KR20100023278A - Preparation method of a catalyst for polyolefin copolymerization and method for polymerizing polyolefin using a catalyst produced by the same - Google Patents

Abstract

PURPOSE: A preparation method of a catalyst for polyolefin copolymerization is provided to increase the amount of the supported alkylaluminoxane and metallocene compounds, to protect the supported metallocene compounds from catalyst poison, and to maintain high activity. CONSTITUTION: A preparation method of a catalyst for polyolefin copolymerization comprises the steps of: (i) dissolving metallocene catalyst components in an alkylaluminoxane solution; (ii) supporting alkylaluminoxane and metallocene components by adding the solution in a carrier slurry and then stirring the mixture at 40~160 °C; (iii) separating supernatant after supporting reaction, washing the supported catalyst with an organic solvent at -10~0 °C, and then again washing the supported catalyst at a room temperature; and (iv) drying the washed solvent and then collecting the catalyst powder.

Description

TECHNICAL FIELD OF THE INVENTION A method for preparing a catalyst for polyolefin polymerization, and a method for preparing a polyolefin polymer using the same, and a method for preparing a polyolefin polymer using the same

The present invention relates to a method for preparing a high active polyolefin polymerization catalyst prepared by supporting methylaluminoxane and a metallocene compound on a porous inorganic support, and more particularly, a metallocene catalyst component desorbed in a washing step of a supporting reaction. By including a low temperature treatment step to minimize the increase of the amount of the supported methyl aluminoxane and metallocene compound, it is not necessary to inject additional methyl aluminoxane during the polymerization reaction, and fully protect the supported metallocene compound from the catalyst poison The present invention relates to a method for producing a polyolefin polymerization catalyst capable of maintaining high activity.

Metallocenes can be represented by the empirical L _n MQ _p , where M is a metal of Group IIIB, IVB, VB or VIB; Q is a hydrocarbyl group or halogen having 1 to 20 carbon atoms; p is valence-2 of M, and L is a ligand bound to the metal M. This metallocene compound is used together with methyl aluminoxane (MAO) which is a promoter to prepare an olefin polymer and a copolymer. Methylaluminoxanes (hereinafter interchangeably referred to as "MAO") include linear and / or cyclic alkylmethylaluminoxane oligomers, wherein the methylaluminoxane is a compound of the formula R- (Al ( R) -O) _n- AlR ₂ , and in the case of cyclic methylaluminoxane oligomers, is represented by the formula (-Al (R) -O-) _m , where R is a C ₁ -C ₈ alkyl group, preferably Is methyl, n is 1-40, Preferably it is 10-20, m is 3-40, Preferably it is 3-20. Methylaluminoxanes are usually prepared by reacting trimethylaluminum with water or with hydrated inorganic salts such as CuSO ₄ .5H ₂ O or Al ₂ (SO ₄ ) ₃ .5H ₂ O. Methylaluminoxane can also be produced in situ in the polymerization reactor by adding trimethylaluminum and water or hydrous inorganic salts to the polymerization reactor. Methylaluminoxane is a mixture of oligomers with a very wide molecular weight distribution, usually having an average molecular weight of about 900-1200. Methylaluminoxane is usually maintained in solution in toluene.

The metallocene catalyst must be supported on an appropriate support in order to be used in a fluidized bed reactor or slurry reactor, and the individual catalyst particles loaded with metallocene must exhibit sufficient activity so as not to cause problems due to catalyst support residues.

Representative metallocene supported catalyst production method currently developed and used is a method in which a metallocene catalyst is supported on silica together with methylaluminoxane, which reacts the hydroxy group of the silica with methylaluminoxane to the surface of the silica. It is a method of supporting methyl aluminoxane and supporting the metallocene catalyst on the supported methyl aluminoxane. The metallocene catalyst component may be supported simultaneously with the methylaluminoxane or through additional reaction after the methylaluminoxane is supported. The activity of the supported catalyst is proportional to the amount of the metallocene component supported, and also to the amount of methylaluminoxane which assists the support of the metallocene catalyst component. Methylaluminoxane not only supports the metallocene catalyst but also serves to protect the metallocene catalyst component from the catalyst poison. Therefore, the supported amount of methylaluminoxane directly affects the activity of the catalyst.

As a method for preparing a metallocene supported catalyst, a method of adding a mixture of alkylaluminum such as trimethylaluminum or triethylaluminum to dehydrated silica and then introducing metallocene (see US Patent No. 4,937,217), Trimethylaluminum is added to silica that is not dehydrated, and then metallocene is introduced to dry and supported (see US Pat. Nos. 4,912,075, 4,937,301 and 4,935,397), and trimethylaluminum is added to silica to which water is added. To produce aluminoxane in the carrier pores and then to carry metallocene (see US Pat. Nos. 5,008,228, 5,086,025 and 5,147,949), after calcining the inert carrier silica, the metallocene and the activating material Supporting methods (see US Pat. Nos. 4,808,561, 4,897,455 and 4,701,432) and the like are known. In addition, a method of mixing metallocene and alkylaluminum and then adding dehydrated silica (US Pat. No. 5,238,892), first, preparing a mixed solution of metallocene and aluminoxane, and adding a porous carrier to the solvent, A method for preparing a catalyst precursor suitable for pre-polymerization by removing the same has been disclosed (US Pat. No. 5,240,894).

However, when the metallocene supported catalyst is prepared by these methods, the supported state of the supported metallocene catalyst is unstable. It is difficult to obtain a desired level of activity due to the loss of a large portion in the washing step of the catalyst preparation process, or the catalyst component on the surface of the carrier particles is desorbed during the washing process. In addition, since the supported catalyst is prepared through several steps, the catalyst production time is long, the activity of the prepared catalyst is low, and when the supported catalysts prepared by the above method are used in the slurry polymerization process, the catalyst is soluble from the porous support. The component melts into the solvent, and the melted catalyst produces fine-sized polymer particles that accumulate inside the reactor or cling to the reactor walls. As the polymerization reaction proceeds in the fine polymer stuck to the reactor wall, it causes fouling and plugging of the reactor, and thus it is impossible to operate both the continuous polymerization and the batch polymerization process.

The problem of low activity and leaching of the supported metallocene catalyst is that the metallocene itself is physically bonded to the support rather than a chemical bond, so that the amount of loading itself is small and due to the hydroxyl group present on the surface of the silica used as the support. This occurs because the metallocene catalyst decomposes and loses activity. In addition, in order for the metallocene to exhibit high activity, an excess amount of methylaluminoxane should be used. When the methylaluminoxane solution is directly supplied to the gas phase reactor in a large amount sufficient to contact the metallocene compound, A liquid film layer is formed on the wall of the reactor, and the metallocene catalyst adheres to this portion, causing a problem that the polymerization reaction proceeds to form sheets and lumps. In order to solve the problem that the catalyst component on the support is desorbed during the washing step and the polymerization reaction in the supported catalyst process, another method is used. A representative method is a ligand of a metallocene catalyst using a hydroxyl group present on the surface of silica. To form chemical bonds (US Pat. Nos. 5,399,636, 5,466,766, 5,473,020 and US Patent Application 08 / 898,460). However, such a method requires a multi-step manufacturing process such as impurity removal and various separation steps, and thus requires a long time to prepare the catalyst, a high catalyst manufacturing cost, and a very small content of the metallocene catalyst to be supported. The activity per catalyst particle has a very low problem, and there is a problem that additional methylaluminoxane should be used in the polymerization reaction.

Metallocene catalysts are known as catalyst systems for producing polyolefins having excellent physical properties with high activity and high copolymerization reactivity compared to conventional Ziegler-Natta catalysts. However, the metallocene catalyst is a homogeneous catalyst, and has a disadvantage in that it cannot be directly used in the process of producing particulate polymer of the same shape using a conventional particulate catalyst. Accordingly, there is a need for an improved method for supporting metallocene catalysts on appropriate supports.

The present invention has been made in order to solve the conventional problems as described above, an object of the present invention is to prevent desorption and leaching during the reaction of the supported alkylaluminoxane and metallocene catalyst components in the washing step. It is to provide a method for producing a polyolefin polymerization catalyst.

Method for producing a catalyst for polyolefin polymerization according to the invention is characterized in that it comprises the following steps:

(1) dissolving the metallocene catalyst component in a solution of alkylaluminoxane,

(2) adding the solution of step (1) to the carrier slurry, stirring at 40-160 ° C. to support the alkylaluminoxane and the metallocene component,

(3) After the supporting reaction in step (2), after decanting the supernatant of the solution, the obtained supported catalyst is first washed with an organic solvent at -10 ~ 0 ℃, and then secondly washed with an organic solvent at room temperature step,

(4) 단계 drying the washed catalyst of step (3) and recovering it as a catalyst powder.

In the method for producing a polyolefin catalyst according to the present invention, the metallocene catalyst component used in step (1) is not particularly limited in kind, but has a structure represented by the following general formula (I) as a preferred example.

(THI) ₂ R "MQ _p (I)

In the above formula (I), THI is a substituted or unsubstituted tetrahydroindenyl derivative, and R ″ is a structural crosslink that imparts steric stiffness between two THI groups; M is Group IIIB, Group IVB, Group VB Or a transition metal selected from group VIB, Q is a hydrocarbyl group or halogen having 1 to 20 carbon atoms, and p is valence-2 of M.

In the metallocene catalyst of formula (I), the two THI ligands may be the same or different, but the same is preferable.

Substitution patterns of THI ligands on metallocene catalysts used in the present invention provide the advantages of the present invention. Substitution patterns and numbering of the ligands of the catalyst of the invention are described in detail below.

When THI is substituted, this means that any position on THI may contain a substituent instead of a hydrogen atom. Thus, each substituted THI ligand may have a substituent on the 5-membered ring, a substituent on the 6-membered ring, or a substituent on both 5- and 6-membered rings.

Substituent positions of the THI ligands in the specification of the present invention are numbered 1 to 7 by the following notation system.

In order to distinguish the substitution in the first THI ligand and the second THI ligand of the two THI ligands, the second THI ligand is numbered by the same system as above, but is numbered 1'-7 '. In this type of catalyst, the position of the crosslinking of the two THI ligands is not particularly limited and is preferably 1,1'-crosslinked, 2,2'-crosslinked or 1,2'-crosslinked, 1,1 ' Crosslinking is most preferred.

The position of the substituent (s) on the two THI ligands is not particularly limited, but at least one THI ligand is substituted at the 2-position and / or 4-position (or 2'-position and / or 4'-position) It is preferable.

In one preferred embodiment, both THI ligands can be substituted. In this case, it is preferred to include substituents at the 2-position (2'-position) and / or 4-position (4'-position) of both THI ligands, and to the 2-position (2) of both THI ligands. Most preferably, they include a substituent at the '-position) and the 4-position (4'-position), and other positions in the THI ring may be substituted or unsubstituted.

Particularly preferred metallocene catalysts having 1,1'-crosslinking are 2; 4; 2,4; 2,2 '; 4,4 '; 2,4 '; 2,4,2 '; 2,4,4 '; And a substitution pattern of 2,4,2 ', 4', and only the positions indicated above include substituents. Here, since the basic structure of the two THI ligands is the same, for example, the substitution patterns of 2,4 'and 4,2' are the same THI substituent structure.

The kind of substituent (s) present on the THI ligand is not particularly limited, and when the THI ligand includes two or more substituents, these THI ligands may be substituted with the same substituents or different substituents.

Preferably, the substituents are independently selected from hydrocarbyl groups, alkyl groups, alkylsilicon groups, alkoxy groups, cycloalkyl groups, aryl groups and halogens having 1 to 20 carbon atoms. Examples thereof include phenyl (Ph), benzyl (Bz), naphthyl (Naph), indenyl (Ind) and benzindenyl (BzInd), methyl (Me), ethyl (Ethyl), n-propyl (n- Pr), i-propyl (i-Pr), n-butyl (n-Bu), t-butyl (t-Bu), trimethylsilicon group (Me ₃ Si), alkoxy (preferably RO, where R is C _1-20 alkyl), cycloalkyl and the like, and halogen. The most preferred substituent at the 2-position of THI is a methyl group. Most preferred substituents at the 4-position of THI are phenyl, naphthyl or benzindenyl.

In one preferred embodiment, examples of THI derivative ligands include 2-Me, 4-PhTHI; 2-Me, 4-NaphTHI; Or 2-Me, 4,5-BzIndTHI.

The type of R ″, which is a crosslinking present between two THI rings in the metallocene catalyst component of formula (I), is not particularly limited, but is preferably an alkylidene group having 1 to 20 carbon atoms , Alkylenyl group, germanium group (eg dialkylgernium group), alkylsilicon group (eg dialkylsilicon group), siloxane group (eg dialkylsiloxane group), alkylphosphine group or amine group Most preferably, ethylenyl radical (-CH ₂ CH _2- ) or Me ₂ Si.

The metal M in the metallocene catalyst of formula (I) is a transition metal selected from group IIIB, IVB, VB or VIB of the periodic table of the elements, preferably selected from Ti, Zr, Hf and V.

Q in the metallocene catalyst of formula (I) is preferably halogen, in particular Cl.

And since the valence of the said metal M is four, p becomes 2 normally.

The most preferred metallocene catalyst components used in the present invention are as follows:

Et (THI) ₂ ZrCl ₂ ,

Me ₂ Si (THI) ₂ ZrCl ₂ ,

Me ₂ Si (2-MeTHI) ₂ ZrCl ₂ ,

Et (2-MeTHI) ₂ ZrCl ₂ ,

Me ₂ Si (2-Me, 4-PhTHI) ₂ ZrCl ₂ ,

Et (2-Me, 4-PhTHI) ₂ ZrCl ₂

Me ₂ Si (2-Me, 4-NaphTHI) ₂ ZrCl ₂ ,

Et (2-Me, 4-NaphTHI) ₂ ZrCl ₂ ,

Me ₂ Si (2-Me, 4,5-BzIndTHI) ₂ ZrCl ₂ ,

Et (2-Me, 4,5-BzIndTHI) ₂ ZrCl ₂ .

The catalyst system of the present invention is not particularly limited, but may include one or more metallocene catalyst components as described above. It may also further comprise other known catalyst components in addition to the additional catalyst, if desired, for example the metallocene catalyst component according to the invention.

Metallocene catalyst components used in the present invention are described in the literature. Spalek; A. Antberg, J. Rohrmann, A. Winter, B. Bachmann, P. Kiprof, J. Behm, and W. A. Hermann, Angew. Chem. Int. Eng. Ed. 1992, 31, 1347, or commercially available from mCAT GmBH (Geschuftfuhrer Dr Markus Ringwald Handelsregister Freiburgi HRB 381812).

The alkylaluminoxane used in step (1) includes a straight chain and / or cyclic alkylaluminoxane oligomer, and when the alkylaluminoxane is a straight chain alkylaluminoxane oligomer, the formula R- (Al (R) -O) _n- AlR ₂ , and in the case of cyclic alkylaluminoxane oligomers, represented by the formula (-Al (R) -O-) _m , where R is a C ₁ -C ₈ alkyl group, preferably methyl and n are 1-40, Preferably it is 10-20, m is 3-40, Preferably it is 3-20. The alkylaluminoxane is a mixture of oligomers having a very wide molecular weight distribution, usually having an average molecular weight of about 800 to 1200, mainly maintained in solution in toluene, and in particular, 10% or 30% methylaluminum produced by Albemarle. Noxic acid, and the like.

In the resulting solution of step (1), the concentration of the alkylaluminoxane is 5 to 30% by weight, and the concentration of the metallocene catalyst component is preferably 0.001 to 0.1% by weight, calculated as the metal element (M). If the concentration of each component is outside the above range, the activity is lowered, which is not preferable.

The solution comprises an aromatic hydrocarbon, aliphatic hydrocarbon or aliphatic ring hydrocarbon as solvent.

In the method for preparing a polyolefin catalyst according to the present invention, the carrier used in step (2) is a solid particulate porous, preferably inorganic material, for example silicon and / or aluminum oxide, most preferably spherical Most preferred are silicas which exist in the form of particles, for example particles obtained by spray drying, and which have other functional groups containing OH groups or active hydrogen atoms.

The carrier has an average particle size of 10 to 250 microns, preferably an average particle size of 10 to 150 microns, an average diameter of 50 to 500 microns, and a micropore volume of 0.1 to 10 ml / g, preferably It is 0.5-5 ml / g, and the surface area of the said carrier is 5-1000 m <2> / g, Preferably it is 50-600 m <2> / g.

When silica is used as the carrier, it should have at least a part of active hydroxy [OH] group, the hydroxy group concentration is preferably 0.5 to 2.5 mmol or more per 1 g of the silica, more preferably 0.7 to 1.6 mmol / g, If the amount is less than 0.5 mmol, the supported amount of alkylaluminoxane decreases and the activity is lowered. If it exceeds 2.5 mmol, the catalyst component is deactivated by OH, which is not preferable.

The hydroxyl group of the silica can be detected by IR spectroscopy, and the hydroxy group concentration on the silica is determined by contacting the silica sample with methylmagnesium bromide and measuring the amount of methane foamed (by pressure measurement).

Silicas having [OH] concentrations and physical properties suitable for the present invention include W.R. The brand names XPO-2402, XPO-2410, XPO-2411 and XPO-2412 available from Grace and Company's Davison Chemical Division may be used, and silicas such as Davision® 948, 952 and 955 may be purchased and heated. Through the process can be used to adjust the desired concentration of [OH].

In the step (2), preferably, the alkyl aluminoxane is supported on the carrier, and then metallocene is supported. When silica is used as the carrier in step (2), the hydroxyl group of the silica is free of oxygen. Under anhydrous conditions, it reacts with alkylaluminoxanes to support the alkylaluminoxanes, providing a site on which the metallocenes will be supported, while being very sensitive to external catalyst poisons to protect metallocenes that tend to lose activity. Play a role. Therefore, the higher the supported amount of the alkylaluminoxane, the higher the supported amount of the metallocene, and the higher the probability of not being poisoned by the external catalyst poison, thereby increasing the activity.

The carrier slurry used in step (2) is prepared by suspending the carrier in a hydrocarbon solvent or a hydrocarbon solvent mixture.

The temperature of the supporting process of step (2) is preferably 40 ~ 160 ℃, more preferably 80 ~ 120 ℃, outside the temperature range, the activity is lowered and polymer aggregation occurs in the reactor is preferred It is preferable that the supporting time is 30 minutes to 4 hours, and more preferably 1 to 2 hours. If it is out of the above time range, the economical efficiency is low or the reaction is not sufficient, so that the function as a catalyst is not sufficient, which is not preferable. .

In the supported catalyst solution in which the supported process of step (2) is completed, trace amounts of unreacted alkylaluminic acid and unsupported metallocene catalyst are present, and they need to be removed before the drying process. In this case, the supported catalysts stick to each other and cause a poor injection problem when the catalyst is injected into the polymerization reactor in a dried form, and the injection of the agglomerated catalyst causes local overreaction in the reactor to form sheets and agglomerates. Will cause problems. In addition, the unsupported metallocene is easily separated from the carrier during the polymerization reaction to form a polymer of very fine particles, causing problems of reactor fouling.

For the purpose of removing such unsupported substances, the supported catalyst is washed twice with an organic solvent such as an aromatic hydrocarbon solvent and an aliphatic hydrocarbon solvent in step (3). In the first washing step, unsupported metallocene and alkylaluminoxane are removed. When desorption of the supported metallocene occurs in this step, it acts as an element that lowers the activity of the supported catalyst. In order to deepen the fixation of the supported metallocene and alkylaluminoxane component by performing the first washing step at a low temperature of -10 ~ 0 ℃, to prevent the desorption of the supported metallocene component in the subsequent secondary washing process Do it. The temperature of the secondary wash is not particularly limited.

Drying in the step (4) can be carried out using a conventional drying process.

The Al content in the metallocene supported catalyst prepared according to the method of the present invention as described above is preferably 20% by weight or more. If the Al content is less than 20% by weight, the activity is lowered, and an additional alkylaluminoxane must be injected into the reactor. Therefore, it is not preferable.

The polyolefin polymerization method using the catalyst for polyolefin polymerization prepared by the production method according to the present invention includes hydrogen, olefin, and comonomer as necessary in the presence of a metallocene supported catalyst prepared as described above as a main catalyst. An olefin polymer or copolymer is prepared by reacting the gas phase polymerization composition.

The polyolefin is an α-olefin homopolymer, a copolymer of α-olefin and α-olefin, a copolymer of α-olefin and diene, and the like, and preferably, high density polyethylene, linear low density polyethylene, ultra low density polyethylene, homo polypropylene, Propylene copolymers such as propylene ethylene copolymers, poly butadiene or butadiene ethylene copolymers and the like.

The α-olefin is preferably selected from the group consisting of ethylene, propylene, butene, hexene and octene, and the dienes are preferably butadiene, hexadiene or octadiene.

Preferably, the α-olefin may be ethylene, and in this case, the comonomer is preferably an alpha-olefin other than ethylene such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, or the like. The content ratio of the comonomer and ethylene is from 0.005 to 0.02 in molar ratio of comonomer / ethylene, preferably from 0.008 to 0.015. In this case, if the comonomer / ethylene molar ratio is less than 0.005 or more than 0.02, the desired level of copolymer cannot be obtained.

In such a method of preparing an olefin (co) polymer, the metallocene catalyst is combined with one or more activators to form an olefin polymerization catalyst system. Preferred activators used at this time include alkylaluminum compounds (e.g., diethylaluminum chloride), alkyl aluminoxanes, modified aluminoxanes, neutral or ionic ionizing activators, noncoordinating anions, noncoordinating group 13 metal or metalloid anions, Borane, borate, and the like.

With the alkyl aluminum compound has the general formula AlR _n X _(3-n) alkyl aluminum compounds represented by (wherein, R is an alkyl group of carbon number 1 ~ 16, X is a halogen element, and 1≤n≤3) Can be used. Specific examples of the alkyl aluminum compound are preferably triethyl aluminum, trimethyl aluminum, trinormal propyl aluminum, trinormal butyl aluminum, triisobutyl aluminum, trinormal hexyl aluminum, trinormal octyl aluminum, tri2-methylpentyl Aluminum etc. are used, Especially preferably, triisobutyl aluminum, triethyl aluminum, trinormal hexyl aluminum, or trinormal octyl aluminum is used.

It is preferable to use the said alkylaluminum compound at the time of gas phase superposition | polymerization in the following molar ratio according to desired polymer property.

1 ≦ transition metal in alkylaluminum compound / main catalyst ≦ 1000

More preferably

10 ≦ alkyl aluminum compound / transition metal in main catalyst ≦ 300

If the molar ratio of the transition metal in the alkylaluminum compound / main catalyst is less than 1 kPa, sufficient polymerization activity cannot be obtained, whereas if it exceeds 100, the adverse effect of lowering the polymerization activity appears.

In the above olefin (co) polymer production method, the polymerization reaction is preferably in the absence of a hydrocarbon solvent, preferably at a temperature of 60 to 120 ° C, more preferably at 65 to 100 ° C, and most preferably at 70 to 80 ° C. Preferably it is carried out at a pressure of 2 to 40 atmospheres, more preferably 10 to 30 atmospheres.

If the polymerization temperature in the reactor is less than 60 ° C., sufficient polymerization efficiency cannot be obtained. If the polymerization temperature is more than 100 ° C., there is a problem that a polymer mass is easily generated. In addition, when the operation pressure in the reaction reactor is less than 2 atmospheres, the ethylene partial pressure is low to obtain sufficient polymerization efficiency. When it exceeds 40 atmospheres, control of the reaction becomes difficult, and the reactor is exerted.

According to the present invention, it is not necessary to inject additional alkylaluminoxane during the polymerization reaction by increasing the amount of the supported alkylaluminoxane and the metallocene compound, and to maintain high activity by sufficiently protecting the supported metallocene compound from the catalyst poison. It works.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example  One

[Preparation of supported metallocene catalyst]

As shown in Table 1, 5 g of dehydrated silica under the trade name XPO-2402 (average particle size 50 microns, surface area 300 m 2 / g, micropore volume 1.6 ml / g, OH concentration 1 mmol / g) was quantified under anhydrous conditions, and 30 ml of toluene Was stirred in a slurry state. It was injected into a 1 L reactor equipped with a stirrer and a cooling condenser. 75 ml of methylaluminoxane solution (10% by weight in toluene) was quantified in a measuring cylinder, and then mixed with 0.3 g of the metallocene catalyst component Et (THI) ₂ ZrCl ₂ , pre-quantified in 250 ml Schlenk, at room temperature. The mixture was stirred for 5 minutes to dissolve and react with the solid metallocene catalyst. The methylaluminoxane-metallocene solution was added while maintaining the temperature of the reactor at 70 ° C. After stirring, the reaction temperature was raised to 110 ° C. At this temperature, the supporting reaction proceeded for 90 minutes. After the reaction was completed, the reaction was transferred to a Schlenk vessel, followed by decantation. After the reaction was stirred, the mixture was allowed to stand for 10 minutes, followed by decantation of the upper solution, and the reaction was first washed with 100 ml of toluene at -5 ° C. After the reaction was stirred, the reaction solution was allowed to stand, and after standing up, the upper solution was decanted and washed twice with 100 ml of toluene at room temperature. The resulting catalyst system was then washed with purified hexane and then dried under mild vacuum. The amount of supported catalyst prepared was 8.2 g. Al and Si content analysis of the catalyst were carried out to calculate the amount of methylaluminoxane supported from the Al content. The measured Al content was 21.2% by weight, and the calculated amount of supported methylaluminoxane was 45.5% by weight.

[Polymerization method]

Under the conditions shown in Table 2, polymerization was carried out by the following method using the metallocene supported catalyst described above.

1000 ml of purified hexane and 10 ml of 1-hexene were injected into a 2 L stainless steel reactor equipped with a stirrer and a heating / cooling device. The reactor was thoroughly washed with pure nitrogen before use. Next, 0.5 cc of 1 M hexane dilutions of triisobutylaluminum (TiBA) were injected into the reactor as a catalyst poison remover, and stirred, and the temperature was raised to 65 ° C, followed by stirring. As the main catalyst, 11 mg of the metallocene supported catalyst prepared in the above step was quantified in a glove box, transferred to a 5 ml syringe, and 1.7 cc of 1 M hexane dilution of triisobutylaluminum (TiBA) was taken as an activator. The activated catalyst slurry was transferred to the reactor and injected into the reactor at 65 ° C. Then, the reactor temperature was raised to 80 ° C., 150 ml of hydrogen was supplied, ethylene was fed so that the reactor voltage was 300 psig, and the reaction was started by stirring at 1000 rpm. During the reaction, the polymerization was carried out for 30 minutes while supplying enough ethylene so that the voltage of the reactor was kept constant at 300 psig. After 30 minutes of polymerization, ethylene injection was stopped to terminate the reaction to obtain a resultant polymer. The obtained polymer was separated by a filter and sufficiently dried to obtain 90 g of a polymer.

Comparative example  One

A supported catalyst was prepared in the same manner as in Example 1, except that the first washing temperature was 110 ° C., except that 18.5 mg of the catalyst was used in the polymerization process and the polymerization reaction time was 60 minutes. The polymerization was carried out in the same manner as in Example 1. 205 g of polymer was obtained.

Example  2

The supported catalyst was prepared in the same manner as in Example 1, except that the supported reaction was performed at 100 ° C. and the first toluene wash was performed at 0 ° C. after the supported reaction was completed.

The polymerization process was carried out in the same manner as in Example 1 except that the amount of catalyst was 24 mg and the polymerization time was 30 minutes. 175 g of polymer was obtained.

Comparative example  2

The supported catalyst was prepared in the same manner as in Example 2, except that the supported reaction was performed at 100 ° C., and the first toluene wash was performed at 80 ° C. after the supported reaction was completed.

The polymerization process was carried out in the same manner as in Example 2, except that 26.5 mg of catalyst was used and the polymerization time was 30 minutes. 178 g of polymer was obtained.

The analysis results and polymerization results of the catalysts prepared together with the catalyst preparation conditions and polymerization conditions of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Tables 1 and 2.

Table 1

Example 1 Comparative Example 1 Example 2 Comparative Example 2 Silica (g) 5 5 5 5 Support reaction temperature (℃) 110 110 100 100 Primary washing (℃) -5 110 0 80 Yield (g) 8.2 7.4 6.3 6.2 Aluminum content (% by weight) 21.2 19.2 14.5 14.1 Methyl aluminoxane (% by weight) 45.5 41.2 31.2 30.4

TABLE 2

Example 1 Comparative Example 1 Example 2 Comparative Example 2 Metallocene catalyst (mg) 11 18.5 24 26.5 H ₂ (cc) 150 150 150 150 Ethylene (psig) 300 300 300 300 1-hexene (cc) 10 10 10 10 TiBA (1M) (cc) 2.2 2.2 2.2 2.2 Polymerization time (minutes) 30 60 30 30 Yield (g) 90 205 175 178 Activity (g / g / h) 16,364 11,081 14,583 13,434 Fouling none none none none

As in Example 1 and Comparative Example 1, when the supporting temperature is the same as 110 ℃, the amount of methyl aluminoxane supported is similar regardless of the first washing temperature, but the activity is -5 ℃ low of the first washing temperature of Example 1 The case is higher than Comparative Example 1, which is 110 ° C. When the supporting temperature is 100 ° C. as in Example 2 and Comparative Example 2, as in Example 1 and Comparative Example 1, the loading amount of methylaluminoxane is similar, but the activity is Example 2, where the primary washing temperature is 0 ° C. The primary washing temperature is higher than Comparative Example 2, which is 80 ° C.

Example 2 having less methyl aluminoxane supported amount than Comparative Example 1 having high methyl aluminoxane content showed high activity of Example 2 having a low first washing temperature. This is the effect of lowering the first washing temperature which is the effect of the present invention.

Claims (5)

A process for preparing a catalyst for polyolefin polymerization, comprising the following steps: (1) dissolving a metallocene catalyst component in an alkylaluminoxane solution, (2) adding the solution of step (1) to the carrier slurry, stirring at 40-160 ° C. to support the alkylaluminoxane and the metallocene component, (3) After the supporting reaction in step (2), after decanting the supernatant of the solution, the obtained supported catalyst is first washed with an organic solvent at -10 ~ 0 ℃, and then secondly washed with an organic solvent at room temperature step, (4) 단계 drying the washed catalyst of step (3) and recovering it as a catalyst powder. The method for preparing a catalyst for polyolefin polymerization according to claim 1, wherein the metallocene catalyst component is represented by the following general formula (I): (THI) ₂ R "MQ _p (I) (Wherein THI is a tetrahydroindenyl derivative, which may be substituted or unsubstituted, R ″ is a crosslinking present between two THIs, and M is a transition metal selected from Groups IIIB, IVB, VB and VIB) Q is a hydrocarbyl group or halogen having 1 to 20 carbon atoms, and p is valence-2 of M). The method of claim 1, wherein the carrier of step (2) has a micropore having an average particle size of 10 to 250 microns, an average diameter of 50 to 500 mm 3, a micro pore volume of 0.1 to 10 ml / g, and a surface area of 5 Method for producing a catalyst for polyolefin polymerization, characterized in that the silica is ~ 1000 m2 / g. A polyolefin polymer prepared by polymerizing an olefin or an olefin and a comonomer in the presence of a metallocene supported catalyst prepared by the process for producing a polyolefin polymerization catalyst according to any one of claims 1 to 3. Way. The method according to claim 4, wherein the polyolefin is an alpha-olefin homopolymer, a copolymer of alpha-olefin and alpha-olefin, or a copolymer of alpha-olefin and dienes.