Ethylene alpha-olefin copolymer and preparation method thereof

Abstract

According to one embodiment of the present invention, there is provided an ethylene-alpha-olefin copolymer comprising an ethylene structural unit and an alpha-olefin structural unit, in which two or more sections in which the tangent slope changes appear in a stress-strain curve measured by ASTM D638, and in which two or more sections in which the tangent slope changes appear in the stress-strain curve measured by ASTM D638. The section in which the slope of the tangent line changes comprises a first section in which the slope of the tangent line decreases; and a second interval in which the tangent slope rises. According to one embodiment of the present invention, there can be provided an ethylene alpha-olefin copolymer having excellent tensile elongation, impact strength, and bending strength by structural characteristics, and excellent processability, and a method for preparing the same.

Description

Technical Field

[0001] The present invention relates to an ethylene-α-olefin copolymer and a method for preparing the same. Background Art

[0002] With the expansion of the new renewable energy market, the solar energy market is also growing rapidly, and olefin materials are widely used as encapsulation materials for solar panels. Generally, the encapsulation material can be made of the same material or formed from two or more different materials. Currently, the most commonly used material in the encapsulation material is an ethylene-vinyl acetate (EVA)-based material, which is used to attach a photovoltaic cell or an array of photovoltaic cells to a strong dielectric and encapsulate them. However, the adhesion of the EVA-based material to glass and other components of the module is poor, so that the long-term use of the photovoltaic cell module easily leads to delamination between the layers of the module, and then causes problems such as a decrease in module efficiency or corrosion caused by moisture penetration.

[0003] In addition, the hitherto known EVA-based encapsulation materials have poor tolerance to ultraviolet rays (UV), etc., and problems such as fading or discoloration will occur after long-term use, which also reduces the efficiency of the module. In addition, the EVA-based encapsulation material generates stress during curing, and there is a problem of damaging the module.

[0004] To solve such problems, the use of ethylene α-olefin copolymers has recently attracted much attention. The ethylene α-olefin copolymer material not only protects the cells that generate solar energy, but also imparts adhesion between the glass and the backsheet, thereby playing a role in protecting the cells from the effects of moisture and external shocks. In order to perfectly perform such a role, it is necessary to develop an ethylene α-olefin copolymer having excellent tensile elongation, impact strength, flexural strength, processability, etc. Summary of the Invention

[0005] An object of the present invention is to provide an ethylene α-olefin copolymer and a method for preparing the same, the ethylene α-olefin copolymer having excellent tensile elongation, impact strength, flexural strength, processability, etc.

[0006] Regarding the ethylene α-olefin copolymer of an embodiment of the present invention, in the stress-strain curve measured by ASTM D638, there are two or more intervals where the tangent slope changes, and the intervals where the tangent slope changes include: a first interval where the tangent slope decreases; and a second interval where the tangent slope increases.

[0007] The first interval may occur at a strain of 0% to 200%, and the second interval may occur at a strain of 500% to 1000%.

[0008] The ethylene α-olefin copolymer may have a yield point in the first range.

[0009] The elongation at break of the ethylene α-olefin copolymer may be 900% or more.

[0010] The diffusion gradient value of the ethylene α-olefin copolymer may be 1 to 5 (×10 6 Pa / m).

[0011] According to one embodiment of the present invention, an ethylene α-olefin copolymer and a method for preparing the same may be provided. The ethylene α-olefin copolymer has excellent tensile elongation, impact strength, and flexural strength due to its structural characteristics, and has excellent processability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a graph showing the analysis result chart of the stress-strain curve of an existing ethylene α-olefin copolymer (comparative example).

[0013] Figure 2 It is a graph showing the analysis result chart of the stress-strain curve of the ethylene α-olefin copolymer of an embodiment of the present invention. DETAILED DESCRIPTION

[0014] Hereinafter, with reference to Figures 1 to 2 Preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be deformed into various different forms, and the scope of the present invention is not limited to the embodiments described below.

[0015] Figure 1 It is a graph showing the analysis result chart of the stress-strain curve of an existing ethylene α-olefin copolymer (comparative example).

[0016] Figure 2 It is a graph showing the analysis result chart of the stress-strain curve of the ethylene α-olefin copolymer of an embodiment of the present invention.

[0017] The term "alkyl" as used in the present invention refers to a monovalent straight-chain or branched-chain saturated hydrocarbon radical composed of only carbon and hydrogen atoms. Examples of such alkyl radicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc., but are not limited thereto.

[0018] In addition, the term "alkenyl" as described in the present invention refers to a straight-chain or branched-chain hydrocarbon radical containing more than one carbon-carbon double bond, including vinyl, propenyl, butenyl, pentenyl, etc., but not limited thereto.

[0019] In addition, the term "alkynyl" as described in the present invention refers to a straight-chain or branched-chain hydrocarbon radical containing more than one carbon-carbon triple bond, including methynyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, etc., but not limited thereto.

[0020] In addition, the term "aryl" as described in the present invention refers to an organic radical derived from an aromatic hydrocarbon by removing one hydrogen atom, including monocyclic or fused-ring systems. Specific examples include phenyl, naphthyl, biphenyl, anthryl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, perylenyl, -yl, tetraphenylenyl, fluoranthenyl, etc., but not limited thereto.

[0021] In addition, the term "alkylaryl" as described in the present invention refers to an organic group in which one or more hydrogens in the aryl are substituted by alkyls, including methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, tert-butylphenyl, etc., but not limited thereto.

[0022] In addition, the term "arylalkyl" as described in the present invention refers to an organic group in which one or more hydrogens in the alkyl are substituted by aryls, including phenylpropyl, phenylhexyl, etc., but not limited thereto.

[0023] In addition, the term "amido" as described in the present invention refers to an amino group (-NH2) bonded to a carbonyl group (C=O), "alkylamido" refers to an organic group in which at least one hydrogen in the -NH2 of the amido is substituted by an alkyl, and "arylamido" refers to an organic group in which at least one hydrogen in the -NH2 of the amido is substituted by an aryl. The alkyl in the alkylamido and the aryl in the arylamido may be the same as the examples of the above alkyl and aryl, but not limited thereto.

[0024] In addition, the term "alkylene" as described in the present invention refers to a divalent aliphatic hydrocarbon group obtained by removing two hydrogen atoms from the same carbon atom of an alkyl, including ethylene, propylene, isopropylene, butylene, pentylene, etc., but not limited thereto.

[0025] In addition, the term "acetal" described in the present invention refers to an organic group formed by the combination of an alcohol and an aldehyde, that is, a substituent with two ether (-OR) bonds on one carbon, including methoxymethoxy, 1-methoxyethoxy, 1-methoxypropoxy, 1-methoxybutoxy, 1-ethoxyethoxy, 1-ethoxypropoxy, 1-ethoxybutoxy, 1-(n-butoxy)ethoxy, 1-(isobutoxy)ethoxy, 1-(sec-butoxy)ethoxy, 1-(tert-butoxy)ethoxy, 1-(cyclohexyloxy)ethoxy, 1-methoxy-1-methylmethoxy, 1-methoxy-1-methylethoxy, etc., but not limited thereto.

[0026] In addition, the term "ether" described in the present invention refers to an organic group containing at least one ether bond (-O-), including 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, 2-phenoxyethyl, 2-(2-methoxyethoxy)ethyl, 3-methoxypropyl, 3-butoxypropyl, 3-phenoxypropyl, 2-methoxy-1-methylethyl, 2-methoxy-2-methylethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, 2-phenoxyethyl, etc., but not limited thereto.

[0027] In addition, the term "silyl" described in the present invention refers to a -SiH3 radical derived from silane, and at least one of the hydrogen atoms in the silyl can be substituted by various organic groups such as alkyl, halogen, etc., specifically including trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, trimethoxysilyl, methyldimethoxysilyl, ethyldiethoxysilyl, triethoxysilyl, vinyldimethoxysilyl, triphenoxysilyl, etc., but not limited thereto.

[0028] In addition, the term "alkoxy" described in the present invention refers to an -O-alkyl radical, where "alkyl" is defined as above. Examples of such alkoxy radicals include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, etc., but not limited thereto.

[0029] In addition, the term "halogen" described in the present invention refers to a fluorine, chlorine, bromine, or iodine atom.

[0030] In addition, the term "C n " in the present invention means that the number of carbon atoms is n.

[0031] Next, the catalyst for polymerizing ethylene α-olefin copolymer and the preparation method of ethylene α-olefin copolymer will be described.

[0032] <Catalyst for Polymerization of Ethylene α-Olefin Copolymer and Preparation Method of Ethylene α-Olefin Copolymer>

[0033] The ethylene α-olefin copolymer provided in the present invention can be polymerized under a composition including a catalyst for polymerization of an ethylene α-olefin copolymer described below. Specifically, the catalyst for polymerization of an ethylene α-olefin copolymer may include: a main catalyst compound, which is a transition metal compound having a symmetric structure represented by the following Chemical Formula 1; and a cocatalyst compound, which is one or more compounds selected from the compounds represented by the following Chemical Formula 2 or 3.

[0034] [Chemical Formula 1]

[0035]

[0036] In the above Chemical Formula 1,

[0037] M is a Group 4 transition metal,

[0038] Q 1 and Q 2 are each independently a halogen, (C1-C 20 ) alkyl, (C2-C 20 ) alkenyl, (C2-C 20 ) alkynyl, (C6-C 20 ) aryl, (C1-C 20 ) alkyl(C6-C 20 ) aryl, (C6-C 20 ) aryl(C1-C 20 ) alkyl, (C1-C 20 ) alkylamido, (C6-C 20 ) arylamido or (C1-C 20 ) alkylene,

[0039] R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 and R 10 are each independently hydrogen; (C1-C 20 ) alkyl including or not including an acetal, ketal or ether group; (C2-C 20 ) alkenyl including or not including an acetal, ketal or ether group; (C1-C 20 ) alkyl(C6-C 20 ) aryl including or not including an acetal, ketal or ether group; (C6-C20 ) an aryl (C1-C 20 ) alkyl; or an (C1-C 20 ) alkylsilyl with or without an acetal, ketal or ether group, wherein the R 1 and R 2 may be connected to each other to form a ring, and the R 3 and R 4 may be connected to each other to form a ring, and the R 5 to R 10 among more than two of them may be connected to each other to form a ring,

[0040] R 11 , R 12 and R 13 are each independently hydrogen; an (C1-C 20 ) alkyl with or without an acetal, ketal or ether group; an (C2-C 20 ) alkenyl with or without an acetal, ketal or ether group; an (C1-C 20 ) alkyl (C6-C 20 ) aryl; an (C6-C 20 ) aryl (C1-C 20 ) alkyl with or without an acetal, ketal or ether group; an (C1-C 20 ) alkylsilyl with or without an acetal, ketal or ether group; an (C1-C 20 ) alkoxy; or an (C6-C 20 ) aryloxy, and the R 11 and R 12 or R 12 and R 13 may be connected to each other to form a ring.

[0041] [Chemical Formula 2]

[0042] [L-H] + [Z(A)4] -

[0043] [Chemical Formula 3]

[0044] [L] + [Z(A)4] -

[0045] In the above Chemical Formula 2 and Chemical Formula 3, L is a neutral or cationic Lewis acid, Z is a Group 13 element, and A is a (C6-C 20 ) aryl or a (C1-C 20 ) alkyl, and the (C6-C 20 ) aryl or (C1-C 20 ) alkyl may be substituted with a halogen, an (C1-C20 ) a hydrocarbyl group, (C1-C 20 ) an alkoxy group or (C6-C 20 ) an aryloxy group, which may be substituted or unsubstituted.

[0046] The main catalyst compound represented by the above Chemical Formula 2 or Chemical Formula 3 has strong electrophilicity, thereby rapidly dissociating Q bonded to the central metal M in the main catalyst compound represented by the above Chemical Formula 1 1 and / or Q 2 . At this time, the faster the dissociation of the said Q 1 and / or Q 2 , the higher the polymerization activity, the longer the stabilization time of the central metal M, and the longer the coordination time of M in the stabilized state with the double bond included in ethylene and α-olefin, thereby a high molecular weight ethylene-α-olefin copolymer can be obtained.

[0047] The transition metal compound represented by the above Chemical Formula 1 includes a ligand with a novel structure, in which an amide ligand forms a fused ring with an o-phenylene group, and a five-membered ring π-ligand bonded to the o-phenylene group is fused through a thiophene heterocycle. Thus, compared with a transition metal compound not fused with a thiophene heterocycle, the transition metal compound has the advantage of high ethylene-α-olefin copolymerization activity.

[0048] According to the present invention, in the compound represented by the above Chemical Formula 1, the R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 and R 13 can each independently be substituted by a substituent including an acetal, a ketal or an ether group, and if substituted by the above-mentioned substituent, it may be more favorable for loading onto the surface of the carrier.

[0049] In addition, in the compound represented by the above Chemical Formula 1, the M is preferably titanium (Ti), zirconium (Zr) or hafnium (Hf).

[0050] In addition, in the transition metal compound represented by the above Chemical Formula 1, it is preferred that the Q 1 and Q 2 can each independently be a halogen or a (C1-C 20 ) alkyl group, and more preferably can be chlorine or methyl.

[0051] In addition, in the transition metal compound represented by the above Chemical Formula 1, the R1 , R 2 , R 3 , R 4 and R 5 may each independently be hydrogen or (C1-C 20 ) alkyl, preferably each independently may be hydrogen or methyl. More preferably, said R 1 , R 2 , R 3 , R 4 and R 5 may each independently be hydrogen or methyl, provided that at least one of R 3 and R 4 is methyl, and R 5 may be methyl.

[0052] Furthermore, in the transition metal compound represented by the above Chemical Formula 1, preferably, said R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are each hydrogen.

[0053] The transition metal compound represented by the above Chemical Formula 1 includes the substituents as described above, which is conducive to controlling the electronic and steric environment around the metal.

[0054] On the other hand, the transition metal compound represented by the above Chemical Formula 1 can be obtained from a precursor compound represented by the following Chemical Formula 4.

[0055] [Chemical Formula 4]

[0056]

[0057] In the above Chemical Formula 4, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are each the same as defined in the above Chemical Formula 1.

[0058] Herein, the precursor compound represented by the above Chemical Formula 4 can be prepared by a method including the following steps: (i) reacting a tetrahydroquinoline derivative represented by the following Chemical Formula 5 with an alkyllithium and then adding carbon dioxide to prepare a compound represented by Chemical Formula 6; and (ii) reacting the compound represented by the above Chemical Formula 6 with an alkyllithium and then adding a compound represented by the following Chemical Formula 7 and performing an acid treatment.

[0059] [Chemical Formula 5]

[0060]

[0061] [Chemical Formula 6]

[0062]

[0063] [Chemical Formula 7]

[0064]

[0065] In the above Chemical Formula 5, Chemical Formula 6, and Chemical Formula 7, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 and R 13 are respectively the same as defined in the above Chemical Formula 1.

[0066] However, in the above Chemical Formula 5, Chemical Formula 6, and Chemical Formula 7, the R 1 , R 2 , R 3 , R 4 and R 5 can be respectively independently hydrogen or (C1-C 20 ) alkyl, preferably can be respectively independently hydrogen or methyl. More preferably, the R 1 , R 2 , R 3 , R 4 and R 5 can be respectively independently hydrogen or methyl, but at least one of R 3 and R 4 can be methyl, and R 5 can be methyl. In addition, preferably the R 6 , R 7 , R 8 , R 9 , R10 , R 11 , R 12 and R 13 are hydrogen, respectively. This can ensure the proximity and reactivity of the starting materials, and is conducive to controlling the electronic and steric environment of the transition metal compound of Formula 1 to be prepared.

[0067] The step (i) is a reaction of reacting the tetrahydroquinoline derivative represented by the above Formula 5 with an alkyllithium and then adding carbon dioxide to convert it into the compound represented by the above Formula 6, which can be carried out according to the methods described in known literature (Tetrahedron Lett. 1985, 26, 5935; Tetrahedron 1986, 42, 2571; J. Chem. SC. Perkin Trans. 1989, 16).

[0068] In addition, in the step (ii), the compound represented by the above Formula 6 can be reacted with an alkyllithium to initiate a deprotonation reaction to generate an ortho-lithium compound, and then the ortho-lithium compound is reacted with the compound represented by Formula 7 and subjected to acid treatment to obtain the transition metal compound precursor represented by the above Formula 4.

[0069] The reaction of reacting the compound represented by the above Formula 6 with an alkyllithium to generate an ortho-lithium compound can be understood from known literature (Organometallics 2007, 27, 6685; Korean Patent Publication No. 2008-0065868). In the present invention, by reacting the ortho-lithium compound with the compound represented by the above Formula 7 and subjecting it to acid treatment, the transition metal compound precursor represented by the above Formula 7 can be obtained.

[0070] Herein, the compound represented by the above Formula 7 can be prepared by a variety of known methods. The following Reaction Scheme 1 shows one of the methods, which can be prepared in only one step reaction, and uses inexpensive starting materials, and can simply and economically prepare the transition metal compound precursor of the present invention (J. Organomet. Chem., 2005, 690, 4213).

[0071] [Reaction Scheme 1]

[0072]

[0073] On the other hand, in order to synthesize the transition metal compound represented by the above Chemical Formula 1 from the precursor compound represented by the above Chemical Formula 4 obtained by the above method, a variety of known methods can be used. It can be prepared by the following method: adding about 2 equivalents of alkyllithium to the precursor compound represented by the above Chemical Formula 4 to initiate a deprotonation reaction to prepare a dilithium compound of cyclopentadienyl anion and amide anion, and then adding (Q 1 )(Q 2 )MCl2 thereto to remove about 2 equivalents of LiCl.

[0074] In addition, the compound represented by the above Chemical Formula 2 can be reacted with the M(NMe2)4 compound to remove about 2 equivalents of HNMe2 to obtain a transition metal compound represented by Chemical Formula 1 in which Q 1 and Q 2 are both NMe2 at the same time, and then the transition metal compound is reacted with Me3SiCl or Me2SiCl3 to convert the NMe2 ligand into a chloro ligand.

[0075] The catalyst of the present invention includes the transition metal compound represented by the above Chemical Formula 1 and a cocatalyst. The cocatalyst plays a role in activating the transition metal compound, and it is a compound represented by the above Chemical Formula 2 or 3, which can activate the main catalyst compound represented by the above Chemical Formula 1.

[0076] According to the present invention, in the cocatalyst compound represented by the above Chemical Formula 2, preferably [LH] + is a dimethylanilinium cation, and [Z(A)4] - is [B(C6F5)4] - . In addition, in the cocatalyst compound represented by the above Chemical Formula 3, preferably [L] + is [(C6H5)3C] + , and [Z(A)4] - is [B(C6F5)4] - .

[0077] Here, the cocatalyst compound represented by the above Chemical Formula 2 is not particularly limited, but its non-limiting examples are preferably one or more selected from the following substances: Trimethylammoniumtetrakis(pentafluorophenyl)borate, Triethylammonium tetrakis(pentafluorophenyl)borate, Tripropylammonium tetrakis(pentafluorophenyl)borate, Tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, Tri(sec-butyl)ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium n-butyltris(pentafluorophenyl)borate, N,N-dimethylanilinium benzyltris(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(4-(t-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl)borate, N,N-dimethylanilinium tetrakis(4-(triisopropysilyl)-2,3,5,6-tetrafluorophenyl)borate, N,N-dimethylanilinium pentafluorophenoxytri(pentafluorophenyl)borate, N,N-N-dimethylanilinium pentafluorophenoxytris(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethyl-2,4,6-trimethylanilinium tetrakis(pentafluorophenyl)borate, trimethylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, triethylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, tripropylammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, dimethyl(t-butyl)ammonium tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,N-dimethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,N-diethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl)borate, N,N-dimethyl-2,4,6-trimethylaniliniumtetrakis(2,3,4,6-tetrafluorophenyl)borate) and dialkylammonium.,

[0078] As a non-limiting example of the dialkylammonium, di-(i-propyl)ammonium tetrakis(pentafluorophenyl)borate or dicyclohexylammonium tetrakis(pentafluorophenyl)borate etc. can be cited.

[0079] In addition, the cocatalyst compound represented by the above Chemical Formula 3 is not particularly limited, but its non-limiting examples are preferably one or more selected from trialkylphosphonium, dialkyloxonium, dialkylsulfonium and carbonium salts.

[0080] As a non-limiting example of the trialkylphosphonium, Triphenylphosphonium tetrakis(pentafluorophenyl)borate, tri(o-tolylphosphonium tetrakis(pentafluorophenyl)borate or Tri(2,6-dimethylphenyl)phosphonium tetrakis(pentafluorophenyl)borate etc. can be cited.

[0081] As a non-limiting example of the dialkyloxonium, diphenyloxonium tetrakis(pentafluorophenyl)borate, di(o-tolyl)oxonium tetrakis(pentafluororphenyl)borate or di(2,6-dimethylphenyl oxonium tetrakis(pentafluorophenyl)borate etc. can be cited.

[0082] As non-limiting examples of the dialkylsulfonium, mention may be made of diphenylsulfonium tetrakis(pentafluorophenyl)borate, di(o-tolyl)sulfonium tetrakis(pentafluorophenyl)borate, bis(2,6-dimethylphenyl)sulfonium tetrakis(pentafluorophenyl)borate, and the like.

[0083] As non-limiting examples of the carbonium salt, mention may be made of tropylium tetrakis(pentafluorophenyl)borate, triphenylmethylcarbenium tetrakis(pentafluorophenyl)borate, benzene(diazonium)tetrakis(pentafluorophenyl)borate, and the like.

[0084] Such cocatalyst compounds may further include trialkylaluminums such as trimethylaluminum, triethylaluminum, tributylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum, and the like.

[0085] On the other hand, the addition amount of the cocatalyst compound can be determined according to the addition amount of the main catalyst compound and the amount required to sufficiently activate the cocatalyst compound, etc. According to the present invention, the cocatalyst compound may be included in a molar ratio of 1:1 to 100,000, preferably 1:1 to 10,000, more preferably 1:1 to 5,000, relative to the main catalyst compound. More specifically, relative to the transition metal compound as the main catalyst compound (for example, the main catalyst compound represented by the above Chemical Formula 1), the cocatalyst compound represented by the above Chemical Formula 2 or Chemical Formula 3 may be included in a molar ratio of 1:1 to 100, preferably 1:1 to 10, more preferably 1:1 to 4.

[0086] On the other hand, the catalyst of the present invention including the main catalyst compound and the cocatalyst compound may further include a carrier.

[0087] Herein, the carrier may be a carrier of an inorganic or organic material used for preparing a catalyst in the technical field to which the present invention pertains without limitation.

[0088] According to an embodiment of the present invention, the carrier may be SiO2, Al2O3, MgO, MgCl2, CaCl2, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, ThO2, SiO2 - Al2O3, SiO2 - MgO, SiO2 - TiO2, SiO2 - V2O5, SiO2 - Cr2O3, SiO2 - TiO2 - MgO, bauxite, zeolite, starch, cyclodextrine or a synthetic polymer.

[0089] Preferably, the carrier is a material having hydroxyl groups on its surface and may be one or more selected from silicon dioxide (SiO2), silica - alumina (SiO2 - Al2O3) and silica - magnesia (SiO2 - MgO).

[0090] As a method for loading the catalyst including the main catalyst compound and the cocatalyst compound onto the carrier, the following methods may be used: a method of directly loading the main catalyst compound onto a dehydrated carrier; a method of pretreating the carrier with the cocatalyst compound and then loading the main catalyst compound; a method of post - treating the main catalyst compound loaded onto the carrier with the cocatalyst compound; a method of reacting the main catalyst compound with the cocatalyst compound and then adding the carrier for reaction, etc.

[0091] The solvent usable in the loading method may be an aromatic hydrocarbon solvent, a halogenated aliphatic hydrocarbon solvent or a mixture thereof.

[0092] As non - limiting examples of the aliphatic hydrocarbon solvent, pentane, hexane, heptane, octane, nonane, decane, undecane or dodecane, etc. may be cited.

[0093] As non - limiting examples of the aromatic hydrocarbon solvent, benzene, monochlorobenzene, dichlorobenzene, trichlorobenzene or toluene, etc. may be cited.

[0094] As non-limiting examples of the halogenated aliphatic hydrocarbon solvents, dichloromethane, trichloromethane, dichloroethane, trichloroethane, etc. can be cited.

[0095] In addition, the loading method is carried out at a temperature of -70°C to 200°C, preferably at -50°C to 150°C, more preferably at 0°C to 100°C, which is beneficial to the efficiency of the loading process.

[0096] The ethylene α-olefin copolymer of the present invention is prepared by copolymerizing ethylene with an α-olefin, and the α-olefin can be C3-C 12 or an aliphatic olefin of C3-C8. More specifically, the α-olefin can be propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, 4,4-dimethyl-1-pentene, 4,4-diethyl-1-hexene, 3,4-dimethyl-1-hexene, etc., and any one or a mixture of two or more of them can be used.

[0097] There is no particular limitation on the ratio of ethylene to α-olefin added to the reactor during polymerization, but preferably ethylene and α-olefin are added in a weight ratio of 1:0.5 to 1:1.3. By adding ethylene and α-olefin in the said weight ratio, an olefin copolymer with high molecular weight and high comonomer content can be obtained.

[0098] On the other hand, the polymerization reaction of ethylene and α-olefin of the present invention can be carried out in a slurry phase, solution phase, gas phase or bulk phase.

[0099] When the polymerization reaction is carried out in a liquid phase or slurry phase, a solvent or ethylene and the α-olefin monomer itself can be used as the medium.

[0100] The solvent available in the polymerization reaction can be a fatty hydrocarbon solvent, an aromatic hydrocarbon solvent, a halogenated aliphatic hydrocarbon solvent or a mixture thereof.

[0101] As non-limiting examples of the aliphatic hydrocarbon solvents, butane, isobutane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, cyclopentane, methylcyclopentane, cyclohexane, etc. can be cited.

[0102] As non-limiting examples of the aromatic hydrocarbon solvents, benzene, monochlorobenzene, dichlorobenzene, trichlorobenzene, toluene, xylene, chlorobenzene, etc. can be cited.

[0103] As non-limiting examples of the halogenated aliphatic hydrocarbon solvents, dichloromethane, trichloromethane, chloroethane, dichloroethane, trichloroethane, 1,2-dichloroethane, etc. can be cited.

[0104] On the other hand, in the polymerization reaction of the present invention, the addition amount of the catalyst can be determined within a range sufficient for the monomers to undergo a polymerization reaction in a slurry phase, liquid phase, gas phase or bulk phase process, and thus there is no particular limitation.

[0105] However, according to the present invention, for each unit volume (L) of the monomers, the addition amount of the catalyst can be 10 -8 mol / L to 1 mol / L based on the concentration of the central metal (M) of the main catalyst compound, preferably 10 -7 mol / L to 10 - 1 mol / L, more preferably 10 -7 mol / L to 10 -2 mol / L.

[0106] In addition, the polymerization reaction of the present invention can be a batch type, semi-continuous type or continuous type reaction, preferably a continuous type reaction.

[0107] The temperature condition of the polymerization reaction of the present invention can be determined according to the type of reaction and reactor applied, taking into account the efficiency of the polymerization reaction. However, the polymerization temperature can be 120 °C or higher, preferably 150 °C to 200 °C. In the polymerization process, as the polymerization temperature increases, the degree of reaction increases. Therefore, the catalyst for polymerizing ethylene α-olefin copolymer has the advantage of being able to polymerize at a high temperature above 150 °C.

[0108] The pressure condition of the polymerization reaction of the present invention can be determined according to the type of reaction and reactor applied, taking into account the efficiency of the polymerization reaction. However, the polymerization pressure can be 1 to 100 atmospheres, preferably 5 to 50 atmospheres.

[0109] For the polymerization reaction of the present invention, the catalyst and reactants can be continuously added. The reactants can be a solvent, ethylene, an α-olefin monomer, or a mixture thereof.

[0110] On the other hand, in the polymerization reaction of the present invention, in order to further improve the formation effect of catalytically active species in the polymerization reactor by removing moisture and impurities in the solution containing the catalyst, a scavenger can be further added.

[0111] The scavenger is not particularly limited, but can be one or more selected from the compounds represented by the following Chemical Formula 8.

[0112] [Chemical Formula 8]

[0113] D(R 31 )3

[0114] In the above Chemical Formula 8, D is aluminum or boron, and R 31 are each independently a halogen radical, a (C1-C 20 ) hydrocarbyl radical, or a (C1-C 20 ) hydrocarbyl radical substituted with a halogen.

[0115] The compound represented by the above chemical formula 8 is not particularly limited, but non-limiting examples include: trialkylaluminums such as trimethylaluminum, triethylaluminum, tributylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, tridecylaluminum; dialkylaluminum alkoxides such as dimethylaluminum methoxide, diethylaluminum methoxide, dibutylaluminum methoxide; dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride; alkylaluminum dialkoxides such as methylaluminum dimethoxide, ethylaluminum dimethoxide, butylaluminum dimethoxide; alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, butylaluminum dichloride; trialkylborons such as trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron; or tris pentafluorophenyl boron, etc.

[0116] The usage amount of the scavenger can be determined according to the usage amount and activity of the main catalyst compound represented by the above chemical formula 1.

[0117] In addition, when using a compound in which D is boron in the compound represented by the above chemical formula 8, this compound can be used in a molar ratio of 1:1 to 1:100, preferably in a molar ratio of 1:1 to 1:10, and more preferably in a molar ratio of 1:1 to 1:3, relative to the main catalyst compound.

[0118] When using a compound in which D is aluminum in the compound represented by the above chemical formula 8, this compound can be used in a molar ratio of 1:1 to 1:1,000, preferably in a molar ratio of 1:1 to 1:500, and more preferably in a molar ratio of 1:1 to 1:100, relative to the main catalyst compound.

[0119] On the other hand, there is no particular limitation on the addition position of the scavenger in the polymerization reactor. For example, the scavenger can be added together with the catalyst and the reactants, or can be added to the primary polymerization reactor or the secondary polymerization reactor through a pipeline separate from the pipelines for adding the catalyst and the reactants.

[0120] <Ethylene α-olefin copolymer>

[0121] The present invention provides an ethylene α-olefin copolymer prepared by the above catalyst for polymerizing ethylene α-olefin copolymer and the preparation method of the ethylene α-olefin copolymer.

[0122] Regarding the ethylene α-olefin copolymer of the present invention, in the stress-strain curve measured by ASTM D638, there are two or more intervals where the tangent slope changes in the strain range of 0% to 1000%. Specifically, the intervals where the tangent slope changes include: a first interval where the tangent slope decreases; and a second interval where the tangent slope increases. The first interval can occur in the strain range of 0% to 200%, and the second interval can occur in the strain range of 500% to 1000%.

[0123] The ethylene α-olefin copolymer of the present invention may have a yield point in the first interval. When the external force applied to an object increases and the stress value reaches a specific value exceeding the elastic limit, even if the external force hardly increases any more, permanent deformation will start to increase sharply. The specific value exceeding the elastic limit is the yield point, and the yield point can appear in the above first interval.

[0124] The density of the ethylene α-olefin copolymer of the present invention can be 0.857 g / cm 3 to 0.910 g / cm 3 . Specifically, the density of the ethylene α-olefin copolymer of the present invention can be 0.860 g / cm 3 or more or 0.865 g / cm 3 or more, and can be 0.900 g / cm3 or less than 0.870 g / cm 3 or less.

[0125] The elongation at break of the ethylene α-olefin copolymer of the present invention can be 900% or more. Specifically, the elongation at break of the ethylene α-olefin copolymer of the present invention can be 1,000% or more. The upper limit value of the elongation at break of the ethylene α-olefin copolymer can be exemplarily 2,000%, but is not limited thereto. Considering measurement conditions and equipment, etc., actual measurement may be difficult.

[0126] The melt flow index (MI) of the ethylene α-olefin copolymer of the present invention can be from 0.1 g / 10 min to 40 g / 10 min. Specifically, the melt flow index (MI) of the ethylene α-olefin copolymer of the present invention can be from 4.8 g / 10 min to 5.1 g / 10 min.

[0127] The diffusion gradient value of the ethylene α-olefin copolymer of the present invention can be from 1 to 5 (×10 6 Pa / m). Specifically, the diffusion gradient value of the ethylene α-olefin copolymer of the present invention can be from 1.2 to 2.1 (×10 6 Pa / m). The diffusion gradient value is the average slope in the strain hardening region where permanent elongation occurs in the stress-strain curve measured according to ASTM D 638, and can be the average slope between the minimum point and the second maximum point. At this time, the upper limit of the measurement range of the second maximum point can be the point where the strain is 1,000%.

[0128] The molecular weight distribution (MWD) value of the ethylene α-olefin copolymer of the present invention can be from 1 to 10. Specifically, the molecular weight distribution value (MWD) of the ethylene α-olefin copolymer of the present invention can be 1.5 or more, 2.1 or more, 2.2 or more, 2.3 or more, or 2.4 or more, and can be 8 or less or 6 or less. The molecular weight distribution (MWD) value can be calculated as the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn).

[0129] Examples and Comparative Examples

[0130] <Synthesis Example> Synthesis of the Main Catalyst Compound (2)

[0131] The transition metal compound (2) was synthesized according to the following Reaction Formula 2. The specific synthesis process is as follows.

[0132] [Reaction Formula 2]

[0133]

[0134] First, at -30 °C, methyllithium (1.63 g, 3.55 mmol, 1.6 M solution in diethyl ether) was added dropwise to a diethyl ether solution (10 mL) containing compound (1) (0.58 g, 1.79 mmol) (step (i)).

[0135] The solution obtained in step (i) was stirred at room temperature overnight and then cooled to -30 °C. Subsequently, 0.37 g (1.79 mmol) of Ti(NMe2)2Cl2 was added in one portion (step (ii)).

[0136] The solution obtained in step (ii) was stirred for three hours, and then all the solvents were removed using a vacuum pump. As a result, a red solid compound (2) (0.59 g, yield 75%) was obtained.

[0137] By 1 1H NMR spectroscopy, it was confirmed that the two stereoisomers existed in a ratio of 1:0.8.

[0138] 1 1H NMR (C6D6): δ 7.12 and 7.09 (d, J = 7.2 Hz, 1H), 6.96 and 6.94 (d, J = 7.2 Hz, 1H), 6.82 and 6.80 (t, J = 7.2 Hz, 1H), 6.47 and 6.46 (d, J = 7.2 Hz, 1H), 6.45 and 6.44 (d, J = 7.2 Hz, 1H), 5.44 (m, 1H, NCH), 2.76 - 2.60 (m, 1H, CH2), 2.44 - 2.18 (m, 1H, CH2), 2.28 and 2.22 (s, 3H), 2.09 (s, 3H), 1.74 and 1.65 (s, 3H), 1.88 - 1.48 (m, 2H, CH2), 1.20 and 1.18 (d, J = 7.2 Hz, 3H), 0.77 and 0.71 (s, 3H, TiMe), 0.49 and 0.40 (s, 3H, TiMe) ppm.

[0139] 13 C{ 11H NMR (C6D6): δ 159.83, 159.52, 145.93, 144.90, 140.78, 139.93, 139.21, 138.86, 135.26, 131.56, 129.69, 129.57, 127.50, 127.46, 127.38, 127.24, 121.29, 121.16, 120.05, 119.96, 118.90, 118.74, 117.99, 117.74, 113.87, 110.38, 57.91, 55.31, 54.87, 51.68, 50.27, 50.12, 34.77, 27.58, 27.27, 23.10, 22.05, 20.31, 19.90, 16.66, 14.70, 13.11, 12.98, 12.68 ppm. Anal. Calc. (C 22 H 27 NSTi): C, 68.56; H, 7.06; N, 3.63. Found: C, 68.43; H, 7.24; N, 3.52%.

[0140] <Example 1>

[0141] Using a reactor equipped with a 2.5 L stirrer, a continuous polymerization process was carried out as follows to prepare an ethylene / 1-octene copolymer.

[0142] After passing 8.5 kg / hr of the solvent n-hexane, 1.5 kg / hr of ethylene, and 0.7 kg / hr of 1-butene through a primary heat exchanger, they were injected into a high-pressure mixer to prepare a first mixture. The prepared first mixture was passed through a secondary heat exchanger and then added to the lower end of the polymerization reactor. 0.114 mmol / hr of the transition metal compound obtained in the above synthesis example and 0.3 mmol / hr of the cocatalyst compound N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were injected into the lower end of the reactor. In addition, the scavenger triisobutylaluminum was injected through a pipeline separate from the injection pipeline of the first mixture. The injection amount of triisobutylaluminum was 23 mmol / hr. A polymerization pressure of 90 bar was set for the reaction. The temperature at the lower end of the polymerization reactor was 135 °C, and the temperature at the upper end rose to 150 °C due to the heat of the polymerization reaction. The reaction was carried out continuously, and the estimated polymerization time from the addition of the catalyst to the discharge at the end of the reaction was about 10 minutes. The reaction product obtained after passing through the polymerization reactor was passed through a high-temperature and high-pressure primary recovery unit to recover the solvent, and then through a high-temperature and low-pressure secondary recovery unit to recover the remaining n-hexane and unreacted ethylene. Subsequently, a granulator was used to obtain a solid ethylene / 1-octene copolymer.

[0143] <Example 2>

[0144] An ethylene / 1-octene copolymer was prepared by a continuous polymerization process as follows using a reactor equipped with a 2.5 L stirrer.

[0145] Experiments were conducted in the same manner as in Example 1 except that the solvent was changed to n-hexane at 8.5 kg / hr, ethylene at 1.3 kg / hr, and 1-butene at 0.9 kg / hr, thereby obtaining an ethylene / 1-octene copolymer.

[0146] <Comparative Examples 1 to 4>

[0147] The copolymers of Comparative Examples 1 to 4 were products of LG Chem (trade name: LC565), Mitsui Chemicals (trade name: DF640), and two products of Dow Chemical (trade names: EG7447, EG8200), respectively.

[0148] Physical Property Analysis of Ethylene α-Olefin Copolymer

[0149] Samples of the ethylene α-olefin copolymers of the examples and comparative examples were placed in a molding die with a thickness of 3 mm and a length and width of 8 cm each. After hot pressing and melting at 125°C for 7 minutes using a press molding machine and then cooling for 5 minutes, specimens were made and their physical properties were measured. The results are shown in Table 1 below.

[0150] (1) Melt Index (MI): Measured by the method of ASTM D-1238 (Condition E, 190°C, 2.16 kg load) using an instrument (manufacturer: Mirage, model: SD-120L).

[0151] (2) Density (g / mL): The copolymer treated with an antioxidant was made into a specimen with a thickness of 3 mm and a radius of 2 cm by hot pressing at 180°C, and after cooling to room temperature, it was measured according to ASTM D-792 (manufacturing company: Toyoselki, model: T-001).

[0152] (3) Molecular Weight Distribution (MWD): Analyzed by gel permeation chromatography (GPC: Gel Permeation Chromatography, equipment name: PLGPC220, manufacturing company: Agilent) and measured at 160°C using 1,2,4-trichlorobenzene solvent.

[0153] (4) Diffusion Gradient: Measured using a Zwick Z010 universal testing machine at a speed of 200 mm / min. The diffusion gradient value was calculated by the aforementioned method, and the average value of a total of five tests was shown as the result.

[0154] (5) Stress-Strain Curve Analysis: In accordance with ASTM D638, the stress curve with respect to the strain of the specimen is measured, and the number of intervals where the tangent slope changes within the strain range of 0% to 1000% is determined, and the results are shown.

[0155] (6) Elongation at Break: After cutting the specimen into the shape for tensile strength test under ASTM D638 specifications, the strain until the specimen breaks is measured according to ASTM D638 at a tensile speed of 5 mm / min.

[0156] [Table 1]

[0157]

[0158] Referring to Table 1 and Figures 1 to 2 , in the cases of Example 1 and Example 2, in the stress-strain curve analysis, in the graph of the stress curve with respect to the strain, more than two intervals where the tangent slope changes appear (specifically, both the first interval where the tangent slope decreases and the second interval where the tangent slope increases appear). In Example 1 and Example 2, no fracture occurs at 1000% strain, and the elongation at break is more than 1000%; while in the cases of Comparative Example 1 to Comparative Example 3, only one interval where the tangent slope changes appears (specifically, only the first interval where the tangent slope decreases appears). Comparative Example 1 to Comparative Example 3 fracture at a strain lower than 1000%, and the elongation at break is lower than 1000%.

[0159] In view of this, it can be judged that in the stress-strain curve analysis, in the graph of the stress curve with respect to the strain, the ethylene α-olefin copolymers of Example 1 and Example 2, in which more than two intervals where the tangent slope changes appear, have relatively excellent tensile elongation at break, flexural strength, processability, etc.

[0160] Industrial Applicability

[0161] As described above, all or part of the features of the present invention can be applied to ethylene α-olefin copolymers and their preparation methods.

Claims

1. An ethylene α-olefin copolymer comprising ethylene structural units and α-olefin structural units, wherein, in the stress-strain curve measured by ASTM D638, there are more than two intervals where the tangent slope changes, the intervals where the tangent slope changes include: a first interval where the tangent slope decreases; and a second interval where the tangent slope increases.

2. The ethylene α-olefin copolymer according to claim 1, wherein, the first interval appears at a strain of 0% to 200%, the second interval appears at a strain of 500% to 1000%.

3. The ethylene α-olefin copolymer according to claim 1, wherein, there is a yield point in the first interval.

4. The ethylene α-olefin copolymer according to claim 1, wherein, the elongation at break of the ethylene α-olefin copolymer is 900% or more.

5. The ethylene α-olefin copolymer according to claim 1, wherein, The diffusion gradient value of the ethylene α-olefin copolymer is 1×10 6 Pa / m to 5×10 6 Pa / m.

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