KR20010057201A - Metallocene Catalysts Having Multi-nuclear Constrained Geometry and Ethylene/Aromatic Vinyl Compound Co-polymers Prepared by Using the Same - Google Patents

Abstract

PURPOSE: A metallocene catalyst useful in the production of copolymer comprising ethylene/aromatic vinyl compounds having constrained geometry is provided to enable the copolymer to have high isotacticity and alternating index by connecting at least two transition metal compounds having the constrained geometry. CONSTITUTION: The multi-nuclear constrained geometry metallocene catalyst useable in the production of specific copolymer having excellent isotacticity and alternating index respresents formula 1 (wherein M is same or different and Ti, Zr or Hf; Cp1 is cyclo pentadienyl groups with no substituent and/or having 1-4 alkyl substituent radicals with or without cyclic structure, or indenyl or fluorenyl groups with or without any substituent radicals; Y is hydrogen, C1-C10 sillyl, alkyl, aryl groups or combination of those; A is hetero atom such as N, O, P or S; X is hydrogen, halogen, alkyl or aryl groups or combination of those; and G is C1-C30 alkyl, cycloalkyl, aryl or alkylamine groups) and includes two transition metals in a single molecular by mutual coupling of ligands connected to core metal of the transition metals.

Description

Metallocene catalyst having a multinuclear constrained arrangement and copolymer of ethylene / aromatic vinyl compound using the same {Metallocene Catalysts Having Multi-nuclear Constrained Geometry and Ethylene / Aromatic Vinyl Compound Co-polymers Prepared by Using the Same}

Field of invention

The present invention relates to a metallocene catalyst for copolymerization of ethylene / aromatic vinyl compounds. More specifically, the present invention provides a metallocene catalyst in which ligands of two or more transition metal compounds having a constrained geometry are connected to each other, and excellent isotacticity in preparing a copolymer of ethylene / aromatic vinyl compound using the same. It relates to an isotactic-altered-ethylene / aromatic vinyl compound copolymer having an isotacticity) and an alternating index and having an improved copolymerization of an aromatic vinyl compound and a method for preparing the same.

Background of the Invention

Generally, olefinic or styrene-based polymers are prepared by radical polymerization, ion polymerization or coordination polymerization by Ziegler-Natta Catalysts. By radical polymerization or ionic polymerization, an atactic polymer is obtained. In the case of coordination polymerization using a Ziegler-Natta catalyst, an isotactic polymer is mainly obtained. Polymers are classified into atactic, isotactic and syndiotactic structures according to the position of the benzene ring, the side chain of the molecular chain. The atactic structure means that the arrangement of the side chains is irregular, and the isotactic structure means that the side chain is biased to one side. In this regard, syndiotactic structure means that the side chains are regularly arranged alternately.

Copolymerization between aromatic vinyl compounds such as ethylene and styrene has been performed for the last decade. First, a method using a homogeneous Ziegler-Nattacatalyst was attempted (Polymer Bulletin 20, 237-241, 1988). However, in the case of traditional non-uniform Ziegler-Natta catalyst systems, the catalyst activity is extremely low, the styrene content in the resulting copolymer is low, the homogeneity of the copolymer is poor and almost all is obtained as a mixture of homopolymers. In addition, an ethylene / styrene copolymer prepared using a homogeneous Ziegler-Natta catalyst system composed of a transition metal compound and an organoaluminum compound, and a method of manufacturing the same are known.

Japanese Patent Application Laid-Open Nos. 3-163088 and 7-53618 disclose a pseudo-random ethylene / styrene copolymer in which a common styrene chain is not present using a constrained geometry catalyst. In this context, the common styrene chain means the head-to-tail bond chain of styrene. However, the phenyl groups present in the alternating structure of pseudo-random ethylene-styrene copolymers do not have stereoregularity, and show characteristics of amorphous resins having no crystallinity below a certain styrene content. do. Therefore, the production method using a large amount of organoaluminum adopted in the above technique produces a large amount of syndiotactic polystyrene in addition to the ethylene styrene copolymer under mild reaction conditions and thus is not an efficient production method.

Japanese Patent Application Laid-open No. Hei 6-49132 and Polymer Preprints (Japan 42, 2292, 1993) disclose the preparation of styrene / ethylene copolymers of similar structure, which is a pseudo-random copolymer because no common styrene chain is present. Named and prepared using Bridged Cp-type Zr complexes and cocatalysts. However, according to Polymer Preprints (Japan 42, 2292, 1993), the phenyl group did not have any stereoregularity in the ethylene / styrene alternating structure in the psedo-random copolymer.

On the other hand, styrene / ethylene alternating copolymers can be prepared using a titanium complex having a phenol substituent, Japanese Patent Laid-Open No.-3-250007 and Stud. Surf. Sci. Catal. 517 (1990). Such copolymers do not contain any structure other than ethylene-styrene alternating arrangements, ie ethylene chains, styrene chains (including the head-head or tail-tail bonds of styrene), and the alternating degree is at least 70 or more, more specifically 90 or more.

That is, the copolymer has a very high level of alternating degree and is almost a perfect alternating copolymer. On the other hand, since the content of ethylene and styrene is fixed at about 50% to 50%, there is a disadvantage that the composition of the copolymer cannot be changed. Moreover, phenyl groups have isotactic stereoregularity, with an isotactic diad index of 0.92. In addition, the copolymer has a molecular weight of 20,000 or less, which is inappropriate in terms of physical properties. In addition, there are many aspects that are not suitable for practical commercialization such as extremely low catalytic activity and a large amount of homopolymer such as sPS (syndiotactic polystyrene) is produced during copolymerization.

Meanwhile, Macromol. Chem., 191, 2387 (1990) disclose a method for preparing styrene / ethylene copolymers using CpTiCl ₃ as a transition metal compound and methyl aluminoxane as a promoter. However, a small amount of pseudo random copolymer without styrene chains is produced at certain catalyst / procatalyst ratios, with very low catalytic activity. In addition, in this document, the content about the stereoregularity of a phenyl group is not reported.

Meanwhile, Eur. Polym. J., 31, 79 (1995) carried out ethylene-styrene copolymerization under various conditions using alkylates (CpTiBz ₃ ) of the same catalyst as described above, resulting in polyethylene and syndiotactic polystyrene (sPS) rather than copolymers. A mixture of homopolymers of was obtained.

In addition, Macromolecules, 29, 1158 (1996) discloses the results of ethylene-styrene copolymerization using CpTiCl ₃ and boron type cocatalysts. As a result, copolymers and syndiotactics having high levels of alternating structures are disclosed. A mixture such as polystyrene (sPS) and polyethylene could be obtained. However, this document does not mention the stereoregularity of the phenyl group.

U.S. Patent No. 5,883,213 (1999) discloses ethylene-styrene copolymerization results using promoters of bridged Cp-type Zr complexes and methylaluminum oxane, wherein the bridged Cp-type Zr complexes used as catalysts are generally iso It has a C2 symmetric structure known to produce isotactic PP. The copolymer can vary the styrene content from 1 to 55 mole percent and has an isotactic diad index of 0.95 or greater. It is known to be visible. However, this copolymer has a low alternating index of less than 60% even at high styrene content of 50 mol% or more.

In addition, the method disclosed in EP 416,815 A2 has a low polymer yield per unit metal, uses a large amount of organoaluminum compound, requires extreme conditions of high temperature and high pressure, and is industrially limited. The resulting polymer has no stereoregularity of the copolymerized styrene and thus has amorphous properties above a certain styrene concentration. Also. Pseudo-random structure is not suitable for the production of alternating copolymer (alternating copolymer).

Accordingly, the inventors have found that olefins / styrenes with novel constrained geometry to improve the low activity, low styrene loading, excess homopolymer production, heterogeneous composition, etc. of conventional heterogeneous Ziegler-Natta catalyst systems. It is to develop a metallocene catalyst for copolymerization.

SUMMARY OF THE INVENTION An object of the present invention is to prepare an ethylene / aromatic vinyl compound copolymer, which is a novel metal, which increases the amount of styrene introduced into a copolymer even under mild reaction conditions, suppresses the production of homopolymers as much as possible, and exhibits a uniform composition. To provide a strong catalyst.

Another object of the present invention is to produce a high amount of ethylene / aromatic vinyl compound copolymer using a small amount of promoter, and to have a highly active metallocene catalyst having a constrained geometry. To provide.

Another object of the present invention is to provide a method for efficiently preparing an ethylene / aromatic vinyl compound copolymer using a metallocene catalyst having a constrained arrangement.

The above and other objects of the present invention can be achieved by the present invention described below.

Hereinafter, the content of the present invention will be described in detail.

1 is a chemical formula showing the microstructure of the ethylene / styrene copolymer.

2 is a diagram in which the peak values obtained by ¹³ C NMR analysis of the ethylene / styrene copolymers prepared in Example 7 and Comparative Example 1 are classified.

3 is a chemical formula showing the structure of an ethylene / styrene copolymer having an isotactic alternating structure.

Multi-nuclear constrained geometry catalyst according to the present invention (Multi-nuclear constrained geometry catalyst) is composed of a structure containing two, three, or four transition metals, the structural formula (1) to (5) Is displayed.

In the above formulas (1), (2), (3), (4), and (5), M is titanium (Ti), zirconium (Zr) or hafnium (Hf) and is the same as or different from each other. Cp ¹ has a cyclopentadienyl group having no substituent, a cyclopentadienyl group containing 1 to 4 alkyl substituents having or without a ring structure, and an indenyl group having a substituent or no substituent Fluorenyl which does not have; Y is hydrogen or a group formed of a silyl group, alkyl group, aryl group having C ₁ to ₁₀ , or a combination thereof (e.g., -CH _2- , CMe _2- , -CPh _2- , -SiH ₂ -,- SiMe _2- , SiPh ₂ -and the like); A is a hetero atom such as nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S); X is hydrogen or an alkyl group such as halogen such as chlorine or bromine, methyl or ethyl, or an aryl group such as phenyl; And G is C _1-30 alkyl group, cycloalkyl group, aryl group, alkylaryl group and the like.

An organometallic compound is used as a cocatalyst with the metallocene catalyst of the present invention, or a mixture of uncoordinated Lewis acid and alkylaluminum is used. Organometallic compounds that can be used here include alkylaluminum oxane or organoaluminum compounds. Representative examples of the alkylaluminum oxane include methylaluminoxane (MAO) and modified methylaluminoxane (MAMAO). The organoaluminum compound has a unit represented by the following formula (6), and these include a chain-shaped aluminum oxane represented by the following formula (7) and a cyclic aluminum oxane represented by the following formula (8).

In the general formulas (6), (7) and (8), R is a C _1-6 alkyl group, and m and n are integers of 0-100.

The cocatalyst may be a mixture of aluminum oxanes of different kinds, if necessary, and may be mixed with aluminum oxane and alkyl aluminum, such as trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, dimethyl aluminum chloride, and the like. have.

In the ratio of the metallocene catalyst component according to the present invention and the component of the organometallic compound that is a promoter, the ratio of aluminum to the Group 4 transition metal in the metallocene catalyst component is usually The molar ratio of aluminum to transition metal (eg, titanium, zirconium, hafnium) is in the range of 1: 1 to 10 ⁶ : 1, more preferably in the range of 10: 1 to 10 ⁴ : 1.

In the mixture of non-coordinated Lewis acid and alkylaluminum used as a promoter, the non-coordinating Lewis acid is N, N-dimethyl aniline tetrakis (pentafluorophenyl) borate, triphenyl carbeni Um tetrakis (pentafluorophenyl) borate, ferrocerium tetrakis (pentafluorophenyl) borate, tris (pentafluorophenyl) borate, and alkyl aluminum include trimethyl aluminum, triethyl aluminum, diethyl aluminum chloride , Dimethylaluminum chloride, triisobutyl aluminum, diisobutylaluminum chloride, tri (n-butyl) aluminum, tri (n-propyl) aluminum, triisopropyl aluminum and the like.

In the catalyst system composed of the metallocene catalyst and the cocatalyst of the present invention, the molar ratio of the non-coordinated Lewis acid: transition metal is preferably in the range of 0.1: 1 to 20: 1, most preferably 1. If the ratio is less than 0.01, the metal complex cannot be effectively activated, and if it exceeds 100, it is economically disadvantageous. The metal complex and the promoter may be mixed and prepared outside the polymerization reactor, or may be mixed in the polymerization reactor during the polymerization. In addition, in the preparation of the copolymer of the present invention, additives, adjuvants, and the like, which are commonly used in polymers, may be included within the range of not impairing the effects of the present invention, and most preferably, antioxidants, lubricants, and plasticizers. plasticizers, ultraviolet absorbers, stabilizers, pigments, staining agents, fillers, and / or foaming agents.

The polymerization temperature for producing the ethylene / aromatic vinyl compound copolymer using the catalyst system of the present invention is preferably 0 to 200 ° C, more preferably 30 to 150 ° C. Polymerization temperatures lower than -78 ° C are industrially disadvantageous, and above 200 ° C, it is not suitable because decomposition of the metal complex occurs.

The ethylene monomer polymerized using the catalyst system according to the present invention is ethylene, an unsaturated ethylenic monomer having a substituent, or α, ω-diene, and the ethylene monomer is copolymerized with an aromatic vinyl compound and used alone or in combination of two or more. Copolymerization can be carried out.

Examples of the aromatic vinyl compound to be polymerized include alkyl styrene, halogenated styrene, halogen-substituted alkyl styrene, alkoxy styrene, vinyl biphenyl, vinyl phenyl naphthalene, vinyl phenyl anthracene, vinyl phenylpyrene, trialkylsilyl vinyl biphenyl, trialkyl stenibi Phenyl, alkylsilyl styrene, carboxymethyl styrene, alkyl ester styrene, vinylbenzene sulfonic acid ester, vinyl benzyl dialkoxy phosphide and the like.

Alkyl styrenes include styrene, methyl styrene, ethyl styrene, butyl styrene, para-methyl styrene, para-t-butyl styrene and dimethyl styrene. Halogenated styrene includes chloro styrene, bromo styrene and fluoro styrene. And halogen-substituted alkyl styrene include chloromethyl styrene, bromomethyl styrene and fluoromethyl styrene. Alkoxy styrene includes methoxy styrene, ethoxy styrene and butoxy styrene. Phenyl, 3-vinylbiphenyl, 2-vinylbiphenyl, and the like, and as vinylphenylnaphthalene, 1- (4-vinylbiphenylnaphthalene), 2- (4-vinylbiphenylnaphthalene), 1- (3-vinyl Biphenylnaphthalene), 2- (3-vinylbiphenylnaphthalene), 1- (2-vinylbiphenylnaphthalene), and the like, and examples of vinylphenyl anthracene include 1- (4-vinylphenyl) anthracene and 2- (4- Vinylphenyl) anthracene, 9- (4-vinylphenyl) anthracene, 1- (3- Nylphenyl) anthracene, 9- (3-vinylphenyl) anthracene, 1- (2-vinylphenyl) anthracene, and the like. As vinylphenylpyrene, 1- (4-vinylphenyl) pyrene, 2- (4-vinylphenyl) ) Pyrene, 1- (3-vinylphenyl) pyrene, 2- (3-vinylphenyl) pyrene, 1- (2-vinylphenyl) pyrene, 2- (2-vinylphenyl) pyrene and the like, and trialkylsilylvinyl Examples of biphenyl include 4-vinyl-4-trimethylsilylbiphenyl, and alkyl silyl styrene includes p-trimethylsilyl styrene, m-trimethylsilyl styrene, o-trimethylsilyl styrene, p-triethyl silyl styrene, and m-. Triethylsilyl styrene, o-triethylsilyl styrene, and the like.

The ethylenically unsaturated monomers are olefins, such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, and the like. Cyclic olefins include cyclobutene, cyclopentene, cyclohexene, and 3-methylcyclone. Pentene, 3-methylcyclohexene, norbornene and the like. In addition, α, ω-diene means non-conjugated diene, 1,4-pentadiene, 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene , 1,8-nonadiene, 1,9-decadiene, 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl norbornene, methyl hexadiene and the like are used, 0 It may be present in the copolymer in a weight ratio of about 25%.

The ethylene / aromatic vinyl compound copolymer of the present invention preferably has a weight average molecular weight (Mw) of 13,000 or more, more preferably of 20,000 or more, most preferably of 30,000 or more, and a melt index (ASTM D-1238 Method A, Condition E) is in the range of 0.001 to 1000, preferably 0.01 to 100, most preferably 0.1 to 30.

In the present invention, the monomer and the solvent (if a solvent is used) before polymerization can be purified by vacuum distillation or by contact with alumina, silica or molecular sieve. In addition, impurities can be removed by using a trialkyl aluminum compound, an alkali metal, a metal alloy (particularly Na / K), or the like.

The styrene derivative may be adjusted in content ratio so as to have styrene in the polymer in polymerization with ethylene, preferably at least 0.1 mol% or more, more preferably 0.1 to 55 mol%. In order to control the polymerization reaction as described above, the pressure is set in the range of from atmospheric pressure to 1,000 atm, and the temperature in the range of from room temperature to 200 ° C. Polymerization at temperatures above the autopolymerization temperature for each monomer involves a small amount of homopolymer resulting from the free radical polymerization.

The polymer produced according to the present invention exhibits various properties depending on the content of styrene. The melting point decreases to a low styrene content (about 0 to 20 mol%), but a higher region (more than 20 to 30 mol% of styrene) is reduced. ), The melting point increases, and above a certain content, it shows a uniform melting point. In particular, when the content of styrene is 50 mol% and the alternating index (Alternative Index) is 0.85, the melting point (Tm) has a value of 124 ℃, this result is obtained in US Patent No. 5,883,213 (1999) Compared with the melting point of about 90 ℃, the difference is about 30 ℃ or more.

The polymers produced according to the invention are particularly suitable for the use of thermoplastic elastomers used as impact modifiers for thermoplastic and thermoset polymers, including bitumen, additives, elastomeric moldings, etc. It can be blended with synthetic or natural polymers without blending to have the desired properties. In particular, polyethylene, ethylene / α-olefin copolymers, polypropylene, polyamides, aromatic polyesters, polyisocyanates, polyurethanes, polyacrylonitriles, silicones, polyphenylene oxides and the like can be blended into the polymer composition of the present invention. It is preferably used in an amount of 0.5 to 50% by weight.

In addition, the copolymer of the present invention is a material returning to its original length after stretching twice the length at room temperature, and the degree of elasticity defined as an elastomer material by ASTM special Technical Rulletin No.184. There is this.

In addition to the modification of synthetic thermoplastic polymers, the polymers produced by the present invention are usefully used as modifiers for asphalt or bitumen compositions. Preferably, ethylene / styrene copolymers can be used for this purpose.

The metallocene catalyst of the present invention may be more clearly understood by the following examples, which are merely illustrative purposes of the present invention and are not intended to limit the scope of the present invention.

Example

The ethylene-styrene copolymer of the present invention is embodied in the following examples, in which 40 to 50 mg of a polymer sample is dissolved in a mixed solvent of about 5 ml of hot trichlorobenzene and benzene-deuterium 6 and placed in a 5 mm NMR tube. It was analyzed by MHz ¹³ C NMR spectrum.

Example 1 Preparation of Catalyst

Preparation of Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ Me ₄ Cp] TiCl ₂

Preparation of Chloro-2,3,4,5-tetramethylcyclopentadienyldimethylsilane [Me ₄ CpSi (Me) ₂ Cl,]

2,3,4,5-tetramethylcyclopentadiene (2.45 g, 20 mmol) was dissolved in dried THF (30 mL) in a 100 mL nitrogen-substituted flask and -78 using a dry ice-acetone bath. It was stirred while cooling to ° C. Then, n-butyllithium (1.6 M hexane solution, 21 mmol) was inject | poured with the syringe, the cooling water tank was removed, and it heated up to normal temperature. After about 10 hours, the solvent was removed under vacuum, washed with dried pentane (50 mL × 3 times), and dried to obtain lithium tetramethylcyclopentanide (Cp ^* -Li ⁺ ) in a yield of 98%. 30 ml of THF solvent was injected and stirred. After slowly injecting Si (Me) ₂ Cl ₂ (3.87 g, 30 mmol) into a syringe at room temperature, the mixture was allowed to react for at least 5 hours and the solvent was removed under vacuum. At this time, the unreacted substance was completely removed and purified at a temperature of about 70 ° C. to give chloro-2,3,4,5-tetramethylcyclopentadienyldimethylsilane [Me ₄ CpSi (Me) ₂ Cl,] of greenish yellow. Obtained in 81% yield.

Preparation of Me ₄ CpSi (Me) ₂ NH-C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NHSi (Me) ₂ CpMe ₄

6.89 g (20 mmol) of 4,4-bi (4-aminophenylpropylidene) benzene was dissolved in THF (100 mL) in a 250 mL nitrogen-substituted flask, and the mixture was cooled to -78 ° C using a dry ice-acetone bath. . After n-butyllithium (1.6 M hexane solution, 42 mmol) was injected thereto, the temperature was raised to room temperature and further reacted for about 10 hours. The solvent was removed in vacuo, washed with pentane and dried to give the dilithium salt in 99% yield. The dilithium salt prepared as described above was dissolved in THF (100 mL) and reacted with 12.9 g (60 mmol) of chloro-2,3,4,5-tetramethylcyclopentadienyldimethylsilane at -78 ° C. After keeping at room temperature overnight, the temperature was raised to 70 ° C. to remove the solvent and unreacted material under vacuum, and washed with pentane to give a pale yellow Me ₄ CpSi (Me) ₂ NH—C ₆ H ₄ —C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NHSi (Me) ₂ CpMe ₄ was obtained in a yield of 76%.

Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] ^4- 4Li ⁺ 4 ^. Manufacture of THF

In a nitrogen-displaced 100 mL flask, 7.01 g (10 mmol) of Me ₄ CpSi (Me) ₂ NH-C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H _4- NHSi (Me) ₂ Me ₄ Cp was dissolved in THF (50 mL), stirred, and cooled to −78 ° C. using a dry ice-acetone bath. After n-butyllithium (1.6 M hexane solution, 42 mmol) was injected thereto, the temperature was raised to room temperature and further reacted for about 10 hours. The solvent was removed in vacuo, washed with pentane and dried to give a slightly yellow THF coordinated tetralithium salt in 95% yield.

Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] ^4- MgCl ^+. Manufacture of 4THF

In a nitrogen-displaced 100 mL flask, 7.01 g (10 mmol) of Me ₄ CpSi (Me) ₂ NH-C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H _4- NHSi (Me) ₂ CpMe ₄ was dissolved in a mixed solvent of THF and toluene (50 ml, v / v = 1: 4) and stirred. Isopropyl magnesium chloride (42 mmol) was inject | poured here, and it was made to react at reflux for 10 hours or more. The solvent was removed in vacuo, washed with pentane and dried to give a tetramagnesium salt coordinated with pale pink THF in 97% yield.

Preparation of [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] Ti ₂ Cl ₄

2.10 g (2.07 mmol) of [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H _4- NSi (Me) ₂ CpMe ₄ ] ^4- 4Li ⁺ 4 ^. THF was dissolved in THF (30 mL) and stirred. At room temperature, a solution of TiCl ₃ THF (1.54 g, 4.14 mmol) / THF (20 mL) was slowly injected. After 2 hours, excess CH ₂ Cl ₂ was injected into the syringe and reacted for at least 3 hours. When the reaction was completed, the solvent was removed and the portion soluble in toluene was taken and concentrated. Recrystallized at -30 ° C using a mixed solvent of hexane and toluene to give [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] Ti ₂ Cl ₄ was obtained in a yield of 31%.

Example 2 Preparation of Catalyst

Except for using AgCl instead of CH ₂ Cl _{2 It} was carried out in the same manner as in Example 1, yellowish orange crystalline phase [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C ( Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] Ti ₂ Cl ₄ was obtained in a yield of 34% to confirm the structure by NMR.

Example 3 Preparation of Catalyst

A tetramagnesium salt was used instead of the tetralithium salt, and the reaction was carried out in the same manner as in Example 1 except that the reaction time was 10 hours or more. [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] Ti ₂ Cl ₄ 41% Obtained in the yield of to confirm the structure by NMR.

Example 4 Preparation of Catalyst

The same process as in Example 1 except that AgCl was used instead of CH ₂ Cl ₂ . [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ ] Ti ₂ Cl ₄ Obtained in the yield of to confirm the structure by NMR.

Examples 5-8 Synthesis of Polymers

Using an external electro-heating 1 L glass autoclave and a 2 L metal high pressure reactor equipped with a magnetic stirrer, vacuum and nitrogen substitution were repeated to completely replace the inside with nitrogen, followed by polymerization. Cooling was selected by installing a cooling coil inside the reactor to flow the cooling water. Solvents such as hexane and toluene were used by adding Na and distilling, and contacting with molecular sieve, alumina, silica or the like was stored under nitrogen.

Example 5 Ethylene Homopolymerization

Hexane (100 mL) and MAO (10 mmol, Al) were added to a 2 L metal high pressure reactor, and the mixture was heated to 70 ° C while stirring. [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ containing 20μmol of titanium (Ti) At the same time as Me ₄ Cp] TiCl ₂ was injected, 10 atmospheres of ethylene were injected to initiate polymerization. At this time, the consumption amount of ethylene, the calorific value and the stirring state were observed. After 30 minutes had elapsed, the ethylene gas was depressurized, a hydrochloric acid / methanol solution was added thereto to stop / wash the reaction, and then powdered polyethylene was recovered. Drying under reduced pressure gave 59 g of polyethylene.

Example 6 Ethylene / 1-Octene Copolymerization

Hexane (1000 mL), 1-octene (50 mL) and MAO (10 mmol, Al) were added to a 2 L metal high-pressure reactor, and the mixture was heated to 70 ° C. [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ Me ₄ Cp] TiCl ₂ of ₂₀ μmol Ti At the same time as the injection, polymerization was started by injecting 10 atm of ethylene. The consumption of ethylene, the calorific value and the stirring state were observed. After 30 minutes, the ethylene gas was released and the reaction was stopped / washed by adding hydrochloric acid / methanol solution, and then the copolymer was recovered. It dried under reduced pressure and obtained 65 g of ethylene / 1-octene copolymers. ¹³ C NMR analysis showed 8.4 mol% of 1-octene and had a Tm of 98 ° C.

Example 7: Ethylene / Styrene Copolymerization

SM (200 mL) and MAO (10 mmol, Al) were put into the 1 L glass high pressure reactor, and it stirred, and it heated up at 70 degreeC. [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ containing 20μmol of titanium (Ti) At the same time as Me ₄ Cp] TiCl ₂ was injected, 4 atmospheres of ethylene were injected to initiate polymerization. The consumption of ethylene, the calorific value and the stirring state were observed. As the polymerization proceeded, it could be seen that a powdery polymer was formed which did not dissolve in the solution. After 30 minutes, the ethylene gas was released and the reaction was stopped by washing with hydrochloric acid / methanol solution, and then the powdered ethylene / styrene copolymer was recovered. It dried over 130 hours under reduced pressure at 130 degreeC, and obtained 15g of polymers. As a result of polymer analysis, it was found that the isotactic alternating copolymer including 50.2 mol% of styrene. At this time, the isotacticity, diad (Isotacticity, diad) was 0.62, the alternating index (Alternating Index) was 0.82.

Example 8 Ethylene / Styrene Copolymerization

SM (1,000 ml) and MAO (10 mmol, Al) were put into a 2 L metal high pressure reactor, and the mixture was stirred and heated to 70 ° C. [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -C (Me) ₂ -C ₆ H ₄ -NSi (Me) ₂ containing 20μmol of titanium (Ti) At the same time as Me ₄ Cp] TiCl ₂ was injected, 10 atm of ethylene was injected to initiate polymerization. The consumption of ethylene, the calorific value and the stirring state were observed. After 30 minutes, the ethylene gas was released and the reaction was stopped by washing with hydrochloric acid / methanol solution, and then the powdered ethylene / styrene copolymer was recovered. It dried over 130 hours under reduced pressure at 130 degreeC, and obtained 49 g of polymers. As a result of polymer analysis, it was found that the isotactic alternating copolymer including 50.8 mol% of styrene. At this time, the isotacticity, diad (Isotacticity, diad) was 65%, the alternating index (Alternating Index) was 84%.

Comparative Example 1: Ethylene / Styrene Copolymerization

The same procedure as in Example 7 was carried out except that the same amount of [Cp (Me) ₄ -Si (Me) ₂ -N- t- Bu] TiCl ₂ (CGC) was used instead of Catalyst 1 in a 1 L glass high pressure reactor. It dried over 130 hours under reduced pressure at 130 degreeC, and obtained 8.5g of copolymers. Analysis of the polymer, it was found that the pseudo-random copolymer containing 35.3 mol% of styrene. At this time, the alternating index was 41%.

Comparative Example 2: Ethylene / Styrene Copolymerization

The same procedure as in Example 7 was carried out except that the same amount of rac- [C ₂ H ₄ (Ind) ₂ ] ZrCl ₂ was used instead of catalyst 1 in a 1 L glass high pressure reactor. It dried over 130 hours under reduced pressure at 130 degreeC, and obtained 62g of copolymers. As a result of polymer analysis, it was found to be a pseudo-random copolymer containing 7.9 mol% of styrene. At this time, the isotacticity, diad (Isotacticity, diad) was 71%, the alternating index (Alternating Index) was 21%.

In the polymerization process, the copolymer produced by changing the injection ratio of ethylene and styrene was analyzed, and styrene content, molecular weight and the like are shown in Table 1.

Physical property analysis of ethylene / styrene copolymer catalyst SM (ml) C2 (㎏ / ㎠) Mw (× 10 ⁴ ) MWD Tm (℃) St content (mol%) Isotacticity (diad,%) Shift Array Index (%) Example 7 Catalyst ^a 200 4 3.88 2.09 124.1 50.2 63 82 Example 8 Catalyst ^a 1000 10 11.3 3.26 124.5 50.1 65 83 Comparative Example 1 CGC ^b 200 4 4.12 2.23 - 35.3 - 41 Comparative Example 2 EBIZ ^c 200 4 0.61 3.54 91.2 7.9 71 21

* Polymerization conditions: catalyst (20μmol), MAO / Ti = 500, 70 ° C, 30 minutes

a is [Me ₄ CpSi (Me) ₂ NC ₆ H ₄ C (Me) ₂ C ₆ H ₄ C (Me) ₂ C ₆ H ₄ -NSi (Me) ₂ CpMe ₄ which is the catalyst used in Examples 7-8. ] TiCl ₂ ;

b means CGC, ie [Cp (Me) ₄ Si (Me) ₂ N- t- Bu] TiCl ₂ ; And

c means EBIZ, ie rac- [C ₂ H ₄ (Ind) ₂ ] ZrCl ₂ .

As shown in Table 1, in the case of ethylene / styrene copolymerization using the catalyst of the present invention, the same conditions as in the case of using the existing CGC or EBIZ (catalyst for ethylenebisindenyl zirconium chloride, iPP polymerization) Styrene copolymerization is excellent in, and shows a particularly high styrene copolymerization property compared to Comparative Example 2 using a zirconium catalyst. In addition, it can be confirmed that the alternating index is significantly higher than that of Comparative Examples 1-2. At the same time, since it has an isotactic degree of 60% or more, it can be seen that it is a semi-crystalline polymer having a melting point (˜125 ° C.) even in a region of high styrene content. The results indicate that, as disclosed in U.S. Patent No. 5,883,213, the melting point is about 90 ° C. for an ethylene / styrene copolymer having an isotactic degree of at least 95% with an alternating index of 55% and a 55% alternating index. Conflict with the results. This appears to be due to having a high alternating index, and it can be seen that it is a new isotactic alternating ethylene / styrene copolymer.

In general, the microstructure of the ethylene / styrene copolymer can be easily known through ¹³ C NMR, has a structure shown in Figure 1, as shown in Table 2 ¹³ C NMR chemical shift according to the microstructure of the ethylene / styrene copolymer (chemical shift) has an analysis result.

Carbon Chemical shift (ppm) S _ββ 25.80 S _ββ 27.89 S _γγ , S _{γγ +} 29.99 S _{αγ +} 35.06 S _αγ 37.05 S _αα 41.61 T 45.2-46.6

In FIG. 1 and Table 2, S means secondary carbon and T indicates methine bonded to the phenyl group of styrene as tertiary carbon. (alpha), (beta), (gamma) means the case where there exists the tertiary carbon by which the phenyl group was substituted in the adjacent position, the one crossing position, and the two crossing position, respectively. For example, S _αγ means that there is a tertiary carbon having a phenyl group of styrene at one neighboring position, and the tertiary carbon is present at two crossing positions on the other side. In addition, + is the case where tertiary carbon exists in the position which crossed more than three.

The structures of the copolymers prepared in Examples 7 to 8 and Comparative Examples 1 and 2 were analyzed using ¹³ C NMR, and the comparison of ¹³ C NMR analysis results of the polymers obtained in Example 7 and Comparative Example 1 was performed. As shown in FIG. Measurement of ¹³ C NMR was performed based on TMS (trimethyl silane) at 100 ° C. using trichlorobenzene and benzene-deuterium-6 as a mixed solvent. The polymer was substantially soluble at least 91% by weight in THF or CHCl ₃ at room temperature and completely dissolved in boiling THF.

Characteristically, in the case of the ethylene / styrene copolymer obtained in Example 7, the integral value near 25 ppm due to the alternating arrangement was higher than that of the pseudo-random copolymer. In addition, it was confirmed that the peak resulting from the ethylene chain in the vicinity of 30 ppm had almost no microstructure of the alternating arrangement. In addition, in both of the ¹³ C NMR spectra, there was no S _αα peak near 42 ppm resulting from the head-to-tail structure of styrene, from which the styrene chain of the styrene-styrene structure was observed. It can be seen that this does not exist.

In addition, the isotacticity was determined from the ratio of the tertiary carbon observed in the range of 45.2 to 46.6 ppm through the ratio of the integral value of the diad (mm) of 45.2 ppm and the total tertiary carbon integration value, As can be seen in Table 1, the results of Examples 7 and 8 were 63% and 65%, respectively. The results were compared with those of the conventional pseudorandom copolymer shown in Comparative Example 1.

As a result, the multi-nuclear constrained geometry catalyst of the present invention has improved copolymerization of styrene compared to the conventional constrained geometry catalyst, particularly isotactic. Alternating Ethylene / Styrene Copolymers can be used to prepare. Compared with the conventional ethylene / styrene copolymer, the polymer has a high polymerization activity under the same polymerization conditions, the copolymerization of styrene is greatly improved, and has a high alternating index of 80% or more, while having a stereoregularity of about 60%. Can be prepared. In addition, even in the case of a copolymer containing high styrene, a new semi-crystalline copolymer having a melting point of 125 ° C. can be prepared.

The metallocene catalyst for preparing the copolymer of ethylene / aromatic vinyl compound of the present invention exhibits high activity while having a constrained geometry and increases the amount of styrene introduced into the copolymer even under mild reaction conditions. It suppresses the production of homopolymer as much as possible and shows a uniform composition. In addition, the ethylene / aromatic vinyl compound copolymer prepared by the metallocene catalyst has an advantage that it can be produced in a large amount even with a small amount of cocatalyst while having excellent isotacticity and alternating arrangement.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (20)

A ligand bound to the central metal of the transition metal compound is linked to each other and includes two transition metals in one molecule, and is represented by the following general formula (1), and has a multinuclear constrained arrangement (Multi- Nuclear Constrained Geometry Metallocene Catalysts: In the formula (1), M is titanium (Ti), zirconium (Zr) or hafnium (Hf), the same or different from each other; Cp ¹ has a cyclopentadienyl group having no substituent, a cyclopentadienyl group containing 1 to 4 alkyl substituents having or without a ring structure, and an indenyl group having a substituent or no substituent Fluorenyl which does not have; Y is hydrogen or a group formed of a silyl group, an alkyl group, an aryl group, or a combination thereof having C ₁ to ₁₀ ; A is a hetero atom that is nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S); X is hydrogen, halogen, alkyl group, or aryl group; And G is a C _1-30 alkyl group, cycloalkyl group, aryl group, or alkylaryl group. A ligand bound to the central metal of the transition metal compound is linked to each other to include two transition metals in one molecule and is represented by the following general formula (2), and has a multinuclear constrained arrangement (Multi- Nuclear Constrained Geometry Metallocene Catalysts: In the formula (2), M is titanium (Ti), zirconium (Zr) or hafnium (Hf), the same or different from each other; Cp ¹ has a cyclopentadienyl group having no substituent, a cyclopentadienyl group containing 1 to 4 alkyl substituents having or without a ring structure, and an indenyl group having a substituent or no substituent Fluorenyl which does not have; Y is hydrogen or a group formed of a silyl group, an alkyl group, an aryl group, or a combination thereof having C ₁ to ₁₀ ; A is a hetero atom that is nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S); X is hydrogen, halogen, alkyl group, or aryl group; And G is a C _1-30 alkyl group, cycloalkyl group, aryl group, or alkylaryl group. A ligand bound to the central metal of the transition metal compound is linked to each other and contains two transition metals in one molecule, and is represented by the following general formula (3), and has a multinuclear constrained arrangement (Multi- Nuclear Constrained Geometry Metallocene Catalysts: In the formula (3), M is titanium (Ti), zirconium (Zr) or hafnium (Hf), the same or different from each other; Cp ¹ has a cyclopentadienyl group having no substituent, a cyclopentadienyl group containing 1 to 4 alkyl substituents having or without a ring structure, and an indenyl group having a substituent or no substituent Fluorenyl which does not have; Y is hydrogen or a group formed of a silyl group, an alkyl group, an aryl group, or a combination thereof having C ₁ to ₁₀ ; A is a hetero atom that is nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S); X is hydrogen, halogen, alkyl group, or aryl group; And G is a C _1-30 alkyl group, cycloalkyl group, aryl group, or alkylaryl group. A ligand bound to the central metal of the transition metal compound is linked to each other and includes three transition metals in one molecule, and is represented by the following general formula (4), and has a multinuclear constrained arrangement (Multi- Nuclear Constrained Geometry Metallocene Catalysts: In the formula (4), M is titanium (Ti), zirconium (Zr) or hafnium (Hf), the same or different from each other; Cp ¹ has a cyclopentadienyl group having no substituent, a cyclopentadienyl group containing 1 to 4 alkyl substituents having or without a ring structure, and an indenyl group having a substituent or no substituent Fluorenyl which does not have; Y is hydrogen or a group formed of a silyl group, an alkyl group, an aryl group, or a combination thereof having C ₁ to ₁₀ ; A is a hetero atom that is nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S); X is hydrogen, halogen, alkyl group, or aryl group; And G is a C _1-30 alkyl group, cycloalkyl group, aryl group, or alkylaryl group. A ligand bound to the central metal of the transition metal compound is linked to each other and includes four transition metals in one molecule, and is represented by the following general formula (5), and has a multinuclear constrained arrangement (Multi- Nuclear Constrained Geometry Metallocene Catalysts: In the formula (4), M is titanium (Ti), zirconium (Zr) or hafnium (Hf), the same or different from each other; Cp ¹ has a cyclopentadienyl group having no substituent, a cyclopentadienyl group containing 1 to 4 alkyl substituents having or without a ring structure, and an indenyl group having a substituent or no substituent Fluorenyl which does not have; Y is hydrogen or a group formed of a silyl group, an alkyl group, an aryl group, or a combination thereof having C ₁ to ₁₀ ; A is a hetero atom that is nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S); X is hydrogen, halogen, alkyl group, or aryl group; And G is a C _1-30 alkyl group, cycloalkyl group, aryl group, or alkylaryl group. An unsaturated ethylenic monomer or a monomer which is α, ω-diene is mixed with a monomer which is an aromatic vinyl compound; Using the metallocene catalyst according to any one of claims 1 to 5 as a main catalyst; And organometallic compounds or mixtures of non-coordinating Lewis acids with alkylaluminum as cocatalysts. The method for producing an ethylene / aromatic vinyl compound copolymer according to claim 6, wherein the organometallic compound is an alkylaluminum oxane or an organoaluminum compound. 8. The method of claim 7, wherein the alkyl aluminum oxane is methylaluminoxane (MAO) or modified methylaluminoxane (MMAO). The organoaluminum compound has a unit represented by the following general formula (6), and is a chain or cyclic aluminum oxane represented by the following structural formulas (7) and (8). Process for preparing ethylene / aromatic vinyl compound copolymer In the formulas (6), (7) and (8), R is a C _1-6 alkyl group, m and n are integers of 0-100. The non-coordinating Lewis acid according to claim 6, wherein the non-coordinating Lewis acid is N, N-dimethyl aniline tetrakis (pentafluorophenyl) borate, triphenyl carbenium tetrakis (pentafluorophenyl) borate, ferrocerium tetrakis (pentafluoro Rophenyl) borate, and tris (pentafluorophenyl) borate; The alkylaluminum is trimethyl aluminum, triethyl aluminum, diethyl aluminum chloride, dimethyl aluminum chloride, triisobutyl aluminum, diisobutyl aluminum chloride, tri (n-butyl) aluminum, tri (n-propyl) aluminum, and triiso Method for producing an ethylene / aromatic vinyl compound copolymer, characterized in that selected from the group consisting of propyl aluminum. The method for producing an ethylene / aromatic vinyl compound copolymer according to claim 6, wherein the molar ratio of aluminum in the organometallic compound and the transition metal in the metallocene catalyst component is 1: 1 to 10 ⁶ : 1. . The method for producing an ethylene / aromatic vinyl compound copolymer according to claim 6, wherein the molar ratio of the non-coordinated Lewis acid and the transition metal in the metallocene catalyst is 0.1: 1 to 20: 1. The method for producing an ethylene / aromatic vinyl compound copolymer according to claim 6, wherein the ethylene / aromatic vinyl compound copolymer is copolymerized at 0 to 200 占 폚. 7. A process according to claim 6, wherein an antioxidant, lubricant, plasticizer, ultraviolet absorber, stabilizer, pigment, colorant, filler, and / or blowing agent is further added. Ethylene / aromatic vinyl compound copolymer, characterized in that prepared by any one of claims 6-14. The ethylene / aromatic vinyl compound copolymer according to claim 15, wherein the ethylene content is 45-99 mol% and the aromatic vinyl compound content is 1-55 mol%. The ethylene / aromatic vinyl compound copolymer according to claim 15, wherein the weight average molecular weight is 13,000 or more and the melt index is 0.001 to 1000. 16. The ethylene / aromatic vinyl compound copolymer according to claim 15, wherein the isotactic degree diad index is at least 60% and the alternating index is at least 80%. 16. The peak according to claim 15, wherein there is no peak around 42 ppm resulting from the head-to-tail structure of the styrene chain in the peak analyzed using ¹³ C NMR based on trimethyl silane (TMS). Ethylene / aromatic vinyl compound copolymer. Polyethylene, ethylene / α-olefin copolymer, polypropylene, polyamide, aromatic polyester, polyisocyanate, polyurethane, polyacrylonitrile, silicone, or polyphenylene oxide is added to the ethylene / aromatic vinyl compound copolymer of claim 15. Blends prepared by addition in amounts of 0.5-50% by weight.