JPH10306128A - Production of butene polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high yield of a butene polymer which allows the use of low-cost raw material, can reduce the catalyst cost, contains a highly reactive terminal vinylidene structure, and has a narrow molecular weight distribution by adding a complex catalyst consisting of boron trifluoride and a dialkyl ether to an olefin component comprising a C4 fraction and subjecting the mixture to liquid-phase polymerization while recovering the complex catalyst for recycling. SOLUTION: A complex catalyst consisting of boron trifluoride and a dialkyl ether of which the number of carbon atoms of each alkyl group is 1 to 8 and in which the carbon atoms bound to an oxygen atom are each a primary carbon atom is added in an amount of 0.1-500 mM in terms of boron trifluoride to an olefin component comprising a C4 fraction consisting of 10-40 wt.% butene-1, 1-40 wt.% butene-2, 35-70 wt.% isobutene, 10-30 wt.% butanes, and at most 0.5 wt.% butadiene, and the mixture is subjected to liquid-phase polymerization at -100 to +50 deg.C for 5 min to 4 hr. On the other hand, the complex catalyst having the same molar ratio of boron trifluoride to the ether as that before the reaction is recovered for circulating through the liquid-phase polymerization region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a highly reactive butene polymer using a boron trifluoride etherate complex catalyst. More specifically, a hydrocarbon containing isobutene is polymerized in a liquid phase to contain at least 80 mol% of a molecule having a vinylidene structure exhibiting high reactivity at a terminal, and preferably contains an isobutene skeleton of the formula (I) in the molecule. The present invention relates to a method for producing a butene polymer containing 80% or more.

[0002]

2. Description of the Related Art U.S. Pat. No. 4,152,499 discloses a polymer obtained by polymerizing pure isobutene using a boron trifluoride complex catalyst using water or alcohol as a complexing agent. It is a butene polymer containing a high proportion of a heavy bond type having a vinylidene structure, and it is disclosed that a high rate maleation reaction proceeds with maleic anhydride or the like. The maleated polybutene described in the publication is said to be superior in performance, economy, environment, etc., to maleated polybutene obtained through conventional chlorination. For this reason, in recent years, many proposals have been made to produce polybutene having many vinylidene double bonds using a boron trifluoride complex catalyst containing a complexing agent represented by alcohol. Such polybutene is excellent not only in the reaction with maleic acid and the like, but also in the epoxidation reaction and the like.

US Pat. No. 5,068,490 discloses that a boron trifluoride catalyst using ether as a complexing agent is more effective than a boron trifluoride complex catalyst using alcohol or the like as a complexing agent for the following reasons. It is claimed to be excellent. That is, (1) the content of vinylidene groups in the obtained polymer is high, (2) a polymer having a higher molecular weight can be obtained under certain conditions, (3) using a boron trifluoride-based catalyst,
In some cases, it is necessary to shorten the polymerization time (residence time) because a rearrangement reaction or the like is likely to occur during the reaction. However, the ether complex catalyst has a longer residence time because the conversion rate is improved and side reactions are reduced. (4) It is superior in selectivity to boron trifluoride alcohol complex catalyst. For the above reasons, the publication proposes the use of a boron trifluoride complex catalyst using an ether having a tertiary carbon atom bonded to an oxygen atom as a complexing agent.

On the other hand, as a reaction raw material, a so-called C which is produced in a large amount is used rather than using 100% pure isobutene.
_{4 It} is economically advantageous to use raffinate as a raw material. However, on the other hand, C ₄ raffinate uses a large amount of catalyst, which may increase the cost of the catalyst. Therefore, recovery and reuse of the catalyst are a major problem from the viewpoint of an industrial production method. Further, although not particularly mentioned in the publication, there is a disadvantage that an ether complex catalyst is generally used in a large amount in polymerization. Therefore, when using a boron trifluoride complex catalyst using ether as a complexing agent, the cost of the catalyst has a greater effect on the overall cost than other complex catalysts. It is essential to consider the recovery of the system complex catalyst.

[0005] From such a viewpoint, US Pat.
A study of the complex catalyst proposed in JP-A-68,490 revealed that trifluoride using an ether in which the carbon atom bonded to the oxygen atom is a tertiary carbon atom as a complexing agent was proposed. It has been found that the boron complex catalyst is far less tolerable for recovery and reuse of the complex.
That is, the boron trifluoride ether complex catalyst using an ether described in the publication, particularly a typical boron trifluoride / methyl tert-butyl ether (MTBE) complex catalyst, undergoes severe decomposition of the complex during polymerization and other steps. It is difficult to recover and reuse the complex after polymerization. In recovering the complex, it is possible to recover boron trifluoride as a gas, but it is naturally advantageous to recover a catalyst as a complex from an industrial viewpoint. The phenomenon of decomposition of the complex was observed not only in the case where the carbon atom bonded to oxygen was a tertiary carbon atom, but also in the case where the carbon atom was a secondary carbon atom.

[0006]

An object of the present invention is to produce a butene polymer having high reactivity in reactions such as maleation and epoxidation while maintaining the cost of raw materials and catalysts inexpensively and at a high yield. It is to provide a method.

[0007]

SUMMARY OF THE INVENTION The present invention provides a complex catalyst comprising boron trifluoride and a dialkyl ether in which all carbon atoms bonded to oxygen atoms are primary carbon atoms. It has been completed based on the finding that decomposition is unlikely to occur during the process. That is,
The first aspect of the present invention relates to a method for producing a butene polymer containing at least 80 mol% of a polymer molecule having a vinylidene terminal structure, comprising the following steps (I) and (II). Step (I): 10 to 40% by weight of butene-1, 1 to 40
Wt% butene-2, 35-70 wt% isobutene,
Relative to 10 to 30 wt% of olefin component 1 mol of butanes and C ₄ fraction in the starting material consisting of 0.5 wt% or less of butadiene, boron trifluoride, carbon atoms carbon atoms in each alkyl group A complex catalyst comprising a dialkyl ether having 1 to 8 carbon atoms each of which is bonded to an oxygen atom and each of which is a primary carbon atom (the two alkyl groups may be the same or different from each other) is prepared by trifluorination. 0.
A step of adding to the polymerization zone at a rate of 1 to 500 mmol and continuously performing liquid phase polymerization at a polymerization temperature of -100 ° C to + 50 ° C and a residence time of 5 minutes to 4 hours; Step (II): boron trifluoride Recovering a complex catalyst having substantially the same molar ratio of ether to that before the reaction from the polymerization solution, and circulating at least a part of the recovered complex catalyst to the liquid phase polymerization zone. According to a second aspect of the present invention, in the first aspect of the present invention, the molar ratio of boron trifluoride to ether in the complex catalyst is in the range of 0.85: 1.00 to 1.10: 1.00. And a method for producing a butene polymer. A third aspect of the present invention relates to the method for producing a butene polymer according to the first aspect of the present invention, wherein the conversion of isobutene in the step (I) is in the range of 60 to 100%. According to a fourth aspect of the present invention, in the first aspect of the present invention, among the repeating structural units in the polymer molecule, the number of repeating structural units represented by the following formula (1) is 80% or more. The present invention relates to a method for producing a butene polymer.

Embedded image (However, n is an integer of 0 or more, preferably 5 or more, more preferably 16 or more and 200 or less.) According to the method of the present invention, an olefin copolymerizable with isobutene such as butene-1 is contained. Even if an inexpensive reaction material such as C ₄ raffinate is used, it is possible to produce a butene polymer having a high content of a vinylidene terminal structure, and to use a specific dialkyl ether as a complexing agent. The boron fluoride complex catalyst can be separated and recovered stably and reused. In other words, the cost of the complex catalyst can be reduced, and a butene polymer having a terminal vinylidene structure having a high reactivity of 80 mol% or more and having a narrow molecular weight distribution can be produced in a high yield. is there.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, polymerizing the C ₄ fraction in the polymerization zone which includes a reactor (reaction zone). As the reactor, any type such as a stirring type reactor and a loop type reactor can be adopted. A plurality of reactors can be provided in the polymerization zone. From the polymerization zone, an unreacted component and a polymerization liquid containing the produced butene polymer and catalyst flow out. Examples of the catalyst used for the polymerization reaction include boron trifluoride and ether R ₁ —O—R ₂ (wherein R ₁ and R ₂ are each a saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms, and Are all primary carbon atoms, and R ₁ and R ₂ may be the same or different.) Useful. Specific examples of the above dialkyl ether include dimethyl ether, methyl ethyl ether, diethyl ether, methyl propyl ether, ethyl propyl ether, dipropyl ether and diisobutyl ether. These dialkyl ethers can be used alone or in a mixture at an appropriate ratio.

[0009] The boron trifluoride etherate complex catalyst can be easily produced according to a conventional method. For example, gaseous boron trifluoride is cooled to the above-mentioned ether which has been cooled to a room temperature or lower while cooling. Can be prepared by blowing into the coordination molar ratio of The desired coordination molar ratio can be easily calculated from the weight of the ether and the weight of the boron trifluoride blown.

In the present invention, the molar ratio between boron trifluoride and ether in the complex catalyst is 0.85: 1.
It is necessary to be in the range of 0.00-1.10: 1.00, preferably in the range of 0.90: 1.00-1.0: 1.00. If the molar ratio of boron trifluoride to ether is less than 0.85, it is difficult to obtain a sufficient olefin conversion, which is economically disadvantageous. Conversely, if the molar ratio of boron trifluoride to ether exceeds 1.10, the activity of the acid catalyst becomes stronger and the conversion of the olefin component improves, but side reactions such as isomerization and rearrangement occur, and the It is difficult to contain a vinylidene structure exhibiting high reactivity of 80% or more. In addition, it is preferable that the storage temperature of the boron trifluoride etherate complex catalyst prepared in the above range of the coordination molar ratio be kept at room temperature or lower in order to maintain the ratio until it is charged into the reactor. In addition, it is preferable to use a method in which a pre-produced complex is supplied to the reaction zone, but if necessary, boron trifluoride and ether are separately supplied to the reaction zone, and the complex is formed in the reaction system and used. Is also possible.

[0011] The C ₄ fraction of the feed used in the polymerization is, for example, in an ethylene plant, naphtha, kerosene, gas oil,
C ₄ raffinate flowing out of a cracker such as butane, from which butadiene has been removed by extraction or the like. C ₄ The distillate, about 10 to 40 wt% of butene-1 as the unsaturated component, from about 1 to 40 wt% of butene-2 and about 35 to 70 wt% isobutene, approximately 1 as saturates
It contains from 0 to 30% by weight of butanes and up to about 0.5% by weight of butadiene (totaling 100% by weight). The feedstock is not particularly limited as long as it is within this composition range, and may be a C ₄ hydrocarbon fraction containing isobutene contained in a decomposition product from a fluid catalytic cracking (FCC) device. The C ₄ fraction is preferably as high as the isobutene content. However, for example, the isobutene in the C ₄ raffinate is at most 70% by weight. Butadiene, if present, is usually on the order of impurities. The water content of the raw material is usually adjusted to 10 ppm or less, but the polymerization can be carried out without any problem even if the water content is about several tens ppm.

The polymerization reaction temperature in the step (I) is in the range of -100 ° C. to + 50 ° C. in order to carry out the reaction in a liquid phase.
Preferably, it is in the range of -40 ° C to + 10 ° C. As the temperature becomes lower, the conversion of the olefin component of the hydrocarbon containing isobutene is suppressed. On the other hand, when the temperature becomes high, the conversion is suppressed and side reactions such as isomerization and rearrangement occur, which makes it difficult to obtain the target product of the present invention.

The amount of the catalyst is 0.1 to 5 as boron trifluoride per mole of the olefin component in the feedstock.
An amount corresponding to 00 mmol is required. When the amount of boron trifluoride is less than 0.1 mmol, the reaction hardly proceeds, and the molecular weight is remarkably increased. If the amount of the catalyst exceeds 500 mmol, the decrease in molecular weight is extremely undesirable. Here, it is assumed that the complex catalyst in the present invention contains boron trifluoride and ether in the proportions of the supplied moles at the time of preparation. That is, the coordination molar ratio of the complex is considered to be equal to the ratio of (the number of moles of boron trifluoride supplied) to (the number of moles of ether supplied). The molecular weight control in the present invention can be carried out by adjusting the reaction temperature and the amount of catalyst charged.

The polymerization reaction in the present invention is economically and efficiently performed in a continuous manner from the viewpoint of industrial production. In the continuous method, the contact time between the complex catalyst and the feed is important, and in the polymerization reaction according to the present invention, the contact time between the boron trifluoride etherate complex catalyst and the feed is in the range of 5 minutes to 4 hours. Is desirable. If the contact time is less than 5 minutes, a sufficient conversion of the isobutene component cannot be obtained, and if the contact time is more than 4 hours, the economical loss is large. All of these are not preferred because they promote side reactions such as reaction and rearrangement.

[0015] In view of the commercial profitability in the production of butene polymer, C ₄ fractions, for example, C ₄ conversion of isobutene component in the raffinate that higher is desired, by employing the conditions of the present invention It is possible to achieve about 60 to 100% conversion of isobutene. As described above, a butene polymer having useful physical properties can be obtained by polymerizing a C ₄ hydrocarbon fraction containing isobutene in a liquid phase using a boron trifluoride etherate complex catalyst as a polymerization catalyst. it can.

As described above, various methods have been proposed for producing a vinylidene structure in a butene polymer in a larger amount. However, it has been inferred that the molecular skeleton of the resulting butene polymer may be a stereoregularly linked polymer, but there is no prior art that has demonstrated the structure. 2. Description of the Related Art In recent years, due to great progress in analysis technology by NMR, a measurement method capable of knowing connection information of a carbon skeleton in an organic polymer compound has been developed. This measuring method is a kind of two-dimensional spectrum, and is a method of examining the connection between carbon and hydrogen and the connection between carbon and carbon, and includes the HSQC method and the INADEQUAT method. In the present invention, the HSQC method and the INADEQ
The structure of the obtained polymer was analyzed using the UATE method, and the structure was verified. That is, for the butene polymer obtained in the present invention, FIG. 1 shows an example of the result obtained by the HSQC method, and FIG. 2 shows an example of the result measured by the INADEQUAT method. In the HSQC method, ¹ H-NMR is plotted on the horizontal axis,
The vertical axis represents the ¹³ C-NMR, a peak of ¹ H-NMR and ¹³
The point at which the C-NMR peaks intersect indicates that the corresponding carbon and hydrogen are linked, whereby the linking state between carbon and hydrogen in the molecule can be known. Also,
In the INADEQUAT method, ¹³ C-NMR is taken on the horizontal axis, and the position of carbon is measured on the vertical axis from the peak.
When the carbon is shifted from the existing position of the carbon in the horizontal direction at the same position as shown in the figure, the carbon peak at the same position at that time becomes connected carbon. Similarly, by arranging in order from the carbon, the connection between carbons in one molecule, that is, the carbon skeleton can be known.

From the measurements of the HSQC method and the INADEQUAT method, the butene polymer of the present invention has a structure in which at least 80% of the number of repeating structural units has the structure represented by the formula (1):
In addition, it is understood that the polymer contains at least 80 mol% of polymer molecules having a vinylidene terminal structure. One of the terminal groups is usually a tert-butyl group. The number n of the repeating structural units shown in the formula (1) is 0 or more, preferably 5 or more, more preferably 16 or more, and the upper limit is 200. As described above, the butene polymer molecule obtained by the present invention accounts for 8% of the total repeating structural units.
0% or more is formed with a molecular structure having the structure of the above formula (1), and this structure is effective as a raw material for a lubricating oil additive and a fuel detergent aid.

The molecular weight of the butene polymer having a polymer structure regularly linked by the isobutene skeleton is 500 to 15,000 as a number average molecular weight (Mn).
, And the value of Mw / Mn measured by GPC is in the range of 1.0 to 2.5, indicating a narrow molecular weight distribution. Due to such a narrow molecular weight distribution, it is possible to obtain a material having a constant viscosity.
Therefore, since it is possible to reliably manufacture a product having a predetermined viscosity, it is possible to omit adjusting the viscosity of the product.

In order to improve the performance as a lubricating oil additive, the olefin structure at the terminal position of the butene polymer becomes a problem. A pair of olefin carbons in the butene polymer is detected with a unique chemical shift value in a range of about 110 to 150 ppm of ¹³ C-NMR, and as shown in FIG. 1, vinylidene represented by the following formula (2): The olefin carbon having the structure corresponds to the peaks at 114.4 ppm and 143.3 ppm, and the olefin carbon having the trisubstituted structure represented by the following formula (3) corresponds to the peaks at 127.7 ppm and 135.4 ppm, respectively. Furthermore, the relative ratio of each double bond type can be indicated by the integrated intensity ratio of the relative height of each detection peak.

[0020]

Embedded image

The butene polymer produced in the present invention contains at least 80 mol% of a molecule having a terminal vinylidene structure. Since the butene polymer of the present invention is used as a raw material in order to contain a large amount of the terminal vinylidene structure in this manner, the modification rate in the case of performing maleation or hydroformylation is improved, and for example, the polystyrene is converted through a maleation reaction. Butenyl succinimide can be produced in high yield.

The fluid leaving the polymerization zone after the polymerization is C
Polymer or complex catalyst dissolved or dispersed in _four fractions, eg, C ₄ raffinate. The complex catalyst of the present invention is stable, and the form of the complex hardly changes before and after polymerization. Therefore, if the complex catalyst is recovered after the polymerization of the present invention, it can be reused. The recovery method is not particularly limited as long as it can be recovered as a complex substantially identical to the complex before the reaction. For example, the complex catalyst of the present invention is stable to heat to some extent, and can be recovered by distillation as it is. Further, if the polymerization reaction solution is allowed to stand for a sufficient time, for example, 5 to 60 minutes, the complex catalyst tends to settle and separate as a lower layer of the reaction layer. After forcibly separating the complex catalyst as described above, the complex catalyst can be recovered by appropriately extracting it. It is also effective to use a mechanical separating means such as a coalescer having a function of promoting sedimentation by a wire net, a filler, or the like. The complex catalyst is stable without decomposing during polymerization. What can be separated by such means is a property unique to an ether complex having an alkyl group in which all carbon atoms bonded to oxygen atoms are primary carbon atoms.

In addition, as a means for separating and recovering the catalyst, a complex catalyst can be precipitated and separated by applying a DC voltage or an AC voltage. A DC voltage and an AC voltage can be applied simultaneously. The voltage can be generated using an ordinary constant voltage generator. Separation of the complex catalyst by applying a voltage is performed when the electric field intensity by the voltage is set to 0.
It can be achieved in the range of 001 to 40 kV / mm, preferably 0.01 to 1 kV / mm. When applying a voltage, the voltage can be varied appropriately within this range. Further, the above-described voltage application can be performed in a pulsed manner. When the electric field intensity is less than 0.001 kV / mm, the effect of sedimentation and separation of the catalyst by applying voltage is not exhibited, and conversely, the electric field intensity becomes 40
If it exceeds kV / mm, dielectric breakdown or electrolysis of the reaction mixture containing the oligomer is liable to occur.

The distance between the electrodes to which a DC and / or AC voltage is applied can be appropriately selected from the range of 0.1 to 100 cm, preferably 1 to 50 cm.
In the present invention, there is no particular limitation on the shape and structure of the device as long as the device includes a configuration in which a pair of electrodes is paired and an electric field is applied to the target fluid between at least one pair of electrodes. For example, as the electrode shape, a plate shape, a solid rod shape,
Any form such as a hollow cylindrical shape and a spherical shape can be adopted. The electrode surface can also be a porous surface or a reticulated surface. That is, in addition to the parallel electrodes, these can be appropriately combined to form a set of electrodes. In this case, the separation effect can be appropriately adjusted by changing the distance (interval) between the electrodes together with the applied voltage, and the polarity of the electrodes can be appropriately changed. Further, a plurality of pairs of electrodes may be combined. Since the target fluid is electrically insulating even when it contains the boron trifluoride complex, almost no current flows even when a voltage is applied, and therefore, the power consumption is small.

The temperature at which the separation effect is exerted by applying a voltage is not particularly limited as long as it is in the range of -100 ° C to + 50 ° C. Usually, it can be applied to the polymerization reaction solution from the polymerization zone as it is or in a temperature range lower than the reaction temperature in order to avoid the influence of the catalyst. Further, the voltage application time is not particularly limited. For example, in the case of applying a voltage in a batch system, it can be appropriately selected usually from a range of 1 minute to 1 hour, depending on the concentration of the complex, the type of ligand of the complex, and the like. During the voltage application, the polymerization reaction solution is preferably allowed to stand without stirring. Although it is possible to separate the boron trifluoride complex only by standing, it is possible to separate the boron trifluoride complex much more quickly and easily by using the application of an electric field. Can be recovered. It is preferable that the reaction mixture is allowed to stand as described above, but it is also possible to flow the reaction mixture to such an extent that the precipitation and separation of the complex is not hindered. Therefore, it is also possible to adopt a method in which an electrode having an appropriate shape is provided while flowing through an appropriate pipe, a voltage is applied, and the complex is continuously settled and separated.

The boron trifluoride complex catalyst precipitated and separated as a lower layer from the reaction polymerization solution by applying a voltage,
The complex catalyst can be separated and recovered from the reaction product by extracting from the system by an appropriate extracting means. In addition, since the coordination molar ratio of the precipitated complex has not changed from the value before the reaction, the same catalytic activity as that before the reaction is maintained, and it can be used again without any adjustment without any adjustment. Can be.

In the second and subsequent reactions, an unused boron trifluoride-based complex catalyst can be appropriately added. For example, an amount corresponding to the amount of the complex catalyst flowing out of the system together with the polymer is supplemented. In addition to the addition of the complex itself, a complex component such as boron trifluoride and a complexing agent can be added simultaneously or individually. Further, when the recovered catalyst is reused, a diluent or the like can be appropriately added. In the polymerization at the time of reuse, the same reaction conditions as in the initial polymerization can be adopted, but can be appropriately changed.

If a small amount of the complex catalyst remains in the obtained polymer, it can be removed as necessary by a conventionally known catalyst removal method, for example, an appropriate neutralization step. Such removal of the remaining complex catalyst can be easily performed because most of the complex catalyst has already been removed. After separation of the catalyst, the desired polymer can be obtained by an appropriate separation means, for example, a distillation operation. As described above, in the present invention, at least a part of the catalyst contained therein is recovered from the polymerization solution, and this is added at a predetermined ratio to the C ₄ fraction, which is a reaction raw material, to be subjected to the reaction. At this time, a new catalyst can be added if necessary. Thus, in the present invention, the catalyst is circulated and used. The circulation of the catalyst may be carried out continuously, or the polymerization itself may be of a continuous type, or a method in which the recovered catalyst is used once after being stored in a catalyst storage tank may be employed. With respect to the reaction solution from which the catalyst has been separated, the desired butene polymer can be obtained by distillation after deactivating the unseparated catalyst by a conventional method.

[0029]

The present invention will be further described with reference to the following examples. As a feedstock for the polymerization reaction, C ₄ raffinate containing isobutene (butadiene extraction residue from ethylene cracker) was used. The composition of the C ₄ mixture are as follows (wt%).

<Preparation of a boron trifluoride etherate complex catalyst> A predetermined amount of ether kept at -10 ° C or lower was cooled to a predetermined coordination molar ratio while cooling so that the content temperature did not exceed -10 ° C. Boron trifluoride (purity 99.7)
%) Was blown to prepare a complex catalyst. Those having a concern about decomposition were stored at a temperature lower than the decomposition temperature and used for the reaction. The coordination molar ratio was determined from the weight of the ether compound and the weight of the boron trifluoride blown.

<Specification of polymerization apparatus and polymerization technique> The polymerization reaction was carried out using a continuous polymerization apparatus shown below. That is, an internal volume 2 equipped with a variable stirrer, a low-temperature circulating cooling device capable of constant temperature control, a supply port for a raw material, a supply port for a complex catalyst, a polymerization temperature indicator, a standing tank, a deactivation tank, and a discharge port. A liter reactor was installed. When feeding the liquefied feed into the reactor at a predetermined flow rate and changing the contact time,
The feed flow rate was varied. A predetermined flow rate of a boron trifluoride etherate complex was fed from a supply port of the complex catalyst by a metering pump to continuously perform a polymerization reaction. The conversion of the isobutene component in the C ₄ raffinate was measured by gas chromatography of the raw materials and the reaction solution before and after the reaction, and was calculated from the change in the composition. The polymerization reaction solution from the reactor was led to a standing tank, and after sufficiently standing, the complex catalyst was extracted from the lower layer. The extracted complex catalyst was circulated to the reaction tank and reused. On the other hand, the upper layer of the standing tank was led to a deactivation tank, washed with a dilute aqueous sodium hydroxide solution until the unseparated complex catalyst was neutralized, and then the organic phase was separated. From the obtained organic phase, unreacted feed materials and light components having 24 or less carbon atoms were distilled off under reduced pressure distillation. The yield of the butene polymer obtained from the remaining product was calculated. The molecular weight of the butene polymer was determined by gel permeation chromatography (GPC), and the assignment and quantification of the molecular skeleton and the olefin structure at the molecular end were carried out by measurement using a nuclear magnetic resonance apparatus (NMR). With respect to the complex catalyst extracted from the standing tank, the coordination molar ratio of the complex was confirmed by NMR analysis as follows. That is, for example, when a boron trifluoride diethyl ether complex is analyzed by ¹³ C-NMR, two carbon peaks derived from carbon of diethyl ether are detected at 12.9 ppm and 69.9 ppm. By utilizing the fact that the positions of these two peaks on the ¹³ C-NMR spectrum shift as the molar ratio of the complex changes, the molar ratio of the complex catalyst is determined from the detected chemical shift value and a previously prepared calibration curve. Can be determined.

Example 1 The above-mentioned feed was fed into the reactor at a flow rate of 2 liter / hour, and the average contact time between the olefin component and the complex catalyst was set to 1 hour. At the same time, as a complex catalyst, an unused boron trifluoride-diethyl ether complex in which the molar ratio of boron trifluoride to diethyl ether (special reagent grade) was adjusted to 1.00: 1.00 was added to 1 mole of the olefin component of the feedstock. , And the complex catalyst separated and recovered in a stationary tank was charged at a rate of 6.62 mmol, and the inside of the reactor was charged with-.
The polymerization reaction was performed while maintaining the temperature at 10 ° C. The product was continuously withdrawn, and the catalyst was separated and recovered according to the above-mentioned polymerization technique, and reused. Finally, the conversion ratio of isobutene, the yield of butene polymer, the molecular weight of the obtained butene polymer, the molecular skeleton and the assignment and quantification of the olefin structure at the molecular terminal were determined. In the obtained polymer, 90% or more of the number of the repeating structural units had the structure represented by the formula (1).
In addition, as shown in FIG. 3 later, as a result of NMR inspection of the complex catalyst, it was found that the coordination molar ratio of the complex catalyst did not change from the value before the reaction even after continuous operation for 10 hours. Was.

<Example 2> A boron-trifluoride dimethyl ether complex was prepared in the same manner as in Example 1 except that diethyl ether was replaced with dimethyl ether, and the molar ratio of boron trifluoride to dimethyl ether was adjusted to 1.00: 1.00. And The polymerization reaction was carried out under the same conditions as in Example 1 such as the amount of the complex catalyst charged, the flow rate of the raw material, and the polymerization temperature. In the obtained polymer, 90% or more of the number of the repeating structural units had the structure represented by the formula (1).

<Example 3> Polymerization temperature in Example 1
Polymerization was carried out by changing 10 ° C to -30 ° C. Conditions such as the complex catalyst and its molar ratio, the amount of the complex catalyst to be charged, and the flow rate of the feedstock were the same as in Example 1. In the obtained polymer, 90% or more of the number of the repeating structural units had the structure represented by the formula (1).

Example 4 Olefin component 1 of feedstock
Polymerization was carried out by reducing the total amount of the boron trifluoride diethyl ether complex catalyst per mol to 8.13 mmol in Example 1 to 4.13 mmol. The conditions such as the complex catalyst and its molar ratio, the flow rate of the feed material, the polymerization temperature and the like were the same as in Example 1. In the obtained polymer, 90% or more of the number of the repeating structural units had the structure represented by the formula (1).

Example 5 The flow rate of the feedstock in Example 1 was increased from 2 liters / hour to 6 liters / hour,
The polymerization was carried out with the average contact time between the olefin component and the complex catalyst being 20 minutes. The conditions such as the complex catalyst and its molar ratio, the amount of the complex catalyst charged, and the polymerization temperature were the same as those in Example 1.
In the obtained polymer, 90% or more of the number of the repeating structural units had the structure represented by the formula (1).

<Comparative Example 1> A boron trifluoride-ethanol complex in which the diethyl ether in Example 1 was changed to ethanol and the molar ratio between boron trifluoride and ethanol was adjusted to 0.90: 1.00 was obtained. The polymerization reaction was carried out by continuously feeding 0.41 mmol of the olefin component of the feed material at a ratio of 0.41 mmol. Also, the catalyst was not allowed to stand or separate. The conditions such as the flow rate of the feed material and the polymerization temperature were the same as in Example 1.

Comparative Example 2 A boron trifluoride-diethyl ether complex was prepared in which the molar ratio of boron trifluoride to diethyl ether in Example 1 was changed from 1.00: 1.00 to 0.50: 1.00. Thus, a polymerization catalyst was obtained. Conditions such as the input amount of the complex catalyst, the flow rate of the feed material, and the polymerization temperature were the same as those in Example 1.

Comparative Example 3 Polymerization Temperature in Example 1
Polymerization was performed by changing 10 ° C. to + 55 ° C. Conditions such as the complex catalyst and its molar ratio, the amount of the complex catalyst to be charged, and the flow rate of the feedstock were the same as in Example 1.

Comparative Example 4 Polymerization was carried out by increasing the flow rate of the feedstock in Example 1 from 2 liters / hour to 120 liters / hour and setting the average contact time between the olefin component and the complex catalyst to 1 minute. The conditions such as the complex catalyst and its molar ratio, the amount of the complex catalyst charged, and the polymerization temperature were the same as those in Example 1.

With respect to the test results of Examples 1 to 5 and Comparative Examples 1 to 4, the conversion of isobutene, the yield of butene polymer, the molecular weight (Mn), the molecular weight distribution (Mw / Mn) and the terminal olefin structure distribution are shown in Table 1. Shown in

[0042]

[Table 1]

Reference Example 1 (When Boron Trifluoride Diethyl Ether Complex Is Used as Catalyst) C ₄ raffinate is polymerized by boron trifluoride diethyl ether complex coordinated at a molar ratio of 1.0: 1.0. After that, the reaction solution was allowed to stand, and the lower layer liquid containing the collected catalyst was analyzed by ¹³ C-NMR. As a result, the carbon content of two diethyl ethers was reduced to 12.9 ppm and 69.9 ppm as described above. Was detected. Since the position of two peaks on the ¹³ C-NMR spectrum shifts with the change of the molar ratio of the complex, the molar ratio of the complex catalyst is determined from the detected chemical shift value and a previously prepared calibration curve. Can be. The results of the measurement of the complex from the lower part collected in the above example were at the same position as the detection peak of the unused complex catalyst (1.0: 1.0 mol adduct), and therefore the same molar ratio as before use. Was confirmed. Further, the activity as a catalyst was maintained. FIG.
Shows the measurement results by ¹³ C-NMR before and after the use of the boron trifluoride diethyl etherate complex.

Reference Example 2 Boron trifluoride methyl tert-butyl ether complex was prepared at room temperature at a molar ratio of 1.0: 1.0 (in the case of using boron trifluoride methyl tert-butyl ether complex as a catalyst). When this was attempted, the decomposition reaction of methyl tert-butyl ether occurred from the start of the injection of boron trifluoride. For the solution after blowing a predetermined amount of boron trifluoride, ¹³ C
-When the NMR measurement was carried out, boron trifluoride methyl
There is no peak derived from the carbon of tert-butyl ether, and instead a peak derived from the carbon of methyl alcohol is detected, and the complex is converted to a boron trifluoride methyl alcohol complex (1.0: 1.0 mol adduct). It has been confirmed that it has changed. In this case, CF ₃ C was used as the NMR solvent.
Since using O ₂ D, two separate peaks derived from the isotope exchange reaction of methanol and deuterated methanol has been detected on the ¹³ C-NMR spectra. FIG. 4 is a ¹³ C-NMR spectrum of the boron trifluoride complex. FIG. 4 (a) is a complex prepared for the purpose of a boron trifluoride methyl tert-butyl ether complex, and FIG. 4 (b) is a separately prepared complex. Boron trifluoride methyl alcohol complex (1: 1 molar adduct)
Is the case. From the above results, boron trifluoride methyl
An ether such as a tert-butyl ether complex which is not in a form in which a primary carbon atom is bonded to oxygen cannot exist stably at room temperature, and a decomposition reaction occurs during preparation and / or reaction, and recovery and It turns out that it cannot endure reuse. Although it becomes more stable at a polymerization temperature lower than room temperature, a boron trifluoride complex of diethyl ether is superior in stability.

[0045]

According to the method of the present invention, it is possible to use an inexpensive reaction material such as C ₄ raffinate having a relatively low isobutene purity, and to convert a primary carbon atom as a catalyst to oxygen. Since the dialkyl ether complex catalyst to be bonded can be stably separated and recovered and reused, the cost of the catalyst can be reduced. In addition, it is possible to produce a butene polymer having a terminal vinylidene structure having a high reactivity of 80 mol% or more and a narrow molecular weight distribution in a high yield.

[Brief description of the drawings]

FIG. 1 is a measurement result of a butene polymer by an HSQC method.

FIG. 2 is a measurement result of a butene polymer by an INADEQUAT method.

FIG. 3. ¹³ C- of boron trifluoride diethyl ether complex
It is a measurement result by NMR.

FIG. 4 is a ¹³ C-NMR spectrum of a boron trifluoride complex, wherein (a) is a complex prepared for the purpose of boron trifluoride methyl tert-butyl ether complex, and (b) is a boron trifluoride methyl alcohol complex ( 1: 1 molar adduct).

Claims (4)

[Claims] 1. A method for producing a butene polymer containing at least 80 mol% of polymer molecules having a terminal vinylidene structure, comprising the following steps (I) and (II): Step (I): 10 to 40% by weight of butene- 1, 1 to 40
Wt% butene-2, 35-70 wt% isobutene,
Against C ₄ fraction of olefin component 1 mol in the starting material consisting of 10 to 30 wt% butanes and 0.5% by weight of butadiene, boron trifluoride and, from 1 carbon atoms in each alkyl group 8 wherein the carbon atoms bonded to the oxygen atoms are all primary carbon atoms.
Alkyl groups may be the same or different from each other)
Is a complex catalyst consisting of 0.1 to 5 as boron trifluoride.
At a polymerization temperature of -1.
A step of continuously performing liquid phase polymerization in the range of 00 ° C. to + 50 ° C. and a residence time of 5 minutes to 4 hours, Step (II): a complex catalyst in which the molar ratio of boron trifluoride to ether is substantially the same as before the reaction From the polymerization solution, and circulating at least a part of the recovered complex catalyst to the liquid phase polymerization zone. 2. The complex catalyst according to claim 1, wherein the molar ratio of boron trifluoride to ether is 0.85: 1.00 to 1.10: 1.
The method for producing a butene polymer according to claim 1, wherein the temperature is in the range of 00. 3. The method for producing a butene polymer according to claim 1, wherein the conversion of isobutene in the step (I) is in the range of 60 to 100%. 4. The butene polymer according to claim 1, wherein the number of repeating structural units represented by the following formula (1) among the repeating structural units in the polymer molecule is 80% or more. Production method. Embedded image (However, n is an integer of 0 or more, preferably 5 or more, more preferably 16 or more and 200 or less.)