KR20190066896A - Method for preparing supported metallocene catalyst, the supported metallocene catalyst prepared by the same method, and polypropylene prepared by using the same - Google Patents

Abstract

The present invention relates to a method for preparing a metallocene supported catalyst, which exhibits excellent catalytic activity, a metallocene supported catalyst prepared thereby, and polypropylene prepared by using the same. The method for preparing a metallocene supported catalyst of the present invention comprises the steps of: immersing an alkylaluminoxane-based cocatalyst on a carrier; and immersing a metallocene compound of chemical formula 1 on the carrier supported with the alkylaluminoxane-based cocatalyst.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a metallocene supported catalyst, a metallocene supported catalyst prepared by the above production method, and a polypropylene prepared by the preparation of the supported metallocene supported catalyst, BY USING THE SAME}

The present invention relates to a process for producing a metallocene supported catalyst useful in the production of a polypropylene having a narrow molecular weight distribution together with a high molecular weight, a metallocene supported catalyst prepared by the above process, and a polypropylene prepared using the metallocene supported catalyst .

Ziegler-Natta catalyst widely applied to existing commercial processes is characterized by a wide molecular weight distribution of the produced polymer because it is a multi-site catalyst and the composition distribution of the comonomer is not uniform.

On the other hand, the metallocene catalyst has a narrow molecular weight distribution of a polymer produced by a single active site catalyst having one kind of active site, and the molecular weight, stereoregularity, crystallinity, especially reactivity of the comonomer, There are advantages that can be adjusted.

The metallocene catalyst system is composed of a combination of a main catalyst mainly composed of a transition metal compound centered on a Group 4 metal and a cocatalyst comprising an organometallic compound mainly composed of a Group 13 metal such as aluminum. Polymers such as polyolefins having a narrow molecular weight distribution can be prepared according to the single active site characteristics of the catalyst.

The molecular weight and molecular weight distribution of polyolefins are important factors in determining the physical properties of the polymer and the flow and mechanical properties affecting the processability of the polymer. In order to produce various polyolefin products, it is important to improve the melt processability by controlling the molecular weight distribution. Particularly, in the case of polyethylene, quality, resistance and resistance to environmental stress are very important. Accordingly, a method of improving the mechanical properties of a high molecular weight resin and the processability in a low molecular weight portion by producing a polyolefin having such a high molecular weight distribution is also proposed.

On the other hand, when the polyolefin is produced through the slurry process, silica is used as a general carrier of the supported catalyst, and methylaluminoxane (MAO) and one or more organometallic catalysts (for example, , A metallocene catalyst) is supported on the supported catalyst. However, the MAO used for the activation of the supported catalyst is expensive and requires a larger amount of the metallocene catalyst than the metallocene catalyst, which accounts for a large portion of the catalyst cost, which is a major factor that lowers the price competitiveness of the metallocene-producing polyolefin in commercial terms.

Therefore, efforts have been made to reduce the amount of aluminoxane such as MAO, which is generally used, or to replace it with another cocatalyst. However, in most of the conventional techniques, when the MAO used for the supported catalyst activation is changed to another catalyst, the catalytic activity thereof is very poor, and a method for preparing the supported catalyst is required.

On the other hand, alkylaluminum is used as a scavenger or cocatalyst in the olefin polymerization process. However, when alkyl aluminum remains, it is difficult to produce a high molecular weight olefin polymer by participating in polymerization and acting as a chain transfer agent.

In order to solve the problems of the prior art, the present invention relates to a polyolefin which exhibits a single type of catalytically active species with high catalytic activity and has a high molecular weight and a narrow molecular weight distribution, particularly a metallocene supported catalyst capable of producing polypropylene A supported metallocene catalyst prepared by the above process, and a polypropylene prepared by using the metallocene supported catalyst.

Thus, according to one embodiment of the present invention, there is provided a method for producing a catalyst, comprising: supporting an alkylaluminoxane- And supporting the metallocene compound represented by the following formula (1) on the carrier carrying the alkylaluminoxane-based promoter,

Further comprising the step of supporting the alkylaluminum on the carrier before or after the loading of the metallocene compound,

[Chemical Formula 1]

In Formula 1,

A is carbon, silicon or germanium,

M is a transition metal of Group 4,

R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl,

R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl group, a C _1-20 ether, C _1-20 silyl ether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,

R ₉ and R ₁₀ are each independently C _1-20 alkyl,

X ₁ and X ₂ are each independently selected from the group consisting of halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro, amido, C _1-20 alkylamino, C _6-20 arylamino, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group.

According to another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: a carrier; And a metallocene supported catalyst comprising the metallocene compound of Formula 1, the alkylaluminum, and the alkylaluminoxane based co-catalyst supported on the support, wherein the metallocene supported catalyst exhibits a single type of catalytically active species.

According to another embodiment of the present invention, there is provided a process for producing a polypropylene comprising the step of polymerizing a propylene monomer in the presence of the above metallocene supported catalyst.

In addition, according to another embodiment of the present invention, there is provided a process for preparing a polymer having a weight average molecular weight of 350,000 to 500,000 g / mol, a z average molecular weight of 700,000 to 1,000,000 g / mol, A distribution of 2.5 or less, and a melt mass flow index of 1 to 4 g / 10 min.

According to another embodiment of the present invention, there is provided a fiber and a film comprising the polypropylene.

The metallocene supported catalyst produced by the production process according to the present invention exhibits excellent catalytic activity and is capable of forming a single type of catalytically active species and is useful for the production of polyolefins having a high molecular weight and a narrow molecular weight distribution, Is possible.

The polypropylene produced by using the above metallocene supported catalyst can be extruded and thus can be applied to the production of various products. In addition, in the production of high-strength fibers and biaxially stretched films which require high molecular weight and narrow molecular weight distribution Can be usefully used.

1 is a graph showing gel permeation chromatography (GPC) analysis results of polypropylene prepared using the metallocene supported catalysts of Examples 1 and 2 and Comparative Example 1. FIG.

The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises", "comprising", or "having" are used to designate the presence of stated features, steps, components, or combinations thereof, and are not intended to preclude the presence of one or more other features, Components, or combinations thereof, as a matter of convenience, without departing from the spirit and scope of the invention.

The invention is capable of various modifications and may take various forms, which illustrate specific embodiments and are described in detail below. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Hereinafter, a method for preparing a metallocene supported catalyst according to a specific embodiment of the present invention, a supported metallocene catalyst prepared by the method, and a method for producing a polyolefin using the metallocene supported catalyst will be described.

A method for preparing a metallocene supported catalyst according to an embodiment of the present invention includes:

Supporting an alkylaluminoxane-based co-catalyst on the carrier; And

Supporting a metallocene compound represented by the following formula (1) on a carrier carrying the alkylaluminoxane-based promoter,

Further comprising the step of supporting the alkylaluminum on the carrier before or after the carrying of the metallocene compound,

[Chemical Formula 1]

In Formula 1,

A is carbon, silicon or germanium,

M is a transition metal of Group 4,

R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl,

R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl group, a C _1-20 ether, C _1-20 silyl ether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,

R ₉ and R ₁₀ are each independently C _1-20 alkyl,

X ₁ and X ₂ are each independently selected from the group consisting of halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro, amido, C _1-20 alkylamino, C _6-20 arylamino, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group.

As described above, in the present invention, by sequentially carrying out alkylaluminum used as a scavenger or cocatalyst in the production of an olefin polymer in sequence with the metallocene compound of Formula 1, ≪ / RTI > represents a single type of catalytically active species coordinated or coodinated. As a result, the olefin polymer, especially polypropylene, produced using the same, has a narrow molecular weight distribution and has a high molecular weight, which enables extrusion molding, and is useful for producing high strength fibers or biaxially stretched films.

When the alkyl aluminum and the metallocene compound are mixed and supported on the carrier at the same time, in addition to the form in which the alkyl aluminum is simply coordinated with the activated and supported form of the precursor, the supported catalyst, Aluminum may be present in coordinated dimer form with aluminum, and in the form of dimer coordinated with aluminum after the methyl bonded to the metal molecule in the precursor is substituted with the alkyl group of the alkyl aluminum. In this case, the molecular weight distribution of the olefin polymer produced by the various types of catalyst precursors is widened, and the melt mass flow index (MFR) is increased. Also, if the support is first activated using a co-catalyst such as alkylaluminoxane prior to loading the alkylaluminum and metallocene compound, the activity of the metallocene compound is reduced during the alkylation.

In the method for preparing a metallocene supported catalyst according to an embodiment of the present invention, the order of carrying the alkylaluminum and the metallocene compound of formula (1) is not limited, and after the alkylaluminum is supported on the carrier, Or the metallocene compound of Formula 1 may be first supported on the support, and then the alkylaluminum may be supported thereon.

Hereinafter, each step will be described. In the method for producing a metallocene supported catalyst according to an embodiment of the present invention, Step 1 is a step of supporting an alkylaluminoxane-based co-catalyst on a support.

The alkylaluminoxane-based co-catalyst may be a compound capable of acting as a Lewis acid capable of forming a bond through a Lewis acid-base interaction with a functional group introduced into a bridge group of the metallocene compound of Formula 1 And includes a metal element to improve not only the catalytic activity but also the process stability. Specific examples thereof include methyl aluminoxane, ethyl aluminoxane, isobutyl aluminoxane, and butyl aluminoxane, and any one or a mixture of two or more thereof may be used. Among them, methylaluminoxane can be used in consideration of the effect of improving catalytic activity and improving the process stability.

The step of supporting the alkylaluminoxane-based co-catalyst may be carried out according to a conventional method. When the carrier is preliminarily supported with the alkylaluminoxane co-catalyst, the contact reaction of the alkylaluminoxane co-catalyst with the carrier may be carried out in a solvent or without a solvent. When the contacting reaction is carried out in a solvent, an aliphatic hydrocarbon solvent such as hexane or pentane; Aromatic hydrocarbon solvents such as toluene or benzene; A hydrocarbon solvent substituted with a chlorine atom such as dichloromethane; Ether solvents such as diethyl ether or tetrahydrofuran (THF); Ketone-based solvents such as acetone; Or an organic solvent such as an ester solvent such as ethyl acetate may be used. Of these, hexane, heptane, toluene, or dichloromethane may be preferable.

When the alkylaluminoxane-based co-catalyst is supported on the carrier simultaneously with the alkylaluminum oxide, the alkylaluminoxane-based co-catalyst may be further added during the step of supporting the alkylaluminum.

In addition, the temperature condition during the step of supporting the alkylaluminoxane may be 25 to 100 ° C, more specifically 50 to 100 ° C. At this time, the time for carrying the alkylaluminoxane is appropriately adjusted depending on the amount of the compound to be supported Lt; / RTI >

The alkylaluminoxane-based co-catalyst may be supported in an amount of 1 to 20 mmol, more preferably 1 to 10 mmol, per 1 g of the carrier. When the catalyst is supported in the above range, not only the activity of the supported metallocene supported catalyst is improved, but also the weight average molecular weight of the polymer produced using the metallocene supported catalyst can be maintained at a higher level.

Next, Step 2 is a step of supporting the metallocene compound of Formula 1 on the support carrying the alkylaluminoxane-based co-catalyst.

In carrying the metallocene compound of Formula 1, the metallocene compound of Formula 1 and the carrier obtained in Step 1 may be carried out in a solvent as in the case of carrying out the alkylaluminoxane co-catalyst, May be performed without a solvent. The solvent is the same as described above.

In the metallocene compound of the formula 1, the temperature may be in the range of -30 to 150 ° C, more specifically 30 to 80 ° C, more specifically 50 to 80 ° C. It is possible to carry out the deposition under the above-described temperature condition with more stable and excellent efficiency when carrying out the respective deposition processes.

The method for preparing a metallocene supported catalyst according to an embodiment of the present invention further includes a step of supporting the alkyl aluminum on the carrier before or after the metallocene compound is supported on the support in step 2 above.

Specifically, when the alkyl aluminum before carrying out the step 2 is carried on the carrier, the carrier carrying the alkylaluminoxane co-catalyst prepared in the step 1 may be contacted with the alkylaluminum, Alkali aluminum may be added to the support in the presence of the oxycarboxylic acid catalyst and the carrier to be supported on the carrier simultaneously with the alkylaluminoxane promoter.

When the alkylaluminum is supported after the step 2, the alkylaluminoxane-based co-catalyst and the support carrying the metallocene compound of Formula 1 may be contacted with the alkylaluminum.

The contact reaction for supporting the alkyl aluminum may be performed in a solvent as described above or may be performed without a solvent, as described above.

The temperature of the carrier for carrying the alkylaluminum may be in the range of 25 to 100 ° C, more specifically 50 to 100 ° C. At this time, the time for carrying the alkylaluminum is appropriately adjusted depending on the amount of the compound to be supported .

The resultant supported catalyst after the completion of the supporting process can be used after filtration of the reaction solvent or by distillation under reduced pressure and, if necessary, after filtration using aromatic hydrocarbons such as toluene.

Meanwhile, in the method for preparing a supported metallocene catalyst according to an embodiment of the present invention, the alkylaluminum contributes to the activation of the metallocene compound, and may be a linear or branched alkyl group having 1 to 10 carbon atoms, Or an alkylaluminum compound having a cyclic alkyl group having 3 to 12 carbon atoms.

Specific examples include trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, Triisobutylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum or methyldiethylaluminum, and any one or a mixture of two or more thereof may be used. Considering that alkylation of a metallocene catalyst is more advantageous in securing a coordination polymerization space in which a reactant such as propylene forms a polymer, the alkylaluminum may be triisobutylaluminum, triisopropylaluminum, tri-sec-butylaluminum , Or alkyl aluminum containing a branched alkyl group having 3 to 6 carbon atoms, such as triisopentyl aluminum, and more specifically triisobutyl aluminum.

The alkylaluminum may be carried in an amount of 0.01 to 3 mmol, more specifically 0.05 to 1 mmol, and more particularly 0.07 to 0.5 mmol, per gram of the carrier. When supported within the above-mentioned range, the number of active species of the metallocene supported catalyst is sufficient, without concern for the remnants of the unsubstituted alkylaluminum, so that the activity of the catalyst itself can be improved.

If the content of the alkylaluminum compound is too low relative to the metallocene compound of the formula (1), the catalytically active species can not be sufficiently formed. If the alkylaluminum compound is excessively high, the catalyst may act as a catalytic poison. In the metallocene supported catalyst thus produced, the molar ratio of the aluminum metal contained in the alkyl aluminum to the transition metal of the group 4 transition metal (M) contained in the metallocene compound of the formula (1) The alkylaluminum may be used in an amount such that the molar ratio is from 1: 1 to 1,000: 1, more specifically from 10: 1 to 100: 1.

In the method for preparing a supported metallocene catalyst according to an embodiment of the present invention, the metallocene compound may include at least one compound represented by the following general formula (1)

[Chemical Formula 1]

In Formula 1,

A is carbon, silicon or germanium,

M is a transition metal of Group 4,

R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl,

R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl group, a C _1-20 ether, C _1-20 silyl ether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,

R ₉ and R ₁₀ are each independently C _1-20 alkyl,

X ₁ and X ₂ are each independently selected from the group consisting of halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro, amido, C _1-20 alkylamino, C _6-20 arylamino, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group.

The substituents of the above formula will be more specifically described below.

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

The C _1-20 alkyl group may be a straight chain, branched chain or cyclic alkyl group. Specifically, the C _1-20 alkyl group is a C _1-15 straight-chain alkyl group; A C _1-10 straight chain alkyl group; A C _1-5 straight chain alkyl group; A C _3-20 branched or cyclic alkyl group; C _3-15 branched or cyclic alkyl; Or a C _3-10 branched or cyclic alkyl group. More specifically, the C1-20 alkyl group may be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert- - pentyl group or cyclohexyl group and the like.

The C _2-20 alkenyl group may be a straight chain, branched chain or cyclic alkenyl group. Specifically, C _2-20 alkenyl groups are C _2-20 straight-chain alkenyl group, C _2-10 linear alkenyl, C _2-5 straight-chain alkenyl group, C _3-20 branched chain alkenyl, C _3-15 branched chain alkenyl A C _3-10 branched alkenyl group, a C _5-20 cyclic alkenyl group, or a C _5-10 cyclic alkenyl group. More specifically, may be a C _{2- 20} alkenyl group is ethenyl group, propenyl group, butenyl group, pentenyl group or cyclohexenyl group.

C _6-30 aryl can mean monocyclic, bicyclic or tricyclic aromatic hydrocarbons. Specifically, C _6-30 aryl may be phenyl, naphthyl or anthracenyl.

C _7-30 alkylaryl may mean a substituent wherein at least one hydrogen of the aryl is substituted by alkyl. Specifically, the C _7-30 alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

C _7-30 arylalkyl may mean a substituent wherein at least one of the hydrogens of the alkyl is substituted by aryl. Specifically, the C _7-30 arylalkyl may be a benzyl group, phenylpropyl or phenylhexyl.

Examples of the Group 4 transition metal include titanium, zirconium and hafnium.

When a supported catalyst is prepared by the method of the present invention using the metallocene compound of Formula 1 having the above structure, a catalytically active species having a single form is formed, and the catalytically active species exhibits excellent polymerization activity It is possible to produce a polypropylene having a narrow molecular weight distribution together with a high molecular weight and further having a low melt mass flow index and having excellent processability and strength properties.

Specifically, the metallocene compound of Formula 1 includes two ligands connected to each other by a bridge group, and the ligand includes an indenyl group, respectively, to thereby produce a polypropylene having improved stereoregularity. Further, in the two indenyl groups, the position 2 is substituted with a methyl group, and the position 4 (R ₁ and R ₅ ) is substituted with a bulky group such as an alkyl-substituted phenyl group, thereby giving a steric hindrance to form a meso form Metallocene structure, and also includes a bifunctional group A substituted by an alkyl group as a bridge group connecting two ligands, whereby the production of polypropylene having a high molecular weight is improved More advantageous.

More specifically, in the above Formula 1, the central metal element M may be Ti, Zr or Hf, and the central metal element M may be Zr in that it exhibits better catalytic activity.

In the above formula (1), R ₁ and R ₅ may each independently be a C _6-12 aryl group substituted with C _1-10 alkyl, more specifically C _3-6 branched such as tert-butylphenyl Or a phenyl group substituted with an alkyl group. The substitution position of the alkyl group with respect to the phenyl group may be a 4-position corresponding to the R ₁ or R ₅ position and the para position bonded to the indenyl group.

In the above formula (1), R ₂ to R ₄ and R ₆ to R ₈ may each independently be hydrogen, and X ₁ and X ₂ each independently may be chloro.

In formula (1), A may more specifically be silicon, and R ₉ and R _{10, which} are substituents of A, may be a C _2-10 alkyl group, more specifically a C _2-4 straight chain alkyl group, More specifically, it may be ethyl. The substituent of such a bridge is superior to the methyl group in solubility and supportability in the preparation of the supported catalyst.

Wherein R ₉ and R ₁₀ may be different may be the same as each other, and R ₉ and R ₁₀ in terms of improving the loading efficiency, to increase the solubility may be equal to each other.

Representative examples of the compound represented by the above formula (1) are as follows:

(1a)

(1a)

The metallocene compound of formula (1) can be synthesized by applying known reactions, and a more detailed synthesis method can be referred to the following production examples.

In addition, the metallocene compound of Formula 1 may be supported at 0.01 to 1 mmol, more specifically 0.07 to 0.5 mmol, per 1 g of the support. When the catalyst is supported within the above-mentioned range, it has an optimal catalyst shape and can exhibit excellent catalytic activity.

In addition, in the method for preparing a supported metallocene catalyst according to an embodiment of the present invention, a carrier containing a hydroxy group on the surface may be used as the carrier, more specifically, a hydroxy group having a high reactivity with the co- Siloxane groups may be used. Specific examples thereof include silica, silica-alumina, silica-magnesia and the like, and any one or two or more of them may be used. The above carriers may also typically include oxides, carbonates, sulphates, and nitrate components such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg (NO ₃ ) ₂ .

In addition, when moisture is present on the surface of the support, moisture may react with the cocatalyst. Therefore, it may be preferable that the support removes water present on the surface through a drying process. However, when the catalyst is excessively dried, the surface of the carrier may be dried at a temperature of 200 to 400 ° C., more specifically 200 to 250 ° C. .

In addition to the drying step, the amount of the hydroxyl group on the surface of the carrier can be controlled by controlling the method of preparing the carrier and the production conditions.

The carrier may be used in a weight ratio of 1 to 1000 based on the weight of the metallocene compound of Formula 1. More specifically, the carrier may be used in a weight ratio of 1 to 50. As the above content, it exhibits proper supported catalyst activity at the time of use, and may be advantageous from the viewpoints of maintenance of the activity and economical efficiency of the catalyst.

The supported catalyst prepared by the above production method shows catalytic active species having a single form together with excellent catalytic activity by supporting the metallocene compound of formula (1) and the alkylaluminum compound, whereby a high molecular weight and a narrow molecular weight distribution Can be produced.

According to another embodiment of the present invention, there is provided a supported metallocene catalyst prepared according to the above process.

Specifically, the metallocene supported catalyst includes a support and at least one metallocene compound of Formula 1 supported on the support, an alkylaluminum, and optionally an alkylaluminoxane-based co-catalyst. The kind and content of the above-mentioned support, the metallocene compound of formula (1), the alkyl aluminum and the alkyl aluminoxane-based co-catalyst are as described above.

The metallocene supported catalyst may itself be used for polymerization of an olefin-based monomer, specifically, a propylene monomer, or may be used in a prepolymerized form by being contact-reacted with an olefin-based monomer. When used in a prepolymerized form, the metallocene supported catalyst may be separately used before contacting the polymerization catalyst with an olefinic monomer such as ethylene, propylene, 1-butene, 1-hexene, 1-octene and the like.

According to another embodiment of the present invention, there is provided a process for producing polypropylene using metallocene supported catalyst prepared according to the above-mentioned production method and polypropylene produced thereby.

Specifically, the method for producing the polypropylene comprises polymerizing the propylene monomer in the presence of the metallocene supported catalyst prepared according to the above production method.

The polymerization reaction may be carried out by polymerizing the propylene monomer using one continuous slurry polymerization reactor, a loop slurry reactor, a gas phase reactor or a solution reactor.

In addition, in the above metallocene-supported catalyst, the catalyst may be an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms such as pentane, hexane, heptane, nonane, decane, and an isomer thereof and an aromatic hydrocarbon solvent such as toluene or benzene , A hydrocarbon solvent substituted with a chlorine atom such as dichloromethane or chlorobenzene, or the like. The solvent used herein is preferably used by removing a small amount of water or air acting as a catalyst poison through a small amount of alkylaluminum treatment, and it is also possible to use a further cocatalyst.

The polypropylene produced by the metallocene supported catalyst obtained according to the production method of the present invention has a high molecular weight and a narrow molecular weight distribution and can exhibit excellent strength characteristics.

Specifically, the polypropylene has a weight average molecular weight (Mw) of 350,000 to 500,000 g / mol and a z average molecular weight of 700,000 to 1,000,000 g / mol, and has a molecular weight of 2.5 or less, more specifically 2 to 2.5 (MWD) of from 2.3 to 2.45, with a weight average molecular weight (Mw) of from 380 to 450,000 g / mol and a z-average molecular weight of from 700,000 to 850,000 g / mol .

In the present invention, Mw and Mz can be measured by standardizing with polystyrene using gel permeation chromatography (GPC) (Waters), and the weight average molecular weight (Mw) and number average From the molecular weight (Mn) value, the molecular weight distribution (MWD) can be calculated by dividing the weight average molecular weight by the number average molecular weight. At this time, the analysis temperature is 160 캜, and trichlorobenzene can be used as the solvent.

In addition, the polypropylene may exhibit a melt mass flow index (MRF) of from 1 to 4 g / 10 min, more specifically from 2 to 3.5 g / 10 min, together with the above molecular weights.

In the present invention, the MFR can be measured according to ISO 1133.

Accordingly, the polypropylene produced by the metallocene supported catalyst produced by the production process according to the present invention can be extruded and can be applied to the production of various products. In addition, the polypropylene having a high molecular weight and a narrow molecular weight distribution Can be usefully used in the production of nano-films, especially high-strength fibers and biaxially stretched films.

Hereinafter, the present invention will be described in detail with reference to examples of the present invention. However, the embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the above-described embodiments.

Manufacturing example

Step 1) ( Diethylsilane - Dill ) - Bis ((2- methyl -4- Rat -Butyl- Phenyl indenyl ) Silane  Produce

Butyllithium solution (2.5 M, hexane solvent, 22.2 g) was dissolved in toluene / THF = 10/1 solution (220 mL) Was slowly added dropwise at 0 ° C, and then stirred at room temperature for one day. Then, diethyldichlorosilane (6.2 g) was slowly added dropwise to the mixed solution at -78 ° C, stirred for about 10 minutes, and then stirred at room temperature for one day. Thereafter, water was added to separate the organic layer, and the solvent was distilled off under reduced pressure to obtain (diethylsilane-diyl) -bis ((2-methyl-4-tert-butylphenylindenyl) silane.

Step 2) [( Diethylsilane - Dill ) - Bis ((2-methyl-4-tert-butyl-phenylindenyl)] - Preparation of zirconium dichloride

The (diethylsilane-diyl) -bis ((2-methyl-4-tert-butylphenylindenyl) silane prepared in the above step 1 was dissolved in toluene / THF = 5/1 solution (120 mL) butyl lithium solution (2.5 M, hexane solvent, 22.2 g) was slowly added dropwise at -78 ° C, and the mixture was stirred at room temperature for one day. Zirconium chloride (8.9 g) was diluted in toluene (20 mL) After the reaction solution was removed under reduced pressure, dichloromethane was added to the reaction mixture, which was then filtered, and the filtrate was distilled off under reduced pressure, and the residue was recrystallized from toluene and hexane to give Zirconium dichloride (10.1 g, 34%, rac: meso = 20: 1) was added to a solution of high purity rac - [(diethylsilanediyl) .

(1a)

(1a)

Example 1

5 g of silica was added to a reactor containing 30 mL of toluene and sufficiently stirred. 50 mmol of 10 wt% methylaluminoxane (MAO) and 2.3 mL of triisobutylaluminum (TIBAL) (25 wt% in Toluene) were added thereto at 30 ° C. and reacted at 90 ° C. for 15 hours. After sedimentation, the filtrate was removed and washed twice with toluene.

0.27 g of the metallocene compound prepared in the above Preparation Example was dissolved in toluene, and the mixture was reacted at 50 ° C for 5 hours. After completion of the reaction, the reaction solution was sedimented to remove the upper layer solution, and the remaining reaction product was washed with toluene and then again with hexane. The resulting product was vacuum-dried to obtain a solid supported catalyst.

Example 2

Add 5 g of silica to a reactor containing 30 mL of toluene and stir well. 50 mmol of 10 wt% methylaluminoxane (MAO) was added at 30 ° C., and the mixture was reacted at 90 ° C. for 15 hours. After sedimentation, the filtrate was removed and washed twice with toluene.

0.27 g of the metallocene compound (1a) was dissolved in toluene, and the mixture was reacted at 50 ° C for 3 hours. Subsequently, 0.3 mL of TIBAL (25 wt% in Toluene) was added and reacted at 50 DEG C for 2 hours. After completion of the reaction, the reaction solution was sedimented to remove the upper layer solution, and the remaining reaction product was washed with toluene and then again with hexane. The resulting product was vacuum-dried to obtain a solid supported catalyst.

Comparative Example 1

5 g of silica was added to a reactor containing 30 mL of toluene, and then sufficiently stirred. Then, 50 mmol of 10 wt% methylaluminoxane (MAO) was added at 30 占 폚, and the mixture was reacted at 90 占 폚 for 15 hours. After sedimentation, the filtrate was removed and washed twice with toluene.

0.27 g of the metallocene compound (1a) was dissolved in toluene, and the mixture was reacted at 50 ° C for 5 hours. After completion of the reaction, the reaction solution was sedimented to remove the upper layer solution, and the remaining reaction product was washed with toluene and then again with hexane. The resulting product was vacuum-dried to obtain a solid supported catalyst.

Comparative Example 2

Add 5 g of silica to a reactor containing 30 mL of toluene and stir well. 50 mmol of 10 wt% methylaluminoxane (MAO), 0.27 g of the metallocene compound (1a) dissolved in toluene and 0.3 mL of TIBAL (25 wt% in Toluene) were added at 30 ° C. and reacted at 90 ° C. for 5 hours . After completion of the reaction, the reaction solution was sedimented to remove the upper layer solution, and the remaining reaction product was washed with toluene and then again with hexane. The resulting product was vacuum-dried to obtain a solid supported catalyst.

The supported catalysts prepared in Examples 1 to 2 and Comparative Example 1 are summarized in Table 1 below.

Order of support Loading MAO
(mmol / g SiO ₂₎ TIBAL
(mmol / g SiO ₂₎ Cat.
(μmol / g SiO ₂ ) Example 1 SiO ₂ / MAO / TIBAL / Cat. 10 0.5 70 Example 2 SiO ₂ /MAO/Cat./TIBAL 10 0.7. 70 Comparative Example 1 SiO ₂ / MAO / Cat. 10 0 70 Comparative Example 2 Simultaneous loading 10 0.7 70

In Table 1, SiO ₂ : silica, MAO: methylaluminoxane, TIBA: triisobutylaluminum, Cat: metallocene compound of Formula 1a.

<Experimental Example>

Manufacture of polypropylene

First, a 2L stainless steel reactor was vacuum dried at 65 deg. C and then cooled. Then, 1.5 mmol of triethyl aluminum was added at room temperature, and 770 g of propylene was added. After stirring for 10 minutes, the silica supported metallocene catalyst prepared in the above Examples and Comparative Examples was introduced into the reactor under a nitrogen pressure. At this time, a certain amount of hydrogen gas was introduced together with the catalyst. After the reactor temperature was gradually raised to 70 ° C, the reactor was polymerized for 1 hour. After the completion of the reaction, unreacted propylene was bubbled.

The polymerization activity of the catalyst in the production of the olefin polymer, the molecular weight and the molecular weight distribution of the olefin polymer thus prepared were measured by the following methods, and the results are shown in Table 2 and FIG.

(1) Catalytic activity: The ratio of the weight (kg) of the polymer produced per unit time (h) to the amount of catalyst (mmol and g of catalyst) used in the polymer synthesis reaction in the above Examples and Comparative Examples was calculated, Of the activity.

(2) MFR: The MFR (melt mass flow index) was measured according to ISO 1133.

(3) Mw, Mz, MWD: The sample was dissolved in 1,2,4-trichlorobenzene containing 0.0125% of BHT at 160 ° C for 10 hours using PL-SP260 and pretreated with PL-GPC220 at 160 ° C Mw (weight average molecular weight), Mz (Z-average molecular weight) and Mn (number average molecular weight) were measured. At this time, each molecular weight was measured by standardizing with polystyrene. MW value (MWD) was calculated by dividing Mw value by Mn value using measured Mw value and Mn value.

division Catalytic activity
(kg-PE / g-Cat.) MFR
(g / 10 min) Mw
(g / mol) Mz
(g / mol) MWD Example 1 7.7 2.4 420,000 831,000 2.41 Example 2 8.7 3.4 382,000 747,000 2.38 Comparative Example 1 7.5 4.5 337,000 688,000 2.35 Comparative Example 2 6.0 4.1 370,000 725,000 2.73

As shown in Table 2 above, when the metallocene compound supported catalyst of Formula 1 is prepared in the same manner as in Examples 1 and 2, when alkyl aluminum is carried in succession, it shows a single type of catalytically active species, The polymerization activity was increased as compared with Comparative Example 1, which was Comparative Example 1 which was not simultaneously carried out, and Comparative Example 2, and that the produced polypropylene had a narrow molecular weight distribution with a high molecular weight of 2.5 or less.

Claims (16)

Supporting an alkylaluminoxane-based co-catalyst on the carrier; And
Supporting a metallocene compound represented by the following formula (1) on a carrier carrying the alkylaluminoxane-based promoter,
A step of supporting the alkylaluminum on the carrier before or after the loading of the metallocene compound;
[Chemical Formula 1]

In Formula 1,
A is carbon, silicon or germanium,
M is a transition metal of Group 4,
R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl,
R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl group, a C _1-20 ether, C _1-20 silyl ether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,
R ₉ and R ₁₀ are each independently C _1-20 alkyl,
X ₁ and X ₂ are each independently selected from the group consisting of halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro, amido, C _1-20 alkylamino, C _6-20 arylamino, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group.
The method according to claim 1,
And M is Zr.
The method according to claim 1,
Wherein R ₁ and R ₅ are each independently a phenyl group substituted with a C _3-6 branched alkyl group.
The method according to claim 1,
Wherein R ₁ and R ₅ are each tert-butylphenyl.
The method according to claim 1,
Wherein A is silicon,
Wherein R ₉ and R ₁₀ are the same and are a C _2-4 straight chain alkyl group.
The method according to claim 1,
Wherein the metallocene compound of formula (1) is a compound represented by the following formula (1a).
[Formula 1a]

The method according to claim 1,
Wherein the supported amount of the metallocene compound of Formula 1 is 0.01 to 1 mmol based on 1 g of the support.
The method according to claim 1,
Wherein the alkyl aluminum is alkylaluminum containing a branched alkyl group having 3 to 6 carbon atoms.
The method according to claim 1,
Wherein the alkyl aluminum comprises at least one member selected from the group consisting of triisobutylaluminum, triisopropylaluminum, tri-sec-butylaluminum, and triisopentylaluminum.
The method according to claim 1,
Wherein the amount of the alkyl aluminum supported is 0.01 to 3 mmol based on 1 g of the support.
The method according to claim 1,
Wherein the molar ratio of the aluminum metal contained in the alkyl aluminum to the transition metal (M) of the Group 4 transition metal contained in the metallocene compound of Formula 1 is 1: 1 to 1,000: 1.
The method according to claim 1,
Wherein the carrier comprises silica, alumina, magnesia, or a mixture thereof.
The method according to claim 1,
Wherein the loading of the alkylaluminum before the metallocene compound is carried out is carried out by adding an alkylaluminum at the time of carrying the carrier of the alkylaluminoxane co-catalyst.
carrier; And
A metallocene supported catalyst comprising a metallocene compound represented by the following formula (1), an alkylaluminum and an alkylaluminoxane-based cocatalyst supported on the carrier and exhibiting a single type of catalytically active species:
[Chemical Formula 1]

In Formula 1,
A is carbon, silicon or germanium,
M is a transition metal of Group 4,
R ₁ and R ₅ are each independently C _6-20 aryl substituted with C _1-20 alkyl,
R ₂ to R ₄ and R ₆ to R ₈ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkylsilyl, C _1-20 silylalkyl, C _1-20 alkoxysilyl group, a C _1-20 ether, C _1-20 silyl ether, C _1-20 alkoxy, C _6-20 aryl, C _7-20 alkylaryl, or C _7-20 arylalkyl,
R ₉ and R ₁₀ are each independently C _1-20 alkyl,
X ₁ and X ₂ are each independently selected from the group consisting of halogen, C _1-20 alkyl, C _2-20 alkenyl, C _6-20 aryl, nitro, amido, C _1-20 alkylamino, C _6-20 arylamino, C _1-20 alkylsilyl, C _1-20 alkoxy, or C _1-20 sulfonate group.
A process for producing a polypropylene comprising the step of polymerizing a propylene monomer in the presence of the metallocene supported catalyst according to claim 14.
A polypropylene having a weight average molecular weight of 350,000 to 500,000 g / mol, a z average molecular weight of 700,000 to 1,000,000 g / mol, a molecular weight distribution of 2.5 or less and a melt mass flow index of 1 to 4 g / 10 min.

Images