KR101454693B1 - Novel transition metal complexes and catalysts compositions for preparing elastomeric copolymers of ethylene and α-olefins - Google Patents

Abstract

The present invention relates to a process for producing a copolymer of ethylene and an? -Olefin, and more particularly to a process for producing a copolymer of ethylene and an? -Olefin having a density of 0.900 or less, which is applicable to films, flexible packaging materials, molding products, electric wires, impact resistant reinforcements, And a method for producing a copolymer of ethylene and an? -Olefin exhibiting elasticity at a density of 0.900 or less by using a catalyst composition containing a transition metal compound as a catalyst for producing a copolymer of? -Olefin. Characterized by including the location of an aryl oxide ligand is a heterocyclic aryl derivative substituted on at least one, and non-crosslinked between the ligand-Group 4 transition metal as a central metal, and a cyclopentadiene derivative and ortho (ortho) around And at least one selected from the group consisting of an aluminum compound and a boron compound as a cocatalyst is used as a catalyst system and has a narrow molecular weight distribution and a uniform density distribution and has a high activity and high activity in ethylene- and provides a polymerization method excellent in reactivity to? -olefins.

An elastic copolymer of ethylene and? -Olefin, a transition metal catalyst composition, a production method, a Group 4 transition metal catalyst, a single site catalyst, a cyclopentadiene, a heterocyclic aryl derivative substituted aryl oxide ligand

Description

TECHNICAL FIELD [0001] The present invention relates to a method for preparing an elastomeric copolymer of ethylene and an alpha -olefin,

The present invention relates to a method for producing elastic copolymers of ethylene and α- olefin using the transition metal catalyst composition, more specifically, around the Group 4 transition metal a cyclopentadiene derivative and ortho (ortho -) heterocyclic aryl where the A transition metal catalyst composition comprising a Group 4 transition metal compound and at least one cocatalyst selected from an aluminum compound and a boron compound, the transition metal catalyst composition comprising at least one derivative of the substituted aryl oxide ligand and being not cross- And a method for producing an elastic copolymer of ethylene and an? -Olefin.

Conventionally, the so-called Ziegler-Natta catalyst system composed of the main catalyst component of a titanium or vanadium compound and the cocatalyst component of an alkyl aluminum compound has been used for preparing ethylene and an alpha -olefin and a copolymer. However, although the Ziegler-Natta catalyst system exhibits high activity for ethylene homopolymerization, the copolymerization reactivity with the higher? -Olefin is not good due to the non-uniform catalytic activity point, and ethylene and? -Olefin having a density of 0.900 or less A large amount of? -Olefin comonomer should be used, and the catalyst activity is lowered under these conditions. In addition, the copolymer produced by using such a catalyst is very uneven in composition distribution and broad in molecular weight distribution, making it difficult to have suitable physical properties as an elastomer.

Recently, a so-called metallocene catalyst system comprising a metallocene compound of Group 4 transition metal such as titanium, zirconium, and hafnium and a promoter, methylaluminoxane, has been developed. Since the metallocene catalyst system is a homogeneous catalyst having a single catalytic active site, it is possible to produce a copolymer of ethylene and an -olefin having a narrow molecular weight distribution and uniform composition distribution as compared with the conventional Ziegler-Natta catalyst system Have. For example, European Patent Publication Nos. 320,762 and 3,726,325 or Nos. 63-092621, 02-84405, and 03-2347 disclose Cp ₂ TiCl ₂ , Cp ₂ ZrCl ₂ , Cp (Mw / Mn) of 1.5 (Mw / Mn) by copolymerizing ethylene and an? -Olefin with high activity by activating a metallocene compound with cocatalyst methylaluminoxane in a solvent such as N, N-dimethylformamide, ₂ ZrMeCl, Cp ₂ ZrMe ₂ , ethylene (IndH ₄ ) ₂ ZrCl _2, To 2.0. ≪ / RTI > However, when the catalyst system is applied to a solution polymerization method which is carried out at a high temperature of 80 ° C or higher, a large amount of high-quality α-olefin such as a Ziegler-Natta catalyst is produced in order to produce a carbon- -Olefin is used, and in this case, the? -Hydrogen elimination reaction is dominant, so that it is not suitable for producing a high molecular weight polymer having a weight average molecular weight (Mw) of 30,000 or more.

On the other hand, as a catalyst capable of producing a polymer having a high catalytic activity and a high molecular weight in the copolymerization of ethylene and an? -Olefin under solution polymerization conditions, a so-called geometrically constrained non-metallocene catalyst in which a transition metal is linked in a ring form is known . EP 0416815 and EP 0420436 disclose an example in which an amide group is linked in the form of a ring to one cyclopentadiene ligand. In EP 0842939, a phenol-based ligand as an electron donor compound is reacted with a cyclopentadiene ligand An example of a catalyst in the form of a ring is shown. However, in the case of this geometric constrained catalyst, the reactivity with the higher? -Olefin was remarkably improved due to the lowered steric hindrance effect of the catalyst itself. However, since the catalyst preparation step is complicated and the yield of the ring-forming reaction process between the ligand and the transition metal compound is very low, it is difficult to realize an economical production process suitable for producing a copolymer of ethylene and an -olefin having a density of 0.900 or less .

On the other hand, examples of non-metallocene catalysts that are not geometrically constrained include U.S. Patent No. 6,329,478 and Korean Laid-Open Patent Publication No. 2001-0074722. In this patent, it can be seen that a single-site catalyst using at least one phosphine-imine compound as a ligand exhibits a high ethylene conversion when ethylene and an -olefin copolymerization is carried out under high temperature solution polymerization conditions of 140 ° C or higher. However, as in the case of the metallocene catalyst, such a catalyst is not highly reactive with the higher? -Olefin, and is suitable for producing an elastic polymer of ethylene and higher? -Olefin, in particular, an ethylene polymer having a density of 0.900 or less and an advanced? I do not.

In order to overcome the problems of the prior art, the present inventors have conducted extensive studies and found that a non-crosslinked transition metal catalyst system including cyclopentadiene derivatives and aryloxide ligands substituted with heterocyclic aryl derivatives at the ortho- The present inventors have found that they are suitable for the production of an elastic copolymer of ethylene and an -olefin having a density of 0.900 or less and a narrow molecular weight distribution and a uniform density distribution.

Therefore, an object of the present invention is to provide a transition metal compound useful as a catalyst for the production of a copolymer of ethylene and an -olefin having a density of 0.900 or less, which can be applied to various applications such as films, flexible packaging materials, molded products, electric wire, impact resistant reinforcement, Olefin having a density of 0.900 or less, and a method for producing a copolymer of ethylene and an? -Olefin having a density of 0.900 or less by using a catalyst composition, And a polymerization method capable of economically producing a copolymer of ethylene and an? -Olefin having a narrow molecular weight distribution and composition distribution and a weight average molecular weight of 30,000 or more from a commercial point of view using such a catalyst component have.

One aspect of the present invention for achieving the above object relates to a cyclopentadiene derivative and ortho (ortho -) around the Group 4 transition metal, as shown in formula (1) where RE for interrogating a substituted aryl oxide ligand cyclic aryl derivative At least one C3-C18 alpha-olefin selected from the group consisting of ethylene and one or more C3-C18 alpha-olefins, in the presence of a transition metal catalyst comprising at least one transition metal catalyst and at least one cocatalyst selected from aluminum compounds and boron compounds, Olefin comonomer to prepare ethylene and an alpha -olefin copolymer having a density of 0.850 to 0.900 g / cc.

 [Chemical Formula 1]

 Wherein M is a transition metal of Group 4 on the periodic table;

Cp is a fused ring containing a cyclopentadienyl ring or cyclopentadienyl ring which may be bonded to the center metal M by 侶⁵ -binding, wherein the cyclopentadienyl ring or cyclopentadienyl fused ring is (C1-C20) (C6-C30) aryl group, (C2-C20) alkenyl group and (C6-C30) aryl (C1-C20) alkyl group;

또는

이고; R¹, R², R³, R⁴, R⁵, R⁶, R⁷ 및 R⁸ 은 서로 독립적으로 수소 원자, (C1-C20)알킬기, (C3-C20)시클 로알킬기, (C1-C20)알킬 치환 또는 (C6-C30)아릴 치환 실릴기, (C6-C30)아릴기, (C6-C30)아릴(C1-C10)알킬기, (C1-C20)알콕시기, (C1-C20)알킬 치환 또는 (C6-C20)아릴 치환 실록시기, (C1-C20)알킬 치환 또는 (C6-C30)아릴 치환 아미노기, (C1-C20) 알킬 치환 또는 (C6-C30)아릴 치환 포스핀기, (C1-C20)알킬 치환 머캡토기 또는 니트로기이며, 상기 R¹ 내지 R⁸ 의 알킬기, 아릴 또는 알콕시기는 할로겐으로 더 치환되거나 인접한 치환체와 함께 융합고리를 형성할 수 있으며; A is a substituent

or

ego; ^{R 1, R 2, R 3} , R 4, R 5, R 6, R 7 and R ⁸ are independently a hydrogen atom, (C1-C20) alkyl, (C3-C20) as a cyclohexane group, (C1-C20 each other ) Alkyl substituted or (C6-C30) aryl-substituted silyl group, (C6-C30) aryl group, (C6-C30) aryl (C1-C20) alkyl substituted or (C6-C60) aryl substituted silyl groups, (C1-C20) alkyl substituted or ) Alkyl substituted mercapto group or a nitro group, and the alkyl group, aryl or alkoxy group of R ¹ to R ⁸ may form a fused ring together with the substituent further substituted or adjacent to halogen;

D is NR < ⁹ >, an oxygen or sulfur atom; R ⁹ is a linear or non-linear (C1-C20) alkyl group, (C6-C30) aryl group, (C1-C20) alkyl substituted or (C6-C30) aryl substituted silyl group;

n is an integer of 1 or 2;

X is independently selected from the group consisting of a halogen atom, a (C1-C20) alkyl group, a (C3-C20) cycloalkyl group, a (C6- (C1-C20) alkyl substituted or (C6-C30) aryl substituted amino group, (C1-C20) alkyl substituted or (C6-C30) aryl substituted phosphine group and .

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

In the transition metal compound of Formula 1, M, which is the central metal, is preferably titanium, zirconium or hafnium. Further, Cp includes a cyclopentadiene anion or a cyclopentadienyl ring which can bond to the center metal η ⁵ -, and specific examples of the substituted or unsubstituted fused ring derivative include cyclopentadienyl, methylcyclopentadienyl, Dimethyl cyclopentadienyl, tetramethyl cyclopentadienyl, pentamethyl cyclopentadienyl, butyl cyclopentadienyl, sec -butyl cyclopentadienyl, tert -butylmethyl cyclopentadienyl, trimethylsilylcyclopentadienyl, Is selected from indenyl, methylindenyl, dimethylindenyl, ethylindenyl, isopropylindenyl, fluorenyl, methylflorenyl, dimethylflorenyl, ethylflorenyl or isopropylflorenyl.

또는

로서, 하기 화학식 2 또는 화학식 3의 화합물로서 표시된다.The transition metal compound of the present invention specifically includes a substituent of A

or

(2) or (3).

(2)

(3)

With respect to R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ on the heterocyclic aryl group substituted aryloxide ligands of the above Chemical Formulas 1 to ³ , examples of the halogen atom include fluorine , Chlorine, bromine or iodine atoms;

Linear or non-linear (C1-C20) for example, methyl, ethyl, n- propyl, isopropyl as the alkyl group, an n- butyl group, sec - butyl, tert - butyl group, n- pentyl group, neopentyl group, ah bran, n- hexyl, n- octyl group, n- decyl group, n- dodecyl group, n- penta-decyl or n- eicosyl group, and the one preferred is methyl, ethyl, isopropyl or tert - butyl ;

(C3-C20) cycloalkyl group is, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, or an adamantyl group, of which a cyclopentyl group or a cyclohexyl group ego;

Examples of the (C1-C20) alkyl-substituted or (C6-C30) aryl-substituted silyl group include methylsilyl, ethylsilyl, phenylsilyl, dimethylethylsilyl, diethylmethylsilyl, diphenylmethylsilyl, trimethyl silyl group, triethylsilyl group, tri -n- propyl silyl group, triisopropylsilyl group, tri -n--butylsilyl group, tri-sec-butylsilyl group, tri-tert-butylsilyl group, tri-iso-butyl silyl group, tert - butyldimethylsilyl group, tri -n- pentyl silyl group, tri -n- hexyl silyl group, a silyl group or a tricyclo-hexyl may be mentioned triphenyl silyl group, of which preferred is trimethylsilyl group, tert - A butyldimethylsilyl group or a triphenylsilyl group;

(C6-C30) aryl group or a (C1-C20) alkyl (C6-C30) aryl group is, for example, a phenyl group, a 2-tolyl group, a 3-tolyl group, a 4-tolyl group, Xylyl group, 2,5-xylyl group, 2,6-xylyl group, 3,4-xylyl group, 3,5-xylyl group, 2,3,4-trimethylphenyl group, 2 , 3,5-trimethylphenyl group, 2,3,6-trimethylphenyl group, 2,4,6-trimethylphenyl group, 3,4,5-trimethylphenyl group, 2,3,4,5-tetramethylphenyl group, 2,3 , 4, 6-tetra-methylphenyl, 2,3,5,6-tetra methylphenyl, penta-methylphenyl group, ethylphenyl group, n- propyl group, isopropyl group, n- butyl group, a sec - butyl group, a tert - butyl N-hexylphenyl, n-octylphenyl, n-decylphenyl, n-dodecylphenyl, n-tetradecylphenyl, biphenyl, fluorenyl, triphenyl, Naphthyl group or anthracenyl group, and among these, preferable are phenyl group, naphthyl group, biphenyl, 2-isopropylphenyl, 3,5-xylyl group It is 2,4,6, and;

Examples of the (C6-C30) aryl (C1-C10) alkyl group include a benzyl group, a (2-methylphenyl) methyl group, a (3- methylphenyl) methyl group, (2,4-dimethylphenyl) methyl group, (4,6-dimethylphenyl) methyl group, (2,5-dimethylphenyl) methyl group, Trimethylphenyl) methyl group, (2,3,5-trimethylphenyl) methyl group, (2,3,5-trimethylphenyl) methyl group, (2,3,4,5-tetramethylphenyl) methyl group, (2,3,4,6-tetramethylphenyl) methyl group, (Butylphenyl) methyl group, (tert-butylphenyl) methyl group, (tert-butylphenyl) methyl group, (N-decylphenyl) methyl group, (n-decylphenyl) methyl group, (n-pentylphenyl) ) Methyl group, (n- tetradecyl-phenyl) methyl, triphenylmethyl group, naphthyl can be mentioned a methyl group or an anthracenyl group, of which preferred is a benzyl group, a triphenylmethyl group, and;

(C1-C20) Examples of alkoxy groups include methoxy, ethoxy, n- propoxy, iso-propoxy, n- butoxy, sec - butoxy, tert - butoxy group, n- pentoxy group, neo-pentoxy group n-hexyl group, n-octyl group, n-dodecyl group, n-pentadecyl group or n-eicosyl group, among which methoxy, ethoxy, isopropoxy or tert- Butoxy group;

Examples of the (C1-C20) alkyl-substituted or (C6-C20) aryl-substituted silyl groups include trimethylsiloxy, triethylsilyl, tri-n-propylsilyl, triisopropylsilyl, tri- , tri-sec-butyl-siloxy group, tri -tert- butyl-siloxy group, tri-iso-butyl-siloxy group, tert-butyldimethylsiloxy group, tri -n- pentyl siloxy, tri -n- hexyl siloxy or tricyclohexylphosphine A silyl group, among which a trimethylsiloxy group or a tert -butyldimethylsiloxy group is preferable;

(C1-C20) alkyl substituted or (C6-C30) aryl dimethylamino group as examples of the substituted amino group, diethylamino group, di -n- propylamino group, diisopropyl amino group, a di -n- butyl group, a di - sec - butyl Amino group, di- tert -butylamino group, diisobutylamino group, tert - butylisopropylamino group, di-n-hexylamino group, di- Methylethylamino group, methylphenylamino group, benzylhexylamino group, bistrimethylsilylamino group or bis-tert-butyldimethylsilylamino group or the same alkyl-substituted phosphine group, and among these, dimethylamino group, diethylamino group or diphenylamino group is preferable;

Examples of the (C1-C20) alkyl-substituted or (C6-C30) aryl-substituted phosphine group include a dimethylphosphine group, diethylphosphine group, di- n -propylphosphine group, diisopropylphosphine group, di- , di - sec - butyl phosphine group, di - tert - butyl phosphine group, diisobutyl phosphine group, tert - butyl isopropyl phosphine group, di -n- hexyl phosphine group, di -n- octyl phosphine group, di -n -Decylphosphine group, diphenylphosphine group, dibenzylphosphine group, methylethylphosphine group, methylphenylphosphine group, benzylhexylphosphine group, bistrimethylsilylphosphine group or bis-tert-butyldimethylsilylphosphine group, Among these, preferred are a dimethylphosphine group, a diethylphosphine group or a diphenylphosphine group;

Examples of (C1-C20) alkyl-substituted mercapto groups are methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, 1-butyl mercaptan, isopentyl mercaptan, preferably ethyl mercaptan, Propyl mercaptan;

The alkyl, aryl or alkoxy group of R ¹ to R ⁸ may form a fused ring together with the substituents further substituted or adjacent to the halogen.

R ⁹ is a linear or a methyl group (C1-C20) alkyl groups of the non-linear group, ethyl group, n- propyl group, isopropyl group, n- butyl group, sec - butyl, tert - butyl group, n- pentyl group, neopentyl group N-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-pentadecyl group or n-eicosyl group, among which methyl group, ethyl group, isopropyl group , a tert -butyl group, or an amyl group;

Examples of the (C1-C20) alkyl-substituted or (C6-C30) aryl-substituted silyl group include methylsilyl, ethylsilyl, phenylsilyl, dimethylsilyl, diethylsilyl or diphenylsilyl, triethylsilyl group, tri -n- propyl silyl group, triisopropylsilyl group, tri -n--butylsilyl group, tri-sec-butylsilyl group, tri-tert-butylsilyl group, tri-iso-butylsilyl group, tert - butyldimethylsilyl group, tri -n- pentyl silyl group, tri -n- hexyl silyl group, a silyl group or a tricyclo-hexyl may be mentioned triphenyl silyl group, it is preferred in a trimethylsilyl group, tert - butyldimethylsilyl Or a triphenylsilyl group.

X is an example of a halogen atom, a fluorine, chlorine, bromine or iodine atom;

A methyl group as an example of the non-Cp derivatives (C1-20) alkyl group, ethyl group, n- propyl group, isopropyl group, n- butyl group, sec - butyl, tert - butyl group, n- pentyl group, neopentyl group, amyl, n- hexyl, n- octyl group, n- decyl group, n- dodecyl group, n- penta-decyl or n- eicosyl group, and the one preferred is methyl, ethyl, isopropyl, tert - butyl Or an amyl group;

(C3-C20) cycloalkyl group is, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group or an adamantyl group, and among these, a cyclopentyl group or a cyclohexyl group ; Examples of (C6-C30) aryl (C1-C20) alkyl groups include benzyl, (2-methylphenyl) methyl, (3- methylphenyl) methyl, (2,4-dimethylphenyl) methyl group, (4,6-dimethylphenyl) methyl group, (2,5-dimethylphenyl) methyl group, Trimethylphenyl) methyl group, (2,3,5-trimethylphenyl) methyl group, (2,3,5-trimethylphenyl) methyl group, (2,3,4,5-tetramethylphenyl) methyl group, (2,3,4,6-tetramethylphenyl) methyl group, (Butylphenyl) methyl group, (tert-butylphenyl) methyl group, (tert-butylphenyl) methyl group, (N-decylphenyl) methyl group, (n-decylphenyl) methyl group, (n-pentylphenyl) ) Methyl group, (n- tetradecyl phenyl) methyl group, can be mentioned a naphthyl group or an anthracenyl group, of which preferred is a benzyl group;

N-propoxy group, isopropoxy group, n-butoxy group, sec -butoxy group, tert -butoxy group, n-pentoxy group, neopentoxy group, n-propoxy group, - hexyl, n-octyl, n-dodecyl, n-pentadecyl or n-eicosyl. Of these, preferred are methoxy, ethoxy, isopropoxy or tert- ; (C3-C20) trimethyl siloxy group, siloxy triethyl, tri -n- propyl siloxy, triisopropyl siloxy, tri -n- butyl-siloxy group, the tree as an example of alkyl siloxy - sec - butyl-siloxy group, N-hexylsilyl group, tricyclohexylsilyl group, tricyclohexylsiloxy group, tri- tert -butylsiloxy group, tri-isobutylsiloxy group, tert -butyldimethylsiloxy group, Preferred is a trimethylsiloxy group, or a tert -butyldimethylsiloxy group;

Examples of the (C1-C20) alkyl-substituted or (C6-C30) aryl-substituted amino group or the (C1- An amino group, a diisopropylamino group, a di-n-butylamino group, a di- sec -butylamino group, a di- tert -butylamino group, a diisobutylamino group, a tert- butylisopropylamino group, A dibenzylamino group, a dibenzylamino group, a methylethylamino group, a methylphenylamino group, a benzylhexylamino group, a bistrimethylsilylamino group or a bis-tert-butyldimethylsilylamino group, or an alkyl-substituted phosphine group , And among these, preferred is a dimethylamino group, a diethylamino group or a diphenylamino group;

Examples of (C1-C20) alkyl substituted mercapto groups are methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, 1-butyl mercaptan or isopentyl mercaptan.

The transition metal compound of Formula 1 according to the present invention may be an active catalyst component used in olefin polymerization. Preferably, the transition metal compound of Formula 1 may be obtained by extracting X ligand in the transition metal compound according to the present invention, A boron compound or an aluminum compound capable of acting as an anion, or a mixture thereof, is used as a cocatalyst. The aluminum compound used herein is for removing a trace amount of polar substance acting as a catalyst poison such as water, but may act as an alkylating agent when the X ligand is halogen.

The boron compound which can be used as a promoter in the present invention can be selected from the compounds represented by the following formulas (4) to (6) as shown in U.S. Patent No. 5,198,401.

[Chemical Formula 4]

B (R ¹⁰ ) ₃

[Chemical Formula 5]

[R ¹¹ ] ⁺ [B (R ¹⁰ ) ₄ ] ^-

[Chemical Formula 6]

_{^{[(R 12) q ZH]}} + [B (R 10) 4] -

In the above Chemical Formulas 4 to 6, B is a boron atom; R ¹⁰ is a phenyl group and the phenyl group is substituted with a fluorine atom or a (C1-C20) alkyl group optionally substituted by a fluorine atom or a (C1-C20) alkoxy group optionally substituted by a fluorine atom, Lt; / RTI >substituents;

R ¹¹ is a (C5-C7) aromatic radical (C1-C20) alkyl (C6-C20) aryl radical or a (C6-C30) aryl (C1-C20) alkyl radical such as triphenylmethyl radical;

Z is a nitrogen or phosphorus atom;

R ¹² is a (C1-C20) alkyl radical or an anilinium radical substituted with two (C1-C10) alkyl groups together with the nitrogen atom; q is an integer of 2 or 3;

Preferable examples of the boron-based co-catalyst include tris (pentafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane, tris (2,3,4,5-tetrafluoro Phenyl) borane, tris (3,4,5-trifluorophenyl) borane, tris (2,3,4-trifluorophenyl) borane, phenylbis (pentafluorophenyl) (Pentafluorophenyl) borate, tetrakis (2,3,5,6-tetrafluorophenyl) borate, tetrakis (2,3,4,5-tetrafluorophenyl) borate, tetrakis (3,5-bistrifluoromethylphenyl) borate, tetrakis (2,2,4-trifluorophenyl) borate, phenylbis (pentafluorophenyl) borate or tetrakis . Specific examples of these compounds include ferrocenium tetrakis (pentafluorophenyl) borate, 1,1'-dimethylferrocenium tetrakis (pentafluorophenyl) borate, silver tetrakis (pentafluorophenyl) borate, tri (Pentafluorophenyl) borate, triphenylmethyltetrakis (3,5-bistrifluoromethylphenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis Tri (n-butyl) ammonium tetrakis (3,5-bistrifluoromethylphenyl) borate, N, N-dimethylanilinium (tetrabutylammonium) N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N, N-2,4,6-pentamethylanilinium tetrakis (pentafluorophenyl) borate, ) Borate, N, N-dimethylanilinium tetrakis (3,5-bistrifluoromethylphenyl) borate, diisopropylammonium tetrakis (pentafluorophenyl) borate, dicyclohexylammonium tetrakis ) Borate, triphenylphosphonium tetrakis (pentafluorophenyl) borate, tri (methylphenyl) phosphonium tetrakis (pentafluorophenyl) borate, or tri (dimethylphenyl) phosphonium tetrakis Among these, N, N-dimethylanilinium tetrakispentafluorophenylborate, triphenylmethylninium tetrakispentafluorophenylborate or trispentafluoroborane are most preferable.

The aluminum compound used in the present invention may be an aluminoxane compound represented by the following formula (7) or (8), an organoaluminum compound represented by the formula (9), or an organoaluminum hydrocarbyl oxide compound represented by the formula (10)

(7)

^{(-Al (R 13) -O-)} m

[Chemical Formula 8]

(R ¹³ ) ₂ Al - (- O (R ¹³ ) -) _p - (R ¹³ ) ₂

[Chemical Formula 9]

(R ¹⁴ ) _r Al (E) _3-r

[Chemical formula 10]

(R ¹⁵ ) ₂ AlOR ¹⁶

(11)

R ¹⁵ Al (OR ¹⁶⁾ ₂

In the general formulas (7) to (11), R ¹³ is a (C 1 -C 20) alkyl group, preferably a methyl group or an isobutyl group, m and p are integers between 5 and 20; R ¹⁴ and R ¹⁵ independently from each other are a (C1-C20) alkyl group; E is a hydrogen atom or a halogen atom; r is an integer from 1 to 3; R ¹⁶ may be selected from a (C 1 -C 20) alkyl group or a (C 6 -C 30) aryl group.

As specific examples of the aluminum compound,

The aluminoxane compound is methyl aluminoxane, modified methyl aluminoxane or tetraisobutyl aluminoxane;

Examples of the organoaluminum compound include trialkylaluminum including trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum or trihexylaluminum; Dialkyl aluminum chlorides including dimethyl aluminum chloride, diethyl aluminum chloride, dipropyl aluminum chloride, diisobutyl aluminum chloride or dihexyl aluminum chloride; Alkylaluminum dichlorides including methylaluminum dichloride, ethylaluminum dichloride, propylaluminum dichloride, isobutylaluminum dichloride or hexylaluminum dichloride; Dialkylaluminum hydride including dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride or dihexylaluminum hydride, and preferably trialkylaluminum hydride, More preferably triethyl aluminum or triisobutyl aluminum.

The molar ratio of the transition metal atom (M): boron atom: aluminum atom which is the central metal is preferably 1: 0.1 to 100: 10 to 1,000, more preferably 1: 0.5 to 5:25 to 500.

The process for preparing a copolymer of ethylene and an alpha -olefin having a density of 0.900 or less using the transition metal catalyst composition of the present invention comprises reacting the transition metal catalyst, the cocatalyst, and the ethylene and alpha -olefin comonomers in the presence of an appropriate organic solvent Contacted in solution. In addition, one or more continuous stirring or pipe type reactors may be used, and when two or more of them are used in series or in parallel, the copolymer having different molecular weights and densities depending on the reaction fractions may be physically and chemically To prepare a mixed copolymer.

Preferred organic solvents that may be used in the above process are C3-C20 hydrocarbons. Specific examples thereof include butane, isobutane, pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, cyclohexane, methylcyclohexane , Benzene, toluene or xylene, and in some cases, a mixture of two or more of the above organic solvents may be used.

As the comonomer, C3-C18 alpha -olefins can be used, and preferable examples thereof include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, Dodecene, 1-hexadecene, and 1-octadecene. More preferably, 1-butene, 1-hexene, 1-octene or 1-decene and ethylene can be copolymerized.

The polymerization reaction is carried out at a pressure and at a temperature such that the reactants inside the reactor can be in a solution state. In this case, the preferred polymerization reactor pressure is 10 to 200 atm, preferably 20 to 150 atm, and the polymerization reaction temperature is 60 to 250 deg. C, preferably 80 to 170 deg.

The copolymer prepared according to the process of the present invention usually contains 40 to 90% by weight of ethylene, preferably contains 50 to 85% by weight of ethylene, more preferably 55 to 80% by weight. The density range is in the range of 0.850 to 0.900 g / cc, preferably 0.855 to 0.899 g / cc, more preferably 0.860 to 0.890 g / cc.

Hydrogen may be used as a molecular weight modifier to control the molecular weight in the preparation of the copolymer, and has a weight average molecular weight (Mw) in the range of 30,000 to 500,000 and a molecular weight distribution in the range of 1.5 to 3.0.

Unlike copolymers prepared from existing Ziegler-Natta catalysts in which the branched ethylene-α-olefin copolymer has a low branching point due to α-olefin and a large number of branched branches in the low molecular weight portion, The α-olefin branch is uniformly distributed in the molecular weight portion, and there are few low-molecular-weight components containing a large amount of the α-olefin branch which can be extracted in hexane and the like, thereby providing important physical properties as an elastomer and greatly improving the hygiene of the final product . Therefore, the copolymer of ethylene and an -olefin thus prepared can be applied to a variety of applications such as an impact-resistant stiffener of a crystalline polymer, a film, a soft packaging material, a molding material, a wire coating, a hot melt adhesive and the like.

Since the catalyst composition presented in the present invention is present in a uniform form in a polymerization reactor, it is preferable to apply to a solution polymerization process carried out at a temperature above the melting point of the polymer. However, the transition metal catalyst and cocatalyst may be supported on a porous metal oxide support as disclosed in U.S. Patent No. 4,752,597, and may be used for slurry polymerization or gas-phase polymerization as a non-uniform catalyst composition.

The transition metal catalyst composition according to the present invention and the process for producing a copolymer of ethylene and an? -Olefin using the same have not only high catalytic activity but also a high copolymerization reactivity with higher? -Olefins and a high molecular weight polymer at a high yield The commercial utility is high in the production of a copolymer having a density of 0.850 to 0.900 g / cc as compared with the already known metallocene and nonmetalocene single point catalysts. In addition, since it is a non-crosslinked single active site catalyst, it is advantageous in economical efficiency of the process because the production step of the catalyst is simple, the production yield is high, and the amount of the α-olefin comonomer is small.

Therefore, the transition metal catalyst composition and the preparation method according to the present invention can be usefully used in the production of a copolymer of ethylene and an -olefin having various physical properties and elasticity.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the scope of the present invention is not limited by the following examples.

Except where otherwise noted, all ligand and catalyst preparation processes were carried out using standard Schlenk or glovebox techniques under a nitrogen atmosphere and the organic solvent used in the reaction was refluxed under sodium metal and benzophenone to remove water And used by distillation just before use. ¹ H-NMR analysis of the prepared ligand and catalyst was carried out using Varian Oxford 300 MHz at room temperature.

Cyclohexane, a polymerization solvent, was used after passing through a Q-5 catalyst (manufactured by BASF), a silica gel and a tube filled with activated alumina and bubbling with high purity nitrogen to sufficiently remove moisture, oxygen and other catalyst poison substances.

The polymerized polymer was analyzed by the method described below.

1. Melt Flow Index (MI)

It was measured according to ASTM D 2839.

2. Density

ASTM D 1505, using a mill tool piping.

3. Melting point (Tm) analysis

Using Dupont DSC2910 was measured at 2 ^nd heating condition at a rate of 10 ℃ / min in a nitrogen atmosphere.

4. Molecular weight and molecular weight distribution

PL Mixed-BX2 + preCol-loaded PL210 GPC at 135 ° C at a rate of 1.0 mL / min in a 1,2,3-trichlorobenzene solvent. The molecular weight was corrected using a PL polystyrene standard material.

5. Content of alpha -olefin in copolymer (% by weight)

Bruker DRX500 nuclear magnetic resonance spectroscopy and by use of benzene / C ₆ D ₆ (7/3 weight fraction) mixed solvent at 125MHz as 1,2,4-trichloroethane was measured at 120C by ¹³ C-NMR mode. (Reference: Randal, JC JMS - Rev . Macromol. Chem . Phys . 1980, C29 , 201)

[Preparation Example 1] Preparation of ( dichloro ) ( pentamethylcyclopentadienyl ) (2-thiophen-2'-yl) phenoxy ) titanium ( IV )

2- (2'- Methoxyphenyl ) Preparation of thiophene

(6.7 g, 43.9 mmol), palladium acetate (0.14 g, 0.62 mmol), triphenylphosphine (0.6 mg, 2.3 mmol), 2-methoxyphenylboronic acid ) And potassium phosphate (9.40 g, 44.3 mmol) are placed in a flask, 10 ml of water and 40 ml of dimethoxyethane mixed solution are added, and the mixture is refluxed for 6 hours. After cooling to room temperature, ammonium chloride aqueous solution (50 mL) and 100 mL of diethyl ether were added. The organic layer was separated, and the residue was extracted with diethyl ether. The combined organic layer was dried over magnesium sulfate, The residue was purified by hexane using a silica gel chromatograph tube to obtain 7.9 g (yield 95%) of 2- (2'-methoxyphenyl) thiophene as a colorless liquid.

¹ H-NMR (C ₆ D ₆ )? = 3.26 (s, 3H), 6.49-6.53 (d, 1H), 6.77-7.03 (m, 4H), 7.47-7.49 (d, 1H), 7.60-7.64 d, 1 H) ppm

Preparation of 2- (thiophen-2'-yl) phenol

The obtained 2- (2'-methoxyphenyl) thiophene (7 g, 36.8 mmol) was dissolved in 100 mL of methylene chloride, and then 40 mL of boron tribromide (1M-methylene chloride solution) was added dropwise at -78 ° C. The temperature was gradually raised to room temperature and reacted for 3 hours. After the reaction, a mixed solution of ice (50 g) and diethyl ether (100 mL) was added. The organic layer was separated, and the aqueous layer was extracted with diethyl ether. The combined organic layer was dried with magnesium sulfate and the volatiles were removed. The silica gel chromatography To obtain 2.9 g (yield 40%) of 2- (thiophen-2 ' -yl) phenol as a colorless liquid.

¹ H-NMR (C ₆ D ₆ )? = 6.54-6.58 (d, 1H), 6.59-6.95 (m, 4H), 7.12-7.15 (d, 1H), 7.36-7.41

( Dichloro ) ( Pentamethylcyclopentadienyl ) (2-thiophen-2'-yl) Phenoxy )titanium( IV )

2- (Thiophen-2'-yl) phenol (2.07 g, 11.76 mmol, Aldrich) was added to the dried flask and dissolved in diethyl ether. After stirring well, the temperature was lowered to 0 ° C. N-Butyl lithium (8.08 ml, 1.6 M in hexane, Aldrich) is slowly added dropwise to the mixture. When the dropwise addition is completed, the temperature is maintained for 1 hour and then the temperature is raised to room temperature and stirred for 12 hours. After removing the solvent layer, the precipitate is washed with hexane, the volatiles of the precipitate are removed, and dissolved in toluene. After the temperature of the mixture was lowered to 0 캜, pentamethylcyclopentadienyl titanium chloride (1.70 g, 5.88 mmol) was dissolved in toluene and slowly added dropwise. After completion of the dropwise addition, the mixture is maintained for 1 hour and then brought up to room temperature and stirred for 24 hours. After the reaction was completed, the solid component was filtered off, and the volatile substances were removed from the obtained solution. The volatile substances were again dissolved in toluene and recrystallized to obtain 1.64 g (yield: 65%) of orange crystals.

_{^{1 H-NMR (C 6 D}} 6) δ = 1.73 (s, 15H), 6.75-6.79 (d, 1H), 6.85-6.94 (m, 3H), 7.14-7.18 (d, 1H), 7.41-7.45 ( (d, 1H)), 7.57-7.59 (d, 1H) ppmMass (APCI mode, m / z): 429

[Preparation Example 2] Preparation of ( dichloro ) ( pentamethylcyclopentadienyl ) (2- (pyridin-2'-yl) phenoxy ) titanium ( IV )

2- (2'- Methoxyphenyl ) Preparation of pyridine

(6.7 g, 43.9 mmol), palladium acetate (0.14 g, 0.62 mmol) and triphenylphosphine (0.6 mg, 2.3 mmol) were added to a solution of 2-bromopyridine (4.28 ml, 43.9 mmol) And potassium phosphate (9.40 g, 44.3 mmol) were put in a flask, 10 ml of water and 40 ml of a mixed solution of dimethoxyethane were added, and the mixture was refluxed for 6 hours. After cooling to room temperature, ammonium chloride aqueous solution (50 mL) and 100 mL of diethyl ether were injected. The organic layer was separated, and the residue was extracted with diethyl ether. The combined organic layer was dried with magnesium sulfate, The residue was purified by normal hexane using a silica gel chromatography tube to obtain 7.7 g (yield 95%) of 2- (2'-methoxyphenyl) pyridine as a colorless liquid.

¹ H-NMR (C ₆ D ₆ )? = 3.22 (s, 3H), 6.55-8.67 (m, 8H) ppm

Preparation of 2- (pyridin-2'-yl) phenol

After 40 ml of pyridine was added to 40 ml of 35% hydrochloric acid, the mixture was stirred at 200 ° C for 30 minutes, and then water was distilled off at 220 ° C. Then, 2- (2'-methoxyphenyl) pyridine (6.8 g, 36.8 mmol) Lt; / RTI > The temperature was lowered to room temperature, distilled water was added, and the solution was titrated with aqueous sodium hydroxide solution. After the organic layer was extracted with methylene chloride, the organic layer was dried with magnesium sulfate, and the volatiles were removed. The residue was purified by silica gel chromatography using hexane and ethyl acetate to obtain 3.5 g of 2- (pyridin-2'- (Yield: 52%).

¹ H-NMR (C ₆ D ₆ )? = 6.30-7.72 (m, 7H), 8.43-8.67 (m, 2H) ppm

( Dichloro ) ( Pentamethylcyclopentadienyl ) (2- (Pyridin-2'-yl) Phenoxy )titanium( IV )

2- (Pyridin-2'-yl) phenol (2.64 g, 15.42 mmol, Aldrich) was added to the dried flask, dissolved in toluene, stirred well and cooled to 0 ° C. N-Butyl lithium (5.86 ml, 2.5 M in hexane Aldrich) is slowly added dropwise to the mixture. When the dropwise addition is completed, the temperature is maintained for 1 hour and then the temperature is raised to room temperature and stirred for 12 hours. After removing the solvent layer, wash the precipitate with purified hexane, remove the volatiles from the precipitate, and dissolve in toluene. After the temperature of the mixture was lowered to 0 占 폚, pentamethylcyclopentadienyl titanium chloride (2.23 g, 12.59 mmol) was dissolved in toluene and slowly added dropwise. After completion of the dropwise addition, the mixture is maintained for 1 hour and then brought up to room temperature and stirred for 24 hours. After the completion of the reaction, the solid component was filtered off, the volatile substances were removed from the obtained solution, and the residue was dissolved again in toluene and recrystallized to obtain 2.1 g (yield: 49%) of orange crystals.

¹ H-NMR (C ₆ D ₆ )? = 1.66 (s, 15H), 6.617.35 (m, 5H), 7.80

Mass (APCI < / RTI > mode, m / z): 424

Example  One

Copolymerization of ethylene and 1-octene was carried out using a batch polymerization apparatus as follows.

1140 mL of cyclohexane and 150 mL of 1-octene were added to a 2000-mL stainless steel reactor which had been thoroughly dried and then purged with nitrogen, and then modified methylaluminoxane-7 (Akzo Nobel, modified MAO-7, 7 wt% Al Isopar solution ), And 11.1 mL of toluene solution were charged into the reactor. Thereafter, the temperature of the reactor was heated up to 140 占 폚, and the solution of (dichloro) (pentamethylcyclopentadienyl) (2-thiophen-2'-yl) phenoxy) titanium (IV) (5 mM toluene solution ) And 0.6 mL of triphenylmethylnitium tetrakispentafluorophenylborate (99%, Boulder Scientific) 10 mM toluene solution were sequentially charged, and then the pressure in the reactor was filled up to 30 kg / cm ² with ethylene, To be polymerized. The maximum temperature reached 162.5 ° C within 1 minute after the start of the reaction. After 1 minute, 100 mL of ethanol containing 10 vol% hydrochloric acid aqueous solution was added to terminate the polymerization and the mixture was stirred with 1.5 L of ethanol for 1 hour. Respectively. The recovered reaction product was dried in a vacuum oven at 60 DEG C for 8 hours to obtain 37.5 g of a polymer. The polymer had a melt index of 10.5 and a density of 0.8835 g / cc. The analysis by gel chromatography showed a weight average molecular weight (Mw) of 48,000 g / mol and a molecular weight distribution (Mw / Mn) of 2.25, 25.1 wt%.

Example  2

Copolymerization of ethylene and 1-octene was carried out in the same manner as in Example 1 except that 230 mL of 1-octene was used.

The maximum temperature reached 164.5 ° C and finally 40.0 g of polymer was obtained. The polymer had a melt index of 14.2 and a density of 0.8710 g / cc, and had a weight average molecular weight (Mw) of 36,000 g / mol and a molecular weight distribution (Mw / Mn) of 2.20 when analyzed by gel chromatography. 31.3% by weight.

Example  3

Copolymerization of ethylene and 1-decene was carried out in the same manner as in Example 1 except that 150 mL of 1-decene instead of 1-octene was used.

The maximum temperature reached 165 ° C and finally 41.0 g of polymer was obtained. The polymer had a melt index of 12.0 and a density of 0.8897 g / cc. When analyzed by gel chromatography, the weight average molecular weight (Mw) was 42,000 g / mol and the molecular weight distribution (Mw / Mn) was 2.60.

Example  4

Copolymerization of ethylene and 1-octene was carried out in the same manner as in Example 1, except that the reaction temperature before the introduction of the catalyst was heated to 80 DEG C and 150 mL of 1-decene was added.

The polymer had a melt index of 8.5 and a density of 0.8840 g / cc. When analyzed by gel chromatography, the weight average molecular weight (Mw) was found to be 61,000 g / mol, The molecular weight distribution (Mw / Mn) was 2.30.

Example  5

The procedure of Example 1 was repeated, except that (dichloro) (pentamethylcyclopentadienyl) (2- (pyridin-2'-yl) phenoxy) titanium (IV) And 1-octene were carried out.

The polymer had a melt index of 12.5 and a density of 0.8795 g / cc. When analyzed by gel chromatography, the weight average molecular weight (Mw) was 41,000 g / mol, The molecular weight distribution (Mw / Mn) was 2.15 and the 1-octene content was 29.3% by weight.

Example  6

Copolymerization of ethylene and 1-octene was carried out in the same manner as in Example 5 except that 60 mL of 1-octene was used.

The polymer had a melt index of 11.0 and a density of 0.8998 g / cc. When analyzed by gel chromatography, the weight average molecular weight (Mw) was 43,000 g / mol, The molecular weight distribution (Mw / Mn) was 2.10, and the 1-octene content was 16.5% by weight.

Example  7

Copolymerization of ethylene and 1-octene was carried out in the same manner as in Example 5 except that 230 mL of 1-octene was used.

The maximum temperature reached 169 ° C and finally 48 g of polymer was obtained. The polymer had a melt index of 17.0 and a density of 0.8690 g / cc. When analyzed by gel chromatography, the weight average molecular weight (Mw) was 31,000 g / mol , A molecular weight distribution (Mw / Mn) of 2.25 and a 1-octene content of 33.5% by weight.

Example  8

Copolymerization of ethylene and 1-octene was carried out in the same manner as in Example 7 except that the reaction temperature before the introduction of the catalyst was heated to 80 캜.

The maximum temperature reached 148 ° C and finally 92 g of the polymer was obtained. The polymer had a melt index of 5.5 and a density of 0.8810 g / cc. When analyzed by gel chromatography, the weight average molecular weight (Mw) was 79,000 g / mol , A molecular weight distribution (Mw / Mn) of 2.05 and a 1-octene content of 26.3% by weight.

As can be seen from the above examples, the copolymer composition of ethylene and alpha -olefin having a high molecular weight of 30,000 or more and a narrow molecular weight distribution of 3 or less at a density of 0.900 g / cc or less through the catalyst composition and the production process through the present invention Can be successfully prepared under batch reaction conditions.

It is also possible to produce a copolymer of ethylene and an alpha -olefin having a density of 0.900 g / cc or less at a high yield while injecting a small amount of an alpha -olefin comonomer under high temperature solution polymerization conditions using the catalyst system of the present invention Show.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. And various modifications may be made to the invention. Therefore, modifications of the embodiments of the present invention will not depart from the scope of the present invention.

Claims (12)

Ethylene and a C3-C18 alpha -olefin comonomer are copolymerized with a catalyst composition comprising a transition metal catalyst of the formula (1) in a single reactor, or in a series or parallel, secondary continuous reactor, to produce an ethylene copolymer having a density of 0.860 to 0.890 g / cc And an alpha -olefin. [Chemical Formula 1]

[Wherein M is a transition metal of Group 4 in the periodic table; Cp is a fused ring containing a cyclopentadienyl ring or cyclopentadienyl ring which may be bonded to the center metal M by 侶⁵ -binding, wherein the cyclopentadienyl ring or cyclopentadienyl fused ring is (C1-C20) (C6-C30) aryl group, (C2-C20) alkenyl group or (C6-C30) aryl (C1-C20) alkyl group; A is a substituent

or

ego; ^{R 1, R 2, R 3} , R 4, R 5, R 6, R 7 and R ⁸ are independently from each other hydrogen atom, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C1-C20) Substituted or (C6-C30) aryl-substituted silyl group, (C6-C30) aryl group, (C6-C30) aryl (C1-C20) aryl-substituted silyl group, (C1-C20) alkyl-substituted or (C6- An alkyl substituted mercapto group or a nitro group, and the alkyl group, aryl or alkoxy group of R ¹ to R ⁸ may form a fused ring together with the substituent further substituted or adjacent to halogen; D is NR < ⁹ >, oxygen or sulfur; R ⁹ is a linear or non-linear (C1-C20) alkyl, (C6-C30) aryl, (C1-C20) alkyl-substituted silyl group, or a (C6-C30) aryl-substituted silyl group; n is an integer of 1 or 2; X is independently selected from the group consisting of a halogen atom, a (C1-C20) alkyl group, a (C3-C20) cycloalkyl group, a (C6- (C1-C20) alkyl substituted or (C6-C30) aryl substituted amino group, (C1-C20) alkyl substituted or (C6-C30) aryl substituted phosphine group and . ≪ / RTI > The method according to claim 1, Wherein M of the transition metal catalyst of Formula 1 is Ti, Zr or Hf. The method according to claim 1, Wherein the catalyst composition comprises the transition metal catalyst of Formula 1; Cocatalysts of aluminoxane compounds or organoaluminum compounds; And a cocatalyst of a boron compound. The method of producing a copolymer of ethylene and an? -Olefin. The method of claim 3, Wherein the ratio of the transition metal catalyst of Formula 1 to the cocatalyst is 1: 0.5 to 50: 1 to 1,000, based on the molar ratio of transition metal atom (M): boron atom: aluminum atom. ≪ / RTI > The method of claim 3, Wherein the cocatalyst of the boron compound is one or a mixture selected from N, N-dimethyl anilinium tetrakispentafluorophenyl borate and triphenylmethylninium tetrakispentafluorophenyl borate. ≪ / RTI > The method according to claim 1, The? -Olefin comonomer is at least one selected from propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, Wherein the copolymer is a copolymer of ethylene and an? -Olefin. The method according to claim 1, Wherein the content of the? -Olefin comonomer in the copolymer is 10% by weight to 60% by weight. delete delete The method according to claim 1, Wherein the copolymer has a weight average molecular weight of 30,000 to 500,000 and a molecular weight distribution (Mw / Mn) of 1.5 to 3.0. The method according to claim 1, Wherein the pressure in the reactor for preparing the copolymer is from 10 to 150 atm and the polymerization temperature is from 80 to 250 ° C. A copolymer of ethylene and an? -Olefin prepared by the process of any one of claims 1 to 7, 10 and 11.