KR102506502B1 - Catalyst composition and preparation method of polyisobutene using the same - Google Patents

Abstract

The present invention relates to a catalyst composition comprising an oxonium ion-based catalyst and an additive, and a method for producing polyisobutene using the same.

Description

Catalyst composition and method for producing polyisobutene using the same

The present invention relates to a catalyst composition comprising an oxonium ion-based catalyst and an additive, and a method for producing polyisobutene using the same.

In general, in a process of producing oligomers or polymers by cationic polymerization of monomers, a growing polymer chain includes an active site having a positive charge. For example, the active site can be a carbenium ion (carbocation) or an oxonium ion.

Aluminum or boron-based Lewis acids are generally used as catalysts or initiators for such cationic polymerization. Examples of Lewis acid catalysts include AlX ₃ , BX ₃ (X=F, Br, Cl, I), which are corrosive and generate halogen components such as HCl and HF during the quenching process, which remain in the product and deteriorate quality There is a problem that causes In addition, Lewis acid catalysts require a large amount of catalyst, use a large amount of base (NaOH, KOH, NH ₄ OH, etc.) to remove the catalyst after the reaction and wash it with water, resulting in a large amount of wastewater. causes

On the other hand, examples of monomers capable of cationic polymerization include styrene, isobutene, cyclopentadiene, dicyclopentadiene and derivatives thereof, and polyisobutene (PIB) obtained by polymerization of isobutene is the most representative example.

Polyisobutene is divided into low molecular weight, medium molecular weight and high molecular weight ranges according to the molecular weight range. Low molecular weight polyisobutene has a number average molecular weight of 10,000 or less, and can be classified according to the content of terminal carbon-carbon double bonds. Common polybutenes having a terminal carbon-carbon double bond content of 20% or less (conventional PIB) and high reactive polybutene (HR-PB). The highly reactive polybutene may be used as a fuel additive or an engine oil additive after introducing a functional group using a terminal vinylidene functional group (>80%).

For the polymerization of the highly reactive polybutene, a boron-based catalyst such as BF ₃ is used as a prior art, but it is toxic and difficult to handle as a gas type. In addition, boron-alcohol or boron-ether complexes are made and used to increase reactivity and selectivity, but there is a problem in that catalyst activity decreases over time.

On the other hand, in the case of the solvent-ligated organometallic catalyst studied by Professor Kuhn of the Technical University of Munich (Macromol. Rapid Commun., vol.20, no.10, pp.555-559), the boron-based catalyst of the prior art Problems such as product quality deterioration and corrosiveness due to toxic components such as Lewis acid catalyst are solved, but the reaction time is basically long as 16 hours for high conversion rate. Since exo-content is lowered by structural isomerization, it is less competitive than the Lewis acid catalyst.

Korean Registered Patent Publication No. 10-0486044 (2005.04.29.)

An object of the present invention is to provide a catalyst composition for producing polyisobutene that can be usefully used because it exhibits high reactivity with a high exo-content while having a desired number average molecular weight, and a method for producing polyisobutene using the same.

In order to solve the above problems, the present invention provides a catalyst composition comprising a catalyst and an additive represented by Formula 1, wherein the additive is an alkylnitrile-based compound:

[Formula 1]

In Formula 1,

R is an alkyl group having 2 to 12 carbon atoms,

R ₁ to R ₄ are each independently hydrogen, a halogen group, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms;

o, p, q and r are each independently an integer of 1 to 5.

When the catalyst composition of the present invention is used, polyisobutene having a high number average molecular weight and an exo-content of 80 mol% or more and excellent reactivity can be prepared.

Specifically, the production method of the present invention has the advantage of producing polyisobutene with an excellent polymerization conversion rate even under mild reaction conditions such as room temperature by using a catalyst represented by Formula 1 and an alkylnitrile-based compound having excellent catalytic activity as additives. there is. In addition, since the catalyst can be easily removed through a step of simply filtering the polyisobutene produced after the polymerization reaction is completed without directly washing with water, problems such as generation of a large amount of wastewater during washing or deterioration in quality due to the catalyst remaining in the product, etc. has been resolved.

Hereinafter, the present invention will be described in more detail to aid understanding of the present invention.

The terms or words used in the description and claims of the present invention should not be construed as being limited to the ordinary or dictionary meaning, and the inventor appropriately defines the concept of the term in order to explain his/her invention in the best way. Based on the principle that it can be done, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

catalyst composition

The catalyst composition of the present invention includes a catalyst and an additive represented by Formula 1 below, and the additive is an alkylnitrile-based compound.

[Formula 1]

In Formula 1,

R is an alkyl group having 2 to 12 carbon atoms,

R ₁ to R ₄ are each independently hydrogen, a halogen group, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms;

o, p, q and r are each independently an integer of 1 to 5.

The "composition" includes mixtures of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

The "alkyl group" may mean a monovalent aliphatic saturated hydrocarbon, and includes linear alkyl groups such as methyl, ethyl, propyl and butyl, isopropyl, sec-butyl, tert-butyl ( tert-butyl) and neopentyl (neo-pentyl) may be meant to include both branched alkyl groups. Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, sec-butyl group, 1-methyl-butyl group, 1-ethyl-butyl group, pentyl group, isopen ethyl group, neopentyl group, tert-pentyl group, 1-methylpentyl group, 2-methylpentyl group, 4-methyl-2-pentyl group, hexyl group, isohexyl group, 4-methylhexyl group, 5-methylhexyl group , heptyl group, etc., but is not limited thereto.

Specifically, R may be an alkyl group having 2 to 5 carbon atoms or an alkyl group having 2 to 5 carbon atoms, R ₁ to R ₄ are each independently hydrogen, a halogen group, or an alkyl group having 1 to 12 carbon atoms substituted with a halogen group, Alternatively, it may be an alkyl group having 1 to 4 carbon atoms, and o, p, q and r may each independently be an integer of 4 or 5. Most preferably, R ₁ to R ₄ may each independently represent a halogen group, and o, p, q and r may be 5.

는 구체적으로 테트라키스(페닐)보레이트, 테트라키스(펜타플루오로페닐)보레이트, 테트라키스[3,5-비스(트리플루오로메틸)페닐]보레이트 및 그 유도체로 이루어진 군으로부터 선택되는 1종 이상일 수 있고, 바람직하게는 테트라키스(펜타플루오로페닐)보레이트일 수 있다.In addition, the organic borate included in the compound represented by Formula 1

may be at least one selected from the group consisting of tetrakis(phenyl)borate, tetrakis(pentafluorophenyl)borate, tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and derivatives thereof. and may preferably be tetrakis(pentafluorophenyl)borate.

In the present invention, the catalyst represented by Formula 1 is used for cationic polymerization of isobutene monomers. At this time, the hydrogen atom present between the oxygen atoms of the catalyst represented by Formula 1 reacts with the isobutene monomer to dissociate the ether compound (R-O-R) and generate the carbocation of isobutene to initiate cationic polymerization. Since the hydrogen atom is located in a sandwich form near the center of the catalyst and there is an alkyl group (R) around it, it is not easy to access the isobutene monomer, so it may be difficult to initiate polymerization. Therefore, it is very important to properly control the number of carbon atoms and the steric size of R included in the catalyst represented by Formula 1 so that the isobutene monomer and hydrogen atoms react easily to initiate cationic polymerization.

On the other hand, it is advantageous for the ether compound (R-O-R) to bind to and stabilize the carbocation of the chain undergoing polymerization. Specifically, the non-shared electron pair of oxygen included in the ether compound can be briefly bonded for the purpose of stabilizing the carbocation of the chain during cationic polymerization, and when the bond with the carbocation is dissociated in a reverse reaction, it continues to polymerize with the isobutene monomer. This is because polyisobutene having a desired high molecular weight can be produced by doing so. That is, in the catalyst represented by Formula 1, when the alkyl group R is dissociated into an ether compound, the contribution to stabilization through bonding with a carbocation should also be taken into consideration.

Therefore, the functional group R included in the catalyst represented by Formula 1 used for polyisobutene in the present invention not only contributes to the initiation step of the cationic polymerization reaction, but also terminates the polymerization reaction or causes chain transfer, resulting in low molecular weight polyisobutene. It was confirmed that it plays an important role in preventing the synthesis of only isobutene. In particular, even if the catalyst represented by Formula 1 cannot be used for polymerization depending on the type of R, as described later, an alkylnitrile-based compound is used as an additive. Not only can this be supplemented by using it, but even if it can be used for polymerization of polyisobutene by itself depending on the type of R, it is more advantageous in terms of securing high molecular weight and exo-content when used together with additives.

The catalyst composition of the present invention includes an alkylnitrile-based compound as an additive together with the catalyst represented by Formula 1 above.

Since the unshared electron pair of nitrogen contained in the alkylnitrile-based compound has an unstable property that easily causes chemical change, it is briefly bonded for the purpose of stabilizing the carbocation of the chain under polymerization during cationic polymerization of isobutene monomer, etc. When the bond with the carbocation is dissociated, the carbocation continues to polymerize with the monomer so that polyisobutene having a high molecular weight can be produced under mild reaction conditions.

However, if the material used as an additive binds too strongly with the carbocation, it becomes difficult for the reverse reaction to proceed, so the reactivity of the carbocation itself disappears and the reaction may be terminated, and in this case, the desired high molecular weight polymer cannot be obtained. In terms of aspects, for example, amine-based compounds, ether-based compounds, phosphine-based compounds, and the like may not be suitable as additives, and as in the present invention, alkylnitrile-based compounds may be preferably used as additives.

Specifically, the additive may include at least one selected from the group consisting of acetonitrile, propionitrile, 2-methylpropanenitrile, trimethylacetonitrile, and benzonitrile, specifically acetonitrile, benzonite It may be a reel or a combination thereof, but is not limited thereto.

In the present invention, the equivalent ratio of the catalyst represented by Formula 1 and the additive may be 1: 1 to 1: 200, and the number average molecular weight of the butene oligomer can be easily controlled to a low molecular weight within a desired range, and the exo-content can be easily controlled. In terms of producing highly reactive butene oligomers, it may be specifically 1: 1 to 1: 20, 1: 1 to 1: 7, or 1: 3 to 1: 5.

When the content of the additive is less than 1 equivalent relative to 1 equivalent of the catalyst represented by Formula 1, the stabilizing effect of carbocations using the additive is not great, making it difficult to efficiently produce polyisobutene having a high number average molecular weight and exo-content. , High catalytic reaction can not be controlled, resulting in poor reproducibility, and when the content of the additive exceeds 200 equivalents relative to 1 equivalent of the catalyst represented by Formula 1, the polymerization reaction is terminated early while the additive binds to carbocations. problems may appear.

In the present invention, the catalyst represented by Formula 1 may be used by dissolving in a halogenated hydrocarbon solvent, or a non-polar hydrocarbon solvent may be mixed with a halogenated hydrocarbon solvent to dissolve the catalyst represented by Formula 1.

In the present invention, in order to initiate cationic polymerization, hydrogen atoms present between oxygen atoms of the catalyst represented by Formula 1 must react with isobutene monomers to dissociate ether compounds (R-O-R) and generate carbocations of isobutene. It is to use a polar halogenated hydrocarbon solvent to increase the polymerization reactivity by maintaining the carbocation in an ionic state for a long time.

However, at the start of the polymerization reaction, it is advantageous to use a halogenated hydrocarbon solvent as described above, but when dissolved in a halogenated hydrocarbon solvent, the stability of the catalyst represented by Formula 1 is low due to halogen toxicity, etc., so do not use it for polymerization immediately after mixing. If not, the activity of the catalyst represented by Chemical Formula 1 gradually decreases with time.

On the other hand, in the case of the catalyst represented by Chemical Formula 1 used in the present invention, even if it is dissolved in a halogenated hydrocarbon solvent such as dichloromethane (DCM) to prepare a composition, stored for a certain period of time, and then used for polymerization, it still has equivalent physical properties with a high polymerization conversion rate. There is an advantage of being able to produce polyisobutene.

In addition, the halogenated hydrocarbon solvent may be one or more selected from the group consisting of chloromethane, dichloromethane, trichloromethane, 1-chlorobutane and chlorobenzene, but is not limited thereto.

The non-polar hydrocarbon solvent may be an aliphatic hydrocarbon solvent or an aromatic hydrocarbon solvent. For example, the aliphatic hydrocarbon solvent may be at least one selected from the group consisting of butane, pentane, neopentane, hexane, cyclohexane, methyl cyclohexane, heptane and octane, and the aromatic hydrocarbon solvent may be benzene, toluene, xylene , It may be one or more selected from the group consisting of ethylbenzene, but is not limited thereto.

Method for producing polyisobutene

The method for producing polyisobutene of the present invention is characterized by comprising the step of polymerizing an isobutene monomer in the presence of the catalyst composition.

In the present invention, the isobutene monomer may be used in an amount of 1 to 50% by weight, preferably 5 to 25% by weight based on the weight of the catalyst composition.

As described above, the catalyst and additives represented by Chemical Formula 1 may be used by dissolving in a halogenated hydrocarbon solvent. At this time, the catalyst represented by Formula 1 may be used in an amount of 5 to 50 ppm or 10 to 40 ppm based on the weight of the catalyst composition. In addition, the content of the catalyst represented by Formula 1 may be 5 to 250 ppm, 10 to 100 ppm, or 10 to 50 ppm based on the weight of the isobutene monomer. When the above numerical range is satisfied, the polymerization reaction can be efficiently performed, and when the amount is added in excess of the above numerical range, the polymerization efficiency may not be significantly improved compared to the increase in raw material cost.

In the present invention, the polymerization of the isobutene monomer can be carried out at a temperature of 10 to 50 ° C., while preparing the high molecular weight polyisobutene targeted in the present invention, exo-content, that is, the terminal carbon-carbon double bond In terms of making the content appear high, specifically, it may be performed at a temperature of 15 to 40 °C, or 25 to 35 °C. In addition, the polymerization reaction at the above temperature may be carried out for 30 minutes to 3 hours, or 1 hour to 3 hours, or 1.5 hours to 2.5 hours.

In the production method of the present invention, after the step of polymerizing the isobutene monomer, the step of filtering the polymerization product to remove the catalyst represented by Formula 1; may be further performed. Since the catalyst represented by Chemical Formula 1 used in the present invention can be efficiently removed through a physically simple filtration step, it is much easier to use and remove than Lewis acid catalysts of the prior art.

In addition, after polymerization of the isobutene monomer, the organic solvent may be removed to adjust the organic solvent to 40% by weight or less, 20% by weight or less, or 5% by weight or less of the polyisobutene.

Subsequently, in the case of polyisobutene having fluidity, a step of filtering insoluble materials is performed using a glass fiber filter having 80 mesh or more, 100 mesh or more, or 200 mesh or more. Alternatively, the catalyst can be removed by passing through a flowable polymer using a silica, celite or zeolite filter.

In the case of polyisobutene having low fluidity, alkyl solvents such as pentane, cyclopentane, hexane, cyclohexane, heptane, octane, and ether solvents such as diethyl ether and petroleum ether are used. After imparting fluidity, a step of filtering through the silica, celite or zeolite filter may be performed.

Typically, the resulting oligomer or polymer is dissolved in an organic solvent such as pentane, cyclopentane, hexane, cyclohexane, heptane, octane, diethyl ether or petroleum ether, and washed with water to remove the organometallic catalyst. However, since the present invention can efficiently remove the catalyst represented by Chemical Formula 1 through the simple filtration step as described above, a separate washing step may not be performed.

In addition, the manufacturing method of the present invention may further include drying the residual solvent after filtering the polymerization product.

For example, the drying temperature may be 30 to 200°C, or 40 to 150°C, and the degree of vacuum may be 300 torr or less, 200 torr or less, or 100 torr or less. In this way, desired polyisobutene can be obtained efficiently. In addition, the drying method is not particularly limited and may be a conventional method.

In addition, in the method for producing polyisobutene of the present invention, after the polymerization step and before the filtering step, the step of drying the halogenated hydrocarbon solvent may or may not be separately performed. When performing the drying step, drying conditions may be performed as described above and are not particularly limited.

When the step of drying the halogenated hydrocarbon solvent is performed separately, there is an advantage that polyisobutene can be obtained with higher purity. However, according to the present invention, since the catalyst can be easily removed through simple filtering as described above, a separate step of drying the halogenated hydrocarbon solvent before the filtering after the polymerization step can be omitted, which simplifies the process. there is

polyisobutene

In addition, the present invention provides polyisobutene prepared according to the method for producing polyisobutene described above.

In the present invention, the polyisobutene may have a number average molecular weight of 1,0000 or less, specifically 1,000 to 10,000, 1,000 to 7,000, or 1,000 to 5,000.

In addition, the exo-content of the polyisobutene, that is, the content of terminal carbon-carbon double bonds may be 80 mol% or more, specifically 80 to 99 mol%. As the exo-content increases, highly reactive polyolefin, such as highly reactive polybutene (HR-PB), is formed.

In addition, the molecular weight distribution (PDI) of the polyisobutene may be 1.5 to 3, specifically 1.5 to 2.5, or 1.5 to 1.9.

When the polymerization time of the isobutene monomer is increased, the exo-content tends to be lowered due to the isomerization reaction of polyisobutene. is a problem that arises Preferably, when a halogenated hydrocarbon solvent is used, the phenomenon in which the catalyst is dissolved in the solvent is reduced, and accordingly, polyisobutene having a high exo-content can be prepared as described above.

Example

Hereinafter, the present invention will be described in more detail by examples. However, the following examples are for exemplifying the present invention, and the scope of the present invention is not limited only thereto.

Preparation Example 1: [H (Et ₂ O) ₂ ][B(C ₆ F ₅ ) ₄ ] manufacturing

In a glove box under argon conditions, 1 g of [Li(Et ₂ O) _n ][B(C ₆ F ₅ ) ₄ ] (purchased from TCI) was put into a round flask and 10 mL of anhydrous diethyl ether was added thereto. After bringing the prepared solution into the glove box, it was connected to the Schlenk line and set under argon conditions. A cooling bath was made using acetonitrile and dry ice, and the prepared solution was stirred at -40 °C. To the stirred solution, 5 equivalents of 1M HCl in diethyl ether (purchased from TCI) was injected through a syringe. After further stirring at -40 °C for 30 minutes, the temperature was slowly raised to room temperature. The solution raised to room temperature was brought back into the glove box, the resulting salt was removed through a filter, and only the transparent solution was collected and dried under vacuum conditions. After vacuum drying all the solvents, washing with anhydrous hexane 5mL × 3 times, and vacuum drying again to obtain the desired product.

Preparation Example 2: [H(iPr ₂ O) ₂ ][B(C ₆ F ₅ ) ₄ ] manufacturing

It was prepared in the same manner as in Preparation Example 1, except that anhydrous diisopropyl ether was used instead of anhydrous diethyl ether.

Preparation Example 3: [H(Bu ₂ O) ₂ ][B(C ₆ F ₅ ) ₄ ] manufacturing

In a glove box, 1 g of [H(Et ₂ O) ₂ ][B(C ₆ F ₅ ) ₄ ] was put into a round flask, and 10 mL of dichloromethane was added thereto. 5 equivalents of anhydrous dibutyl ether (purchased from Aldrich) was added to this solution at room temperature and stirred for 30 minutes. After stirring, all solvents were removed under vacuum conditions. The obtained white powder was washed 5 mL × 3 times with anhydrous hexane, and then dried under vacuum again to obtain the desired product.

Comparative Preparation Example 1

Brookhart's acid represented by the following chemical formula was prepared according to a known method.

Specifically, NaBAr'4 and chlorine were reacted in diethyl ether, and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate was purchased from Sigma-Aldrich and used.

NaBAr' ₄ + HCl + 2Et ₂ O → [H(OEt ₂ ) ₂ ] + BAr' ₄ + NaCl

Comparative Preparation Example 2

[BF ₃ ][(OEt) ₂ ] (Sigma-Aldrich) was purchased and prepared.

Example 1

20 g of isobutene monomer was added by connecting an isobutene line to an Andrew glass flask in a vacuum state cooled at 10° C. or lower. The toluene solvent was quantified using a syringe at the same temperature and then injected. Thereafter, the Andrew glass flask was maintained at 30° C., which is a polymerization temperature.

The catalyst was quantified in a glove box according to the prescription amount shown in Table 1 below, dissolved in 0.5 mL DCM, and then injected using a syringe. After reacting for 2 hours, all solvents were dried to obtain polyisobutene.

Examples 2 to 8, Comparative Examples 1 to 9

Polyisobutene was prepared in the same manner as in Example 1, except that polymerization conditions were changed as shown in Table 1 below.

catalyst Catalytic amount (ppm) Additive type additive equivalent Temperature (℃) Example 1 Preparation Example 1 40 acetonitrile 5 30 Example 2 Preparation Example 1 40 benzonitrile 3 30 Example 3 Preparation Example 1 40 benzonitrile 5 30 Example 4 Preparation Example 1 20 acetonitrile 5 30 Example 5 Preparation Example 1 20 benzonitrile 3 30 Example 6 Preparation Example 2 20 acetonitrile 3 30 Example 7 Preparation Example 2 20 benzonitrile 5 30 Example 8 Preparation Example 3 20 Aceto(benzo)nitrile 5 30 Comparative Example 1 Comparative Preparation Example 1 10 - - 30 Comparative Example 2 Comparative Preparation Example 2 100 - - 30 Comparative Example 3 Preparation Example 1 20 triethylamine 5 30 Comparative Example 4 Preparation Example 1 20 - - 30 Comparative Example 5 Preparation Example 1 20 etheric compounds 5 30 Comparative Example 6 Preparation Example 1 20 sulfide compounds 5 30 Comparative Example 7 Preparation Example 1 20 phosphine compounds 5 30 Comparative Example 8 Preparation Example 2 20 - - 30 Comparative Example 9 Preparation Example 3 20 - - 30

Experimental Example 1

The physical properties of the polyisobutene prepared in Examples and Comparative Examples were measured according to the following method, and the results are summarized in Tables 2 and 3.

(1) polymerization conversion rate (%)

The conversion rate was calculated by measuring the weight of the dried polyisobutene.

(2) exo-content (%)

(content of exo-olefin with carbon-carbon double bond at the end/total content of produced exo-olefin and endo-olefin) × 100

(3) number average molecular weight and molecular weight distribution

The resulting polyisobutene was measured under the following gel permeation chromatography (GPC) analysis conditions to determine the number average molecular weight (Mn) and weight average molecular weight (Mw), and the molecular weight as (weight average molecular weight)/(number average molecular weight) value distribution was calculated.

- Column: PL MiniMixed B × 2

- Solvent: THF

- Flow rate: 0.3 ml/min

- Sample concentration: 2.0 mg/ml

- Injection amount: 10 μl

- Column temperature: 40 ℃

- Detector: Agilent RI detector

- Standard: Polystyrene (correction with cubic function)

- Data processing: ChemStation

Polymerization conversion (%) exo-content (mol %) number average molecular weight molecular weight distribution Example 1 93 82 1,780 1.6 Example 2 95 83 1,740 1.5 Example 3 91 80 1,920 1.8 Example 4 82 85 2,880 1.5 Example 5 86 90 2,760 1.6 Example 6 90 80 1,540 1.7 Example 7 84 85 2,800 1.5 Example 8 95 91 2,800 1.5 Comparative Example 1 97 73 1,220 3.5 Comparative Example 2 100 20 410 5.2 Comparative Example 3 no reactivity - - - Comparative Example 4 79 80 1,500 2.4 Comparative Example 5 78 81 1,300 2.2 Comparative Example 6 no reactivity - - - Comparative Example 7 no reactivity - - - Comparative Example 8 90 65 920 2.5 Comparative Example 9 85 87 1,970 1.9

As shown in Table 2, in the case of the examples using the catalyst represented by Formula 1 and the alkylnitrile-based additive according to the present invention, the highly reactive polyiso part with a high number average molecular weight of 1,000 or more and a high exo-content It was confirmed that Ten could be efficiently produced.

On the other hand, when the catalyst of Comparative Preparation Example 1 or 2 that does not correspond to Formula 1 was used as in Comparative Examples 1 and 2, polyisobutene was produced, but polyisobutene having a low exo-content of less than 80% was produced, In particular, Comparative Example 2 obtained polyisobutene of very low molecular weight.

In Comparative Examples 3, 6 and 7, although the catalyst of Preparation Example 1 was used, polyisobutene could not be obtained because the polymerization reaction was not performed properly because a compound other than alkylnitrile was used as an additive. In addition, Comparative Example 5 using an ether-based compound as an additive and Comparative Example 4 not using an additive were similarly compared to Examples 4 and 5 using an alkylnitrile as an additive while using the same catalyst, polymerization conversion rate, exo-content, It was confirmed that all of the number average molecular weights were low.

In the case of Comparative Example 8, polyisobutene having a lower number average molecular weight than Examples 6 and 7 was prepared without using an additive, and it was found that Comparative Example 9 also produced polyisobutene having lower physical properties compared to Example 8. .

Experimental Example 2

After polymerizing polyisobutene according to Example 1, the polymerized solution was passed through a column filled with celite, silica, zeolite or glass fiber as shown in Table 3 below.

As described above, the filtering result of Example 1 and the unfiltered polymerization solution were analyzed according to the following method, and the results are shown in Table 3.

1) F analysis: measured under the following conditions using combustion IC (ICS-2100/AQF-5000, Thermo Scientific Dionex).

- Column: IonPac AS18 analytical (4 × 250 mm), IonPac AG18 guard (4 × 50 mm)

- Eluent type: KOH (30.5 mM)

- Eluent flow rate: 1 mL/min

- Detector: Suppressed Conductivity Detector

- SRS Current: 76 mA

-Injection volume: 20 μL

- Isocratic/Gradient conditions: Isocratic

filtering method F elemental analysis result (mg/kg) before filtering 38~48 Celite < 10 silica < 10 zeolite < 10 fiberglass 24-49 Suse < 10

As shown in Table 4, in the production method of the present invention through Experimental Example 2, it was confirmed that the catalyst represented by Formula 1 can be easily removed by filtering the product solution after the polymerization step.

Specifically, when filtering was performed with a column containing celite, silica, and zeolite with respect to Example 1, it was found that the catalyst was well removed from the fact that a small amount of element F was detected at a level similar to that of washing with water. .

Claims (12)

A catalyst composition comprising a catalyst and an additive represented by Formula 1, wherein the additive is an alkylnitrile-based compound:
[Formula 1]

In Formula 1,
R is an alkyl group having 2 to 12 carbon atoms,
R ₁ to R ₄ are each independently hydrogen, a halogen group, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms;
o, p, q and r are each independently an integer of 1 to 5.
The method of claim 1,
The equivalent ratio of the catalyst and additives represented by Formula 1 is 1: 1 to 1: 200, the catalyst composition.
The method of claim 1,
The additive is a catalyst composition comprising at least one selected from the group consisting of acetonitrile, propionitrile, 2-methylpropanenitrile, trimethylacetonitrile and benzonitrile.
The method of claim 1,
Organic borates included in the catalyst represented by Formula 1 are tetrakis(phenyl)borate, tetrakis(pentafluorophenyl)borate, tetrakis[3,5-bis(trifluoromethyl)phenyl]borate and derivatives thereof. At least one selected from the group consisting of, the catalyst composition.
The method of claim 1,
Wherein R ₁ to R ₄ are each independently hydrogen, a halogen group, or an alkyl group having 1 to 12 carbon atoms substituted with a halogen group, the catalyst composition.
The method of claim 1,
The R is an alkyl group having 2 to 5 carbon atoms, the catalyst composition.
Polymerizing an isobutene monomer in the presence of the catalyst composition according to any one of claims 1 to 6; A method for producing polyisobutene comprising a.
The method of claim 7,
The polymerization is carried out at a temperature of 10 to 50 ℃, a method for producing polyisobutene.
The method of claim 7,
The method for producing polyisobutene, wherein the content of the terminal carbon-carbon double bond of the polyisobutene is 80 mol% or more.
The method of claim 7,
The number average molecular weight of the polyisobutene is 1,000 to 10,000, a method for producing polyisobutene.
The method of claim 7,
After the step of polymerization, filtering the polymerization product to remove the catalyst represented by Formula 1; further comprising a method for producing polyisobutene.
The method of claim 11,
Wherein the filtering is performed using a filter containing at least one selected from the group consisting of silica, celite and zeolite.