KR100328870B1 - Metallocene Catalysts for Ethylene/Styrene Co-polymerization and Method of preparing Same - Google Patents

Abstract

The metallocene catalyst of the present invention has a complex structure in which a cyanide group and a transition metal compound included in a styrene-acrylonitrile (SAN) copolymer are bonded to each other, and are represented by the following chemical formula:

In the above, Z ¹ , Z ² and Z ³ are represented by M ¹ L _n , M ¹ L _n-1 , and M ¹ L _n-2 , where M ¹ is Group 4, 5, 6, and 7 Or a transition metal of group 8, L is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen, or a combination thereof, and n is 1 to 4 Is an integer of; M ² is a metal of Group 1 or 2; X is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof; n is an integer from 1 to 4; And R ¹ is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof.

Description

Metallocene catalyst for ethylene / styrene copolymerization and its preparation method {Metallocene Catalysts for Ethylene / Styrene Co-polymerization and Method of preparing Same}

Field of invention

The present invention relates to a metallocene catalyst for producing an ethylene / styrene copolymer and a method for producing the same, and to an ethylene / styrene copolymer having a syndiotactic polystyrene structure using the specific metallocene catalyst. More specifically, the present invention is a metallocene catalyst prepared by treating SAN (poly (styrene-co-acrylonitrile)], an irregular copolymer of styrene and acrylonitrile, with an alkali alkyl compound and reacting the metal compound with a transition metal compound. And to a method for producing the same, and also to an ethylene / styrene copolymer including a syndiotactic polystyrene block capable of controlling styrene content using the catalyst.

Background of the Invention and Prior Art

The study for preparing copolymers of ethylene and aromatic vinyl compounds (styrene derivatives) was first carried out using a non-uniform Ziegler-Natta catalyst (Polymer Bulletin vol. 20, pp237-241). However, typical non-homogeneous Ziegler-Natta catalyst systems have limited activity and styrene reactivity (less than 1 mol% styrene) and produce low molecular weight copolymers, making them extremely limited. Homogeneous Ziegler-Natta catalysts using transition metals and organoaluminum compounds are also known in the art, but only a small amount of ethylene / styrene copolymer is produced.

Biscyclopentadienyl metallocene catalysts exhibit very low activity in this copolymerization reaction and also have very low regiospecificity. This occurs because the active point of the mixture of the homopolymer and the copolymer is different.

In addition, many efforts have been made to obtain ethylene / styrene copolymers using homogeneous titanocene and zirconocene catalysts, but in most cases, it was found to be produced as a mixture with a homopolymer and a polymer copolymerized in a small amount of styrene.

Meanwhile, Dow has a pseudo random structure using INSITE ^TM Technology Constrained Geometry Catalyst (CGC) in Japanese Patent Laid-Open Nos. 3-163088, 7-53618, and European Patent No. 416815 A2. The synthesis of ethylene / styrene copolymers is disclosed. The pseudo-random structure means a head-to-tail bond chain which is a general styrene chain. The copolymer contains 37 mol% of styrene.

Xu reported the synthesis of ethylene / styrene copolymers with perfect alternating in "Macromolecules" (1998, vol 31, p2395), where 50 mol% of styrene was copolymerized using ¹³ C NMR. The structure was analyzed. However, in this case, even if the concentration of copolymerized styrene was increased, the sequence of styrene-styrene could not be observed in the main chain, and more than 50 mol% of styrene was reported to be difficult to copolymerize. In addition, the phenyl groups in these copolymers have no stereoregularity and exhibited physical properties of the amorphous resin at a predetermined concentration or higher.

As described above, the ethylene / styrene copolymerization reaction using the Ziegler-Natta catalyst and the metallocene catalyst generates a mixture of homopolymers and copolymers or produces a copolymer having no stereoregularity, in particular styrene in the copolymer. The content is limited to 50 mol% or less.

Accordingly, the present inventors have stereoregularity unlike conventional amorphous random copolymers, and in particular, a metallocene catalyst for producing an ethylene / styrene copolymer including a syndiotactic polystyrene block and an ethylene / styrene air using the catalyst It is about to develop a coalition.

It is an object of the present invention to provide a novel high activity metallocene catalyst for producing ethylene / styrene copolymers having stereoregularity.

Another object of the present invention is to provide a catalyst comprising syndiotactic polystyrene blocks and capable of producing ethylene / styrene copolymers having stereoregularity.

Still another object of the present invention is to provide an ethylene / styrene copolymer having a crystalline structure even in a region of high styrene content, having a high melting point and excellent heat resistance and mechanical properties.

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.

In the metallocene catalyst of the present invention, a cyanide group included in a styrene-acrylonitrile (SAN) copolymer and a transition metal compound of Group 4, 5, 6, 7 or 8 Connected complex structure and reactant of the cyanide group and the metal compound of Group 1A or 2A and transition metal compound of Group 4, Group 5, Group 6, Group 7 or Group 8 combined to have a complex structure, It is represented by the formula (1), (2) or (3):

In formulas (1), (2), and (3), Z ¹ , Z ^2, and Z ³ are each represented by M ¹ L _n , M ¹ L _n-1 , M ¹ L _n-2 , where M ¹ Group 4 (Ti, Zr, Hf), Group 5 (V, Nb, Ta), Group 6 (Cr, Mo, W), Group 7 (Mn, Tc, Re) or Group 8 (Re, Ru, Os, Rh, Ir, Ni, Pd, Pt) is a transition metal, L is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen, or a combination thereof, And n is an integer from 1 to 4; M ² is Group 1A (Li, Na, K, Rb, Cs, Fr) or Group 2A (Be, Mg, Ca, Sr, Ba, Ra) on the periodic table; X is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof; n is an integer from 1 to 4; And R ¹ is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof.

Formula (1) is produced through a non-coordinated bond between a transition metal compound and a cyanide group of a SAN, and Formula (2) can be obtained by controlling the molar ratio of a cyanide group and an alkali alkyl compound of a SAN, and formula (3) The catalyst of is obtained by changing all cyanide groups in the SAN into imino groups and then reacting with the transition metal compound.

The transition metal compounds of the Group 4 of the periodic table include titanium tetrachloride (TiCl ₄ ), zirconium tetrachloride (ZrCl ₄ ), hafnium tetrachloride (HfCl ₄ ), titanium tetrafluoro (TiF ₄ ), tetrafluorozirconium (ZrF ₄ ), and tetrafluoro Lohafnium (HfF ₄ ), and the like.

Representative examples of such transition metal compounds are as follows:

Titanium (III) chloride, titanium (IV) chloride, titanium (III) methoxide, titanium (III) ethoxide, titanium (III) isopropoxide, titanium (III) propoxide, titanium (III) butoxide, Titanium (IV) methoxide, titanium (IV) ethoxide, titanium (IV) isopropoxide, titanium (IV) propoxide, titanium (IV) butoxide, pentamethylcyclopentadienyl titanium trichloride, pentamethyl Cyclopentadienylmethoxytitanium dichloride, pentamethylcyclopentadienyldimethoxytitanium monochloride, 1,2,3,4-tetramethylcyclopentadienyltitanium trichloride, 1,2,3,4-tetramethylcyclo Pentadienylmethoxytitanium dichloride, 1,2,3,4-tetramethylcyclopentadienyldimethoxytitanium monochloride, 1,2,4-trimethylcyclopentadienyltitanium trichloride, 1,2,4-trimethyl Cyclopenta Enylmethoxytitanium dichloride, 1,2,4-trimethylcyclopentadienyldimethoxytitanium monochloride, 1,2-dimethylcyclopentadienyltitanium trichloride, 1,2-dimethylcyclopentadienylmethoxytitanium dichloride , 1,2-dimethylcyclopentadienyldimethoxytitanium monochloride, methylcyclopentadienyltitanium trichloride, methylcyclopentadienylmethoxytitanium dichloride, methylcyclopentadienyldimethoxytitanium monochloride, cyclopentadienyl Titanium trichloride, cyclopentadienylmethoxytitanium dichloride, cyclopentadienyldimethoxytitanium monochloride, pentamethylcyclopentadienylmethyltitanium dichloride, pentamethylcyclopentadienyldimethyltitanium monochloride, 1,2, 3,4-tetramethylcyclopentadienylmethyltitanium dichloride, 1,2,3, 4-tetramethylcyclopentadienyldimethyltitanium monochloride, 1,2,4-trimethylcyclopentadienylmethyltitanium dichloride, 1,2,4-trimethylcyclopentadienyldimethyltitanium monochloride, 1,2-dimethyl Cyclopentadienylmethyltitanium dichloride, 1,2-dimethylcyclopentadienyldimethyltitanium monochloride, methylcyclopentadienylmethyltitanium dichloride, methylcyclopentadienyldimethyltitanium monochloride, cyclopentadienylmethyltitanium dichloride Chloride, and cyclopentadienyldimethyltitanium monochloride.

The styrene-acrylonitrile (SAN) copolymer used in the present invention has a molecular weight of the polymer main chain in the range of 1,000 to 1,000,000, preferably in the range of 10,000 to 300,000. The content of acrylonitrile is in the range of 1 to 99% by weight, preferably in the range of 5 to 50% by weight.

The metallocene catalyst of the present invention is prepared as follows:

Styrene-acrylonitrile (SAN) is dissolved in an organic solvent and the solution is directly reacted with a transition metal compound of Group 4, 5, 6, 7 or 8 of the periodic table, or SAN is dissolved in an organic solvent. The solution is reacted with a metal compound of Group 1A or 2A and then with the transition metal compound described above; Separating the solid layer and the liquid layer formed through the reaction; After washing only the separated solid layer (catalyst) again with an organic solvent, a metallocene catalyst is obtained by vacuum drying the washed catalyst.

The organic solvent used in the manufacturing process is an aliphatic hydrocarbon, an aromatic hydrocarbon or a halogenated hydrocarbon thereof. That is, representative examples of organic solvents that can be used when dissolving SAN in an organic solvent include toluene and dichloromethane, and a liquid layer is separated from a solid layer and a liquid layer formed by reacting the SAN with a transition metal compound. Representative organic solvents used when the layers are washed again with organic solvents are hydrocarbon solvents such as hexane and toluene.

The reaction of the SAN and the transition metal compound dissolved in the organic solvent is represented by the following reaction formula (1):

In Reaction Scheme (1), M ¹ , M ² , L and n are as defined in Formulas (1), (2), and (3), respectively, and p and q are relative to styrene and acrylonitrile monomers. Is an integer representing the statistical distribution according to reactivity, and m is an integer from 1 to 2.

In the above scheme (1), the SAN copolymer can be reacted with the transition metal compound represented by M ¹ L _n to obtain the metallocene catalyst of the present invention represented by the formula (1). In addition, the present invention is represented by the formula (2) or (3) when the SAN copolymer is first treated with an alkali alkyl compound represented by R ¹ M ² L _m and then reacted with a transition metal compound represented by M ¹ L _n . The metallocene catalyst of can be obtained.

The metallocene catalyst prepared by the present invention is usually used as a catalyst for polymerizing olefins by being supported on a dehydrated support. Examples of the support include silica, alumina, MgR ¹ R ² (where R ¹ and R ² are alkyl groups, aryl groups, alkoxy, amido groups or halogens), zeolites, aluminum phosphates, zirconia and the like.

As a method of supporting the metallocene catalyst of the present invention, a method of directly supporting the catalyst on a support and a support on the support body after treating the surface of the support with a promoter of aluminum, a non-aluminum compound, or an organometallic compound are supported. There is a way to.

Cocatalysts are already known in the art, using organometallic compounds, or mixtures of non-coordinated Lewis acids with alkylaluminum. The organometallic compound is an alkyl aluminum oxane or an organoaluminum compound. Representative examples of the alkyl aluminum oxane include methyl aluminum oxane (MAO) and modified methyl aluminum oxane (MAMAO), and the alkyl aluminum oxane has a unit represented by the following formula (4) And aluminum oxanes, which are chain and cyclic aluminum oxanes represented by the following formulas (5) and (6):

In the formula (4), (5) and (6) R ² is an alkyl group of C _1~6, and r is an integer from 0 to 100.

In the present invention, the ratio of the aluminum to the transition metal in the metallocene catalyst component, that is, the molar ratio of aluminum to the transition metal (for example, titanium, zirconium, and hafnium) in the alkylaluminum oxalate component is 1: 1 to 1 × 10 ⁶ : 1 More preferably, the range of 10: 1 to 1x10 < ⁴ : 1 is good.

In the mixture of non-coordinated Lewis acid and alkylaluminum used as a promoter, the non-coordinated Lewis acid is N, N'-dimethylanilinetetrakis (pentafluorophenyl) borate, triphenyl carbeni Um tetrakis (pentafluorophenyl) borate and the like, and the alkyl aluminum is trimethyl aluminum, triethyl aluminum, diethyl aluminum chloride, dimethyl aluminum chloride, triisobutyl aluminum, diisobutyl aluminum chloride, tri (n-butyl Aluminium, tri (n-propyl) aluminum, triisopropyl aluminum and the like.

In the catalyst system comprising the metallocene catalyst and the cocatalyst of the present invention, the molar ratio of non-coordinated Lewis acid: transition metal is preferably in the range of 0.1: 1 to 20: 1, and the molar ratio of alkylaluminum: transition metal in the catalyst component is The range of 1: 1 to 1000: 1 is preferable, and the range of 1: 1 to 500: 1 is more preferable.

The polymerization temperature for polymerizing styrene or olefins using the catalyst system of the present invention is preferably 0 to 140 ° C, more preferably in the range of 30 to 100 ° C.

The monomers polymerized using the catalyst system of the present invention are styrene and styrene derivatives, or unsaturated olefins, and the monomers may be homopolymerized or two or more of the monomers may be copolymerized.

The structures of the styrene-based and styrene-based derivatives polymerized using the catalyst system of the present invention can be represented by the following formulas (7) and (8):

In formula (7) J ¹ is a hydrogen atom; Halogen atom; Or a substituent including at least one carbon atom, oxygen atom, silicon atom, phosphorus atom, sulfur atom, serenium or tin atom, and when m is 2 to 3, each may independently have a different substituent.

In Formula (8), J ¹ is the same as defined in Formula (7), J ² is a substituent consisting of C ₂ to ₁₀ having at least one unsaturated bond, m is an integer from 1 to 3, n Is 1 or 2, and when m is 2 or more and n is 2, each may independently have a different substituent.

Specific examples of the compound having the formula (7) include alkyl styrene, halogenated styrene, halogen-substituted alkyl styrene, alkoxy styrene, vinyl biphenyl, vinylphenylnaphthalene, vinylphenylanthracene, vinylphenylpyrene, trialkylsilylvinylbiphenyl, trialkyl Stenibiphenyl, alkylsilyl styrene, carboxymethyl styrene, alkyl ester styrene, vinyl benzene sulfonic acid ester, vinyl benzyl dialkoxy phosphide and the like.

Alkyl styrene includes styrene, methyl styrene, ethyl styrene, butyl styrene, para-methyl styrene, para-t-butyl styrene and dimethyl styrene. Halogenated styrene includes chloro styrene, bromostyrene, and fluoro styrene. Examples of the halogen-substituted alkyl styrene include chloromethyl styrene, bromomethyl styrene and fluoromethyl styrene. Examples of the alkoxy styrene include methoxy styrene, ethoxy styrene and butoxy styrene. Vinyl biphenyl, 3-vinyl biphenyl, 2-vinyl biphenyl, and the like, and as vinyl phenyl naphthalene, 1- (4-vinyl biphenyl naphthalene), 2- (4-vinyl biphenyl naphthalene), 1- (3 -Vinylbiphenylnaphthalene), 2- (3-vinylbiphenylnaphthalene), 1- (2-vinylbiphenylnaphthalene), and the like, and examples of vinylphenylanthracene include 1- (4-vinylphenyl) anthracene and 2- ( 4-vinylphenyl) anthracene, 9- (4-vinylphenyl) anthracene, 1- (3-ratio 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.

Specific examples of the compounds having the formula (8) include divinylbenzene such as p-divinylbenzene, m-divinylbenzene and the like; Trivinylbenzene; And aryl styrene such as p-aryl styrene, m-aryl styrene and the like.

In addition, the structure of the unsaturated olefin polymerized using the catalyst of the present invention can be represented by the following formula (9):

Wherein E ¹ , E ² , E ³ and E ⁴ are each independently a hydrogen atom; Halogen atom; Represents a substituent including at least one carbon atom, oxygen atom, silicon atom, phosphorus atom, sulfur atom, serenium or tin atom, and each of E ¹ , E ² , E ³ and E ⁴ independently have a different substituent Can be.

Examples of the formula (9) include α-olefin, cyclic olefin, diene, vinyl ketone, acrolein, acrylonitrile, acrylamide, acrylic acid, vinyl acetate and the like.

α-olefins include ethylene, propylene, 1-butene, 1-hexene, 1-octene, and the like, and cyclic olefins include cyclobutene, cyclopentene, cyclohexene, 3-methylcyclopentene, 3-methylcyclohexene, Norbornene and the like, dienes include 1,3-butadiene, isoprene, 1-ethoxy-1,3-butadiene, and chloroprene; and vinyl ketones include methyl vinyl ketone, phenyl vinyl ketone, ethyl vinyl ketone, and n. -Propyl vinyl ketone, and the like, and acrolein include acrolein and methacrolein. Acrylonitrile includes vinylidene cyanide, methoxy acrylonitrile, phenyl acrylonitrile, and the like. -Methyl acrylamide, N-ethyl acrylamide, N-isopropyl acrylamide, and the like, acrylic acid chloride and the like, and vinyl acetate, vinyl acetate and the like.

The solvent used in the preparation of the ethylene / styrene copolymer of the present invention may be a hydrocarbon solvent such as toluene, hexane, heptane, and the copolymer may be obtained even through bulk polymerization without using any solvent. The amount of the polymerization catalyst is 10 ^-7 to 10 ^-2 mol per 1 L solvent, preferably 10 ^-5 to 10 ^-4 mol. Styrene polymerization temperature is 0-100 degreeC, Preferably it is 30-90 degreeC.

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.

Examples 1-4: Catalytic Synthesis

Example 1 SAN-TiCl ₄

SAN (poly (styrene-co-acrylonitrile) compound (2g, 7.54mmol CN) containing 20% acrylonitrile was dissolved in organic solvent (toluene, 100ml) and titanium tetrachloride (TiCl ₄₎ (10 mmol) compound immediately precipitates an orange solid, and the reaction mixture is reacted for about 10 hours, then the liquid phase and the solid phase are separated, and the solid phase is taken. The organic solvent [toluene (100 ml × 1) and hexane ( 100 ml x 4)] and dried under vacuum to prepare a SAN-TiCl ₄ catalyst, wherein the polymer-catalyst obtained contained 10.1 wt% Ti.

Example 2: SAN-Mg-TiCl ₄

SAN compounds containing 20% acrylonitrile (2 g, 7.54 mmol CN) and 5 g calcinated silica (1.45 mmol OH / g silica) were dissolved in an organic solvent (100 ml of toluene) and butylmagnesium chloride at low temperature. chloride) (8mmol) is injected into the syringe and allowed to react for 10 hours or more. A white solid precipitates out. The reaction mixture is filtered, washed with toluene (80 ml x 1) and purified hexane (100 ml) is injected into the cannular. Titanium tetrachloride (16 mmol) is injected into the syringe and reacted at room temperature for 4 hours. The liquid and solid phases were separated, and only the solid phase was taken up, washed with an organic solvent (100 ml × 5 of nucleic acid), and dried under vacuum to prepare a SAN-Mg-TiCl ₄ catalyst. The polymer-catalyst thus obtained contained 3.3 wt% Ti and 2.6 wt% Mg.

Example 3: SAN-Mg-Cp * TiCl ₃

SAN compound containing 20% acrylonitrile (2 g, 7.54 mmol CN) was dissolved in an organic solvent (100 ml of toluene), and butylmagnesium chloride (8 mmol) was injected into a syringe at a low temperature. When reacted for more than a time, a white solid precipitates. The reaction mixture was filtered, washed with toluene (80 ml x 1), and purified hexane (100 ml) was injected into a cannular. Herein, pentamethylcyclopentadienyltitanium trichloride (Cp * TiCl ₃ , 1.6 g, 5.5 mmol) was dissolved in toluene (50 ml) and reacted at room temperature for 4 hours. The liquid and solid phases were separated, and only the solid phase was taken, washed with an organic solvent [toluene (100 ml × 2) and hexane (100 ml × 3)], and dried under vacuum to prepare a SAN-Mg-TiCl ₄ catalyst. The polymer-catalyst thus obtained contained 2.2 wt% Ti and 5.5 wt% Mg.

Example 4 SAN-Mg-Cp * Ti (OMe) ₃

Pentamethylcyclopentadienyltitanium trimethoxide (Cp * Ti (OMe) ₃ , 1.2 g, 4.35 mmol) was prepared in the same manner as in Example 3 except that the mixture was dissolved in toluene (50 ml). The polymer-catalyst thus obtained contained 1.2 wt% Ti and 6.3 wt% Mg.

Comparative Examples 1 to 3: Catalyst Synthesis

Comparative Example 1

Anhydrous magnesium chloride 4.76 g (0.05 mmol) was suspended in 50 ml of decane in the presence of nitrogen, 30 ml (0.2 mmol) of 2-ethylhexyl alcohol was added thereto, and the mixture was slowly heated to react at 100 ° C. for 2 hours to prepare a uniform solution. After the temperature was lowered to room temperature, 12 ml (0.1 mmol) of SiCl ₄ was slowly added dropwise and reacted at 50 ° C. for 1 hour to form a carrier. After lowering the temperature to room temperature, 30 ml (0.27 mmol) of TiCl ₄ was slowly added dropwise and 80 ° C. The catalyst was prepared by reacting for 2 hours at. The prepared catalyst was washed with 100 ml of purified hexane until free titanium was removed, and then dried and stored. The polymerization process was carried out in the same manner as described in Example 1. 150 g of the polymer was obtained and had an activity of 8.3 kg-PE / mmol-Ti. The average particle size of the polymer was 350 μm, the span was 1.5, and the apparent density was 0.27 g / ml.

Comparative Example 2: 1,2,3,4,5-pentamethylcyclopentadienyl titanium trichloride

126 mmol (4.93 g) of potassium was weighed into the flask, followed by 150 ml of THF (Tetra hydrofuran). After the reaction vessel was lowered to 0 ° C., 126 mmol (17.17 g) of Cp * (1,2,3,4,5-pentamethylcyclopentadiene) was slowly added, and the reaction temperature was raised to reflux. As the reaction progressed, a white solid insoluble in the bottom subsided. After refluxing, the reflux was stopped for a further 1 hour, the reflux was stopped, the temperature was lowered to 0 ° C., and 130 mmol (14.12 g) of chlorotrimethylsilane was slowly added using a syringe. After stirring for 2 hours through a celite (filter) to obtain a slightly yellow clear solution, to remove the solvent (THF) under a reduced pressure of about 0.1torr Cp * (1, 2, A compound in which trimethylsilan was substituted with 3,4,5-pentamethylcyclopentadiene) was obtained in a yield of 90%. 88.9 mmol (18.5 g) of this compound was mixed with toluene (50 ml), and 16.86 g of TiCl ₄ (88.9 mmol) was added to the toluene (200 ml) solution and added slowly. After stirring this red solution for 2 hours, toluene was removed under reduced pressure, washed with pentane or hexane and dried well to obtain 1,2,3,4,5-pentamethyl, a kind of typical half metallocene. Cyclopentadienyl titanium trichloride (Cp * TiCl ₃ ) was obtained in 95% yield.

Comparative Example 3: 1,2,3,4,5-pentamethylcyclopentadienyl titanium trimethoxide

20 mmol (5.79 g) of a compound (Cp * TiCl ₃ ) synthesized as in Comparative Example 2 was placed in a flask, and THF (100 ml) was added thereto to dissolve. In another flask, 60 mmol (1.92 g) of dried MeOH was dissolved in THF (100 ml), and the temperature of the reaction vessel was lowered to -78 ° C. Triethylamine 61mmol (6.1g) was added to the vessel, stirred at that temperature for about 30 minutes, and Cp * TiCl ₃ dissolved in 100 ml of THF was dissolved in methanol and triethylamine THF. (100 ml) was added slowly to the solution. After the addition, the temperature of the reaction vessel was gradually raised to room temperature. Thereafter, after reacting at room temperature for about 12 hours, THF was removed under reduced pressure, 100 ml of hexane was added thereto, stirred for 30 minutes, and filtered through celite to obtain a yellow solution. The solvent of this yellow solution was dried in vacuo to give 1,2,3,4,5-pentamethylcyclopentadienyl titaniumtrimethoxide (Cp * Ti (OMe) ₃ ) at a yield of 79%.

Examples 5-11 and Comparative Examples 4-6: Ethylene / Styrene Copolymerization

Ethylene / styrene polymerization was carried out using novel metallocene catalysts (catalysts 1-4) prepared in Examples 1-4.

Styrene polymerization was carried out in a 1 L glass reactor with an external thermostat, a magnetic stirrer and a valve capable of supplying monomers and nitrogen. After vacuum ethylene was injected into the glass reactor under vacuum, a predetermined amount of purified styrene (200 mL) was added thereto, and triisobutyl aluminum was treated to remove impurities such as moisture. After a certain time, the required amount of MAO as a promoter was added, and then a required amount of catalyst was injected to carry out polymerization. After the polymerization for a certain time, a small amount of methanol was added to terminate the polymerization, and the obtained mixture was poured into a large amount of methanol added with sodium hydroxide to obtain a polymer, washed with water and methanol, and then vacuum dried for several hours. The polymer thus obtained was dissolved in boiling THF to dissolve the copolymers.

Other polymerization was carried out under polymerization conditions at 70 ° C. for 1 hour, and the characteristics of various polymerization conditions are shown in Table 1.

division Ethylene (psig) [MAO] / [Ti] [TiBA] / [Ti] Yield (g) THF dissolved wt% Styrene content (mol%) Melting Point (℃) Average molecular weight (× 10 ⁴ ) Molecular weight distribution Example 5 Catalyst 1 30 700 200 14.3 10.8 59 262 20.9 2.53 Example 6 30 420 200 9.4 20.6 53 260 19.8 2.60 Example 7 30 140 200 2.88 42 72 267 7.56 2.57 Example 8 Catalyst 2 30 400 200 35.5 17 55 94/242/262 15.5 8.46 Example 9 180 700 200 10.8 50 4.5 121 29.2 4.51 Example 10 Catalyst 3 30 400 200 3.5 71 82 - 8.6 7.79 Example 11 Catalyst 4 30 400 200 10.7 25.4 97 - 1.9 3.34 Comparative Example 4 Comparative Catalyst 1 30 700 200 7.8 <5 97 - 2.0 1.55 Comparative Example 5 Comparative Catalyst 2 30 700 200 5.3 0 - - - - Comparative Example 6 Comparative Catalyst 3 30 700 200 7.2 0 - - - -

¹³ C NMR was measured using a mixed solvent of trichlorobenzene and benzene-d6 using TMS (tetramethylsilane) as a standard. These polymers were measured at high temperature (100 ° C.) because of their reduced solubility in the solvent at room temperature.

The distribution of peaks in methine and methylene carbon is shown in Table 2 below. Here, the symbol S means methylene group (secondary carbon), and the symbol T means methine group (tertiary carbon). In addition, the symbols alpha, beta, and gamma respectively mean mutual relations with adjacent carbons, carbon at one crossing position, and carbon at two crossing positions.

In general, the microstructure of the ethylene / styrene copolymer is known to be determined using ¹³ C NMR, and the chemical shift of the ethylene / styrene copolymer is as follows (Macromolecules vol. 13, p849).

δ ppm (TMS standard) carbon Sequence Remarks 27.97 Sβδ ESE, SEEn> 1 29.89 Sγδ + Sδδ SEEn> 1 29.99 Sδδ EEE 37.30 Sαγ + Sαδ SES + SEE 41.83 Tββ SSS Syndiotactic 44.08 Tβδ SSE Syndiotactic 45.2 Sαα SSS Syndiotactic 145.79 Ph- SSS Syndiotactic 146.36 ESE

In Table 2, the peaks of 41.83, 44.08, 45.2 and 145.79 ppm appear when two or more neighboring styrene repeat units have syndiotactic conformation with each other, in particular 41.83, 45.2 and 145.72 ppm resulting from the SSS sequence. Peaks are also shown in homo syndiotactic polystyrene. The copolymers of the present invention showed characteristic peaks of syndiotactic polystyrene in the portion dissolved in boiling THF, and it was found that syndiotactic polystyrene blocks exist in the ethylene / styrene copolymer. In addition, the peaks seen at 29.7 ppm and 37.3 ppm are attributable to the structure of ethylene-styrene-ethylene and the structure of styrene-ethylene-styrene, respectively. In the copolymer of the present invention, the peak at this position was very small.

The reactivity ratio of ethylene and styrene (r _s r _e ) and the length of repeating units of ethylene and styrene were obtained by the methods disclosed in the literature (US Pat. No. 5,543,484), and the results are shown in Table 3 below. In the reactivity ratio (r _s r _e ), r _s is the reactivity of styrene, r _e is the reactivity of ethylene, and their product is expressed as the reactivity ratio.

division [Styrene] / [ethylene] r _s r _e n _{s Number of} styrene repeat units n _e ethylene repeat unit average number Catalyst 1 7.5 109 3 20 Catalyst 2 7.5 31.9 19 7 Catalyst 2 2 59.2 8 21 Catalyst 3 7.5 24 20 5.5 Comparative Catalyst 1 7.5 - polystyrene Polyethylene

It can be seen from the above-described reactivity ratio that the polymer-catalysts can produce block copolymers, and the length of the syndiotactic polystyrene block can be easily adjusted according to the concentration of the monomer.

In addition, in the case of the copolymer polymerized under the conditions of [Styrene] / [ethylene] = 7.5 using the catalyst 2 of Example 2, the resultant was subjected to cross-fractionation chromatography (CFC) in 1,2-dichlorobenzene solvent at 0 ° C. It was confirmed that the homopolymer completely eluted. This copolymer was then observed on the Differential Scanning Calorimeter (DSC) at around 260 ° C., which appears to be due to syndiotactic polystyrene blocks (secondary melting point, 10 ° C./min).

The present invention provides a catalyst for producing an ethylene / styrene copolymer having stereoregularity, including a syndiotactic polystyrene block, and a method for preparing the same, wherein the catalyst has a crystalline structure even in a region of high styrene content. It has the effect of providing an ethylene / styrene copolymer having a high melting point and excellent heat resistance and mechanical properties.

Simple modifications or variations of the present invention can be readily understood 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 (15)

Styrene-acrylonitrile (SAN) copolymer is dissolved in an organic solvent; Reacting the solution with a metal compound of group 1A or 2A; Reacting the solution with a transition metal compound of Group 4, 5, 6, 7 or 8 of the Periodic Table; Separating the reaction solution into a solid layer and a liquid layer; Washing the separated solid layer (catalyst) again with an organic solvent; And Vacuum drying the washed catalyst; Method for producing a metallocene catalyst for ethylene / styrene copolymer, characterized in that consisting of steps. delete The method of claim 1, further comprising supporting a solution of the SAN copolymer dissolved in an organic solvent on a support. 4. The support of claim 3 wherein the support is selected from the group consisting of silica, alumina, MgR ¹ R ² (where R ¹ and R ² are alkyl groups, aryl groups, alkoxy, amido groups or halogens), zeolites, aluminum phosphates and zirconia Method for producing a metallocene catalyst for ethylene / styrene copolymer, characterized in that. The metallocene catalyst for ethylene / styrene copolymerization of claim 1, wherein the SAN copolymer has a molecular weight of the polymer main chain in the range of 1,000 to 1,000,000 and an acrylonitrile content in the range of 1 to 99% by weight. Manufacturing method. The method of claim 1, wherein the transition metal compound is titanium (III) chloride, titanium (IV) chloride, titanium (III) methoxide, titanium (III) ethoxide, titanium (III) isopropoxide, titanium (III) Propoxide, titanium (III) butoxide, titanium (IV) methoxide, titanium (IV) ethoxide, titanium (IV) isopropoxide, titanium (IV) propoxide, titanium (IV) butoxide, penta Methylcyclopentadienyl titanium trichloride, pentamethylcyclopentadienylmethoxytitanium dichloride, pentamethylcyclopentadienyldimethoxytitanium monochloride, 1,2,3,4-tetramethylcyclopentadienyltitanium trichloride, 1,2,3,4-tetramethylcyclopentadienylmethoxytitanium dichloride, 1,2,3,4-tetramethylcyclopentadienyldimethoxytitanium monochloride, 1,2,4-trimethylcyclopentadienyl titanium Rechloride, 1,2,4-trimethylcyclopentadienylmethoxytitanium dichloride, 1,2,4-trimethylcyclopentadienyldimethoxytitanium monochloride, 1,2-dimethylcyclopentadienyltitanium trichloride, 1 , 2-dimethylcyclopentadienylmethoxytitanium dichloride, 1,2-dimethylcyclopentadienyldimethoxytitanium monochloride, methylcyclopentadienyltitanium trichloride, methylcyclopentadienylmethoxytitanium dichloride, methylcyclopenta Dienyldimethoxytitanium monochloride, cyclopentadienyltitanium trichloride, cyclopentadienylmethoxytitanium dichloride, cyclopentadienyldimethoxytitanium monochloride, pentamethylcyclopentadienylmethyltitanium dichloride, pentamethylcyclo Pentadienyldimethyltitanium monochloride, 1,2,3,4-tetramethylcyclo Tadienylmethyltitanium dichloride, 1,2,3,4-tetramethylcyclopentadienyldimethyltitanium monochloride, 1,2,4-trimethylcyclopentadienylmethyltitanium dichloride, 1,2,4-trimethyl Cyclopentadienyldimethyltitanium monochloride, 1,2-dimethylcyclopentadienylmethyltitanium dichloride, 1,2-dimethylcyclopentadienyldimethyltitanium monochloride, methylcyclopentadienylmethyltitanium dichloride, methylcyclopenta A method for producing a metallocene catalyst for ethylene / styrene copolymerization, which is selected from the group consisting of dienyldimethyltitanium monochloride, cyclopentadienylmethyltitanium dichloride, and cyclopentadienyldimethyltitanium monochloride. The method of claim 1, wherein the organic solvent is an aliphatic, aromatic hydrocarbon or a halogenated hydrocarbon thereof. A metallocene catalyst for ethylene / styrene copolymerization prepared by any one of claims 1 to 7 and represented by the following general formula (3): Formula 3 In Formula (3), Z ³ is represented by M ¹ L _n-2 (wherein M ¹ is Group 4 (Ti, Zr, Hf), Group 5 (V, Nb, Ta), Group 6 (Cr, Mo, W), Group 7 (Mn, Tc, Re) or Group 8 (Re, Ru, Os, Rh, Ir, Ni, Pd, Pt) transition metal, L is hydrogen, alkyl group, aryl group, silyl group, alkoxy A group formed of a group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof, and n is an integer of 1 to 4); M ² is a metal of Group 1 (Li, Na, K, Rb, Cs, Fr) or Group 2 (Be, Mg, Ca, Sr, Ba, Ra); X is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof; n is an integer from 1 to 4; And R ¹ is a group formed of hydrogen, an alkyl group, an aryl group, a silyl group, an alkoxy group, an aryloxy group, a siloxy group, an amido group, a halogen or a combination thereof. A polymerization method of ethylene / styrene copolymers, which comprises polymerizing ethylene and styrene using a catalyst system comprising a metallocene catalyst and a promoter according to claim 8. 10. The method of claim 9, wherein the cocatalyst is an organometallic compound. The polymerization method of ethylene / styrene copolymer according to claim 10, wherein the organometallic compound comprises at least one of an alkylaluminum oxane and an organoaluminum compound. The method of claim 11, wherein the alkyl aluminum oxane is methyl aluminum oxane and modified methyl aluminum oxane. The organoaluminum compound according to claim 11, wherein the organoaluminum compound has aluminum oxane represented by the following formula (4) as a unit, and is a chain-shaped and cyclic aluminum oxane represented by the following formulas (5) and (6). Polymerization method of ethylene / styrene copolymer: Formula 4 Formula 5 Formula 6 In formulas (4), (5) and (6), R ² is a C _1-6 alkyl group, and r is an integer from 0 to 100. Ethylene / styrene copolymer prepared according to any one of claims 9 to 13, characterized in that the average molecular weight is at least 30,000, the styrene content is from 1 to 99 mol% and comprises syndiotactic polystyrene blocks. . 15. The ethylene / styrene copolymer of claim 14, wherein the syndiotactic polystyrene block has at least three styrene repeat units.