KR20220062210A - Hybride supported metallocene catalyst and process for preparing polyethylene copolymer using the same - Google Patents

Abstract

The present invention provides a hybrid-supported metallocene catalyst suitable for providing a polymer for a pipe which exhibits high activity in olefin polymerization and exhibits high copolymerization properties, resulting in excellent processability and long-term physical properties and a preparation method of a polyethylene copolymer using the same.

Description

Hybrid supported metallocene catalyst and method for preparing polyethylene copolymer using same

The present invention relates to a hybrid supported metallocene catalyst and a method for preparing a polyethylene copolymer using the same.

Olefin polymerization catalyst systems can be classified into Ziegler-Natta and metallocene catalyst systems. These two highly active catalyst systems have been developed according to their respective characteristics.

Ziegler-Natta catalyst has been widely applied to existing commercial processes since its invention in the 1950s. There is a problem in that there is a limit to securing the desired physical properties because the composition distribution is not uniform.

On the other hand, the metallocene catalyst consists of a combination of a main catalyst containing a transition metal compound as a main component and a cocatalyst containing an organometallic compound containing aluminum as a main component. Such a catalyst is a homogeneous complex catalyst and exhibits the characteristics of a single site catalyst. According to the single site characteristic, a molecular weight distribution is narrow, a polymer with a uniform composition distribution of comonomer is obtained, and the catalyst It has the ability to change the stereoregularity, copolymerization characteristics, molecular weight, crystallinity, etc. of the polymer according to the modification of the ligand structure and the change of polymerization conditions.

Recently, many product groups are seeking to reduce the occurrence of volatile organic compounds (VOCs) due to changes in environmental awareness. However, in the case of a Ziegler-Natta catalyst (Z/N, ziegler-natta) used in the production of polyethylene, there is a problem of generating high total volatile organic compounds (TVOC). In particular, in the case of various commercially available polyethylenes, products applied with a Ziegler-Natta catalyst are the mainstream, but the conversion to products using a metallocene catalyst with low odor and low dissolution characteristics is accelerating.

On the other hand, polyolefin resins used for high-pressure heating tubes or PE-RT (Polyethylene-Raised Temperature) pipes require excellent processability as well as high flexibility properties to improve workability. However, there is a trade-off relationship between high flexibility and processability in terms of product properties. High flexibility characteristics require lowering the density of the product, which leads to a drop in internal pressure, which leads to deterioration in processability. In addition, mechanical properties are increased to secure workability, and when the density of the product is increased, if the flexibility property is lowered, the workability is deteriorated.

U.S. Patent No. 6,180,736 describes a process for the production of polyethylene in a single gas phase reactor or in a continuous slurry reactor using one metallocene catalyst. When this method is used, polyethylene manufacturing cost is low, fouling hardly occurs, and polymerization activity is stable. In addition, U.S. Patent No. 6,911.508 describes the preparation of polyethylene with improved rheological properties by polymerization in a single gas phase reactor using a novel metallocene catalyst compound and 1-hexene as a comonomer. However, polyethylene produced in the above patents also has a narrow molecular weight distribution, so it is difficult to exhibit sufficient impact strength and processability.

In particular, in the case of the existing PE-RT (Polyethylene-Raised Temperature) pipe product, as an ethylene copolymer using a metallocene catalyst, the molecular weight distribution is narrow, and there is an advantage in that desired properties can be obtained. On the other hand, there is a problem in that long-term physical properties such as stress cracking resistance (FNCT) and workability are inferior to existing PE-RT pipes due to a narrow molecular weight distribution.

The present invention compensates for the shortcomings in product processing by improving Broad Orthogonal Comonomer Distribution (BOCD) and Melt flow rate ratio (MFRR), and it is possible to manufacture an olefin polymer for pipes having excellent physical properties. An object of the present invention is to provide a hybrid supported metallocene catalyst.

In addition, the present invention is to provide a method for preparing a polyethylene copolymer using the hybrid supported metallocene catalyst.

The present invention, at least one first metallocene compound selected from compounds represented by the following formula (1); at least one second metallocene compound selected from compounds represented by the following formula (2); and a carrier supporting the first and second metallocene compounds. It provides a hybrid supported metallocene catalyst comprising a.

[Formula 1]

In Formula 1,

M ¹ is a Group 4 transition metal;

R ^a are the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _6-20 aryl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or C _2-20 heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S, provided that at least one of R ^a above is C _1-20 alkyl;

R ^b is the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _1-20 alkoxy, C _2-20 alkoxyalkyl, C _6-20 aryl, C _6-20 aryloxy, C _2-20 At least one selected from the group consisting of alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or N, O and S C _2-20 heteroaryl comprising heteroatoms, provided that at least one of R ^b is C _2-20 alkoxyalkyl;

X ¹ and X ² are the same as or different from each other, and each independently halogen, C _1-20 alkyl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _6-20 aryl, substituted or unsubstituted C _1-20 alkylidene, substituted or unsubstituted amino group, C _2-20 alkylalkoxy, or C _7-40 arylalkoxy;

n and m are each independently an integer from 1 to 4;

[Formula 2]

In Formula 2,

M ² is a Group 4 transition metal;

X ³ and X ⁴ are the same as or different from each other, and each independently a halogen, a nitro group, an amido group, a phosphine group, a phosphide group, a C _1-30 hydrocarbyl group, a C _1-30 hydrocarbyloxy group, C _2-30 hydrocarbyloxyhydrocarbyl group, -SiH ₃ , C _1-30 hydrocarbyl (oxy)silyl group, C _1-30 sulfonate group, or C _1-30 sulfone group;

Z is -O-, -S-, -NR ^c -, or -PR ^c -;

R ^c is hydrogen, a C _1-20 hydrocarbyl group, a C _1-20 hydrocarbyl (oxy)silyl group, and a C _1-20 silylhydrocarbyl group;

또는

이고,T is

or

ego,

T ¹ is C, Si, Ge, Sn or Pb,

Q ³ is hydrogen, C _1-30 hydrocarbyl group, C _1-30 hydrocarbyloxy group, C _2-30 hydrocarbyloxyhydrocarbyl group, -SiH ₃ , C _1-30 hydrocarbyl (oxy) A silyl group, a halogen-substituted C _1-30 hydrocarbyl group, and -NR ^d R ^e , any one of,

Q ⁴ is any one of a C _2-30 hydrocarbyloxy hydrocarbyl group,

R ^d and ^Re are each independently any one of hydrogen and a C _1-30 hydrocarbyl group, or are connected to each other to form an aliphatic or aromatic ring;

C ¹ is any one of the ligands represented by Formula 2a or 2b,

[Formula 2a]

[Formula 2b]

In Formulas 2a and 2b,

Y is O or S;

R ¹ to R ⁴ are the same as or different from each other, and each independently represent any one of hydrogen, a C _1-30 hydrocarbyl group, or a C _1-30 hydrocarbyloxy group,

ㆍ indicates the site binding to T,

* indicates a site for binding with M ² .

In addition, the present invention provides a method for preparing a polyethylene copolymer, comprising the step of copolymerizing ethylene and alpha-olefin in the presence of the above-described hybrid supported metallocene catalyst.

In addition, the present invention provides a polyethylene copolymer obtained by the above-described manufacturing method and a pipe comprising the same.

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the present invention.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

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

In addition, in this specification, when it is said that each layer or element is formed "on" or "over" each layer or element, it means that each layer or element is directly formed on each layer or element, It means that other layers or elements may additionally be formed between each layer, on the object, on the substrate.

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

Unless otherwise defined herein, "copolymerization" may mean block copolymerization, random copolymerization, graft copolymerization, or alternating copolymerization, and "co-polymer" means block copolymer, random copolymer, graft copolymer. may mean a copolymer or an alternating copolymer.

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

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

, 또는

는 다른 치환기에 연결되는 결합을 의미한다. In this specification,

, or

means a bond connected to another substituent.

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

Hereinafter, the present invention will be described in detail.

According to an aspect of the present invention, at least one first metallocene compound selected from compounds represented by the following formula (1); at least one second metallocene compound selected from compounds represented by the following formula (2); and a carrier supporting the first and second metallocene compounds; is provided a hybrid supported metallocene catalyst comprising a.

[Formula 1]

In Formula 1,

M ¹ is a Group 4 transition metal;

R ^a are the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _6-20 aryl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or C _2-20 heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S, provided that at least one of R ^a above is C _1-20 alkyl;

R ^b is the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _1-20 alkoxy, C _2-20 alkoxyalkyl, C _6-20 aryl, C _6-20 aryloxy, C _2-20 At least one selected from the group consisting of alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or N, O and S C _2-20 heteroaryl comprising heteroatoms, provided that at least one of R ^b is C _2-20 alkoxyalkyl;

X ¹ and X ² are the same as or different from each other, and each independently halogen, C _1-20 alkyl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _6-20 aryl, substituted or unsubstituted C _1-20 alkylidene, substituted or unsubstituted amino group, C _2-20 alkylalkoxy, or C _7-40 arylalkoxy;

n and m are each independently an integer from 1 to 4;

[Formula 2]

In Formula 2,

M ² is a Group 4 transition metal;

X ³ and X ⁴ are the same as or different from each other, and each independently a halogen, a nitro group, an amido group, a phosphine group, a phosphide group, a C _1-30 hydrocarbyl group, a C _1-30 hydrocarbyloxy group, C _2-30 hydrocarbyloxyhydrocarbyl group, -SiH ₃ , C _1-30 hydrocarbyl (oxy)silyl group, C _1-30 sulfonate group, or C _1-30 sulfone group;

Z is -O-, -S-, -NR ^c -, or -PR ^c -;

R ^c is hydrogen, a C _1-20 hydrocarbyl group, a C _1-20 hydrocarbyl (oxy)silyl group, and a C _1-20 silylhydrocarbyl group;

또는

이고,T is

or

ego,

T ¹ is C, Si, Ge, Sn or Pb,

Q ³ is hydrogen, C _1-30 hydrocarbyl group, C _1-30 hydrocarbyloxy group, C _2-30 hydrocarbyloxyhydrocarbyl group, -SiH ₃ , C _1-30 hydrocarbyl (oxy) A silyl group, a halogen-substituted C _1-30 hydrocarbyl group, and -NR ^d R ^e , any one of,

Q ⁴ is any one of a C _2-30 hydrocarbyloxy hydrocarbyl group,

R ^d and ^Re are each independently any one of hydrogen and a C _1-30 hydrocarbyl group, or are connected to each other to form an aliphatic or aromatic ring;

C ¹ is any one of the ligands represented by Formula 2a or 2b,

[Formula 2a]

[Formula 2b]

In Formulas 2a and 2b,

Y is O or S;

R ¹ to R ⁴ are the same as or different from each other, and each independently represent any one of hydrogen, a C _1-30 hydrocarbyl group, or a C _1-30 hydrocarbyloxy group,

ㆍ indicates the site binding to T,

* indicates a site for binding with M ² .

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

The hydrocarbyl group is a monovalent functional group in which a hydrogen atom is removed from hydrocarbon, and is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an aralkenyl group, an aralkynyl group, an alkylaryl group, an alkenylaryl group, and an alkyl group. It may include a nylaryl group and the like. And, the C _1-30 hydrocarbyl group may be a C _1-20 or C _1-10 hydrocarbyl group. For example, the hydrocarbyl group may be a straight chain, branched chain or cyclic alkyl group. More specifically, the C _1-30 hydrocarbyl group is a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, and a n-hexyl group. straight-chain, branched-chain or cyclic alkyl groups such as a sil group, n-heptyl group, and cyclohexyl group; or an aryl group such as phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, or fluorenyl. In addition, it may be an alkylaryl such as methylphenyl, ethylphenyl, methylbiphenyl, or methylnaphthyl, and may be an arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, or naphthylmethyl. In addition, it may be an alkenyl such as allyl, allyl, ethenyl, propenyl, butenyl, pentenyl.

The hydrocarbyloxy group is a functional group in which a hydrocarbyl group is bonded to oxygen. Specifically, the C _1-30 hydrocarbyloxy group may be a C _1-20 or C _1-10 hydrocarbyloxy group. For example, the hydrocarbyloxy group may be a straight chain, branched chain or cyclic alkyl. More specifically, the C _1-30 hydrocarbyloxy group is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, tert-butoxy group, n-pentoxy group , a straight-chain, branched-chain or cyclic alkoxy group such as n-hexoxy group, n-heptoxy group, and cyclohexoxy group; Alternatively, it may be an aryloxy group such as a phenoxy group or a naphthalenoxy group.

A hydrocarbyloxyhydrocarbyl group is a functional group in which one or more hydrogens of a hydrocarbyl group are substituted with one or more hydrocarbyloxy groups. Specifically, the C _2-30 hydrocarbyloxyhydrocarbyl group may be a C _2-20 or C _2-15 hydrocarbyloxyhydrocarbyl group. For example, the hydrocarbyloxyhydrocarbyl group may be a straight chain, branched chain or cyclic alkyl group. More specifically, a C _2-30 hydrocarbyloxyhydrocarbyl group is a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhexyl group, a tert- part alkoxyalkyl groups such as a oxymethyl group, a tert-butoxyethyl group, and a tert-butoxyhexyl group; or an aryloxyalkyl group such as a phenoxyhexyl group.

The hydrocarbyl(oxy)silyl group is a functional group in which 1 to 3 hydrogens of -SiH ₃ are substituted with 1 to 3 hydrocarbyl groups or hydrocarbyloxy groups. Specifically, the C _1-30 hydrocarbyl (oxy) silyl group may be a C _1-20 , C _1-15 , C _1-10 , or C _1-5 hydrocarbyl (oxy) silyl group. More specifically, a C _1-30 hydrocarbyl (oxy) silyl group is an alkyl group such as a methylsilyl group, a dimethylsilyl group, a trimethylsilyl group, a dimethylethylsilyl group, a diethylmethylsilyl group or a dimethylpropylsilyl group. silyl group; Alkoxysilyl groups, such as a methoxysilyl group, a dimethoxysilyl group, a trimethoxysilyl group, or a dimethoxyethoxysilyl group; It may be an alkoxyalkylsilyl group such as a methoxydimethylsilyl group, a diethoxymethylsilyl group, or a dimethoxypropylsilyl group.

In addition, the C _1-20 silylhydrocarbyl group is a functional group in which one or more hydrogens of the hydrocarbyl group are substituted with a silyl group. The silyl group may be -SiH ₃ or a hydrocarbyl (oxy)silyl group. Specifically, the C _1-20 silylhydrocarbyl group may be a C _1-15 or C _1-10 silylhydrocarbyl group. More specifically, the C _1-20 silylhydrocarbyl group is -CH ₂ -SiH ₃ A silylalkyl group such as; alkylsilylalkyl groups such as a methylsilylmethyl group, a methylsilylethyl group, a dimethylsilylmethyl group, a trimethylsilylmethyl group, a dimethylethylsilylmethyl group, a diethylmethylsilylmethyl group, or a dimethylpropylsilylmethyl group; Or it may be an alkoxysilylalkyl group, such as a dimethylethoxysilylpropyl group.

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

The sulfonate group has a structure of -O-SO ₂ -R ^f and R ^f may be a C _1-30 hydrocarbyl group. Specifically, the C _1-30 sulfonate group may be a methanesulfonate group or a phenylsulfonate group.

In addition, the C _1-30 sulfone group has a structure of -R ^c' -SO ₂ -R ^c" , wherein R ^c' and R ^c" are the same or different from each other and each independently any one of the _C1-30 hydrocarbyl groups. can be Specifically, the C _1-30 sulfone group may be a methylsulfonylmethyl group, a methylsulfonylpropyl group, a methylsulfonylbutyl group, or a phenylsulfonylpropyl group.

In the present specification, that two substituents adjacent to each other are connected to each other to form an aliphatic or aromatic ring means that the atom(s) of the two substituents and the valence (atoms) to which the two substituents are bonded are connected to each other to form a ring do. Specifically, an example in which R ^g and R ^h or R ^g' and R ^h' of -NR ^g R ^h or -NR ^g _' R ^h' are connected to each other to form an aliphatic ring, such as a piperidinyl group and R ^g and R ^h or R ^g' and R ^h' of -NR ^g R ^h or -NR ^g _' R ^h' are linked to each other to form an aromatic ring, for example, a pyrrolyl group, etc. can be exemplified.

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

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

And, C _1-20 alkyl may be a straight chain, branched chain or cyclic alkyl. Specifically, C _1-20 alkyl is C _1-20 straight chain alkyl; C _1-10 straight chain alkyl; C _1-6 straight chain alkyl; C _1-3 straight chain alkyl; C _3-20 branched or cyclic alkyl; C _3-15 branched or cyclic alkyl; or C _3-10 branched chain or cyclic alkyl. More specifically, C _1-20 alkyl may include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl, or cyclohexyl. , but is not limited thereto.

Also, C _2-20 Alkenyl can be straight-chain, branched-chain or cyclic alkenyl. Specifically, C _2-20 alkenyl is C _2-20 straight chain alkenyl, C _2-10 straight chain alkenyl, C _2-5 straight chain alkenyl, C _3-20 branched chain alkenyl, C _3-15 branched chain alkenyl kenyl, C _3-10 branched chain alkenyl, C _5-20 cyclic alkenyl or C _5-10 cyclic alkenyl. More specifically, C _2-20 alkenyl may include, but is not limited to, ethenyl, propenyl, butenyl, pentenyl, or cyclohexenyl.

C _6-20 aryl may also mean a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. Specifically, C _6-20 aryl may be C _6-18 aryl, or C _6-12 aryl. More specifically, C _6-20 aryl may include, but is not limited to, phenyl, naphthyl, or anthracenyl.

Also, C _7-20 Alkylaryl may mean a substituent in which one or more hydrogens of aryl are substituted with alkyl. Specifically, C _7-20 Alkylaryl is C _7-18 Alkylaryl, or C _7-12 It may be an alkylaryl. More specifically, C _7-20 alkylaryl may include methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl, or cyclohexylphenyl. , but is not limited thereto.

Also, C _7-20 Arylalkyl may mean a substituent in which one or more hydrogens of the alkyl are substituted by aryl. Specifically, C _7-20 arylalkyl is C _7-18 arylalkyl, or C _7-12 arylalkyl. More specifically, C _7-20 Arylalkyl may include, but is not limited to, benzyl, phenylpropyl, or phenylhexyl.

In addition, C _1-20 alkyloxy is a substituent in the form in which the above-described alkyl is bonded to an oxygen atom, and may be a straight chain, branched chain or cyclic alkyloxy group. Specifically, C _1-20 alkyloxy is C _1-20 straight chain alkyl; C _1-10 straight chain alkyl; C _1-5 straight chain alkyl; C _3-20 branched or cyclic alkyl; C _3-15 branched or cyclic alkyl; or C _3-10 branched chain or cyclic alkyl. More specifically, C _1-20 alkyl is methyloxy, ethyloxy, n-propyloxy, iso-propyloxy, n-butyloxy, iso-butyloxy, tert-butyloxy, n-pentyloxy, iso-pentyloxy or cyclohexyloxy, and the like, but is not limited thereto.

Also, C _1-20 Alkoxy may be straight-chain, branched-chain or cyclic alkoxy. Specifically, the C _1-20 alkoxy may include, but is not limited to, methoxy, ethoxy, n-butoxy, tert-butoxy, cyclohexyloxy, and the like.

In addition, C _2-20 alkoxyalkyl may mean a substituent in which one or more hydrogens of alkyl are substituted by alkoxy. Specifically, as C _2-20 alkoxyalkyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxybutyl, butoxyheptyl, butoxy and hexyl, but is not limited thereto.

In addition, C _6-20 aryloxy is a substituent in the form in which the above-described alkyl is bonded to an oxygen atom, and may have a form in which a monocyclic, bicyclic or tricyclic aromatic hydrocarbon is bonded to an oxygen atom. Specifically, C _6-20 aryloxy may be C _6-18 aryloxy, or C _6-12 aryloxy. More specifically, C _6-20 aryloxy may include, but is not limited to, phenyloxy, naphthyloxy, or anthracenyloxy.

The above-mentioned substituents are optionally a hydroxyl group within the range of exhibiting the same or similar effect as the desired effect; halogen; hydrocarbyl group; hydrocarbyloxy group; a hydrocarbyl group or a hydrocarbyloxy group containing at least one hetero atom among the heteroatoms of Groups 14 to 16; silyl group; hydrocarbyl (oxy) silyl group; phosphine group; phosphide group; sulfonate group; And it may be substituted with one or more substituents selected from the group consisting of a sulfone group.

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

In the hybrid supported metallocene catalyst according to the embodiment, the first metallocene compound represented by Formula 1 increases the long chain branch (LCB) content to improve the molecular structure and change the distribution to improve mechanical properties , and the second metallocene compound represented by Formula 2 may contribute to improving shrinkage and processability by increasing the short chain branch (SCB) content. The hybrid supported metallocene catalyst is prepared by using a low molecular weight, low copolymerizable first metallocene compound and a high molecular weight, high copolymerizable second metallocene compound together as a hybrid catalyst, thereby providing excellent supported performance, catalyst It can exhibit activity and high copolymerizability. In addition, when low-density polyethylene is manufactured in a slurry process under such a hybrid supported metallocene catalyst, process stability is improved, thereby preventing the fouling problem that has occurred in the past.

In particular, the hybrid supported metallocene catalyst can exhibit high activity and copolymerizability by using the first metallocene compound represented by Formula 1 and the second metallocene compound represented by Formula 2 together. , it is possible to secure excellent processability by slightly broadening the molecular weight distribution of the synthesized olefin polymer to improve BOCD and melt flow rate ratio (MFRR). In addition, long-term physical properties such as stress cracking resistance (FNCT) of the synthesized olefin polymer may be secured, and thus the olefin polymer may be suitable for use in pipes.

Specifically, in Formula 1, the bis-cyclopentadienyl ligand has a bridge-bonded form with a Group 4 transition metal, and the substituents of the two cyclopentadienyl ligands have different asymmetric structures. For example, the cyclopentadienyl ligand is unsubstituted or substituted with a C _1-20 hydrocarbon or a C _1-12 hydrocarbon. In particular, one of the cyclopentadienyl ligands is substituted with at least one alkyl and the other one is substituted with at least one alkoxyalkyl. By applying the bis-cyclopentadienyl ligand of this specific structure, catalytic activity and copolymerizability can be improved, the resulting polymer molecular structure is improved, and the reactivity control is excellent.

In Formula 1,

M ¹ is a Group 4 transition metal;

R ^a are the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _6-20 aryl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or C _2-20 heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S, provided that at least one of R ^a above is C _1-20 alkyl;

R ^b is the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _1-20 alkoxy, C _2-20 alkoxyalkyl, C _6-20 aryl, C _6-20 aryloxy, C _2-20 At least one selected from the group consisting of alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or N, O and S C _2-20 heteroaryl comprising heteroatoms, provided that at least one of R ^b is C _2-20 alkoxyalkyl;

X ¹ and X ² are the same as or different from each other, and each independently halogen, C _1-20 alkyl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _6-20 aryl, substituted or unsubstituted C _1-20 alkylidene, substituted or unsubstituted amino group, C _2-20 alkylalkoxy, or C _7-40 arylalkoxy;

n and m are each independently an integer of 1 to 4.

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

In addition, in Formula 1, R ^a and R ^b may each be hydrogen, C _1-6 alkyl, C _7-12 arylalkyl, C _2-12 alkoxyalkyl, C _6-12 aryl, or C _2-6 alkenyl, , provided that at least one of R ^a is C _1-6 alkyl and at least one of R ^b is C _2-12 alkoxyalkyl. More specifically, each R ^a can be hydrogen, methyl, ethyl, propyl, or butyl, and R ^b can each be hydrogen, methyl, or tert-butoxyhexyl. More preferably, all R ^a are methyl, one of R ^b is tert-butoxyhexyl and the other is hydrogen.

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

And, in Formula 1, n is an integer of 1 to 4, preferably 1, 2, or 4, and more preferably 4. m is an integer of 1 to 4, preferably 1 or 2, and more preferably 1.

Specifically, the first metallocene compound may be represented by any one of the following Chemical Formulas 1-1 and 1-2.

[Formula 1-1]

[Formula 1-2]

In Formulas 1-1 and 1-2, M ¹ , X ¹ , and X ² are as defined in Formula 1,

R ^a1 is C _1-20 alkyl, R ^a2 is hydrogen or C _1-20 alkyl,

R ^b1 is C _2-20 alkoxyalkyl and R ^b2 is hydrogen or C _1-20 alkyl.

Specifically, R ^a1 is C _1-6 alkyl, or C _1-4 alkyl, more specifically, R ^a1 is methyl, ethyl, n-propyl, or n-butyl, preferably methyl, n-propyl, or n-butyl.

Also, R ^a2 is hydrogen or C _1-6 alkyl, C _1-4 alkyl, or C _1-3 alkyl, more specifically, R ^a2 is hydrogen or methyl.

Further, R ^b1 is C _2-12 alkoxyalkyl, or C _2-10 alkoxyalkyl, more specifically, R ^b1 is tert-butoxyhexyl.

Also, R ^b2 is hydrogen or C _1-6 alkyl, C _1-4 alkyl, or C _1-3 alkyl, more specifically, R ^b2 is hydrogen or methyl.

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

.

.

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

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

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

Specifically, in Formula 2, the cyclopentadienyl ligand fused with a thiophene ring is characterized in that it has a form in which a Group 4 transition metal is bonded to an amide through a carbon or silicon bridge. In this way, as the thiophene ring adopts a form similar to the bis-cyclopentadienyl structure fused with the cyclopentadienyl ring, catalytic activity and copolymerizability can be improved, the resulting polymer molecular structure is improved, and reactivity control is improved. It has excellent features.

In addition, in Formula 2, Z is -NR ^c -, wherein R ^c may be a C _1-10 hydrocarbyl group, specifically, R ^c may be a C _1-6 straight-chain or branched alkyl group. And, more specifically, it may be a tert-butyl group.

이고, T¹은 탄소(C) 또는 실리콘(Si)이며, Q³은 C_1-30의 하이드로카빌기, 또는 C_1-30의 하이드로카빌옥시기이고, Q⁴는 C_2-30의 하이드로카빌옥시하이드로카빌기일 수 있다. 구체적으로, Q³은 C_1-10의 하이드로카빌기이고, Q⁴는 탄소수 C_2-12의 하이드로카빌옥시하이드로카빌기일 수 있으며, 좀더 구체적으로 Q³은 C_1-6의 알킬기이고, Q⁴는 C_1-6의 알콕시 치환된 C_1-6의 알킬기일 수 있다. 보다 구체적으로, T¹은 실리콘(Si)이며, Q³은 메틸이고, Q⁴는 tert-부톡시 치환된 헥실일 수 있다.And, in Formula 2, T is

and T ¹ is carbon (C) or silicon (Si), Q ³ is a C _1-30 hydrocarbyl group, or a C _1-30 hydrocarbyloxy group, and Q ⁴ is a C _2-30 hydrocarbyl group. It may be an oxyhydrocarbyl group. Specifically, Q ³ is a C _1-10 hydrocarbyl group, Q ⁴ may be a C _2-12 hydrocarbyloxyhydrocarbyl group, and more specifically, Q ³ is a C _1-6 alkyl group, Q ⁴ may be a C _1-6 alkoxy-substituted C _1-6 alkyl group. More specifically, T ¹ may be silicon (Si), Q ³ may be methyl, and Q ⁴ may be tert-butoxy-substituted hexyl.

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

[Formula 2-1]

[Formula 2-2]

In Formulas 2-1 and 2-2, M ² , X ³ , X ⁴ , R ^c , T ¹ , Q ³ , Q ⁴ , R ¹ , R ² , R ³ , and R ⁴ are defined in Formula 2 above. It's like a bar.

And, in Chemical Formulas 2 and 2-1 and 2-2, R ¹ and R ² are each hydrogen or a C _1-10 hydrocarbyl group, and R ³ and R ⁴ are each a C _1-10 hydrocarbyl group. can be Specifically, R ¹ and R ² may each be hydrogen or C _1-10 alkyl, and R ³ and R ⁴ may each be C _1-10 alkyl. More specifically, R ¹ and R ² may each be hydrogen or methyl, and R ³ and R ⁴ may be methyl.

And, in Chemical Formulas 2 and 2-1 and 2-2, M ² is titanium (Ti), zirconium (Zr), or hafnium (Hf). For example, M ² is preferably titanium (Ti) in terms of olefin polymerization activity.

And, in Chemical Formulas 2 and 2-1 and 2-2, X ³ and X ⁴ may each be a halogen or a C _1-10 alkyl group or a C _1-6 alkyl group, specifically chlorine or methyl. there is.

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

.

.

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

Meanwhile, in the hybrid supported metallocene catalyst of the present invention, the first metallocene compound is represented by any one of the following Chemical Formulas 1-1 and 1-2, and the second metallocene compound is represented by the following Chemical Formula 2-1 and 2-2 may be represented by any one of:

[Formula 1-1]

[Formula 1-2]

In Formulas 1-1 and 1-2, M ¹ , X ¹ , X ² are as defined in Formula 1,

R ^a1 is C _1-20 alkyl, R ^a2 is hydrogen or C _1-20 alkyl,

R ^b1 is C _2-20 alkoxyalkyl, R ^b2 is hydrogen or C _1-20 alkyl,

[Formula 2-1]

[Formula 2-2]

In Formulas 2-1 and 2-2,

M ² , X ³ , X ⁴ , R ^c , T ¹ , Q ³ , Q ⁴ , R ¹ , R ² , R ³ , and R ⁴ are as defined in claim 1 .

More specifically, in Formula 1-1 or 1-2, M ¹ is Zr; X ¹ and X ² are both Cl; R ^a1 is methyl, n-propyl, or n-butyl; R ^a2 is hydrogen or methyl; R ^b1 is tert-butoxyhexyl; R ^b2 is hydrogen or methyl. In addition, in Formula 2-1 or 2-2, M ² is Zr; X ³ and X ⁴ are Cl or methyl; Z is NR ^c -(R ^c is t-butyl); T is T ¹ (Q ³ )(Q ⁴ ), T ¹ is Si; Q ³ is methyl, Q ⁴ is t-butoxyhexyl; C ¹ is one of Formulas 2a to 2b, Y is S; R ¹ to R ⁴ are hydrogen or methyl.

In addition, in the hybrid supported metallocene catalyst of the present invention, the first metallocene compound and the second metallocene compound may be supported in a molar ratio of 1:4 to 4:1. By including the first and second metallocene compounds in the above-described mixing molar ratio, excellent supporting performance, catalytic activity, and high copolymerizability may be exhibited. In particular, in the case of producing low-density polyethylene in a slurry process under such a hybrid supported metallocene catalyst, process stability is improved and a fouling problem that has occurred in the past can be prevented. In addition, by using the hybrid supported metallocene catalyst, it is possible to provide a polyolefin having excellent physical properties, for example, polyethylene having high activity and high BOCD.

Specifically, the hybrid supported metallocene catalyst supported in a molar ratio of 1:3 to 3:1 or 1:2 to 2:1 of the first metallocene compound and the second metallocene is used for ethylene polymerization. It is preferable to prepare polyethylene with high activity, excellent copolymerization, excellent mechanical properties, and improved processability and shrinkage.

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

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

For example, at least one selected from the group consisting of silica dried at high temperature, silica-alumina, and silica-magnesia may be used, and these are typically Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) ₂ and the like oxide, carbonate, sulfate, and nitrate components.

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

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

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

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

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

In addition, the hybrid supported metallocene catalyst of the present invention may further include one or more cocatalysts selected from the group consisting of compounds represented by the following Chemical Formulas 3 to 5.

[Formula 3]

-[Al(R ³¹ )-O] _c -

In Formula 3,

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

c is an integer greater than or equal to 2,

[Formula 4]

D(R ⁴¹ ) ₃

In Formula 4,

D is aluminum or boron,

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

[Formula 5]

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

In Formula 5,

L is a neutral or cationic Lewis base,

[LH] ⁺ is a Bronsted acid,

Q is B ³⁺ or Al ³⁺ ,

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

The compound represented by Formula 3 may be, for example, alkylaluminoxane such as modified methylaluminoxane (MMAO), methylaluminoxane (MAO), ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, and the like.

The alkyl metal compound represented by the formula (4) is, for example, trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, dimethylisobutylaluminum, dimethylethylaluminum, diethylchloro Aluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolyl aluminum, dimethylaluminummethoxide, dimethylaluminumethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, and the like.

The compound represented by the formula (5) is, for example, triethylammonium tetraphenyl boron, tributyl ammonium tetraphenyl boron, trimethyl ammonium tetraphenyl boron, tripropyl ammonium tetraphenyl boron, trimethyl ammonium tetra (p- Tolyl) boron, tripropylammonium tetra(p-tolyl) boron, triethylammonium tetra(o,p-dimethylphenyl) boron, trimethylammonium tetra(o,p-dimethylphenyl) boron, tributylammonium tetra (p-trifluoromethylphenyl) boron, trimethylammonium tetra (p-trifluoromethylphenyl) boron, tributylammonium tetrapentafluorophenyl boron, N,N-dimethylanilinium tetraphenyl boron, N,N -Diethylanilinium tetraphenylboron, N,N-diethylaniliniumtetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphoniumtetraphenylboron, trimethylphosphoniumtetraphenyl Boron, triethyl ammonium tetraphenyl aluminum, tributyl ammonium tetraphenyl aluminum, trimethyl ammonium tetraphenyl aluminum, tripropyl ammonium tetraphenyl aluminum, trimethyl ammonium tetra (p-tolyl) aluminum, tripropyl ammonium tetra ( p-tolyl) aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, Tributylammonium tetrapentafluorophenylaluminum, N,N-dimethylaniliniumtetraphenylaluminum, N,N-diethylaniliniumtetraphenylaluminum, N,N-diethylaniliniumtetrapentafluorophenyl Aluminum, diethyl ammonium tetrapentafluorophenyl aluminum, triphenyl phosphonium tetraphenyl aluminum, trimethyl phosphonium tetraphenyl aluminum, triphenyl carbonium tetraphenyl boron, triphenyl carbonium tetraphenyl aluminum, triphenyl carbon umtetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetrapentafluorophenylboron, and the like.

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

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

At this time, if the molar ratio is less than about 1, the metal content of the cocatalyst is too small, so the catalytically active species is not well made, and the activity may be lowered. there is.

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

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

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

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

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

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

Meanwhile, the present invention provides a method for preparing a polyethylene copolymer, comprising copolymerizing ethylene and alpha-olefin in the presence of the hybrid supported metallocene catalyst.

The above-described hybrid supported metallocene catalyst can exhibit excellent supported performance, catalytic activity and high copolymerizability, and even when low-density polyethylene is prepared in a slurry process under such a hybrid supported metallocene catalyst, conventional productivity degradation and problems related to fouling can be prevented and process stability can be improved.

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

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

In addition, the alpha-olefin is 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, It may be at least one selected from the group consisting of 1-octadecene, 1-eicocene, and mixtures thereof.

Specifically, in the method for preparing the polyethylene copolymer, for example, 1-hexene may be used as the alpha-olefin. Accordingly, in the slurry polymerization, a low-density polyethylene copolymer may be prepared by polymerizing the ethylene and 1-hexene.

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

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

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

In this case, the polyethylene to be prepared may be an ethylene 1-hexene copolymer.

According to another embodiment of the invention, there is provided a polyethylene copolymer obtained by the above-described production method.

The olefin polymer prepared by the above method has a rather broad molecular weight distribution as it is prepared using the aforementioned hybrid supported metallocene catalyst, and has excellent processability by improving BOCD and melt flow rate ratio (MFRR). In addition, long-term physical properties such as stress cracking resistance (FNCT) of the synthesized olefin polymer can be secured.

In particular, when the polymer polymerized using the hybrid supported catalyst is, for example, an ethylene-alpha olefin copolymer, preferably an ethylene-1-hexene polymer, the above-described physical properties can be more appropriately satisfied.

In addition, the polyethylene copolymer may have a melt index (ASTM D 1238, MI _2.16 , 190 ^o C, measured under a load of 2.16 kg) of 0.1 g/10min to 1.0 g/10min.

Specifically, the melt index (MI _2.16 , 190 ^o C, 2.16 kg load) of the polyethylene copolymer is 0.2 g/10min or more, or 0.3 g/10min or more, or 0.53 g/10min or more, and 1.0 g/10min or less, or 0.6 g/10 min or less, or 0.58 g/10 min or less.

By having the melt index (MI _2.16 , 190 ^o C, 2.16 kg load) as described above, the molecular structure of the polyethylene copolymer can be optimized to improve long-term pressure resistance properties to be suitable for pipe products.

In addition, the polyethylene copolymer may have a melt flow rate ratio (MFRR; MI ₅ /MI _2.16 ) of 30 to 70.

The MFRR is the melt index (MI ₅ ) measured at 190° C. and a load of 5 kg for the polyethylene according to ASTM D1238 divided by the melt index measured at 190° C. and a load of 2.16 kg (MI _2.16 ).

Specifically, the melt flow index (MFRR, Melt flow rate ratio, MI ₅ / MI _2.16 ) of the polyethylene copolymer is 32 or more, or 34 or more, or 35 or more, and 68 or less, or 60 or less, or 50 or less. .

By having the same melt flow rate (MFRR, Melt flow rate ratio, MI ₅ /MI _2.16 ) as above, the molecular weight distribution of the polyethylene copolymer is optimized to maintain mechanical properties suitable for pipe products, and long-term pressure resistance and processability can be improved. there is.

In addition, the polyethylene copolymer can express high mechanical properties by controlling the molecular structure even though it has a somewhat wider molecular weight distribution than in the prior art.

In particular, the polyethylene copolymer has a BOCD index (Broad Orthogonal Co-monomer Distribution Index) of 1.5 or more or 1.5 to 5.0.

As used herein, the BOCD structure refers to a structure in which the content of comonomers such as alpha olefins is concentrated in a high molecular weight main chain, that is, a structure in which the content of Short Chain Branch (SCB) increases toward the high molecular weight. do.

Here, the short chain branch, that is, a short chain branch (SCB) refers to a branch consisting of 2 to 7 carbon atoms.

The BOCD Index uses a GPC-FTIR device to simultaneously and continuously measure the weight average molecular weight, molecular weight distribution, and SCB content, and take the log value (log M) of the weight average molecular weight (M) as the x-axis, and When the molecular weight distribution curve is drawn with the molecular weight distribution (dwt/dlog M) for After measuring the content of branch (branch) having 2 to 7 carbon atoms, unit: dog/1,000C), it can be obtained by calculating according to Equation 1 below using the measured value. 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 boundary and the left boundary, respectively, in the middle 60% range except for the left and right ends of 20%.

[Equation 1]

At this time, if the BOCD Index is 0 or less, it is not a BOCD-structured polymer, and if it is greater than 0, it can be considered a BOCD-structured polymer. have

The polyethylene copolymer according to an embodiment of the present invention has a BOCD Index of 1.5 to 5.0, and thus has a high comonomer content in the high molecular weight portion, and as a result maintains mechanical properties suitable for pipe products, long-term pressure resistance properties and processability, etc. This excellent characteristic can be exhibited. More specifically, the polyethylene copolymer has a BOCD Index of 1.8 or more, or 2.0 or more, or 2.2 or more, or 2.5 or more, and 4.5 or less, or 4.0 or less, or 3.5 or less, or 3.0 or less.

In addition, the polyethylene copolymer may have a stress crack resistance (FNCT) measurement result according to ISO/FDIS 16770 of 1000 hr or more, or 1000 hr to 6000 hr.

The stress cracking resistance (FNCT) is an evaluation of a molded article of an olefin polymer, and a specific stress cracking resistance test method is described in M. Fleissner in Kunststoffe 77 (1987), pp. 45 et seq.], and corresponds to ISO/FDIS 16770, which is still in effect. For example, in ethylene glycol, a stress crack promoting medium using a tension of 3.5 Mpa at 80 ° C., the failure time is shortened due to the shortening of the stress initiation time by the notch (1.6 mm/safety razor blade).

For example, in order to prepare a specimen for evaluation of the stress cracking resistance (FNCT), a primary antioxidant (Irganox 1010, CIBA) 750 ppm, a secondary antioxidant (Irgafos 168) in the polyethylene copolymer of each Example and Comparative Example , CIBA) 1500 ppm and processing aids (SC110, Ca-St, Soybean Powder Co., Ltd.) 1000 ppm were added and 170 ~ 220 using a twin screw extruder (W&P Twin Screw Extruder, 75 pie, L/D = 36). Granulated at an extrusion temperature of °C. Extrusion test of resin processability was performed under conditions of 190 ℃ ~ 220 ℃ (Temp. profile(℃): 190/200/210/220) using a Haake Single Screw Extruder (19 pie, L/D = 25). do. In addition, pipe molding is performed using a single screw extruder (Battenfeld Pipe M/C, 50 pie, L/D=22, compression ratio=3.5) at an extrusion temperature of 220°C to have an outer diameter of 32 mm and a thickness of 2.9 mm. . Thereafter, the molded article is manufactured by sawing three specimens having dimensions of 10 mm in width, 10 mm in length, and 90 mm in length from a compressed name plate having a thickness of 10 mm. A central notch is provided on the specimen using a safety razor blade in a notch device specifically manufactured for this purpose. The notch depth is 1.6 mm.

The polyethylene copolymer may have a stress cracking resistance (FNCT) according to ISO/FDIS 16770 of 1200 hr or more, or 1350 hr or more, or 1500 hr or more, and in some cases 5000 hr or less, or 4000 hr or less, or 3500 hr or more. hr or less.

The polyethylene copolymer of the present invention can optimize molecular weight distribution by using a specific hybrid supported catalyst as described above to maintain mechanical properties suitable for pipe products as described above and improve long-term pressure resistance properties.

According to another embodiment of the present invention, there is provided a pipe comprising the above-described polyethylene copolymer.

According to the present invention, the polyethylene copolymer has excellent activity and high BOCD index due to an optimized molecular weight distribution, thereby compensating for disadvantages in processing and exhibiting excellent physical properties suitable for pipe products. Due to the satisfaction of the above physical properties, the polyethylene copolymer according to the present invention has good processability and extrusion properties, and excellent stress cracking resistance, so that it can be preferably applied to a high pressure heating pipe, a PE-RT pipe, or a large diameter pipe.

According to the present invention, a hybrid supported metallocene catalyst suitable for providing a polymer for pipes that exhibits high activity in olefin polymerization and exhibits high copolymerizability to exhibit excellent processability and long-term physical properties, and a method for preparing a polyethylene copolymer using the same can be provided.

Therefore, the polyethylene copolymer prepared according to the method of the present invention has excellent processability and long-term physical properties, so it is suitable for use for pipes.

Hereinafter, through specific examples of the invention, the operation and effect of the invention will be described in more detail. However, these embodiments are merely presented as an example of the invention, and the scope of the invention is not defined thereby.

[Example]

<Preparation of the first metallocene compound>

Synthesis Example 1

2,3,4,5-tetramethyl-cyclopentadiene (TMCP, 2,3,4,5-tetramethyl-cyclopentadiene) is n-butyllithium (n- After lithiation with BuLi, 1 equivalent), it was filtered and used as TMCP-Li salts.

Further, using 6-chlorohexanol, t-butyl-O-(CH ₂ ) ₆ -Cl was prepared by the method described in the literature (Tetrahedron Lett. 2951 (1988)), and cyclopentadienyl sodium (NaCp) ) to obtain tert-butyloxyhexylcyclopentadiene (t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ ) (yield 60%, bp 80 ^o C/0.1 mmHg).

The thus obtained t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ is lithiated with n-butyllithium (n-BuLi, 1 equivalent) in tetrahydrofuran (THF, 0.5 M) and filtered to tert-butyl Oxyhexylcyclopentadienyl lithium salts (t-butyl-O-(CH ₂ ) ₆ -CP-Li salts) were used.

Thereafter, the synthesized TMCP-Li salts solution (1 equivalent, THF 1M solution) was added to a suspension solution prepared by mixing ZrCl ₄ (THF) ₂ (1 equivalent) with THF (1.2 M) at -78 ^o C. and t-butyl-O-(CH ₂ ) ₆ -CP-Li salts solution (1 equivalent, THF 1M solution) were slowly added thereto, followed by further reaction at room temperature for 6 hours. All volatiles were removed by vacuum drying, and hexane was added to the obtained oily liquid material and filtered. After vacuum drying the filter solution, hexane was added to induce a precipitate at low temperature (-20 ^o C). The obtained precipitate was filtered at low temperature to obtain the title metallocene compound.

Comparative Synthesis Example 1: Preparation of the first metallocene compound

Using 6-chlorohexanol, t-butyl-O-(CH ₂ ) ₆ -Cl was prepared by the method described in the literature (Tetrahedron Lett. 2951 (1988)), and cyclopentadienyl sodium (NaCp) was added thereto. By reaction, t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ was obtained (yield 60%, bp 80 ^o C/0.1 mmHg).

In addition, t-butyl-O-(CH ₂ ) ₆ -C ₅ H ₅ was dissolved in tetrahydrofuran (THF) at -78 ^o C, n-butyllithium (n-BuLi) was slowly added thereto, and the temperature was raised to room temperature. Then, the reaction was carried out for 8 hours. The solution was again slowly added to a suspension solution of ZrCl ₄ (THF) ₂ (170 g, 4.50 mmol)/THF (30 mL) at -78 ^o C, and the resulting lithium salt solution was further reacted at room temperature for 6 hours. made it All volatiles were removed by vacuum drying, and hexane was added to the obtained oily liquid material and filtered. After vacuum drying the filter solution, hexane was added to induce a precipitate at low temperature (-20 ^o C). The obtained precipitate was filtered at low temperature to obtain [tert-butyl-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 ): δ 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 (300 MHz, CDCl ₃ , ppm): δ 135.09, 116.66, 112.28, 72.42, 61.52, 30.66, 30.31, 30.14, 29.18, 27.58, 26.00.

<Preparation of the second metallocene compound>

Synthesis Example 2

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

10 g (101.9 mmol) of 2-methylthiophene was quantified in a Schlenk flask, and then 100 mL of THF was added and dissolved. At -78 ^o C, n-BuLi (1.05 eq, 4.3 mL) was added dropwise, followed by reaction at RT overnight. After quantifying CuCN (0.5eq, 4.6g) in another Schlenk flask, 30 mL of THF was added, and the reaction solution was transferred after lowering to -78 ^o C. After 2 hours of reaction at RT, tigloyl chloride (1 eq, 11.2 mL) was added dropwise at -78 ^o C. After overnight reaction at RT, after work up with Na ₂ CO ₃ aqueous solution and EA, the organic layer was concentrated and a brown liquid product, 15.35 g, was obtained in a yield of 83.6%.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): δ 7.37 (s, 1H), 6.52 (s, 1H), 6.52 (d, 1H), 2.52 (s, 3H), 1.93 (s, 3H), 1.87 (d, 3H)

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

After quantifying 15.35 g (85.2 mmol) of (E)-2-methyl-1-(5-methylthiophen-2-yl)but-2-en-1-one obtained above in a 1L round-bottom flask (one neck) 15 mL of chlorobenzene was added and stirred. After pouring 100 mL of sulfuric acid, the reaction was carried out at RT overnight. After adding 800 mL of deionized water (DIW), stirring, it was transferred to a separate pannel and extracted with ethyl acetate (EA). After washing the organic layer with an aqueous solution of Na ₂ CO ₃ , the organic layer was concentrated to obtain an oil product, 10.38 g of an orange color in a yield of 67.6%.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): δ 6.74 (s, 2H), 3.38-3.36 (m, 1H), 3.04-3.01 (m, 1H), 2.83-2.81 (m, 1H), 2.45 -2.44 (m, 1H), 1.35 (d, 3H), 1.31 (d, 3H), 1.21-1.19 (m, 6H)

(3) Synthesis of 2,4,5-trimethyl-5,6-dihydro-4H-cyclopenta[b]thiophened

After quantifying 2.5 g (15.2 mmol) of 2,4,5-trimethyl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one obtained above in a vial, 20 mL of THF and 7 mL of MeOH were added and dissolved. The vial was immersed in ice water at 0 ^o C, and while stirring, NaBH4 (1.5eq, 863 mg) was added little by little to the spatula. After the overnight reaction at RT, DIW was added, the organic layer was separated and concentrated, and 50 mL of THF and DIW were mixed 1:1, and 10 mL of 3N HCl was added to dissolve the mixture, followed by heating at 80 ^o C for 3 hours. Hexane and DIW were added, the organic layer was separated, neutralized with Na ₂ CO ₃ aqueous solution, and the organic layer was concentrated to obtain a red liquid product, 1.89 g, in 82.8% yield.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): δ 6.67 (s, 1H), 6.30 (s, 1H), 3.05-3.03 (m, 1H), 2.50 (s, 3H), 2.03 (s, 3H) ), 2.02 (d, 3H)

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

In a Schlenk flask, quantify 1.89 g (11.5 mmol) of 2,4,5-trimethyl-5,6-dihydro-4H-cyclopenta[b]thiophened obtained above, add 57 mL of THF to dissolve, and -78 ^o C n-BuLi (1.05eq, 4.8 mL) was added dropwise. After overnight reaction at RT, tether silane (1.05 eq, 3.3 g) was quantified in another Schlenk flask, 30 mL of THF was added, and the temperature was lowered to 0 ^o C. After transfer to the reaction solution, overnight at RT. The solvent was dried by pressure distillation, filtered with hexane, concentrated, and 30 mL of t-BuNH ₂ was added, followed by reaction overnight at RT. After drying the solvent by distillation under reduced pressure, it was concentrated by filtering with hexane, and 5 g of a product with a brown crude blue-like shape was obtained in a yield of 99.3%.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): δ 6.61 (s, 2H), 3.31-3.28 (m, 4H), 2.51 (s, 6H), 2.09-2.01 (m, 12H), 1.49-1.27 (m, 20H), 1.20 (s, 6H), 1.19 (s, 18H), 1.16 (s, 18H)

(5) Synthesis of Silane bridged dimethyl titanium compound

1-(6-(tert-butoxy)hexyl)-N-(tert-butyl)-1-methyl-1-(2,4,5-trimethyl-6H-cyclopenta[b]thiophen-6-yl) obtained above After quantifying 2.48 g (5.7 mmol) of silanamine in a Schlenk flask, 30 mL of methyl tert-butyl ether (MTBE, methyl-t-butyl ether) was added and dissolved. At -78 ^o C, n-BuLi (2.05 eq, 4.7 mL) was added dropwise, followed by reaction at RT overnight. At -78 ^o C, MMB (2.5 eq, 4.7 mL) and TiCl ₄ (1eq, 5.7 mL) were added dropwise, followed by reaction overnight at RT. After vacuum drying, hexane was filtered, and DME (3 eq, 1.8 mL) was added dropwise. After overnight reaction at RT, the solvent was vacuum dried, filtered with hexane, and concentrated to obtain 2.35 g of a transition metal compound (Silane bridged dimethyl titanium compound) in a yield of 80.9%.

¹ H-NMR (500 MHz, CDCl ₃ , ppm): δ 6.39 (s, 2H), 3.30 (s, 6H), 2.19 (s, 6H), 1.91 (s, 6H), 1.63-1.59 (m, 4H) ), 1.55 (s, 18H), 1.49-1.22 (m, 16H), 1.14 (s, 18H), 0.70 (s, 6H), 0.30 (s, 6H), 0.02 (s, 3H)

Comparative Synthesis Example 2

At room temperature, 50 g of Mg(s) was put into a 10 L reactor, and 300 mL of THF was added thereto. After adding 0.5 g of I ₂ , the temperature of the reactor was maintained at 50 ^o C. After the reactor temperature was stabilized, 250 g of 6-t-butoxyhexyl chloride was added to the reactor at a rate of 5 mL/min using a feeding pump. As 6-t-butoxyhexyl chloride was added, it was observed that the reactor temperature increased by 4 to 5 ^o C. Subsequently, 6-t-butoxyhexyl chloride was added and stirred for 12 hours to obtain a black reaction solution. After taking 2 mL of the resulting black solution, water was added to obtain an organic layer, and it was confirmed that it was 6-t-butoxyhexane through ¹ H-NMR, from which it was confirmed that the Grignard reaction proceeded well. From this, 6-t-butoxyhexyl magnesium chloride was synthesized.

After 500 g of MeSiCl ₃ and 1 L of THF were added to the reactor, the temperature of the reactor was cooled to -20 ^o C. 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 Grignard reagent was fed, the reactor was stirred for 12 hours while slowly raising the temperature to room temperature, and it was confirmed that a white MgCl ₂ salt was produced. By adding 4 L of hexane, salt was removed through a labdori to obtain a filter solution. After adding the obtained filter solution to the reactor, hexane was removed at 70 ^o C to obtain a pale yellow liquid. It was confirmed that the obtained liquid was methyl (6-t-butoxyhexyl) dichlorosilane [methyl (6-t-butoxyhexyl) dichlorosilane] through ¹ H-NMR.

¹ H-NMR (300 MHz, CDCl ₃ , ppm): δ 3.3 (t, 2H), 1.5 (m, 3H), 1.3 (m, 5H), 1.2 (s, 9H), 1.1 (m, 2H), 0.7 (s, 3H)

After adding 1.2 mol (150 g) of tetramethylcyclopentadiene and 2.4 L of THF to the reactor, the temperature of the reactor was cooled to -20 ^o C. 480 mL of n-BuLi was added to the reactor at a rate of 5 mL/min using a feeding pump. After adding n-BuLi, the reactor was stirred for 12 hours while slowly raising the temperature to room temperature. Then, an equivalent of methyl(6-t-butoxyhexyl)dichlorosilane (326 g, 350 mL) was quickly added to the reactor. After stirring for 12 hours while slowly raising the temperature of the reactor to room temperature, the temperature of the reactor was cooled to 0 °C again, and 2 equivalents of t-BuNH ₂ was added thereto. The reactor was stirred for 12 hours while slowly raising the temperature to room temperature. Then, THF was removed and 4 L of hexane was added to obtain a filter solution from which salt was removed through Labdory. After the filter solution was added to the reactor again, hexane was removed at 70 ^o C to obtain a yellow solution. This was confirmed to be methyl(6-t-butoxyhexyl)(tetramethylCpH)t-butylaminosilane [methyl(6-t-butoxyhexyl)(tetramethylCpH)t-butylaminosilane] through ¹ H-NMR.

TiCl ₃ (THF) ₃ 10 mmol in the dilithium salt of the ligand at -78 ^o C synthesized from n-BuLi and the ligand dimethyl(tetramethylCpH)t-butylaminosilane [dimethyl(tetramethylCpH)t-butylaminosilane] was added quickly. The reaction solution was stirred for 12 hours while slowly raising the temperature from -78 ^o C to room temperature. Then, at room temperature, an equivalent of PbCl ₂ (10 mmol) was added and stirred for 12 hours to obtain a dark blue solution with blue color. After removing THF from the resulting reaction solution, hexane was added to filter the product. After removing hexane from the obtained filter solution, it was confirmed by ¹ H-NMR that it was [tBu-O-(CH ₂ ) ₆ ](CH ₃ )Si(C ₅ (CH ₃ ) ₄ )(tBu-N)TiCl ₂ ]. .

¹ H-NMR (300 MHz, CDCl ₃ , ppm): δ 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)

<Preparation of supported catalyst>

Example 1: Preparation of Hybrid Supported Metallocene Catalyst

First, silica (SYLOPOL 948 manufactured by Grace Davison) was dehydrated and dried under vacuum at a temperature of 650 ^o C for 15 hours to prepare a carrier.

Then, 10 g of silica dried at 40° C. was put into a glass reactor, and 100 mL of toluene was further added thereto, followed by stirring. 0.1 mmol of the first metallocene compound of Synthesis Example 1 was dissolved in toluene and added together to react for 2 hours. After the reaction was completed, 50 mL of 10 wt% methylaluminoxane (MAO)/toluene was added, the temperature was raised to 60 °C, and the reaction was conducted for 12 hours while stirring. After lowering the reactor temperature to 40 °C, stirring was stopped, settling was performed for 10 minutes, and then decantation was performed. Toluene was filled up to 100 mL of the reactor, and 0.1 mmol of the second metallocene compound of Synthesis Example 2 was dissolved in toluene and added, followed by further reaction for 2 hours.

After the reaction was completed, stirring was stopped, the toluene layer was separated and removed, and then the toluene was removed under reduced pressure at 50° C. to prepare a supported catalyst.

Example 2: Preparation of Hybrid Supported Metallocene Catalyst

Hybrid supported metal using the same method as in Example 1, except that 0.05 mmol of the metallocene compound prepared in Synthesis Example 1 was added and 0.1 mmol of the metallocene compound prepared in Synthesis Example 2 was added. A Rosene catalyst was prepared.

Example 3: Preparation of Hybrid Supported Metallocene Catalyst

Hybrid supported metal using the same method as in Example 1, except that 0.1 mmol of the metallocene compound prepared in Synthesis Example 1 was added and 0.05 mmol of the metallocene compound prepared in Synthesis Example 2 was added. A Rosene catalyst was prepared.

Comparative Example 1: Preparation of Ziegler-Natta catalyst (Z/N catalyst)

To prepare the Ziegler-Natta catalyst, 500 kg of magnesium ethylate was dispersed in sufficient hexane, and then 1700 kg of titanium tetrachloride was slowly added dropwise at 85° C. over 5.5 hours, followed by tempering at 120° C. After that, the unreacted by-products including the titanium compound are removed until the titanium concentration of the entire solution becomes 500 mmol, and then pre-activated by contacting with triethylaluminum at 120° C. for 2 hours, and the final catalyst is obtained by removing the unreacted by-products. got it

Comparative Example 2: Preparation of Hybrid Supported Metallocene Catalyst

Except that 0.05 mmol of the metallocene compound prepared in Synthesis Example 1 was added, and 0.1 mmol of the metallocene compound prepared in Comparative Synthesis Example 2 was added instead of the metallocene compound prepared in Synthesis Example 2 , a hybrid supported metallocene catalyst was prepared using the same method as in Example 1.

Comparative Example 3: Preparation of Hybrid Supported Metallocene Catalyst

Except that 0.05 mmol of the metallocene compound prepared in Comparative Synthesis Example 1 was added instead of the metallocene compound prepared in Synthesis Example 1, and 0.1 mmol of the metallocene compound prepared in Synthesis Example 2 was added , a hybrid supported metallocene catalyst was prepared using the same method as in Example 1.

Comparative Example 4: Preparation of Hybrid Supported Metallocene Catalyst

0.05 mmol of the metallocene compound prepared in Comparative Synthesis Example 1 was added instead of the metallocene compound prepared in Synthesis Example 1, and prepared in Comparative Synthesis Example 2 instead of the metallocene compound prepared in Synthesis Example 2 A hybrid supported metallocene catalyst was prepared in the same manner as in Example 1, except that 0.1 mmol of the metallocene compound was added.

<Production of polyethylene>

Preparation Example 1: Preparation of polyethylene copolymer

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

At this time, the polymerization reactor was a continuous polymerization reactor that is an iso-butane (i-C4) slurry loop process, the reactor volume was 140 L, and the reaction flow rate was about 7 m/s. Gases (ethylene, hydrogen) and 1-hexene, which are comonomers, required for polymerization were constantly and continuously introduced, and the individual flow rates were adjusted to suit the target product. The concentrations of all gases and comonomer 1-hexene were confirmed by on-line gas chromatograph. The supported catalyst was introduced into the isobutane slurry, the reactor pressure was maintained at about 40 bar, and the polymerization reaction was performed at a polymerization temperature of about 90 ^o C for 1 hour.

Preparation Examples 2 to 3: Preparation of polyethylene copolymer

As shown in Table 1 below, in Preparation Example 1, in the same manner as in Example 1, ethylene-1- A hexene copolymer was prepared.

Comparative Preparation Example 1: Preparation of Polyethylene Copolymer

As shown in Table 1 below, in Preparation Example 1, the same method as in Example 1, except that the Ziegler-Natta catalyst of Comparative Example 1 (Z/N catalyst) was used instead of the hybrid supported catalyst of Example 1 to prepare an ethylene-1-hexene copolymer.

Comparative Preparation Examples 2 to 4: Preparation of polyethylene copolymer

As shown in Table 1 below, in Preparation Example 1, in the same manner as in Example 1, ethylene-1- A hexene copolymer was prepared.

first precursor second precursor Catalyst precursor molar ratio Example 1 Synthesis Example 1 Synthesis Example 2 1:1 Example 2 Synthesis Example 1 Synthesis Example 2 1:2 Example 3 Synthesis Example 1 Synthesis Example 2 2:1 Comparative Example 1 -
(Z/N catalyst) -
(Z/N catalyst) -
(Z/N catalyst) Comparative Example 2 Synthesis Example 1 Comparative Synthesis Example 2 1:2 Comparative Example 3 Comparative Synthesis Example 1 Synthesis Example 2 1:2 Comparative Example 4 Comparative Synthesis Example 1 Comparative Synthesis Example 2 1:2

In Table 1, the catalyst precursor molar ratio is expressed as the molar ratio of the first metallocene compound to the second metallocene compound.

<Test Example>

The catalyst activity and process stability of Examples and Comparative Examples and the physical properties of the polyethylene copolymers of Preparation Examples and Comparative Preparation Examples obtained using the same were measured by the following method, and the results are shown in Table 2 below.

1) Catalyst activity (Activity, kg PE/g·cat·hr)

It was calculated as the ratio of the weight (kg PE) of the polyethylene copolymer produced per content of the supported catalyst used (g·Cat) per unit time (h).

2) melt index (MI)

Melt index (MI _2.16 , g/10min) was measured under a load of 2.16 kg at 190 ^o C according to ASTM D 1238, the standard of the American Society for Testing and Materials, and expressed as the weight (g) of the polymer melted for 10 minutes.

3) Melt Flow Rate Ratio (MFRR)

Melt Flow Rate Ratio (MFRR, 5/2.16) was calculated by dividing MI ₅ by MI _2.16 , MI ₅ was measured under a temperature of 190 ^o C and a load of 5 kg according to ASTM D1238, and MI _2.16 was Measured according to ASTM D1238 at a temperature of 190 ^o C and a load of 2.16 kg.

4) BOCD Index

For the ethylene-1-hexene copolymers of Examples and Comparative Examples, the weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw/Mn), and short chain branching per 1000 carbon atoms ( SCB) was counted.

Specifically, when the molecular weight distribution curve is drawn with the log value (log M) of the weight average molecular weight (M) as the x-axis and the molecular weight distribution (dwt/dlog M) for the log value as the y-axis, compared to the total area The following mathematics by measuring the SCB (Short Chain Branch) content (branch content of 2 to 7 carbon atoms per 1,000 carbons, unit: ea/1,000C) at the left and right boundaries of 60% of the middle excluding 20% of the left and right ends Based on Equation 1, the BOCD Index was calculated.

[Equation 1]

If the BOCD index is 0 or less, it is not a BOCD-structured polymer, and if it is greater than 0, it can be considered a BOCD-structured polymer. The higher the value, the better the BOCD properties. Based on this, the case of a polymer having a BOCD structure is indicated by “O”, and a polymer not having a BOCD structure is indicated by an “X”.

5) Stress crack resistance (FNCT, hr)

As an evaluation of molded articles of olefin polymers, a stress cracking resistance test method is described in M. Fleissner in Kunststoffe 77 (1987), pp. 45 et seq.], and corresponds to ISO/FDIS 16770, which is still in effect. In ethylene glycol, a stress crack promoting medium using a tension of 3.5 Mpa at 80 °C, the failure time was shortened due to the shortening of the stress initiation time by the notch (1.6 mm/safety razor blade).

Specifically, for specimen preparation, 750 ppm of a primary antioxidant (Irganox 1010, CIBA), 1500 ppm of a secondary antioxidant (Irgafos 168, CIBA) and a processing aid (SC110) in the polyethylene copolymer of each Example and Comparative Example , Ca-St, Soybean Powder Emulsion Co., Ltd.) 1000 ppm was added and granulated at an extrusion temperature of 170 ~ 220 °C using a twin screw extruder (W&P Twin Screw Extruder, 75 pie, L/D = 36). Extrusion test of resin processability was performed under conditions of 190 ~ 220 ℃ (Temp. profile(℃): 190/200/210/220) using a Haake Single Screw Extruder (19 pie, L/D = 25). . In addition, pipe molding was performed using a single screw extruder (Battenfeld Pipe M/C, 50 pie, L/D=22, compression ratio=3.5) at an extrusion temperature of 220° C. to have an outer diameter of 32 mm and a thickness of 2.9 mm. .

Thereafter, the molded article was manufactured by sawing three specimens having dimensions of 10 mm in width, 10 mm in length, and 90 mm in length from a compressed name plate having a thickness of 10 mm. A central notch is provided on the specimen using a safety razor blade in a notch device specifically manufactured for this purpose. The notch depth is 1.6 mm.

catalyst Activity (kg PE/g·cat·hr) MI _2.16 (g/10min) MFRR BOCD Index FNCT
(hr) Preparation Example 1 Example 1 17 0.53 43 2.5 2100 Preparation 2 Example 1 21 0.54 50 3.0 2300 Preparation 3 Example 1 15 0.58 35 2.7 1500 Comparative Preparation Example 1 Comparative Example 1 14 0.58 35 1.0 800 Comparative Preparation Example 2 Comparative Example 2 15 0.54 45 1.3 1000 Comparative Preparation Example 3 Comparative Example 3 10 0.52 30 0.5 700 Comparative Preparation Example 4 Comparative Example 4 10 0.52 30 0.5 700

As shown in Table 2, it can be confirmed that the polyethylene copolymers of Examples 1 to 3 according to the present invention exhibit high activity using a supported catalyst using a combination of specific precursors. In addition, the polyethylene copolymers of Examples 1 to 3 have significantly superior MFRR, BOCD, and FNCT compared to Comparative Examples, thereby providing a polymer for pipes with improved processability and long-term physical properties.

Claims (20)

at least one first metallocene compound selected from compounds represented by the following formula (1);
at least one second metallocene compound selected from compounds represented by the following formula (2); and
a carrier supporting the first and second metallocene compounds;
A hybrid supported metallocene catalyst comprising:
[Formula 1]

In Formula 1,
M ¹ is a Group 4 transition metal;
R ^a are the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _6-20 aryl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or C _2-20 heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S, provided that at least one of R ^a above is C _1-20 alkyl;
R ^b is the same as or different from each other, and each independently hydrogen, C _1-20 alkyl, C _1-20 alkoxy, C _2-20 alkoxyalkyl, C _6-20 aryl, C _6-20 aryloxy, C _2-20 At least one selected from the group consisting of alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _8-40 arylalkenyl, C _2-20 alkynyl, or N, O and S C _2-20 heteroaryl comprising heteroatoms, provided that at least one of R ^b is C _2-20 alkoxyalkyl;
X ¹ and X ² are the same as or different from each other, and each independently halogen, C _1-20 alkyl, C _2-20 alkenyl, C _7-40 alkylaryl, C _7-40 arylalkyl, C _6-20 aryl, substituted or unsubstituted C _1-20 alkylidene, substituted or unsubstituted amino group, C _2-20 alkylalkoxy, or C _7-40 arylalkoxy;
n and m are each independently an integer from 1 to 4;
[Formula 2]

In Formula 2,
M ² is a Group 4 transition metal;
X ³ and X ⁴ are the same as or different from each other, and each independently a halogen, a nitro group, an amido group, a phosphine group, a phosphide group, a C _1-30 hydrocarbyl group, a C _1-30 hydrocarbyloxy group, C _2-30 hydrocarbyloxyhydrocarbyl group, -SiH ₃ , C _1-30 hydrocarbyl (oxy)silyl group, C _1-30 sulfonate group, or C _1-30 sulfone group;
Z is -O-, -S-, -NR ^c -, or -PR ^c -;
R ^c is hydrogen, a C _1-20 hydrocarbyl group, a C _1-20 hydrocarbyl (oxy)silyl group, and a C _1-20 silylhydrocarbyl group;
T is

or

ego,
T ¹ is C, Si, Ge, Sn or Pb,
Q ³ is hydrogen, C _1-30 hydrocarbyl group, C _1-30 hydrocarbyloxy group, C _2-30 hydrocarbyloxyhydrocarbyl group, -SiH ₃ , C _1-30 hydrocarbyl (oxy) A silyl group, a halogen-substituted C _1-30 hydrocarbyl group, and -NR ^d R ^e , any one of,
Q ⁴ is any one of a C _2-30 hydrocarbyloxy hydrocarbyl group,
R ^d and ^Re are each independently any one of hydrogen and a C _1-30 hydrocarbyl group, or are connected to each other to form an aliphatic or aromatic ring;
C ¹ is any one of the ligands represented by the following formula 2a or 2b,
[Formula 2a]

[Formula 2b]

In Formulas 2a and 2b,
Y is O or S;
R ¹ to R ⁴ are the same as or different from each other, and each independently represent any one of hydrogen, a C _1-30 hydrocarbyl group, or a C _1-30 hydrocarbyloxy group,
ㆍ indicates the site binding to T,
* indicates a site for binding with M ² .
The method of claim 1,
In Formula 1, M ¹ is zirconium (Zr) or hafnium (Hf); R ^a and R ^b are each hydrogen, C _1-6 alkyl, C _7-12 arylalkyl, C _2-12 alkoxyalkyl, C _6-12 aryl, or C _2-6 alkenyl, provided that at least R ^a is at least one is C _1-6 alkyl and at least one or more of R ^b is C _2-12 alkoxyalkyl; X ³ and X ⁴ are each halogen;
Hybrid supported metallocene catalysts.
According to claim 1,
The first metallocene compound is a compound represented by any one of the following structural formulas,
Hybrid supported metallocene catalysts:

.
The method of claim 1,
In Formula 2, Z is -NR ^c -, wherein R ^c is a C _1-10 hydrocarbyl group,
Hybrid supported metallocene catalysts.
The method of claim 1,
T is

ego,
T ¹ is carbon (C) or silicon (Si),
Q ³ is a C _1-30 hydrocarbyl group, or a C _1-30 hydrocarbyloxy group,
Q ⁴ is a C _2-30 hydrocarbyloxyhydrocarbyl group,
Hybrid supported metallocene catalysts.
The method of claim 1,
The second metallocene compound is any one of the compounds represented by the following Chemical Formulas 2-1 and 2-2,
Hybrid supported metallocene catalysts:
[Formula 2-1]

[Formula 2-2]

In Formulas 2-1 and 2-2,
M ² , X ³ , X ⁴ , R ^c , T ¹ , Q ³ , Q ⁴ , R ¹ , R ² , R ³ , and R ⁴ are as defined in claim 1 .
The method of claim 1,
R ¹ and R ² are each hydrogen or a C _1-10 hydrocarbyl group
R ³ and R ⁴ are each a C _1-10 hydrocarbyl group,
Hybrid supported metallocene catalysts.
The method of claim 1,
M ² is titanium (Ti), zirconium (Zr), or hafnium (Hf),
X ³ and X ⁴ are each a halogen, or a C _1-10 alkyl group,
Hybrid supported metallocene catalysts.
The method of claim 1,
The second metallocene compound is a compound represented by any one of the following structural formulas,
Hybrid supported metallocene catalysts:

.
According to claim 1,
The first metallocene compound and the second metallocene compound are supported in a molar ratio of 1:4 to 4:1,
Hybrid supported metallocene catalysts.
According to claim 1,
The carrier will contain a hydroxyl group and a siloxane group on the surface,
Hybrid supported metallocene catalysts.
12. The method of claim 11,
The carrier is at least one selected from the group consisting of silica, silica-alumina and silica-magnesia,
Hybrid supported metallocene catalysts.
According to claim 1,
Further comprising at least one cocatalyst selected from the group consisting of compounds represented by the following formulas 3 to 5,
Hybrid supported metallocene catalysts:
[Formula 3]
-[Al(R ³¹ )-O] _c -
In Formula 3,
R ³¹ is each independently halogen, C _1-20 alkyl or C _1-20 haloalkyl,
c is an integer greater than or equal to 2,
[Formula 4]
D(R ⁴¹ ) ₃
In Formula 4,
D is aluminum or boron,
R ⁴¹ is each independently hydrogen, halogen, C _1-20 hydrocarbyl or halogen-substituted C _1-20 hydrocarbyl;
[Formula 5]
[LH] ⁺ [Q(E) ₄ ] ^- or [L] ⁺ [Q(E) ₄ ] ^-
In Formula 5,
L is a neutral or cationic Lewis base,
[LH] ⁺ is a Bronsted acid,
Q is B ³⁺ or Al ³⁺ ,
each E is independently C _6-40 aryl or C _1-20 alkyl, wherein said C _6-40 aryl or C _1-20 alkyl is unsubstituted or halogen, C _1-20 alkyl, C _1-20 alkoxy; and C _6-40 aryloxy, substituted with one or more substituents selected from the group consisting of.
In the presence of the hybrid supported metallocene catalyst of claim 1, comprising the step of copolymerizing ethylene and alpha-olefin,
A method for producing a polyethylene copolymer.
15. The method of claim 14,
The alpha-olefin is 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1- At least one selected from the group consisting of octadecene, and 1-eicocene,
A method for producing a polyethylene copolymer.
A polyethylene copolymer obtained by the method of claim 14 .
17. The method of claim 16,
ethylene 1-hexene copolymer,
polyethylene copolymer.
17. The method of claim 16,
Melt index (ASTM D 1238, MI _2.16 , 190 ^o C, measured under a load of 2.16 kg) is 0.1 g/10 min to 1.0 g/10 min,
Melt flow rate ratio (MFRR, Melt flow rate ratio, MI ₅ /MI _2.16 ) is 30 to 70,
polyethylene copolymer.
17. The method of claim 16,
BOCD (Broad Orthogonal Comonomer Distribution) index of 1.5 or higher;
polyethylene copolymer.
A pipe comprising the polyethylene copolymer of claim 16 .