TW201638114A - Production method and production system for conjugated diene polymer - Google Patents

Abstract

The present invention is capable of recovering the yield rate when the yield rate gradually becomes lower during production of a conjugated diene polymer. The conjugated diene polymer is produced by using a transition metal catalyst, and an organoaluminum compound as a co-catalyst. The yield rate gradually becomes lower when successive production of the conjugated diene polymer is continued. In response, the supplied amount the co-catalyst is adjusted on the basis of the generation level of inactivate substances generated in the reaction system. Specifically, increasing the amount of the co-catalyst is started when the generation level becomes equal to or lower than a predetermined value. Furthermore, increasing the amount of the co-catalyst is stopped when determined that sufficient recovery has occurred. More specifically, supply of the predetermined amount that had been supplied before the amount was increased is started.

Description

Manufacturing method and manufacturing system of conjugated diene polymer

The present invention relates to a method and system for producing a conjugated diene polymer which recovers a reduced yield.

As a method for producing a conjugated diene polymer, a method of adding a transition metal catalyst as a catalyst to an organoaluminum compound as a secondary catalyst to a solution containing a conjugated diene monomer is proposed (for example, Patent Documents 1 and 2).

Specifically, a cobalt-based catalyst, a non-halogenated organoaluminum compound, and a halogenated organoaluminum compound are added to the monomer solution of 1,3-butadiene. Thereby 1,4-polybutadiene was obtained. PRIOR ART DOCUMENT Patent Document Patent Document 1: Japanese Patent Laid-Open Publication No. 2013-209470. Patent Document 2: Japanese Laid-Open Patent Publication No. 2013-227524.

[The problem that the invention wants to solve]

A higher yield can be obtained by appropriately using the catalyst and the auxiliary catalyst as described above.

However, there is a problem that the yield is gradually lowered when the production of the conjugated diene polymer is continuously continued in the apparatus.

The present invention has been made in view of the above problems, and an object thereof is to provide a method and a manufacturing system for producing a conjugated diene polymer which can recover a yield when the yield is gradually lowered. [Technical means to solve the problem]

The present inventors have conducted intensive studies on the causes and countermeasures for the decrease in yield, and as a result, have completed the present invention.

The present invention relates to a method for producing a conjugated diene polymer, which is based on the degree of generation of a deactivated substance generated in the reaction system in a polymerization reaction of a conjugated diene using an organoaluminum compound as a secondary catalyst. The supply amount of the auxiliary catalyst is adjusted.

In the above invention, the polymerization activity index of the reaction is determined based on the degree of occurrence of the deactivated substance generated in the reaction system, and when the polymerization activity index is equal to or lower than the first reference value, the secondary catalyst and the auxiliary catalyst are The polymerization activity index is supplied incrementally before being equal to or lower than the first reference value.

In the above aspect, when the polymerization catalyst is supplied in an incremental manner and the polymerization activity index is equal to or higher than the second reference value, the supply amount is equal to the same as the polymerization activity index is equal to or lower than the first reference value. The secondary catalyst.

In the above invention, the polymerization activity index when the deactivated substance is not produced is set to 100. The first reference value is set to 80% or more. The second reference value is set to 95% or more.

In the above invention, the organoaluminum compound has an organoaluminum compound containing a halogen and an organoaluminum compound containing no halogen.

The present invention relates to a conjugated diene polymer production system for controlling a conjugated diene polymerization reactor using an organoaluminum compound as a secondary catalyst, comprising: a detection portion, which is deactivated in the reaction system The degree of occurrence of the substance is detected; and the auxiliary catalyst supply amount adjustment unit adjusts the supply amount of the auxiliary catalyst based on the detected value. [Effects of the Invention]

In the production method and production system of the conjugated diene polymer of the present invention, the yield can be recovered in the case where the yield is gradually lowered.

<summary>

The invention of the present invention is a method for producing a conjugated diene polymer using a transition metal catalyst and an organoaluminum compound as a secondary catalyst. At this time, the supply amount of the auxiliary catalyst is adjusted based on the degree of generation of the deactivated substance generated in the reaction system. Specifically, the secondary catalyst increment is started at an appropriate time, and the secondary catalyst increment is stopped at an appropriate time. For details, the following description will be made. <diene monomer>

In the present embodiment, examples of the diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene. - phenyl-1,3-butadiene or the like. These may be used alone or in combination of two or more kinds, and may be further copolymerized with another diene such as 1,3-hexadiene. Among them, preferred is 1,3-butadiene.

The concentration of the conjugated diene monomer in the monomer liquid is preferably in the range of 10 to 90% by weight, more preferably 20 to 70% by weight, still more preferably 25 to 50% by weight.

For example, 1,4-polybutadiene can be obtained by performing cis-1,4 polymerization using 1,3-butadiene as a conjugated diene monomer. <transition metal catalyst>

Examples of the transition metal catalyst include a cobalt-based catalyst, a nickel-based catalyst, a ruthenium-based catalyst, a vanadium-based catalyst, and a titanium-based catalyst. Among them, a cobalt-based catalyst or a nickel-based catalyst is preferred, and a cobalt-based catalyst is more preferred. The transition metal catalyst may be used singly or in combination of two or more.

Examples of the cobalt-based catalyst include cobalt halide salts such as cobalt chloride and cobalt bromide; cobalt salts such as cobalt sulfate and cobalt nitrate; cobalt octoate, cobalt octoate, cobalt naphthenate, cobalt acetate, and cobalt malonate. Organic acid cobalt salt; acetoacetate cobalt, triethyl hydrazide cobalt, acetonitrile ethyl acetate cobalt, cobalt salt pyridine complex, cobalt salt methyl pyridine complex, cobalt salt ethanol complex A cobalt complex. Among them, cobalt octoate is preferred.

On the addition amount of cobalt-based catalyst, a diene monomer with respect to 1 mole, usually cobalt-based catalyst is preferably 1 × 10 ^-7 ~1 × 10 ^-4 mole, particularly preferably 1 × 10 ^-6 ~1×10 ^-5 Mo. <Organic aluminum auxiliary catalyst>

Use of organic aluminum cocatalysts with transition metal catalysts. The amount of addition of the organoaluminum auxiliary catalyst is preferably in the range of 50 to 2000 moles with respect to the transition metal catalyst 1 mole.

In particular, in the present embodiment, an organoaluminum compound containing a halogen is used in combination with an organoaluminum compound containing no halogen.

Examples of the non-halogenated organoaluminum compound include hydrogenated organoaluminum such as trialkyl aluminum, hydrogenated dialkyl aluminum, and sesquihydroalkyl aluminum alkyl. It is preferably a trialkyl aluminum, more preferably triethyl aluminum (TEA).

Examples of the organoaluminum halide include dialkyl aluminum chloride, dialkyl aluminum bromide, alkyl aluminum dichloride, alkyl aluminum dibromide, alkyl aluminum sesquichloride, and alkyl sesquichloride. aluminum. Among them, preferred is chlorinated organoaluminum, more preferably diethylaluminum chloride (DEAC).

The molar amount of the halogenated organoaluminum/non-halogenated organoaluminum compound is preferably from 1 to 5, more preferably from 2 to 4. <degree of inactivation of substances and inactive substances>

When a cobalt-based catalyst and an organoaluminum auxiliary catalyst are added to the butadiene monomer solution to carry out polymerization, 4-vinyl-1-cyclohexene (4-VCH) as a deactivated substance (poisoning substance) is produced. The amount of deactivated material produced was measured by gas chromatography (GC) at any time from the start of polymerization.

As an indicator of the degree of generation of the deactivated substance, the amount of the deactivated substance produced / the molar ratio of the amount of the halogenated organoaluminum supplied is used. For example, 4-VCH/DEAC molar ratio is used. The amount of inactivating substance produced can also be used as an indicator.

Further, the activity index of the polymerization reaction can be judged based on the degree of generation of the deactivated substance. For example, a relationship (approximate curve) between the amount of generated catalyst deactivator and the polymerization activity index can be obtained by plotting experimental data (see, for example, FIG. 2 below). <Incremental start judgment and incremental stop judgment>

The polymerization activity index is judged based on the degree of generation of the inactive matter. Further, the increment start and/or the incremental stop are judged based on the polymerization activity index. The degree of generation of the deactivated substance can also be set as a criterion for the start of the increment and/or the stop of the increment.

For example, when the polymerization activity index is equal to or lower than the first reference value, the auxiliary catalyst is supplied incrementally before the polymerization activity index is equal to or lower than the first reference value. If the first reference value is set to 80% or more in advance (approximately equivalent to a 4-VCH/DEAC molar ratio of 2.5 or less), it is expected that sufficient recovery can be achieved in actual operation.

On the other hand, when the polymerization activity index is increased to a second reference value or more by feeding the auxiliary catalyst in an incremental manner, the increment is stopped, and the supply is equal to the same before the polymerization activity index is equal to or lower than the first reference value. Auxiliary catalyst. If the second reference value is set to 95% or more in advance (approximately equivalent to a 4-VCH/DEAC molar ratio of 2.1 or less), it can be regarded as being sufficiently restored in actual operation.

Furthermore, it is also possible to determine the incremental stop based on the second reference value, and to determine the incremental stop when the decrease of 4-VCH/DEAC is stopped (time differential=0) by monitoring the amount of deactivated substance generated. Benchmark. <incremental ratio>

When it is judged that the increment is necessary, the auxiliary catalyst is supplied in increments of 5-30%. More preferably, the increment is 10-20%. Example

Figure 1 is a conceptual diagram of a manufacturing system for polybutadiene. The basic manufacturing method in the manufacturing system will be described.

The polymerization monomer conditioning solution containing the butadiene monomer solution is continuously supplied. Add water before the raw material adjustment tank. Then, a secondary catalyst was added in a ratio of MoAC to DEA of DEAC/TEA before the ripening tank. Thereafter, a cobalt-based catalyst was added to the polymerization tank to carry out polymerization.

Then, a mixed solution of the anti-aging agent and the reaction stopper is added to the reaction stop tank to stop the polymerization. The polymer solution obtained from the above was dried in a hot air dryer to obtain a polymer product.

On the other hand, a part of the single system in which polymerization is carried out, the unpolymerized monomer solution is supplied again as a raw material.

When the continuous production is continued as described above, a catalyst deactivation substance (4-vinyl-1-cyclohexene (4-VCH)) is generated in the polymerization tank, which is affected by the catalyst deactivating substance and the yield is slow. Slowly lower.

Fig. 2 is a graph showing the relationship between the amount of catalytically inactive matter produced and the polymerization activity index determined based on experimental data. The horizontal axis is taken as the molar ratio of 4-VCH/DEAC, and the vertical axis is taken as the polymerization activity index.

The amount of 4-VCH produced was measured by gas chromatography (GC) at any time from the start of polymerization. The DEAC system continuously supplies a certain amount.

The polymerization activity index is defined as the yield at which the inactive material is produced/the yield at which no deactivated material is produced. That is, the polymerization activity index when no deactivated substance was produced was set to 100%.

However, if only the auxiliary catalyst is incremented, the catalyst and the secondary catalyst are out of balance, and the desired physical property cannot be obtained. Further, since the organoaluminum compound is relatively expensive, it is not preferable to carry out the increase in terms of economy. Therefore, in the invention of the present invention, the following methods are conceivable.

Fig. 3 is a view showing an operation history based on the above approximation curve. The details are shown in Table 1. [Table 1]

Embodiment 1 will be described. In the approximate curve 1, it is assumed that the catalyst deactivated material is produced due to continuous production until 4-VCH/DEAC = 2.46, and the polymerization activity index is lowered to 80%.

In this case, the first reference value is set to 80%, and the polymerization activity index is determined to be equal to or lower than the first reference value, and the auxiliary catalyst is continuously supplied in an amount of 16%. It is assumed that this is slowly shifted from the approximation curve 1 to the approximation curve 2. It is assumed that the amount of the catalyst-inactivated substance does not change immediately (unchanged), and since the amount of the auxiliary catalyst increases, it becomes 4-VCH/DEAC = 2.12. Therefore, in the approximate curve 2, the polymerization activity index was restored to 95%.

The second reference value is set to 95% in advance, and it is confirmed that the second reference value is equal to or greater than the second reference value, and the sufficient yield recovery is considered, and the increment is stopped. That is, the specific supply amount before the increment is restored. Furthermore, the polymerization activity index is correlated with the yield.

Thereby, the yield can be restored without changing the physical properties of the article. Further, since the increment is stopped at an appropriate timing, waste of useless auxiliary catalyst can be suppressed.

Embodiment 2 will be described. When it is desired to recover in advance, the first reference value may be set to 80% or more (for example, 90%). When 4-VCH/DEAC=1.23 is generated, the polymerization activity index is determined to be equal to or less than the first reference value (90%), and the auxiliary catalyst is continuously supplied in an amount of 16% by weight.

Thereby, the approximation curve 1 is slowly shifted to the approximate curve 2 to become 4-VCH/DEAC=1.06, and the polymerization activity index can be restored to 98% theoretically.

In this case, the second reference value may be set to 95% in advance, and it is regarded as a sufficient recovery of the yield, and the increment is stopped until the polymerization activity index returns to 98%. Of course, the second reference value can also be set to 98%, and more yield recovery is expected.

Further, it is also possible to determine the decrease in 4-VCH/DEAC (time differential=0) without determining the second reference value as the criterion for determining the incremental stop.

Example 3 (Reference Example) will be described. It was set to generate a catalyst deactivated substance to be 4-VCH/DEAC = 7.33, and the polymerization activity index was lowered to 34%. At this point, if the increment is 16%, the curve 1 is slowly shifted from the approximate curve 1 to the approximate curve 2 to become 4-VCH/DEAC=6.32, and theoretically, the polymerization activity index can be restored to 83%.

However, for the recovery of about 83%, there are also practical problems that are considered insufficient.

However, when the auxiliary catalyst is not increased, the approximate curve is not shifted, and the ratio of 4-VCH/DEAC is only increased, and the polymerization activity index is getting lower and lower.

According to the above embodiment, it is preferred to start the auxiliary catalyst increment before the polymerization activity index is lowered to 80%, and after confirming that the polymerization activity index is restored to 95% or more, the auxiliary catalyst increment is stopped.

Fig. 4 is a view for explaining the results of actual application of the present invention. The horizontal axis takes time (year/month), and the vertical axis takes the average yield (%). Furthermore, in practice, a plurality of varieties are randomly produced, and the yield is obtained based on the average production amount of each variety.

Although the production was carried out at an average yield (%) of 99% to 100%, the average yield (%) was gradually lowered since last April. Therefore, the auxiliary catalyst increment was started in January this year when the polymerization activity index became 80% (the polymerization activity index was correlated with the yield).

Continued by the auxiliary catalyst increment, the yield has a tendency to recover. The secondary catalyst increment was stopped at the point when the polymerization activity index returned to 95% (January this year).

Thereafter, the specific supply amount before the increment is restored, and the auxiliary catalyst is supplied. Production is carried out in a production yield of approximately 100%. ~Control System~

Figure 5 is a functional block diagram of the control system for incremental start/incremental stop.

The control system includes a reference value storage unit 11, a deactivated substance detecting unit 12, an incremental start/stop determination unit 13, and a secondary catalyst supply amount adjustment unit 14.

The reference value storage unit 11 stores the first reference value and the second reference value. The first reference value and the second reference value are set in advance based on experimental data.

The deactivated substance detecting unit 12 detects the amount of deactivated substance generated at any time via a gas chromatograph provided in the raw material adjusting tank.

The incremental start/stop determination unit 13 determines the incremental start and the incremental stop of the secondary catalyst based on the detected value of the deactivated substance generation amount. First, the polymerization activity index is estimated based on the detected value of the amount of deactivated substance. When the polymerization activity index falls below the first reference value, the determination of the increment start is performed. On the other hand, when the polymerization activity index returns to the second reference value or more when the increment is continued, the incremental stop determination is performed.

The auxiliary catalyst supply amount adjustment unit 14 continuously supplies a certain amount of the secondary catalyst. Among them, the self-determination unit 13 receives the incremental start command and continuously supplies the incremented amount of the secondary catalyst. Further, the self-determination unit 13 receives the incremental stop command, and continuously supplies the auxiliary catalyst in the amount before the increment. ~ Supplementary matters ~

Supplement 1

The inventors of the present invention added a cobalt-based catalyst and an organoaluminum-based auxiliary catalyst to a monomer solution of butadiene to produce a polymer of butadiene in a high yield. However, as the manufacturing continues continuously, the yield is lowered.

The inventors of the present invention studied the cause of the decrease in yield, and as a result, it was found that 4-vinyl-1-cyclohexene (4-VCH) was produced. Therefore, it is suspected whether 4-VCH functions as a deactivated substance.

Supplement 2

The inventors of the present invention have studied the method of restoring the yield. First, the method of removing the deactivated substance was studied, but no effective method was found. Then, a method of increasing the catalyst to activate the polymerization was studied, but even if the catalyst was incremented, no significant effect was obtained. Therefore, focus on the secondary catalyst.

On the other hand, it is suspected that the secondary catalyst (especially TEA) is the cause of the indirect connection between the inactive materials. Therefore, it is also studied to reduce the supply of auxiliary catalyst. However, the supply amount of the auxiliary catalyst or the catalyst is determined by various studies to determine the optimum amount of balance, and therefore it is not easy to study the increase and decrease of the change.

Supplement 3

According to the experiment, it is presumed that if the auxiliary catalyst is increased, the yield reduction is suppressed (refer to Fig. 2). However, if only the secondary catalyst is incremented, the catalyst and the secondary catalyst are out of balance, and the desired physical properties cannot be obtained (the branching degree is different). Further, since the organoaluminum compound is relatively expensive, it is not preferable to carry out the increase in terms of economy.

Based on this premise, it is thought that the auxiliary catalyst is temporarily incremented. The hypothesis is established that the incremental fraction (especially the DEAC incremental fraction) does not assist the catalyst and inhibits the action of the deactivated material when the secondary catalyst is temporarily increased after the production of the inactive material. That is, the incremental component does not function as an auxiliary catalyst, and therefore it is presumed that it does not affect the physical properties of the product.

As a result of the experiment, it was confirmed that the physical properties of the product were not changed. On the other hand, the yield was successfully restored. The validity of the hypothesis was verified as described above.

Furthermore, the increase in the auxiliary catalyst is temporary because of the temporary economic impact.

11‧‧‧Reference value memory
12‧‧‧Degraded Substance Testing Department
13‧‧‧Incremental start/stop judgment department
14‧‧‧Auxiliary Catalyst Supply Adjustment Department

Figure 1 is a conceptual diagram of a manufacturing system of a conjugated diene polymer. Fig. 2 is a graph showing the relationship between the amount of catalytically inactive matter produced and the polymerization activity index determined based on experimental data. Figure 3 is a diagram showing the envisioned course of action. Fig. 4 is a view for explaining the results of actual application of the present invention. Figure 5 is a functional block diagram of the control system.

Claims (7)

A method for producing a conjugated diene polymer, characterized in that in the polymerization of a conjugated diene using an organoaluminum compound as a secondary catalyst, the degree of generation of the deactivated substance generated in the reaction system is The supply amount of the auxiliary catalyst is adjusted. A method for producing a conjugated diene polymer, characterized in that in the polymerization of a conjugated diene using an organoaluminum compound as a secondary catalyst, it is judged based on the degree of generation of a deactivated substance generated in the reaction system. When the polymerization activity index is equal to or lower than the first reference value, the polymerization catalyst is supplied in an incremental manner as compared with the case where the polymerization activity index is equal to or lower than the first reference value. The method for producing a conjugated diene polymer according to claim 2, wherein the polymerization activity index is equal to or higher than a second reference value when the auxiliary catalyst is supplied in an incremental manner, and the polymerization activity is supplied The index is the same amount of the secondary catalyst before the first reference value. The method for producing a conjugated diene polymer according to claim 2, wherein a polymerization activity index when the deactivated material is not produced is 100, and the first reference value is set to 80% or more. The method for producing a conjugated diene polymer according to claim 3, wherein a polymerization activity index when the deactivated material is not produced is 100, and the second reference value is set to 95% or more. The method for producing a conjugated diene polymer according to any one of claims 1 to 5, wherein the organoaluminum compound has: an organoaluminum compound containing a halogen, and an organoaluminum compound containing no halogen. A conjugated diene polymer production system for controlling a conjugated diene polymerization reaction using an organoaluminum compound as a secondary catalyst, and comprising: a detection unit that deactivates a substance generated in the reaction system The degree of occurrence is detected; and the auxiliary catalyst supply amount adjustment unit adjusts the supply amount of the secondary catalyst based on the detected value.