KR20190086304A - Method of removing a bromine compound in a catalytic composition - Google Patents

Abstract

The present invention is to provide a method for removing a bromine compound in a catalytic composition comprising the following steps: (S1) removing an ether solvent in a catalytic composition comprising an alkylated transition metal compound, a bromine compound and the ether solvent; (S2) adding a hydrocarbon solvent in catalytic solids in which the ether solvent is removed, and dissolving the alkylated transition metal compound at the temperature of -25 to 5°C; and (S3) filtering the compound with a filter having the pore of 0.1 to 20 μm. Accordingly, by-products such as a bromine compound generated in an alkylation process can be removed with a high removal ratio, a recovery ratio of an alkylated transition metal compound is excellent and degeneration does not occur. The high purity can be maintained.

Description

[0001] METHOD OF REMOVING A BROMINE COMPOUND IN A CATALYTIC COMPOSITION [0002]

The present invention relates to a catalyst composition, and more particularly to a process for removing a bromine compound contained in a metallocene catalyst composition such as a transition metal compound.

Dow, in the early 1990s, [Me ₂ Si (Me ₄ C ₅ ) N t Bu] TiCl ₂ (U.S. Patent No. 5,064,802) discloses that the CGC is superior to conventional metallocene catalysts in the copolymerization reaction of ethylene and alpha-olefins (hereinafter referred to as " Constrained-Geometry Catalyst " (1) high molecular weight polymers exhibiting high activity even at high polymerization temperatures; (2) alpha-olefins with high steric hindrance such as 1-hexene and 1-octene; The copolymerization is also excellent. In addition, various characteristics of CGC were gradually known during the polymerization reaction, and efforts to synthesize the derivative and use it as a polymerization catalyst have actively been made in academia and industry.

One approach has been attempted to synthesize and polymerize metal compounds in which various other bridges and nitrogen substituents have been introduced instead of silicon bridges. Representative metal compounds known until recently are as follows (Chem. Rev. 2003, 103, 283).

(1), ethylene or propylene (2), methylidene (3), and methylene (4) bridges were introduced in place of the silicon bridge of the CGC structure, Or in the case of copolymerization with an alpha-olefin, no improvement in terms of activity or copolymerization performance versus CGC was obtained.

In addition, as another approach, a large amount of compounds composed of oxydolides were synthesized instead of the amido ligands of CGC, and some polymerization using the compounds was attempted. The examples are summarized as follows.

Compound (5) is reported by T. J. Marks et al. In which Cp (cyclopentadiene) derivatives and oxydolides are crosslinked by ortho-phenylene groups (Organometallics 1997, 16, 5958). Compounds having the same cross-linking and polymerization using them have also been reported by Mu et al. (Organometallics 2004, 23, 540). Also, Rothwell et al. (Chem. Commun. 2003, 1034) have reported that an indenyl ligand and an oxydol ligand are bridged by the same ortho-phenylene group. Compound (6) is reported by Whitby et al. (Organometallics 1999, 18, 348) in which a cyclopentenylidene ligand and an oxydoligand are bridged by three carbon atoms (Syndiotactic ) Was reported to exhibit activity in polystyrene polymerization. Similar compounds have also been reported by Hessen et al. (Organometallics 1998, 17, 1652). Compound (7) is reported by Rau et al. And is characterized in that it exhibits activity in ethylene polymerization and ethylene / 1-hexene copolymerization at high temperature and high pressure (210 ° C., 150 MPa) (J. Organomet. . Then, the catalyst synthesis (8) having similar structure and the high temperature and high pressure polymerization using the same were patented by Sumitomo Co. (US Patent No. 6,548,686). However, among the above attempts, only a few catalysts have actually been applied to commercial plants. Therefore, a catalyst showing improved polymerization performance is required, and a method of simply producing such catalysts is required.

On the other hand, such metallocene catalysts are generally used by methylation, and the methylation is tried in various ways. However, since the impurities generated in the methylation process are adsorbed on the active sites of the catalyst, the activity of the catalyst is largely lowered, or the washing frequency is increased due to solidification in the reactor or in the heat exchangers before and after the reactor. It is a fact that is raising.

Due to these problems, there is a need for research on a method capable of maintaining a high purity without denaturing the metallocene catalyst while minimizing impurities or removing impurities in the methylation process.

US Patent No. 5,064,802 US Patent No. 6,548,686

Chem. Rev. 2003, 103, 283 Organometallics 1997, 16, 5958 Organometallics 2004, 23, 540 Chem. Commun. 2003, 1034 Organometallics 1999, 18, 348 Organometallics 1998, 17, 1652 J. Organomet. Chem. 2000, 608, 71

DISCLOSURE Technical Problem The present invention has been devised to solve the problems of the prior art described above, and it is an object of the present invention to remove by-products such as bromine compounds generated in the alkylation process, which are necessarily accompanied with the production of a metallocene catalyst such as a transition metal compound, The present invention provides a method for removing a bromine compound having a high recovery rate of a compound.

In order to solve the above-mentioned problems, the present invention provides a process for producing a catalyst composition, comprising: (S1) removing an ether-based solvent in a catalyst composition comprising an alkylated transition metal compound represented by the following general formula (1), a bromine compound and an ether-based solvent; (S2) adding a hydrocarbon solvent to the catalyst solid from which the ether-based solvent has been removed to dissolve the alkylated transition metal compound at a temperature of -25 to 5 占 폚; And filtering (S3) the solution with a filter having pores of 0.1 to 20 占 퐉.

[Chemical Formula 1]

In the above formula (1), the Ligand is an organic compound having two coordination sites capable of coordinating with a transition metal, M is a Group 4 transition metal, and R ₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms to be.

The method of removing a bromine compound in a catalyst composition according to the present invention can remove a byproduct such as a bromine compound generated in an alkylation process, which is essentially accompanied with the preparation of a metallocene catalyst such as a transition metal compound, at a high removal rate, And the purity can be maintained because denaturation does not occur.

Hereinafter, the present invention will be described in detail in order to facilitate understanding of the present invention.

The terms and words used in the present specification and claims should not be construed in an ordinary or dictionary sense and the inventor can properly define the concept of the term to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention.

According to an embodiment of the present invention, there is provided a process for producing a catalyst composition, comprising: (S1) removing an ether-based solvent in a catalyst composition comprising an alkylated transition metal compound represented by the following general formula (1), a bromine compound and an ether-based solvent; Adding a hydrocarbon solvent to the catalyst solid from which the ether-based solvent has been removed to dissolve the alkylated transition metal compound (S2) at a temperature of -25 to 5 占 폚; And filtering (S3) the solution with a filter having pores of 0.1 to 20 占 퐉.

[Chemical Formula 1]

In the above formula (1), the Ligand is an organic compound having two coordination sites capable of coordinating with a transition metal, M is a Group 4 transition metal, and R ₁ and R ₂ are each independently an alkyl group having 1 to 10 carbon atoms to be.

The method of removing a bromine compound in a catalyst composition according to an embodiment of the present invention can overcome the problem of removal by removal or recrystallization using a conventional filter aid.

Specifically, the removal of the bromine compound using the filter aid may be a relatively simple method in which a filter aid such as Celite is disposed in the filter to perform filtration. However, when the filtration aid is removed, the bromine compound is hardly removed The removal efficiency of the transition metal compound is extremely low. In the case of using the method of removing the filtrate by using the solid component as a target component through recrystallization, the loss ratio of the transition metal compound as the target component is considerable, and even when the bromine compound is removed, There has been a problem of loss of 50% or more.

The method for removing a bromine compound in a catalyst composition according to an embodiment of the present invention is a method for solving the above problems, which can remove a by-product such as a bromine compound at a high removal rate, Denaturation does not occur and purity can be maintained at a high level.

Step S1

Step S1 is a step of solidifying the alkylated transition metal compound, which means removing the ether-based solvent from the composition containing the ether-based solvent and the bromine compound.

The alkylated transition metal compound is represented by the general formula (1), and the ligand may be an organic compound, and may be a ligand coordinated at two sites with M as a transition metal of Group 4. For example, a compound represented by the following formula (1a).

[Formula 1a]

Wherein R ₁ , R _2, and M are the same as those in Formula 1, and R ₃ to R ₆ are the same or different from each other and each independently represents hydrogen; Alkyl having 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl having 6 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Arylalkyl having 7 to 20 carbon atoms; Or a metalloid radical of a Group 14 metal substituted with hydrocarbyl of 1 to 20 carbon atoms; Two or more of R ₃ to R ₆ may be connected to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms; The aliphatic ring or aromatic ring may be substituted with halogen, alkyl of 1 to 20 carbon atoms, alkenyl of 2 to 20 carbon atoms, or aryl of 6 to 20 carbon atoms,

R ₇ to R ₁₅ are the same or different from each other, and each independently hydrogen; Alkyl having 1 to 20 carbon atoms; Alkenyl having 2 to 20 carbon atoms; Aryl having 6 to 20 carbon atoms; Alkylaryl having 7 to 20 carbon atoms; Or arylalkyl having 7 to 20 carbon atoms; At least two adjacent to each other of R ₇ to R _{11 may} be connected to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms; The aliphatic ring or aromatic ring may be substituted with halogen, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, or aryl having 6 to 20 carbon atoms.

R ₃ to R ₁₅ may each independently be unsubstituted or substituted. When substituted, the substituent may be, for example, halogen, alkyl of 1 to 20 carbon atoms, hydrocarbyl of 1 to 20 carbon atoms, Or an aryloxy group having 6 to 20 carbon atoms.

R ₃ to R ₁₅ are the same or different from each other and each independently represents hydrogen; Alkyl having 1 to 20 carbon atoms; Or alkenyl having 2 to 20 carbon atoms, preferably hydrogen; Or an alkyl having 1 to 20 carbon atoms.

Further, M may preferably be Ti, Hf or Zr, and more preferably Ti.

The formula (Ia) is an exemplary compound of the formula (1) to show the coordination site of the ligand and the metal M. The transition metal compound having the structure is not particularly limited, but R1 and R2 bonded to the metal M Alkylated transition metal compound.

According to one embodiment of the present invention, R ₁ and R ₂ are each preferably independently an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group Lt; / RTI > R ₁ and R ₂ may be determined depending on which compound the transition metal compound is alkylated with, and the carbon number of the alkyl group may influence the performance of the catalyst, such as activity or copolymerization.

According to an embodiment of the present invention, the catalyst composition may further comprise an ether-based solvent and a bromine compound in addition to the alkylated transition metal compound represented by Formula 1, An unpurified product or a product in which only primary purification has been performed, and the like.

The ether solvent may be, for example, a compound such as methyl t-butyl ether, diethyl ether, or tetrahydrofuran, and the ether solvent may be used as a solvent for the reaction have.

In addition, the bromine compound is a by-product generated in the alkylation process or an unreacted product in the alkylation process during the process of producing the alkylated transition metal compound represented by Formula 1, and is a substance to be removed with bromine- For example, it may be one containing an alkyl magnesium bromide (wherein alkyl is methyl, ethyl or isopropyl), magnesium dibromide, a compound represented by the following formula 1-1 or a compound represented by the following formula 1-2 have.

[Formula 1-1]

In Formula 1-1, X ₁ and X ₂ are each independently Br or an alkyl group having 1 to 10 carbon atoms, and at least one of X ₁ and X ₂ is Br.

[Formula 1-2]

In Formula 1-2, each of X ₁ and X ₂ is independently Br or an alkyl group having 1 to 10 carbon atoms.

As described above, such a bromine compound is added as a reactant in the process of alkylating the alkylated transition metal compound and is included as an impurity. The bromine compound is reacted with a metallocene catalyst such as the transition metal compound to perform copolymerization or the like It is adsorbed on the active site of the catalyst to deteriorate the catalytic activity, and adverse effects such as formation of a scale on the agitator and the inner wall of the reactor may occur.

According to the present invention, the step S1 is a step of removing the ether-based solvent in the catalyst composition, and the ether-based solvent may be removed so as to be 0.01 wt% or less based on the total weight of the catalyst composition.

The ether solvent may be removed by various methods. In general, the solvent may be evaporated by heating under a vacuum of 0.1 to 400 torr. In this case, the heating may be performed at a temperature of 10 to 80 캜, and the heating may be performed for 1 to 24 hours so that the ether solvent evaporates to a target content. When the temperature range and the pressure range are satisfied, removal of the solvent can be smoothly performed, and removal to a level of 0.01 wt% or less, that is, to a level that can not be detected, may be possible.

Step S2

Step S2 is a step of adding a hydrocarbon solvent to the catalyst solids from which the ether-based solvent has been removed, and dissolving the alkylated transition metal compound at a temperature of -25 to 5 占 폚.

According to the present invention, the hydrocarbon solvent which can be used in the step S2 may be a nonpolar solvent, for example, hexane, heptane, 2-methylpentane or pentane. The alkylated transition metal compound represented by the formula Any solvent capable of dissolving can be used without particular limitation.

The amount of the hydrocarbon solvent may need to be controlled to an appropriate level, and the ether solvent may be removed to add 15 to 50 times the total weight of the remaining catalyst solids, preferably 20 to 25 times It may be to put in weight. If the hydrocarbon solvent is not fed at a rate of 15 times the catalyst solid content, the alkylated transition metal compound can not be sufficiently dissolved so that the bromine compound can be removed from the filter together with the catalyst, thereby substantially reducing the recovery of the catalyst component. In addition, when the amount exceeds 50 times the solid content of the catalyst, the bromine compound may be dissolved in some cases, and the removal rate of the bromine compound may be lowered, resulting in an economical loss due to an unnecessary amount.

The dissolving process of the solid catalyst component through the hydrocarbon solvent is preferably performed at a low temperature. For example, at a temperature lower than room temperature, such as -25 to 5 ° C, preferably at -15 to 5 ° C, to dissolve the solid content.

If the reaction is carried out at a temperature lower than -25 DEG C, the solubility of the alkylated transition metal compound may be lowered and the alkylated transition metal compound may not be dissolved sufficiently, which may result in lowered recovery. There is a problem that the bromine compound can be dissolved, and consequently, a subsequent problem may arise.

In order to dissolve the solid catalyst, the temperature range and the amount of the hydrocarbon solvent should be appropriately controlled. According to the present invention, at a temperature of -25 to 5 ° C., about 15 to 50 times the total weight of the solid catalyst, It is preferable that an adequate amount of a hydrocarbon solvent is added to dissolve and the recovery rate of the alkylated transition metal compound and the removal rate of the bromine compound can be maximized.

Step S3

Step S3 is filtration with a filter having pores of 0.1 to 20 mu m.

According to an embodiment of the present invention, the step S3 may be a step of dissolving the solid catalyst component in a hydrocarbon solvent, and then filtering the solution with a filter, wherein the solution contains an alkylated transition metal The compound and the bromine compound remaining in a solid state in which most of the compound is not dissolved.

Thus, the bromine compound can be removed by filtering the remaining solid without dissolving the bromine compound through a filter. The filter used herein may have a pore size of 0.1 to 20 μm, and the filtration step may be performed by appropriately adjusting the pore size within the above range.

Preferably, the filtration can be performed using two or more filters. It is preferable that a filter having a large pore is used as the first filter and a filter having a small pore is used as the second filter. For example, it may be desirable for the primary main filter to have pores of 10 to 20 microns, the secondary filter preferably to have the form of a line filter, and the pores to have a diameter of 0.1 to 1.0 microns can do.

When the pore size of the filter is smaller than 0.1 탆, the filtration efficiency may be significantly lowered because the filtration efficiency may be lowered. The pore size of the filter needs to be adjusted appropriately.

Alkylation step

According to an embodiment of the present invention, there is provided a method for removing a bromine compound in a catalyst composition, comprising: alkylating a transition metal compound by introducing an alkyl bromide metal into a transition metal compound represented by the following formula (2) S0) < / RTI >

(2)

In the formula (2), the Ligand is an organic compound having two coordination sites capable of coordinating with a transition metal, and M is a Group 4 transition metal.

That is, the transition metal compound represented by Formula 2 may be a compound before alkylation, and specifically may be represented by Formula 2a.

(2a)

In formula (2a), R ₃ to R ₁₅ and M have the same definitions as in formula (1a).

The compound that can be used to alkylate the transition metal compound represented by the above formula (2) may be at least one selected from the group consisting of methyl bromide, ethyl magnesium bromide and isopropyl magnesium bromide as the alkyl bromide metal .

Specifically, the metal of the alkyl brominated metal may be an alkaline earth metal or an alkali metal, but when an organometallic compound containing an alkali metal is used, the alkali metal may be an alkaline earth metal The reactivity is very high as compared with the metal, and the reaction and ignition are very easily caused by the contact with a small amount of moisture and air. Therefore, there is a great risk in the process, there is a storage problem such as frozen storage, It is advantageous to apply a compound having an alkaline earth metal bond such as the above-mentioned alkyl magnesium bromide.

The methylation using the alkyl magnesium bromide may be carried out by replacing the chlorine of the transition metal compound represented by the formula (2) with the alkyl group of the alkylated transition metal compound represented by the formula (1), and may be a reaction represented by the following reaction formula (1).

[Reaction Scheme 1]

As the nucleophilic substitution reaction of the organomagnesium compound, it may be a reaction in which the methyl group is bonded and the chlorine is released to the leaving group. The bromine compound as a side reaction product generated in this process may be a problem, and the bromine compound may be removed according to the method of removing the bromine compound according to the present invention.

When the method for removing bromine compounds in the catalyst composition according to the present invention is applied, the bromine compound as a by-product generated in the alkylation process can be removed with high efficiency, and the recovery rate of the alkylated transition metal compound, The removal rate of bromine can be increased while maintaining a high level, and denaturation does not occur in the alkylated transition metal compound, so that high purity can be maintained.

Example

Hereinafter, the present invention will be described more specifically based on the following examples. These examples are provided to aid understanding of the present invention and the scope of the present invention is not limited thereto.

Example  One

1) Preparation of Catalyst Composition

Alkylation step

As a composition after preparing the transition metal compound represented by the following formula (2a-1), 203.2 g of a catalyst composition comprising methyl t-butyl ether (MTBE) as an ether solvent was dissolved in diethyl ether having a concentration of 36 wt% Chlorine (Cl) was methylated from the compound of the following formula (2a-1) by the addition of 50.2 g of methylmagnesium bromide.

Evaporation and room temperature filtration step

The catalyst composition was then heated at 60 DEG C for 5.5 hours at a vacuum of 10 torr to remove the MTBE contained in the composition to a level of 0.0 wt.% (At a level that is undetectable, zero to the first decimal place as an effective number of digits) , 400 g of a hexane solvent was added thereto, and the mixture was stirred at 25 DEG C to selectively dissolve the methylated transition metal compound in the solid content.

Next, the LiCl component was removed from the primary main filter having pores of 10 mu m and the secondary line filter having pores of 0.2 mu m and filtered to obtain a catalyst composition. The yield of the methylated transition metal compound represented by the following formula (1a-1) obtained by the composition at this time was 14.6 g (recovery: 83.6%, purity: 85%, Br content: 1.38%).

2) Removal of bromine compounds

The catalyst composition obtained in the above manner was fed into a reactor and heated in a vacuum of 10 torr for 5.5 hours at 60 ° C to remove 0.0 wt% of hexane in the catalyst composition (at a level that can not be detected, Lt; RTI ID = 0.0 > 0) < / RTI >

350 g of a hexane solvent was added and stirred at -10 DEG C to selectively dissolve the methylated transition metal compound in the solid component. Then, the methylene transition metal compound was dissolved in a secondary filter having a primary main filter having 10 mu m pores and a pore having 0.2 mu m The catalyst solution was recovered while removing the bromine compound by filtration. The quantitative determination of the obtained catalyst solution was 13.0 g based on the solid catalyst.

[Formula 2a-1]

[Formula 1a-1]

Example  2

In Example 1, the bromine compound was removed by repeating the process of removing the bromine compound of 2) twice.

Example  3

In the same manner as in Example 1 except that the hexane solvent was added during the step of removing the bromine compound in the above Example 2 to thereby dissolve the solid content, the bromine compound was obtained in the same manner as in Example 1 except that the temperature was changed to 0 ° C instead of -10 ° C. Respectively.

Example  4

The bromine compound was removed in the same manner as in Example 1, except that 700 g of hexane solvent was added instead of 350 g of hexane solvent in the step of dissolving the solid content by adding hexane solvent during the bromine compound removing process of Example 2 above Respectively.

Comparative Example  One

A catalyst composition (purity of methylated transition metal compound: 85%, Br content: 1.38%) was obtained in the same manner as in Example 1, and a hexane solvent was removed from 100 g of this catalyst composition to obtain a solid content of 6.11 g. The solid was dissolved in purified hexane (10.6 g) at room temperature (25 ° C) and allowed to stand at -22 ° C for 15 hours to allow the transition metal catalyst to be recrystallized. The solid was recrystallized from a dry ice / acetone bath at -76 ° C And the bromine compound was removed by filtration in such a manner that 4.25 g of a recrystallized solid was obtained by using a tube equipped with a 3 占 퐉 filter.

Comparative Example  2

The bromine compound was removed in the same manner as in Comparative Example 1, except that the temperature of the dry ice / acetone bath was changed from -76 ° C to -10 ° C.

Comparative Example  3

The catalyst composition (purity of methylated transition metal compound: 95%, Br content: 1.38%) was obtained in the same manner as in Example 1, and 20 g of celite was laid on the primary main filter having pores of 10 m, And filtered through a secondary line filter having pores of < RTI ID = 0.0 >

Experimental Example

The removal rate of the bromine compound, the purity of the methylated transition metal compound in the filtered composition, and the recovery rate of the methylated transition metal compound in the brominated compound-removed liver were measured for Examples 1 to 4 and Comparative Examples 1 to 3, Respectively.

Removal rate of bromine compound

The Br absolute value (B1) was obtained by multiplying the Br content contained in the catalyst composition as the feed solution at the time of removing the bromine compound by the weight, and the absolute Br amount (A1) was obtained by multiplying the Br content in the catalyst composition after the completion of the removal of the bromine compound by the weight, Is derived by the following equation (1).

[Equation 1]

Removal rate (%) = [(B1-A1) / B1] x 100

Purity of methylated transition metal compound

After completion of the removal of the bromine compound, the solvent in the catalyst composition was completely evaporated and the residue was dissolved in an NMR solvent (CDCl ₃ ), followed by 1H-NMR (500 MHz) to obtain the methylated transition metal compound represented by the formula (C1) of the peak corresponding to 4.6 ± 0.5 ppm (chemical shift) at which a peak of hydrogen attached to the alpha carbon of the N element appears in the peak and a peak (D1), which is the sum of the integral ratios of the peaks other than the peak corresponding to the compound, was measured and then derived by the following formula (2).

&Quot; (2) "

Purity (%) = [C1 / (C1 + D1)] x 100

Recovery of methylated transition metal compound

The weight (G1) of the methylated transition metal compound is determined by multiplying the solids content (E1) contained in the catalyst composition as the feed solution at the time of removing the bromine compound by the solution weight (F1), and the solid content The weight (G2) of the methylated transition metal compound was obtained by multiplying the content (E2) by the solution weight (F2) and was derived by the following equation (3).

&Quot; (3) "

Recovery rate (%) = (G2 / G1) x 100

The solids content E1 and E2 are derived from the weight (G1 and G2) of the remaining solids after sufficiently evaporating the solvent from the total solution (solution weights F1 and F2), and the weight of the solids is determined by methylation The transition metal compounds accounted for the majority and were therefore considered as the weight of the methylated transition metal compound.

Bromine compound removal rate (%), The Br content in the final catalyst composition Purity of methylated transition metal compound (%) Recovery rate of methylated transition metal compound (%) Example 1 73.0 0.37 85.0 89.0 Example 2 93.0 0.09 82.0 83.0 Example 3 65.0 0.42 83.0 88.0 Example 4 68.0 0.40 82.0 90.0 Comparative Example 1 22.2 1.10 0.2 69.6 Comparative Example 2 35.0 1.16 76.0 45.0 Comparative Example 3 15.0 1.17 83.0 95.0

Referring to Table 1, it can be seen that the removal rate of the bromine compound in Example 1 in which the bromine compound is removed by dissolving it in a hexane solvent at -10 ° C through filtration through the filter is considerably higher than the comparative examples , And in the case of Example 2 in which it is repeatedly performed, it is also confirmed that the efficiency is greatly increased. It can also be seen that the efficiencies of Examples 3 and 4 in which the amount of hexane solvent used and the dissolution temperature were changed were remarkably excellent. In Examples 1 to 4, not only the removal rate of bromine but also the amount of bromination The purity of the metal compound and the recovery rate are also remarkably excellent.

However, when the bromine compound is removed through recrystallization and extraction at a very low temperature as in Comparative Example 1, the removal rate of the bromine compound is considerably poor and the methylation transition metal compound is denatured so that the catalyst can not be used at a purity of 0.2% In the case of Comparative Example 2 in which the recrystallization temperature was increased to -10 ° C, which is the same level as the low temperature filtration temperature of the present invention, the methylation transition metal compound was prevented from being denatured compared to Comparative Example 1 and the purity was somewhat improved. It can be seen that 50% is not reached, and the removal rate of the bromine compound is still at a poor level.

Further, in the case of Comparative Example 3 using celite as a filter aid as a simple method, it can be confirmed that the purity and the recovery rate of the methylated transition metal compound are considerably excellent, but the bromine compound remains at the level remained.

As a result, in the case of a transition metal compound prepared by performing an alkylation step such as methylation, the bromine compound is not removed by purification such as recrystallization or filtration using a filter aid, and the method of removing the bromine compound according to the present invention It was confirmed that the bromine compound can be removed with high efficiency by carrying out the step of injecting and dissolving hexane solvent at a low temperature and filtering it, and it is possible to maintain the recovery and purity of the methylated transition metal compound as the target product.

Claims (10)

(S1) removing an ether-based solvent in a catalyst composition comprising an alkylated transition metal compound represented by the following formula (1), a bromine compound, and an ether-based solvent;
(S2) adding a hydrocarbon solvent to the catalyst solid from which the ether-based solvent has been removed to dissolve the alkylated transition metal compound at a temperature of -25 to 5 占 폚; And
And filtering (S3) the solution with a filter having pores of 0.1 to 20 占 퐉.
[Chemical Formula 1]

In Formula 1,
The ligand is an organic compound having two coordination sites capable of coordinating with a transition metal,
Wherein M is a Group 4 transition metal,
Each of R ₁ and R ₂ is independently an alkyl group having 1 to 10 carbon atoms.
The method according to claim 1,
Wherein R ₁ and R ₂ are each independently an alkyl group having 1 to 3 carbon atoms.
The method according to claim 1,
Wherein R ₁ and R ₂ are a methyl group, an ethyl group or an isopropyl group.
The method according to claim 1,
Wherein the ether solvent is removed to a concentration of 0.01 wt% or less based on the total weight of the catalyst composition.
The method according to claim 1,
Wherein the ether solvent is evaporated by heating at 10 to 80 캜 under a vacuum of 0.1 to 400 torr to remove the bromine compound in the catalyst composition.
The method according to claim 1,
Wherein the hydrocarbon solvent is at least one member selected from the group consisting of hexane, heptane, 2-methylpentane and pentane.
The method according to claim 1,
Wherein the hydrocarbon solvent is added 15 to 50 times the total weight of the catalyst solid.
The method according to claim 1,
Wherein the step S3 is filtration with a primary main filter having pores of 10 to 20 mu m and then filtration with a secondary line filter having pores of 0.1 to 1.0 mu m.
The method according to claim 1,
Further comprising a step (S0) of alkylating the transition metal compound by introducing a metal alkyl bromide into a transition metal compound represented by the following general formula (2) before the step (S1):
(2)

In Formula 2,
The ligand is an organic compound having two coordination sites capable of coordinating with a transition metal,
The M is a transition metal of Group 4.
The method of claim 9,
Wherein the alkyl bromide metal is at least one member selected from the group consisting of methyl magnesium bromide, ethyl magnesium bromide and isopropyl magnesium bromide.