectly elastic materials and viscous liquids in the molten state, which is called viscoelasticity. That is, when polymers are subjected to shear stress in the molten state, their deformation is not proportional to the shear stress, and their viscosity also changes depending on the shear stress, which is also called a non-Newtonian fluid. These properties are due to the complexity of deformation according to shear stress, as polymers have large molecular sizes and complex intermolecular structures.

In particular, when manufacturing a molded product using a polymer, shear thinning is an important characteristic of a non-Newtonian fluid. The shear thinning phenomenon refers to a phenomenon in which the viscosity of a polymer decreases as the shear rate increases, and the molding method of the polymer is determined according to this shear thinning characteristic. In particular, when manufacturing a large molded product such as a large-diameter pipe or a composite pipe as in the present invention or a molded product that requires high-speed polymer extrusion, since considerable pressure must be applied to the molten polymer, if the molded product does not exhibit shear thinning characteristics, it is difficult to manufacture such a molded product. Therefore, shear thinning characteristics are important to consider.

Accordingly, in the present invention, shear fluidization characteristics are measured through complex viscosity (η*[Pa.s]) according to frequency (frequency, ω[rad/s]). In particular, by optimizing the complex viscosity at frequencies (ω, frequency, ω) of 0.05 rad/s and 500 rad/s, excellent chlorination productivity and excellent compound properties can be realized. In addition, the property range such as pattern viscosity (MV) of chlorinated polyethylene can be predicted through the complex viscosity at a frequency (ω, frequency, ω) of 500 rad/s.

In particular, polyethylene made with a molecular structure optimized by melting index, density, and complex viscosity according to a specific frequency according to the present invention can minimize particle changes due to high temperatures during chlorination processing at high temperatures, thereby improving thermal stability and preventing clumping and lumping, and while particle changes are minimized, chlorine distribution is evenly substituted, thereby improving the tensile strength of the compound.

Meanwhile, it is preferable that the polyethylene of the present invention optimizes the melt index MI ₅ as described above, and also optimizes the melt flow rate (MFRR _21.6/5 , a value obtained by dividing the melt index measured at 190° C. and 21.6 kg load by the method of ASTM D 1238 by the melt index measured at 190° C. and 5 kg load). At this time, the melt flow rate (MFRR _21.6/5 , a value obtained by dividing the melt index measured at 190° C. and 21.6 kg load by the method of ASTM D 1238 by the melt index measured at 190° C. and 5 kg load) of the polyethylene may be about 16 to about 25. Specifically, the melt flow rate may be about 17 to about 23 or about 18 to about 22. The above melt flow index may be about 16 or more in terms of processability during extrusion, and may be about 25 or less in terms of securing excellent mechanical properties by increasing the MV (Mooney viscosity) of CPE.

The above polyethylene may have a weight average molecular weight of about 150,000 g/mol to about 200,000 g/mol, or about 153,000 g/mol to about 190,000 g/mol, or about 155,000 g/mol to about 185,000 g/mol. This means that the molecular weight of the polyethylene is high and the content of a high molecular weight component is high, which causes an effect of increasing the content of a linking molecule to be described later.

In addition, the molecular weight distribution of the polyethylene may be about 5.5 to about 10, or about 6 to about 9, or about 6.5 to about 8. This means that the molecular weight distribution of the polyethylene is narrow. If the molecular weight distribution is wide, the difference in molecular weight between the polyethylenes is large, so that the chlorine content between the polyethylenes may be different after the chlorination reaction, making it difficult to uniformly distribute chlorine. In addition, when the low molecular weight component is melted, it has high fluidity, so that it may block the pores of the polyethylene particles and reduce the chlorination productivity. However, in the present invention, since it has the molecular weight distribution as described above, the difference in molecular weight between the polyethylenes after the chlorination reaction is not large, so that chlorine can be uniformly substituted.

For example, the molecular weight distribution (MWD, polydispersity index) can be calculated by measuring the weight average molecular weight (Mw) and number average molecular weight (Mn) of polyethylene using gel permeation chromatography (GPC, gel permeation chromatography, manufactured by Water), and dividing the weight average molecular weight by the number average molecular weight.

Specifically, a Waters PL-GPC220 instrument can be used as a gel permeation chromatography (GPC) instrument, and a Polymer Laboratories PLgel MIX-B 300 mm long column can be used. At this time, the measurement temperature is 160 °C (Celsius temperature), 1,2,4-trichlorobenzene can be used as a solvent, and a flow rate of 1 mL/min can be applied. Each of the above polyethylene samples can be pretreated by melting in 1,2,4-trichlorobenzene containing 0.0125% BHT at 160 °C for 10 hours using a GPC analysis instrument (PL-GP220), preparing a concentration of 10 mg/10 mL, and then supplying it in an amount of 200 μL. The values of Mw and Mn can be derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weight of polystyrene standard specimens can be used in nine types: 2000 g/mol, 10000 g/mol, 30000 g/mol, 70000 g/mol, 200000 g/mol, 700000 g/mol, 2000000 g/mol, 4000000 g/mol, and 10000000 g/mol.

Meanwhile, according to another embodiment of the invention, a method for producing polyethylene as described above is provided.

A method for producing polyethylene according to the present invention may include a step of polymerizing ethylene by introducing hydrogen gas at 50 to 125 ppm in the presence of at least one first metallocene compound represented by the following chemical formula 1; and at least one second metallocene compound selected from compounds represented by the following chemical formula 2.

[Chemical formula 1]

In the above chemical formula 1,

At least one of R ₁ to R ₈ is -(CH ₂ ) _n -OR, wherein R is a straight or branched chain alkyl of C _1-6 , n is an integer from 2 to 6,

The remainder of R ₁ to R ₈ are the same or different and each independently a functional group selected from the group consisting of hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl, or two or more adjacent groups may be connected to each other to form a C _6-20 aliphatic or aromatic ring substituted or unsubstituted with a C _1-10 hydrocarbyl group,

Q ₁ and Q ₂ are the same or different, and are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _2-20 alkoxyalkyl, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl;

A ₁ is carbon (C), silicon (Si), or germanium (Ge);

M ₁ is a group 4 transition metal;

X ₁ and X ₂ are the same or different, and each independently represents halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro group, amido group, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group;

m is an integer of 0 or 1,

[Chemical formula 2]

In the above chemical formula 2,

Q ₃ and Q ₄ are the same or different, and are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _2-20 alkoxyalkyl, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl;

A ₂ is carbon (C), silicon (Si), or germanium (Ge);

M ₂ is a group 4 transition metal;

X ₃ and X ₄ are the same or different, and each independently represents halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro group, amido group, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group;

C ₁ and C ₂ is represented by one of the following chemical formulas 3a or 3b, and C ₁ and C ₂ is represented by the following chemical formula 3c, chemical formula 3d, or chemical formula 3e;

[Chemical formula 3a]

[Chemical formula 3b]

[Chemical formula 3c]

[chemical formula 3d]

[Chemical formula 3e]

In the above chemical formulas 3a, 3b, 3c, 3d and 3e, R ₉ to R ₃₉ and R _17' to R _21' are the same as or different from each other and are each independently hydrogen, halogen, C _1-20 alkyl, C _1-20 haloalkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl, C _1-20 alkoxy, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl, provided that at least one of R ₁₇ to R ₂₁ and R _17' to R _21' is C _1-20 haloalkyl,

At least two adjacent ones of R ₂₂ to R ₃₉ may be connected to each other to form a C _6-20 aliphatic or aromatic ring which is unsubstituted or substituted with a C _1-10 hydrocarbyl group;

* Indicates the site of binding to A ₂ and M ₂ .

Unless otherwise specified in this specification, the following terms may be defined as follows:

A halogen can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

A hydrocarbyl group is a monovalent functional group in which a hydrogen atom is removed from a hydrocarbon, and may include 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 alkynylaryl group. In addition, 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, the hydrocarbyl group having 1 to 30 carbon atoms may be a straight-chain, branched-chain or cyclic alkyl group such as 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, an n-hexyl group, an n-heptyl group, a cyclohexyl group, or an aryl group such as phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, or fluorenyl. In addition, it may be an alkylaryl such as methylphenyl, ethylphenyl, methylbiphenyl, or methylnaphthyl, and may also be an arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, or naphthylmethyl. In addition, it may be an alkenyl such as allyl, allyl, ethenyl, propenyl, butenyl, or pentenyl.

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

Alkenyl having 2 to 20 carbon atoms ( _C2-20 ) includes straight-chain or branched-chain alkenyl, and specifically includes, but is not limited to, allyl, allyl, ethenyl, propenyl, butenyl, pentenyl, etc.

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

An alkoxyalkyl group having 2 to 20 carbon atoms (C _2-20 ) is a functional group in which at least one hydrogen of the above-mentioned alkyl is replaced with alkoxy, and specifically, examples thereof include alkoxyalkyl such as methoxymethyl, methoxyethyl, ethoxymethyl, iso-propoxymethyl, iso-propoxyethyl, iso-propoxypropyl, iso-propoxyhexyl, tert-butoxymethyl, tert-butoxyethyl, tert-butoxypropyl, and tert-butoxyhexyl, but are not limited thereto.

Aryloxy having 6 to 40 carbon atoms (C _6-40 ) includes, but is not limited to, phenoxy, biphenoxy, and naphthoxy.

An aryloxyalkyl group having 7 to 40 carbon atoms (C _7-40 ) is a functional group in which at least one hydrogen of the above-mentioned alkyl is replaced with aryloxy, and specific examples thereof include, but are not limited to, phenoxymethyl, phenoxyethyl, and phenoxyhexyl.

Alkylsilyl having 1 to 20 carbon atoms (C _1-20 ) or alkoxysilyl group having 1 to 20 carbon atoms (C _1-20 ) is a functional group in which 1 to 3 hydrogens of -SiH ₃ are replaced with 1 to 3 of the above-described alkyl or alkoxy groups, and specifically, examples thereof include, but are not limited to, alkylsilyl such as methylsilyl, dimethylsilyl, trimethylsilyl, dimethylethylsilyl, diethylmethylsilyl, or dimethylpropylsilyl; alkoxysilyl such as methoxysilyl, dimethoxysilyl, trimethoxysilyl, or dimethoxyethoxysilyl; and alkoxyalkylsilyl such as methoxydimethylsilyl, diethoxymethylsilyl, or dimethoxypropylsilyl.

Silylalkyl having 1 to 20 carbon atoms (C _1-20 ) is a functional group in which one or more hydrogens of the above-described alkyl are replaced with silyl, and specifically, examples thereof include, but are not limited to, -CH ₂ -SiH ₃ , methylsilylmethyl, or dimethylethoxysilylpropyl.

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

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

The alkylaryl having 7 to 20 carbon atoms (C _7-20 ) may refer to a substituent in which at least one of the hydrogens of the aromatic ring is substituted by the above-described alkyl. As an example, the alkylaryl having 7 to 20 carbon atoms (C _7-20 ) may include, but is not limited to, methylphenyl, ethylphenyl, methylbiphenyl, methylnaphthyl, etc.

The above C _7-20 arylalkyl may refer to a substituent in which one or more hydrogens of the above-described alkyl are substituted by the above-described aryl. As examples, the C _7-20 arylalkyl may include, but is not limited to, phenylmethyl, phenylethyl, biphenylmethyl, naphthylmethyl, and the like.

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

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

Additionally, the group 13 element may be boron (B), aluminum (Al), gallium (Ga), indium (In), or thallium (Tl), specifically, but not limited to, boron (B) or aluminum (Al).

Meanwhile, the first metallocene compound may be represented by any one of the following chemical formulas 1-1 to 1-4.

[Chemical Formula 1-1]

[Chemical Formula 1-2]

[Chemical Formula 1-3]

[Chemical Formula 1-4]

In the above chemical formulas 1-1 to 1-4, Q ₁ , Q ₂ , A ₁ , M ₁ , X ₁ , X ₂ , and R ₁ to R ₈ are as defined in the above chemical formula 1, and R' and R'' are the same as or different from each other and are each independently a C _1-10 hydrocarbyl group.

Specifically, each of Q ₁ and Q ₂ may be C _1-3 alkyl, preferably methyl.

Specifically, X ₁ and X ₂ may each be halogen, and preferably chloro.

Specifically, the above A ₁ may be silicon (Si).

Specifically, the above M ₁ may be zirconium (Zr) or hafnium (Hf).

Specifically, each of R ₁ to R ₈ may be hydrogen, or C _1-20 alkyl, or C _1-10 alkyl, or C _1-6 alkyl, or C _2-6 alkyl substituted with C _1-6 alkoxy, or C _4-6 alkyl substituted with C _1-4 alkoxy. Alternatively, two or more adjacent ones of R ₃₂ to R ₃₉ may be connected to each other to form an aliphatic or aromatic ring of C _6-20 substituted with C _1-3 .

Preferably, each of R ₃ and R ₆ may be C _1-6 alkyl, or C _2-6 alkyl substituted with C _1-6 alkoxy, or C _4-6 alkyl, or C _4-6 alkyl substituted with C _1-4 alkoxy, respectively. For example, R ₃ and R ₆ may be n-butyl, n-pentyl, n-hexyl, tert-butoxy butyl, or tert-butoxy hexyl.

And, R ₁ , R ₂ , R ₄ , R ₅ , R ₇ , and R ₈ can be hydrogen.

The compound represented by the above chemical formula 1 may be, for example, a compound represented by one of the structural formulas below, but is not limited thereto.

The first metallocene compound represented by the above structural formulas can be synthesized by applying known reactions, and more detailed synthetic methods can be found in the Examples.

The method for producing polyethylene according to the present invention uses at least one first metallocene compound represented by the chemical formula 1, or chemical formulas 1-1, 1-2, 1-3, and 1-4 as described above, together with at least one second metallocene compound described below, thereby optimizing the melting index and density of polyethylene, while maximizing the complex viscosity in a low-frequency range and maintaining the complex viscosity in an optimal range in a high-frequency range, thereby ensuring high productivity and excellent processability during extrusion in the CPE process described below.

In particular, the second metallocene compound represented by the chemical formula 2 in the present invention has the characteristic of increasing molecular entanglement by increasing the number of intermediate molecular regions within the polyethylene molecular structure, thereby improving thermal stability.

Meanwhile, the second metallocene compound may be represented by the following chemical formula 2-1.

[Chemical Formula 2-1]

In the above chemical formula 2-1, Q ₃ , Q ₄ , A ₂ , M ₂ , X ₃ , X ₄ , R ₁₁ , and R ₁₇ to R ₂₉ are as defined in the above chemical formula 2.

Specifically, the above Q ₃ and Q ₄ may each be C _1-3 alkyl, or C _2-12 alkoxyalkyl, preferably methyl or tert-butoxyhexyl.

Specifically, X ₃ and X ₄ may each be halogen, and specifically, chloro.

Specifically, the above A ₂ may be silicon (Si).

Specifically, the above M ₂ may be zirconium (Zr) or hafnium (Hf), and preferably zirconium (Zr).

Specifically, R ₁₇ to R ₂₁ and R _17' to R _21' may each be hydrogen or C _1-6 haloalkyl, or may each be hydrogen or C _1-3 haloalkyl. For example, R ₁₇ to R ₂₀ or R _17' to R _20' are hydrogen, and R ₂₁ or R _21' is trihalomethyl, preferably trifluoromethyl.

Specifically, R ₁₁ and R _11' may each be a straight-chain or branched-chain alkyl of C _1-6 , or a straight-chain or branched-chain alkyl of C _1-3 , and preferably may be methyl.

Specifically, each of R ₂₂ to R ₂₉ may be hydrogen, or C _1-20 alkyl, or C _1-10 alkyl, or C _1-6 alkyl, or C _1-3 alkyl. Alternatively, two or more adjacent ones of R ₂₂ to R ₂₉ may be connected to each other to form an aliphatic or aromatic ring of C _6-20 substituted with C _1-3 .

Specifically, each of R ₃₀ to R ₃₅ may be hydrogen, or C _1-20 alkyl, or C _1-10 alkyl, or C _1-6 alkyl, or C _1-3 alkyl.

Specifically, each of R ₂₆ to R ₂₉ can be hydrogen, or C _1-20 alkyl, or C _1-10 alkyl, or C _1-6 alkyl, or C _1-3 alkyl.

The compound represented by the above chemical formula 2 may be, for example, a compound represented by the following structural formula, but is not limited thereto.

The second metallocene compound represented by the above structural formula can be synthesized by applying known reactions, and more detailed synthetic methods can be referred to the examples.

The method for producing the above metallocene compound is specifically described in the examples described below.

The metallocene catalyst used in the present invention may be supported on a carrier together with a cocatalyst compound.

In the supported metallocene catalyst according to the present invention, the cocatalyst supported together on the carrier to activate the metallocene compound is an organometallic compound containing a Group 13 metal, and is not particularly limited as long as it can be used when polymerizing olefin under a general metallocene catalyst.

The above cocatalyst is not particularly limited as long as it is an organometallic compound containing a Group 13 metal and can be used when polymerizing ethylene under a general metallocene catalyst.

Specifically, the cocatalyst may be at least one selected from the group consisting of compounds represented by the following chemical formulas 4 to 6:

[Chemical Formula 4]

-[Al(R ₄₀ )-O] _c -

In the above chemical formula 4,

R ₄₀ is each independently halogen, C _1-20 alkyl or C _1-20 haloalkyl,

c is an integer greater than or equal to 2,

[Chemical Formula 5]

D(R ₄₁ ) ₃

In the above chemical formula 5,

D is aluminum or boron,

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

[Chemical formula 6]

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

In the above chemical formula 6,

L is a neutral or cationic Lewis base,

[LH] ⁺ is Bronsted acid,

Q is Br ³⁺ or Al ³⁺ ,

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

The compound represented by the above chemical formula 4 may be an alkylaluminoxane, such as modified methylaluminoxane (MMAO), methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, etc.

The alkyl metal compound represented by the above chemical formula 5 may be, for example, trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, dimethylisobutylaluminum, dimethylethylaluminum, diethylchloroaluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylaluminum methoxide, dimethylaluminum ethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, and the like.

The compound represented by the above chemical formula 6 is, for example, triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, 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 tetrapentafluorophenylboron, N,N-diethylanilinium tetraphenylboron, N,N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron, Trimethylphosphonium tetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra(p-tolyl)aluminum, tripropylammonium tetra(p-tolyl)aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, tributylammonium tetrapentafluorophenylaluminum, N,N-diethylanilinium tetraphenylaluminum, N,N-diethylanilinium tetrapentafluorophenylaluminum, diethylammonium tetrapentafluorophenylaluminum, It may be triphenylphosphoniumtetraphenylaluminum, trimethylphosphoniumtetraphenylaluminum, triphenylcarboniumtetraphenylboron, triphenylcarboniumtetraphenylaluminum, triphenylcarboniumtetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetrapentafluorophenylboron, etc.

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

In the supported metallocene catalyst according to the present invention, a carrier containing a hydroxyl group on the surface can be used as the carrier, and preferably, a carrier having a highly reactive hydroxyl group and a siloxane group, which has been dried to remove moisture from the surface, can be used.

For example, silica, silica-alumina, and silica-magnesia dried at high temperatures can be used, and these can typically contain oxide, carbonate, sulfate, and nitrate components such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) ₂ .

The drying temperature of the carrier is preferably about 200° C. to 800° C., more preferably about 300° C. to about 600° C., and most preferably about 300° C. to about 400° C. If the drying temperature of the carrier is less than about 200° C., the moisture content is too high, causing the moisture on the surface to react with the cocatalyst. If it exceeds about 800° C., the pores on the surface of the carrier merge, reducing the surface area. In addition, many hydroxyl groups on the surface disappear, leaving only siloxane groups, reducing the reaction sites with the cocatalyst, which is not preferable.

The amount of hydroxyl groups on the surface of the carrier is preferably from about 0.1 mmol/g to about 10 mmol/g, and more preferably from 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 manufacturing method and conditions of the carrier or drying conditions, such as temperature, time, vacuum or spray drying.

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

In the supported metallocene catalyst according to the present invention, the mass ratio of the total transition metal to the carrier included in the metallocene catalyst may be 1:10 to 1:1000. When the carrier and the metallocene compound are included at the above mass ratio, an optimal shape can be exhibited. In addition, the mass ratio of the cocatalyst compound to the carrier may be 1:1 to 1:100.

The above ethylene polymerization reaction can be carried out using a continuous slurry polymerization reactor, a loop slurry reactor, a gas phase reactor, or a solution reactor.

In particular, the polyethylene according to the present invention can be produced by homopolymerizing ethylene in the presence of at least one first metallocene compound represented by the chemical formula 1; and at least one second metallocene compound selected from compounds represented by the chemical formula 2.

The weight ratio of the first metallocene compound and the second metallocene compound (first metallocene compound: second metallocene compound) may be about 25:75 to about 65:35, or about 30:70 to about 62:38, or about 35:65 to about 60:40. The weight ratio of the catalyst precursor may be the weight ratio as described above in terms of increasing the content of medium and high molecular weight and minimizing the low molecular weight so as to manufacture chlorinated polyethylene having excellent chlorination productivity and thermal stability. In particular, when the weight ratio of the first metallocene compound and the second metallocene compound is applied in the above-described range, the hydrogen input amount in the polymerization process can be applied as about 125 ppm with respect to ethylene, so that the wax content can be maintained at a low level of 10% or less. The above wax content can be measured by separating the polymerization product using a centrifuge, sampling 100 mL of the remaining hexane solvent, and allowing it to settle for 2 hours, and then measuring the volume ratio occupied by the wax.

And, the polymerization temperature may be from about 25° C. to about 500° C., preferably from about 25° C. to about 200° C., more preferably from about 50° C. to about 150° C. In addition, the polymerization pressure may be from about 1 kgf/cm ² to about 100 kgf/cm ² , preferably from about 1 kgf/cm ² to about 50 kgf/cm ² , more preferably from about 5 kgf/cm ² to about 30 kgf/cm ² .

In addition, the polymerization reaction is performed under conditions of hydrogen gas injection.

At this time, the hydrogen gas activates the inactive site of the metallocene catalyst and causes a chain transfer reaction to control the molecular weight. The metallocene compound of the present invention has excellent hydrogen reactivity, and therefore, by controlling the amount of hydrogen gas used during the polymerization process, polyethylene having a melting index, density, and complex viscosity range at a desired level can be effectively obtained.

The hydrogen gas may be introduced in an amount of about 50 ppm to about 125 ppm, or about 70 ppm to about 120 ppm, or about 90 ppm to about 115 ppm based on the total weight of ethylene. By controlling the amount of hydrogen gas used within the above range, it is possible to control the melt index, density, and complex viscosity of the polyethylene produced within a desired range while exhibiting sufficient catalytic activity, and thus polyethylene having appropriate properties depending on the intended use can be produced. More specifically, in the catalyst system using the specific first and second metallocene compounds as described above, when the amount of hydrogen introduced is less than about 50 ppm relative to ethylene, the melt index MI of the polyethylene decreases and the complex viscosity increases, and accordingly, the patterned viscosity (MV) increases after the chlorination process, which may cause a high processing load during subsequent compound processing and an unsmooth surface. On the other hand, if the amount of hydrogen input is excessive, exceeding about 120 ppm compared to ethylene, a large amount of low molecular weight is generated, which reduces the complex viscosity of polyethylene, and the particle shape changes a lot during chlorination, which reduces productivity, and the degree of cross-linking may decrease, which may reduce the tensile strength.

Meanwhile, in the polymerization reaction, the metallocene catalyst can be dissolved or diluted and injected in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof; an aromatic hydrocarbon solvent such as toluene and benzene; a hydrocarbon solvent substituted with a chlorine atom, such as dichloromethane and chlorobenzene. It is preferable to use the solvent used here after removing a small amount of water or air, which act as catalyst poisons, by treating it with a small amount of alkyl aluminum, and it is also possible to perform the reaction using a cocatalyst.

Meanwhile, according to another embodiment of the invention, chlorinated polyethylene (CPE) using polyethylene as described above is provided.

The chlorinated polyethylene according to the present invention can be produced by polymerizing ethylene in the presence of the supported metallocene catalyst described above and then reacting it with chlorine.

The above reaction with chlorine can be carried out by dispersing the manufactured polyethylene with water, an emulsifier, and a dispersant, and then adding a catalyst and chlorine.

As the above emulsifier, polyether or polyalkylene oxide can be used. As the above dispersant, a polymer salt or an organic acid polymer salt can be used, and as the above organic acid, methacrylic acid or acrylic acid can be used.

The above catalyst may be a chlorination catalyst used in the art, and for example, benzoyl peroxide may be used. The above chlorine may be used alone, but may be used in combination with an inert gas.

The above chlorination reaction is preferably carried out at about 60° C. to about 150° C., or about 70° C. to about 145° C., or about 80° C. to about 140° C., and the reaction time is preferably about 10 minutes to about 10 hours, or about 1 hour to about 9 hours, or about 2 hours to about 8 hours.

The chlorinated polyethylene manufactured by the above reaction can be additionally subjected to a neutralization process, a washing process, and/or a drying process, and can thus be obtained in a powder form.

The above chlorinated polyethylene has improved heat stability during chlorination processing by increasing the content of the high-molecular-weight region and minimizing the content of the low-molecular-weight region in the molecular structure of the polyethylene, and, for example, when manufactured by reacting chlorine under conditions of about 60° C. to about 150° C. in a slurry (water or HCl aqueous solution) state, the Mooney viscosity (MV) measured under conditions of 121° C. may be from about 60 or more to less than about 85, or from about 62 or more to about 82 or less, or from about 65 or more to about 80 or less. In particular, when the Mooney viscosity of the chlorinated polyethylene is less than about 60, there may be a problem that the tensile strength of wires and cables manufactured with the compound of such chlorinated polyethylene is reduced. In addition, when the patterned viscosity of the above chlorinated polyethylene exceeds about 85, as described below, when processing a CPE compound for use in wires and cables by compounding with inorganic additives and crosslinking agents, the surface may be rough and lack luster, resulting in an unsmooth and poor appearance.

In addition, the chlorinated polyethylene may have a tensile strength of about 12 MPa or more, or about 12 MPa to about 30 MPa, or about 12.5 MPa or more, or about 12.3 MPa to about 20 MPa, or about 12.5 MPa or more, or about 12.5 MPa to about 15 MPa, as measured by the method of ASTM D 412. The chlorinated polyethylene may have a tensile elongation of about 500% or more, or about 500% to about 2000%, or about 700% or more, or about 700% to about 1500%, or about 900% or more, or about 900% to about 1200%, as measured by the method of ASTM D 412.

Specifically, the Mooney viscosity (MV) and tensile strength and tensile elongation may be values measured for chlorinated polyethylene obtained by heating about 500 kg to about 600 kg of polyethylene in a slurry (water or HCl aqueous solution) state from about 75 °C to about 85 °C to a final temperature of about 120 °C to about 140 °C at a rate of about 15 °C/hr to about 18.5 °C/hr, and then performing a chlorination reaction with gaseous chlorine at the final temperature of about 120 °C to about 140 °C for about 2 hours to about 5 hours. At this time, the chlorination reaction may be performed by injecting gaseous chlorine while maintaining the pressure inside the reactor at about 0.2 MPa to about 0.4 MPa simultaneously with the temperature elevation, and the total amount of chlorine introduced may be about 650 kg to about 750 kg.

In addition, the method for measuring the Mooney viscosity (MV), tensile strength, and tensile elongation of the chlorinated polyethylene is as described in Test Example 2 below, and the specific measurement method is omitted.

The chlorinated polyethylene may have, for example, a chlorine content of about 20 wt% to about 50 wt%, about 31 wt% to about 45 wt%, or about 35 wt% to about 40 wt%. Here, the chlorine content of the chlorinated polyethylene can be measured using combustion ion chromatography (Combustion IC, Ion Chromatography) analysis. For example, the combustion ion chromatography analysis can be measured using a combustion IC (ICS-5000/AQF-2100H) device equipped with an IonPac AS18 (4 x 250 mm) column, at a combustion temperature of an internal device temperature (inlet temperature) of 900 ℃ and an external device temperature (outlet temperature) of 1000 ℃, using KOH (30.5 mM) as an eluent, under conditions of a flow rate of 1 mL/min. In addition, the conditions of the device and measurement conditions for measuring the above-mentioned chlorine content are as described in Test Example 2 described below, and a detailed description is omitted.

Specifically, the chlorinated polyethylene according to the present invention may have a Mooney viscosity (MV) of about 65 to about 80, a tensile strength of about 12.5 MPa or more, or about 12.5 MPa to about 15 MPa, and a tensile elongation of about 900% or more, or about 900% to about 1200%, under the condition that the chlorine content is 35 wt% to 40 wt%.

The above chlorinated polyethylene may be, for example, random chlorinated polyethylene.

Chlorinated polyethylene manufactured according to the present invention is widely used in wires and cables due to its excellent chemical resistance, weather resistance, flame retardancy, processability, etc.

In addition, the method for manufacturing a molded article using chlorinated polyethylene according to the present invention can apply a conventional method in the art. For example, the chlorinated polyethylene can be roll-mill compounded and extruded to manufacture a molded article.

Hereinafter, preferred examples are presented to help understand the present invention. However, the following examples are provided only to help understand the present invention more easily, and the content of the present invention is not limited thereby.

[Preparation of catalyst precursor]

Synthesis Example 1: Preparation of the first metallocene compound

t-Butyl-O-(CH ₂ ) ₆ -Cl was prepared using 6-chlorohexanol according to the method described in the literature (Tetrahedron Lett. 2951(1988)), and this was reacted with NaCp to obtain t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ (yield 60%, bp 80 ℃/0.1 mmHg).

Also, t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ was dissolved in THF at -78 ℃, n-BuLi was slowly added, the mixture was warmed to room temperature, and reacted for 8 hours. The above solution was again added slowly to a suspension solution of ZrCl ₄ (THF) ₂ (170 g, 4.50 mmol)/THF (30 mL) at -78 ℃, and the synthesized lithium salt solution was further reacted at room temperature for 6 hours. All volatile substances were removed by vacuum drying, and hexane was added to the obtained oily liquid substance and filtered. After the filter solution was vacuum dried, hexane was added to induce a precipitate at a low temperature (-20 ℃). The obtained precipitate was filtered at a 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

Synthesis Example 2: Preparation of a Second Metallocene Compound

2-1 Preparation of ligand compounds

2.9 g (7.4 mmol) of 8-methyl-5-(2-(trifluoromethyl)benzyl)-5,10-dihydroindeno[1,2-b]indole was dissolved in 100 mL of hexane and 2 mL (16.8 mmol) of MTBE (methyl tertialry butyl ether). 3.2 mL (8.1 mmol) of 2.5 M n-BuLi hexane solution was added dropwise in a dryice/acetone bath, and the mixture was stirred at room temperature overnight. In another 250 mL schlenk flask, 2 g (7.4 mmol) of (6-tert-butoxyhexyl)dichloro(methyl)silane was dissolved in 50 mL of hexane, and the mixture was stirred at room temperature overnight. To this solution, 3.2 mL (8.1 mmol) of a 2.5 M n-BuLi hexane solution was added dropwise in a dryice/acetone bath via a cannula. After the injection, the mixture was slowly warmed to room temperature and stirred at room temperature overnight. At the same time, 1.2 g (7.4 mmol) of fluorene was also dissolved in 100 mL of THF, and 3.2 mL (8.1 mmol) of a 2.5 M n-BuLi hexane solution was added dropwise in a dryice/acetone bath, and the mixture was stirred at room temperature overnight.

The reaction solution (Si solution) of 8-methyl-5-(2-(trifluoromethyl)benzyl)-5,10-dihydroindeno[1,2-b]indole and (6-(tert-butoxy)hexyl)dichloro(methyl)silane was sampled by NMR to confirm the completion of the reaction.

^1H NMR (500 MHz, CDCl ₃ ): 7.74-6.49 (11H, m), 5.87 (2H, s), 4.05 (1H, d), 3.32 (2H, m), 3.49 (3H, s), 1.50-1.25(8H, m), 1.15 (9H, s), 0.50 (2H, m), 0.17 (3H, d)

After confirming the synthesis above, the lithiated solution of fluorene was slowly added dropwise to the Si solution in a dryice/acetone bath and stirred overnight at room temperature. After the reaction, extraction was performed with ether/water, and the residual moisture in the organic layer was removed with MgSO ₄ , and the solvent was removed under vacuum and reduced pressure to obtain 5.5 g (7.4 mmol) of the ligand compound in an oil phase, which could be confirmed by 1H-NMR.

^1H NMR (500 MHz, CDCl ₃ ): 7.89-6.53 (19H, m), 5.82 (2H, s), 4.26 (1H, d), 4.14-4.10 (1H, m), 3.19 (3H, s), 2.40 (3H, m), 1.35-1.21 (6H, m), 1.14 (9H, s), 0.97-0.9 (4H, m), -0.34 (3H, t).

2-2 Preparation of metallocene compounds

5.4 g (Mw 742.00, 7.4 mmol) of the ligand compound synthesized in the above 2-1 was dissolved in 80 mL of toluene and 3 mL (25.2 mmol) of MTBE. 7.1 mL (17.8 mmol) of 2.5 M n-BuLi hexane solution was added dropwise in a dry ice/acetone bath, and the mixture was stirred at room temperature overnight. _3.0 g (8.0 mmol) of ZrCl ₄ (THF) 2 was prepared as a slurry by adding 80 mL of toluene. 80 mL of toluene slurry of ZrCl ₄ (THF) ₂ was transferred to the ligand-Li solution in a dry ice/acetone bath, and the mixture was stirred at room temperature overnight.

The reaction mixture was filtered to remove LiCl, and the toluene in the filtrate was removed by vacuum drying. 100 mL of hexane was added and sonicated for 1 hour. The mixture was filtered to obtain 3.5 g (yield 52 mol%) of a purple metallocene compound as a filtered solid.

¹ H NMR (500 MHz, CDCl ₃ ): 7.90-6.69 (9H, m), 5.67 (2H, s), 3.37 (2H, m), 2.56 (3H,s), 2.13-1.51 (11H, m), 1.17 (9H, s).

Synthesis Example 3: Preparation of a Second Metallocene Compound

3-1 Preparation of ligand compounds

At room temperature, 50 g of Mg(s) was placed in a 10 L reactor, and 300 mL of THF was added. After adding 0.5 g of I ₂ , the temperature of the reactor was maintained at 50 ℃. After the reactor temperature stabilized, 250 g of 6-t-butoxyhexyl chloride was added to the reactor at a rate of 5 mL/min using a feeding pump. It was observed that the reactor temperature increased by 4 to 5 ℃ as 6-t-butoxyhexyl chloride was added. While continuously adding 6-t-butoxyhexyl chloride, stirring was performed for 12 hours to obtain a black reaction solution. 2 mL of the generated black solution was taken, and water was added to obtain an organic layer, and it was confirmed to be 6-t-butoxyhexane through ¹ H-NMR, and from this, it was confirmed that the Grignard reaction had proceeded well. From this, 6-t-butoxyhexyl magnesium chloride was synthesized.

After adding 500 g of MeSiCl ₃ and 1 L of THF to the reactor, the reactor temperature was cooled to -20 ℃. 560 g of the previously synthesized 6-t-butoxyhexyl magnesium chloride was added to the reactor at a rate of 5 mL/min using a feeding pump. After the feeding of the Grignard reagent was completed, the reactor temperature was slowly raised to room temperature and stirred for 12 hours, and it was confirmed that a white MgCl ₂ salt was produced. 4 L of hexane was added, and the salt was removed through a labdori to obtain a filter dydddor. The obtained filter solution was added to the reactor, and hexane was removed at 70 ℃ to obtain a pale yellow liquid. The obtained liquid was confirmed to be methyl(6-t-butoxyhexyl)dichlorosilane through ¹ H-NMR.

¹ H-NMR (CDCl ₃ ): 3.3 (t, 2H), 1.5 (m, 3H), 1.3 (m, 5H), 1.2 (s, 9H), 1.1 (m, 2H), 0.7 (s, 3H)

Tetramethylcyclopentadiene (1.2 mol, 150 g) and 2.4 L of THF were added to the reactor, and the reactor temperature was cooled to -20 ℃. n-BuLi (480 mL) was added to the reactor at a rate of 5 mL/min using a feeding pump. After adding n-BuLi, the reactor temperature was slowly increased to room temperature and stirred for 12 hours. Then, an equivalent amount of methyl(6-t-butoxyhexyl)dichlorosilane (326 g, 350 mL) was rapidly added to the reactor. The reactor temperature was slowly increased to room temperature and stirred for 12 hours. After cooling the reactor temperature to 0 ℃ again, 2 equivalents of t-BuNH ₂ were added. The reactor temperature was slowly increased to room temperature and stirred for 12 hours. Then, THF was removed, 4 L of hexane was added, and a filter solution was obtained through a labdori to remove salts. After the filter solution was added back to the reactor, hexane was removed at 70°C to obtain a yellow solution. This was confirmed to be methyl(6-t-butoxyhexyl)(tetramethylcyclopentadienyl)t-butylaminosilane through ¹ H-NMR.

3-2 Preparation of metallocene compounds

From n-BuLi and the ligand dimethyl(tetramethylCpH)t-butylaminosilane, 10 mmol of TiCl ₃ (THF) ₃ was rapidly added to the dilithium salt of the ligand at -78 °C in THF solution. The reaction solution was stirred for 12 h while slowly warming from -78 °C to room temperature. Then, an equivalent amount of PbCl ₂ (10 mmol) was added at room temperature, and the mixture was stirred for 12 h to obtain a dark black solution tinged with blue. After removing THF from the resulting reaction solution, hexane was added, and the product was filtered. After removing hexane from the ^obtained filter solution, it was confirmed as [tBu-O-(CH ₂ ) ₆ ](CH ₃ )Si(C ₅ (CH ₃ ) ₄ )(tBu-N)TiCl ₂ ].

¹ H-NMR (CDCl ₃ ): 3.3 (s, 4H), 2.2 (s, 6H), 2.1 (s, 6H), 1.8 - 0.8 (m), 1.4 (s, 9H), 1.2 (s, 9H), 0.7 (s, 3H)

[Manufacture of supported catalyst]

Manufacturing Example 1: Manufacturing of a supported catalyst

5.0 kg of toluene solution was placed in a 20 L stainless steel (SUS) high-pressure reactor, and the reactor temperature was maintained at 40°C. 1 kg of silica (SP948, manufactured by Grace Davison) dehydrated by applying vacuum at a temperature of 600°C for 12 hours was placed in the reactor, and after sufficiently dispersing the silica, 128 g of the metallocene compound of Synthesis Example 1 dissolved in toluene was placed therein, and the mixture was stirred at 200 rpm for 2 hours at 40°C to carry out a reaction. Thereafter, stirring was stopped, the mixture was allowed to settle for 30 minutes, and the reaction solution was decanted.

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

3.0 kg of toluene was charged into the reactor, and 142.3 g of the metallocene compound of Synthesis Example 2 was dissolved in 1 L of toluene solution and charged into the reactor, followed by stirring at 40° C. and 200 rpm for 2 hours to cause a reaction. At this time, the ratio of the metallocene compound of Synthesis Example 1 and the metallocene compound of Synthesis Example 2 was 47:53 on a weight basis. After the reactor temperature was lowered to room temperature, stirring was stopped, settling was performed for 30 minutes, and the reaction solution was decanted.

2.0 kg of toluene was added to the reactor and stirred for 10 minutes. Then, stirring was stopped, the solution was allowed to settle for 30 minutes, and the reaction solution was decanted.

3.0 kg of hexane was added to the reactor, the hexane slurry was transferred to a filter dryer, and the hexane solution was filtered. It was dried under reduced pressure at 40°C for 4 hours to produce a 910 g-SiO ₂ hybrid supported catalyst.

Manufacturing Example 2: Manufacturing of a supported catalyst

A hybrid supported catalyst was manufactured using the same method as in Manufacturing Example 1, except that the metallocene compound of Synthesis Example 1 and the metallocene compound of Synthesis Example 2 were added in a weight ratio of 60:40.

Manufacturing Example 3: Manufacturing of a supported catalyst

A hybrid supported catalyst was manufactured using the same method as in Manufacturing Example 1, except that the metallocene compound of Synthesis Example 1 and the metallocene compound of Synthesis Example 2 were added in a weight ratio of 35:65.

Comparative Manufacturing Example 1: Manufacturing of Supported Catalyst

A hybrid supported catalyst was manufactured using the same method as Manufacturing Example 1, except that the metallocene compound of Synthesis Example 3 was used instead of the metallocene compound of Synthesis Example 2, and the ratio of the metallocene compound of Synthesis Example 1 to the metallocene compound of Synthesis Example 3 was changed to 30:70 by weight.

[Manufacture of polyethylene]

Example 1-1

The supported catalyst manufactured in the above Manufacturing Example 1 was introduced into a single slurry polymerization process to manufacture high-density polyethylene, which is a homopolymer, without a separate comonomer.

First, hexane of 25 tons/hr, ethylene of 10 tons/hr, hydrogen of 15 ^m3 /hr, and triethylaluminum (TEAL) of 10 kg/hr were injected into a reactor having a capacity of 100 ^m3 , and also, the hybrid supported metallocene catalyst according to Manufacturing Example 1 was injected at 0.5 kg/hr. Here, the amount of hydrogen gas injected was 106 ppm based on the ethylene content. Accordingly, the ethylene was continuously reacted in the form of a hexane slurry at a reactor temperature of 82 ℃ and a pressure of 7.0 kg/ ^cm2 to 7.5 kg/ ^cm2 , and then, through a solvent removal and drying process, a high-density polyethylene in a powder form was manufactured.

Example 1-2

A high-density polyethylene in powder form was manufactured using the same method as in Example 1-1, except that the supported catalyst manufactured in Manufacturing Example 2 was used instead of the supported catalyst manufactured in Manufacturing Example 1, and the amount of hydrogen added was changed to 90 ppm.

Example 1-3

A high-density polyethylene in powder form was manufactured using the same method as in Example 1-1, except that the supported catalyst manufactured in Manufacturing Example 3 was used instead of the supported catalyst manufactured in Manufacturing Example 1, and the amount of hydrogen added was changed to 115 ppm.

Comparative Example 1-1

A commercially available high-density polyethylene (HDPE) product (product name CE2080, manufacturer LG Chem) manufactured using a Zeiger-Natta catalyst (Z/N-1) and having a melting index (MI ₅ , 190°C, 5 kg) of 1.3 g/10 min was prepared as Comparative Example 1-1.

Comparative Example 1-2

A commercially available high-density polyethylene (HDPE) product (product name CE6040K, manufacturer LG Chem) manufactured using a Zeiger-Natta catalyst (Z/N-2) and having a melting index (MI ₅ , 190°C, 5 kg) of 0.95 g/10 min was prepared as Comparative Example 1-1.

Comparative Example 1-3

A high-density polyethylene in powder form was manufactured using the same method as in Example 1-1, but using the supported catalyst manufactured in Comparative Manufacturing Example 1 instead of the supported catalyst manufactured in Manufacturing Example 1, and varying the amount of hydrogen input to 30 ppm.

Comparative Example 1-4

An ethylene/1-butene copolymer was produced using the same method as in Example 1-1, except that 1-butene was used as a comonomer together with ethylene, the 1-butene was fed at a rate of 45 kg/hr, and the amount of hydrogen fed was varied to 98 ppm.

Comparative Example 1-5

High-density polyethylene in powder form was manufactured using the same method as in Example 1-1, but using a different amount of hydrogen at 140 ppm.

Comparative Example 1-6

High-density polyethylene in powder form was manufactured using the same method as in Example 1-1, but the amount of hydrogen added was changed to 25 ppm.

Test Example 1

The physical properties of the polyethylene manufactured in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-6 were measured by the following methods, and the results are shown in Table 1 below.

1) Melting index (MI, g/10 min)

The melting indices (MI ₅ , MI _21.6 ) were measured under the conditions of a temperature of 190 ℃ and a load of 5 kg and 21.6 kg, respectively, by the method of ASTM D 1238, and were expressed as the weight (g) of the polymer melted for 10 minutes.

2) Melt flow rate (MFRR, MI) _21.6/5 )

The melt flow rate (MFRR, MI _21.6/5 ) was calculated by dividing the melt index measured at 190°C and 21.6 kg load by the melt index measured at 190°C and 5 kg load using the ASTM D 1238 method.

3) Density (g/cm) ³ )

The density (g/cm ³ ) of polyethylene was measured using the ASTM D 1505 method.

4) Measurement of complex viscosity according to frequency

Complex viscosity as a function of frequency: η*(ω0.05) and η*(ω500) was measured using an Advanced Rheometric Expansion System (ARES G2) of TA instruments. The samples were prepared using parallel plates with a diameter of 25.0 mm and a gap of 2.0 mm at 190°C. The measurements were performed in dynamic strain frequency sweep mode, with a strain of 5% and a frequency from 0.05 to 500 rad/s, with 10 points per decade for a total of 41 points.

Example Comparative example 1-1 1-2 1-3 1-1 1-2 1-3 1-4 1-5 1-6 catalyst Manufacturing example
1 Manufacturing example
2 Manufacturing example
3 Z/N-1 Z/N-2 comparison
Manufacturing example
1 Manufacturing example
1 Manufacturing example
1 Manufacturing example
1 hydrogen
input
(ppm) 106 90 115 - - 30 106 140 25 polymer HomoPE HomoPE HomoPE HomoPE HomoPE HomoPE Ethylene/1-butene copolymer HomoPE HomoPE MI ₅ (5kg, 190℃, g/10min) 0.91 0.99 0.79 1.3 0.95 0.81 0.95 1.26 0.31 MFRR (21.6/5) 18.1 17.2 19.8 15.3 10.1 11.2 16.3 19.5 15.2 Density (g/cm ³ ) 0.955 0.954 0.956 0.958 0.953 0.951 0.949 0.957 0.952 η* (ω0.05, Paㆍs) 47060 45240 52300 39160 55136 35440 44300 43500 74300 η* (ω500, Paㆍs) 670 710 690 680 980 1160 620 510 1110

In the above Table 1, Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-3, 1-5, and 1-6 produced ethylene homopolymers (homo PE), and Comparative Example 1-4 produced an ethylene/1-butene copolymer.

In addition, as shown in Table 1 above, it was confirmed that the melting index and density of the examples were optimized compared to the comparative examples, and the complex viscosity was implemented within the optimized range at frequencies of 0.05 rad/s and 500 rad/s.

Test Example 2

Using the polyethylene manufactured in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-5, chlorinated polyethylene of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-5 was manufactured.

[Manufacture of chlorinated polyethylene]

5000 L of water and 550 kg of the high-density polyethylene manufactured in Example 1-1 were charged into the reactor, then sodium polymethacrylate was added as a dispersant, oxypropylene and oxyethylene copolyether as emulsifiers, and benzoyl peroxide as a catalyst, and the temperature was increased from 80 ℃ to 132 ℃ at a rate of 17.3 ℃/hr, and then chlorination was performed with gaseous chlorine at a final temperature of 132 ℃ for 3 hours. At this time, the chlorination reaction was performed by injecting gaseous chlorine at the same time as the temperature was increased so that the pressure inside the reactor was 0.3 MPa, and the total amount of chlorine introduced was 700 kg. The chlorinated reactant was neutralized in NaOH for 4 hours, washed with running water for 4 hours, and then finally dried at 120 ℃ to manufacture chlorinated polyethylene in a powder form.

In addition, the polyethylene manufactured in Examples 1-2 to 1-3 and Comparative Examples 1-1 to 1-5 were each manufactured as chlorinated polyethylene in powder form using the same method as above.

As described above, the physical properties of the chlorinated polyethylenes of Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-5, which were manufactured using the polyethylene manufactured in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-5, were measured by the following methods, and the results are shown in Table 2 below.

1) Mooney viscosity (MV) of CPE

The rotor in the Mooney viscometer was wrapped with the CPE sample and the die was closed. After preheating to 121 °C for 1 minute (min), the rotor was rotated for 4 minutes to measure the MV (Mooney viscosity, 121 °C, ML1+4).

2) Drying time of CPE (min)

CPE was manufactured by reacting chlorine in a slurry (water or HCl aqueous solution) state at a temperature of about 60°C to about 150°C, then the manufactured CPE was neutralized by adding it to NaOH for 4 hours, washed again with running water for 4 hours, and finally dried at 120°C to manufacture a final chlorinated polyethylene product in powder form.

Here, drying was performed until the moisture content of the final product became 0.4 wt% or less, and the time taken for this to occur was measured in minutes and expressed as the drying time (min).

Example Comparative example 2-1 2-2 2-3 2-1 2-2 2-3 2-4 2-5 CPE MV (121℃, ML1+4) 70 72 70 70 90 95 68 58 Drying time (min) 135 150 110 200 150 165 300 200

As shown in Table 2 above, compared to the comparative examples, the examples facilitate the deoxidation, dehydration and drying processes during chlorination processing, enable an increase in the chlorination temperature, thereby enhancing CPE productivity and ensuring that the viscosity after chlorination is also within an optimal range, thereby improving processability during extrusion in the compounding process and ensuring excellent tensile strength.

Claims (12)

As an ethylene homopolymer,
The melting index MI ₅ (measured at 190°C, 5 kg load) is 0.7 g/10 min to 1.0 g/10 min,
The density is 0.953 g/cm ³ or more,
The complex viscosity (η*(ω0.05), complex viscosity) measured at a frequency (ω, frequency, ω) of 0.05 rad/s is 43000 Paㆍs or more,
The complex viscosity (η*(ω500), complex viscosity) measured at a frequency (ω, frequency, ω) of 500 rad/s is 550 Paㆍs to 850 Paㆍs,
The molecular weight distribution (Mw/Mn) is 5.5 to 10,
The melt flow rate (MFRR _21.6/5 , the melt index measured at 190°C, 21.6 kg load divided by the melt index measured at 190°C, 5 kg load by the method of ASTM D 1238) is 16 to 25.
Polyethylene.
In the first paragraph,
The above polyethylene has a molecular weight distribution (Mw/Mn) of 6 to 9.
Polyethylene.
In the first paragraph,
The above polyethylene has a density of 0.953 g/cm ³ to 0.960 g/cm ³ .
Polyethylene.
In the first paragraph,
The above polyethylene has a complex viscosity (η*(ω0.05), complex viscosity) of 43,000 Paㆍs to 110,000 Paㆍs measured at a frequency (ω, frequency, ω) of 0.05 rad/s.
Polyethylene.
In the first paragraph,
The above polyethylene has a melt flow rate (MFRR _21.6/5 , the melt index measured at 190°C and 21.6 kg load divided by the melt index measured at 190°C and 5 kg load by the method of ASTM D 1238) of 16 to 19.8.
Polyethylene.
A step of polymerizing ethylene by introducing hydrogen gas at 50 ppm to 125 ppm in the presence of at least one first metallocene compound represented by the following chemical formula 1; and at least one second metallocene compound selected from compounds represented by the following chemical formula 2,
The weight ratio of the first metallocene compound and the second metallocene compound is 25:75 to 65:35.
A method for producing polyethylene according to any one of claims 1 to 5:
[Chemical Formula 1]

In the above chemical formula 1,
At least one of R ₁ to R ₈ is -(CH ₂ ) _n -OR, wherein R is a straight or branched chain alkyl of C _1-6 , n is an integer from 2 to 6,
The remainder of R ₁ to R ₈ are the same or different and each independently a functional group selected from the group consisting of hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl, or two or more adjacent groups may be connected to each other to form a C _6-20 aliphatic or aromatic ring substituted or unsubstituted with a C _1-10 hydrocarbyl group,
Q ₁ and Q ₂ are the same or different, and are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _2-20 alkoxyalkyl, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl;
A ₁ is carbon (C), silicon (Si), or germanium (Ge);
M ₁ is a group 4 transition metal;
X ₁ and X ₂ are the same or different, and each independently represents halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro group, amido group, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group;
m is an integer of 0 or 1,
[Chemical formula 2]

In the above chemical formula 2,
Q ₃ and Q ₄ are the same or different, and are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _2-20 alkoxyalkyl, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl;
A ₂ is carbon (C), silicon (Si), or germanium (Ge);
M ₂ is a group 4 transition metal;
X ₃ and X ₄ are the same or different, and each independently represents halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro group, amido group, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group;
C ₁ and C ₂ is represented by one of the following chemical formulas 3a or 3b, and C ₁ and C ₂ is represented by the following chemical formula 3c, chemical formula 3d, or chemical formula 3e;
[Chemical formula 3a]

[Chemical formula 3b]

[Chemical formula 3c]

[chemical formula 3d]

[Chemical formula 3e]

In the above chemical formulas 3a, 3b, 3c, 3d and 3e,
R ₉ to R ₃₉ and R _9' to R _21' are the same or different and are each independently hydrogen, halogen, C _1-20 alkyl, C _1-20 haloalkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _{1-20 silylalkyl, C 1-20 alkoxysilyl} , C _1-20 alkoxy, C _6-20 aryl, C _7-40 alkylaryl, C _7-40 arylalkyl, provided that at least one of R ₁₇ to R ₂₁ and R _17' to R _21' is C _1-20 haloalkyl,
At least two adjacent ones of R ₂₂ to R ₃₉ may be connected to each other to form a C _6-20 aliphatic or aromatic ring which is unsubstituted or substituted with a C _1-10 hydrocarbyl group;
* Indicates the site of binding to A ₂ and M ₂ .
In Article 6,
The above first metallocene compound is represented by any one of the following chemical formulas 1-1 to 1-4:
Method for producing polyethylene:
[Chemical Formula 1-1]

[Chemical Formula 1-2]

[Chemical Formula 1-3]

[Chemical Formula 1-4]

In the above chemical formulas 1-1 to 1-4,
Q ₁ , Q ₂ , A ₁ , M ₁ , X ₁ , X ₂ , and R ₁ to R ₈ are as defined in Article 6,
R' and R'' are the same or different and each independently a C _1-10 hydrocarbyl group.
In Article 6,
The above second metallocene compound is represented by the following chemical formula 2-1:
Method for producing polyethylene:
[Chemical Formula 2-1]

In the above chemical formula 2-1,
Q ₃ , Q ₄ , A ₂ , M ₂ , X ₃ , X ₄ , R ₁₁ , and R ₁₇ to R ₂₉ are as defined in paragraph 6.
In Article 6,
R ₁₇ to R ₂₁ and R _17' to R _21' are each hydrogen or C _1-6 haloalkyl,
Method for producing polyethylene.
In Article 6,
The weight ratio of the first metallocene compound and the second metallocene compound is 35:65 to 60:40.
Method for producing polyethylene.
Chlorinated polyethylene, produced by reacting the polyethylene of any one of claims 1 to 5 with chlorine.
In Article 11,
The above chlorinated polyethylene has a Mooney viscosity (MV) of 60 to 85 measured under conditions of 121°C,
Tensile strength measured by the ASTM D 412 method is 12 MPa to 30 MPa.
Chlorinated polyethylene.