JP2002128709A - Method for continuously manufacturing ethylidene- tetracyclododecene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently use high boiling byproducts and secure a stable continuous manufacturing of ethylidene-tetracyclododecene, by reacting 5-ethylidene-2- norbornene with cyclopentadiene and/or dicyclopentadiene. SOLUTION: The purpose is achieved as follows: ethylidenetetracyclododecene is separated from the products of the above reaction; and at least 1 mass% of the remaining heavy components is discharged outside the reaction system; and the remaining portion of the heavy components is recycled to the reaction system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ethylidenetetracyclododecene (hereinafter sometimes referred to as EdTCD).
And a method for continuously producing the same.

[0002]

2. Description of the Related Art Cycloolefin (co) polymers have attracted attention as polymers having excellent optical properties, high transparency, heat resistance, and oil absorption. Tetracyclododecene (hereinafter sometimes referred to as TCD) is used as a raw material thereof. ) Are useful. JP-A-6-7290
No. 9 discloses a method for producing a TCD in which a heavy liquid composed of a high-boiling by-product is circulated to a reactor in order to effectively use a bottom obtained by distilling and separating tetracyclododecene, that is, a by-product having a higher boiling point than TCD. A method has been proposed. The high-boiling by-product is said to contain an adduct of tricyclopentadiene (hereinafter, sometimes referred to as TCPD) or cyclopentadiene (hereinafter, sometimes referred to as CPD) and TCD. However, TC
Since a PD is included, C in practice such as TCPD
The generation of a high polymer exceeding the trimer of PD cannot be avoided.
And such a high polymer of a tetramer or more is usually used in TC
It is hard to decompose under the conditions of D production reaction. As a result, as described in JP-A-6-72909, simply circulating a heavy liquid composed of high-boiling by-products into the reactor requires a circulating flow even if a high polymer is slightly generated. It has been found that high polymers accumulate therein, which makes continuous operation difficult. This publication does not describe EdTCD at all.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to provide 5-
In a method for producing EdTCD by reacting ethylidene-2-norbornene with CPD and / or dicyclopentadiene (hereinafter sometimes referred to as DCPD), by-products having a boiling point higher than that of EdTCD are effectively used and stable. An object of the present invention is to provide a method for producing EdTCD, which can ensure continuous operation.

[0004]

That is, the present invention relates to a process for continuously producing ethylidenetetracyclododecene represented by the following formula [II], which comprises the following steps (1) to (3). . (1) 5-ethylidene-2-norbornene represented by the following formula [I] and cyclopentadiene and / or dicyclopentadiene are supplied to a reactor to react with each other, and ethylidenetetracyclododecene represented by the following formula [II] is reacted. Obtaining a reaction mixture comprising:

Embedded image (2) a step of separating and recovering ethylidenetetracyclododecene from the reaction mixture, and (3) discarding at least 1% by mass of the remaining heavy matter in the step (2) outside the reaction system,
Circulating the remaining heavy matter to the reactor of step (1). According to the method of the present invention, by circulating the heavy material to the reaction step, EdT is efficiently used by efficiently utilizing the by-product heavy material.
A CD can be manufactured, and furthermore, a target EdTCD can be continuously manufactured in a stable state.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The 5-ethylidene-2-norbornene (hereinafter sometimes referred to as EBH) supplied to the reactor in the step (1) of the present invention is 5-vinyl, which is a Diels-Alder reaction adduct of butadiene and cyclopentadiene. It is industrially produced by isomerizing an olefin of 2-norbornene to an internal olefin with a strong base. In the present invention, it is preferable to use the EBH thus produced.

C supplied to the reactor in step (1) of the present invention
As PD, preferably, DCPD obtained by previously subjecting DCPD to thermal decomposition distillation can be used. In the present invention, DCPD is decomposed into CPD under ordinary reaction conditions, and DCPD is used as a raw material because DCPD is industrially easily available.
PD can be used. In addition, CPD and D
A mixture of CPD can also be used as a raw material. That is, C
Using PD and / or DCPD and EBH as raw materials, ethylidenetetracyclododecene is produced under the conditions described below.

In the present invention, EBH / DCPD (CPD
When a part or all of are used, they are converted to DCPD. ) Is from 0.1 to 20, preferably from 0.5 to 17, more preferably from 1 to 15. At a temperature lower than the above lower limit, many by-products such as heavy substances are generated. At a temperature higher than the upper limit, efficient synthesis of ethylidenetetracyclododecene cannot be achieved. The reaction temperature is 100 to 300 ° C, preferably 120 to 280 ° C.
° C, more preferably 140 to 270 ° C. If the value is lower than the lower limit, the dissociation into CPD when DCPD is used is so small that efficient production of ethylidenetetracyclododecene is impossible. On the other hand, a value higher than the upper limit is not preferable because the amount of heavy substances increases and a decomposition reaction of ethylidenetetracyclododecene occurs. The reaction pressure is normal pressure to 10 MPa, preferably normal pressure to 8 MPa, and more preferably normal pressure to 5 MPa. The residence time is 1 minute to 24 hours, preferably 10 minutes to 12 hours, more preferably 15 minutes to 2 hours, both in a batch system and a continuous system. If the time is shorter than the lower limit, efficient production of ethylidenetetracyclododecene becomes impossible. A time longer than the upper limit is not preferable because the amount of heavy substances increases and a decomposition reaction of ethylidenetetracyclododecene occurs.

The present invention relates to a completely mixed type, a piston flow type,
Either reactor can be used. Commercially available piston flow reactors include "Static Mixer" manufactured by Noritake Company, Ltd., "Sluzer Mixer" manufactured by Sumitomo Heavy Industries, Ltd., and "Skeya Mixer" manufactured by Sakura Seisakusho Co., Ltd. The reactor may have a single-stage structure or a multi-stage structure having two or more stages. The complete mixing type reactor and the piston flow type reactor can be used in combination in series or in parallel.

In the present invention, the reaction mixture continuously withdrawn from the reactor is then led to a distillation step. First, an optional step is led to a step of separating CPD generated by decomposition of DCPD or used as a raw material, and isoprene and piperylene derived from impurities of CPD and / or DCPD. The CPD separated here can be reused as a raw material. Here, CPD, isoprene, and piperylene are extracted from the top of the column at a pressure of normal pressure to about 500 kPa by using a suitable still (not shown in FIG. 1). This may use a distillation column or just flash. The liquid obtained from the bottom of this column is sent to the next distillation column.

Next, the process leads to the step of separating and recovering EBH by distillation. The first distillation column (reference numeral 5 in FIG. 1) is operated at 1 kPa to normal pressure, and EBH is extracted from the top of the column. If there is no optional preceding step for extracting CPDs, CP
Separate D, isoprene and piperylene from EBH at the same time. Alternatively, CPD, isoprene and piperylene may be extracted from the top of the column, and EBH may be extracted from the inside of the column. Here, the EBH separated by distillation can be reused as a raw material. The liquid obtained from this bottom is sent to the next second distillation column 6. This step of separating and recovering EBH is optional, but is preferably carried out.
At 100 kPa, methyltetrahydroindene (hereinafter sometimes referred to as MeTHI) derived from DCPD and / or impurities of DCPD is separated from the top of the column. The liquid obtained from the bottom of the second distillation column 6 is sent to the next third distillation column 7.

Next, the process proceeds to the step (2) for separating and recovering ethylidenetetracyclododecene. In the absence of the optional step, at 10 Pa to 100 kPa, DC
PD and / or MeTHI are withdrawn, and ethylidenetetracyclododecene is separated from the column. When the optional step is present, ethylidenetetracyclododecene is extracted from the top of the column at the same pressure. In order to increase the separation efficiency, any of the distillation columns can be filled with various packing materials or refluxed. The number of theoretical plates in each distillation column is 1 to 100 plates, preferably 2 to 50 plates,
More preferably, it is 3 to 30 stages. The reflux ratio is determined based on the separation state of each distillation column, but is preferably 1 to 50.

The liquid extracted from the bottom of the third distillation column 7 is a fraction containing by-products having a boiling point higher than that of EdTCD, and its composition is mainly that of CPD added to ethylidenetetracyclododecene. Adduct or CPD trimer (T
In addition to (CPD), a heavy substance of tetramer or more of CPD may be included.

In the method of the present invention, at least 1% by mass of by-products having a boiling point higher than EdTCD is discarded out of the reaction system (step (3)). The disposal can be performed via the disposal line 10. When the whole amount is returned to the reactor as described above, heavy substances accumulate, and long-term operation cannot be performed. By discharging part of the system, continuous operation becomes possible. That is, the heavy matter circulated to the reactor causes a reverse Diels-Alder reaction in the reactor to produce ethylidenetetracyclododecene, cyclopentadiene, dicyclopentadiene, and a raw material or a target product. The yield is improved. Further, as described above, some parts are further heavier. Adducts of CPD added to ethylidenetetracyclododecene in heavy substances and TC
It is difficult to separate only PD from heavy substances by distillation, because this distillation is a high-temperature distillation, which causes decomposition, polymerization, and the like. Therefore, after separating and collecting EdTCD, by-products having a boiling point higher than that of EdTCD are collected without performing distillation or the like, and at least a part thereof is discarded and circulated to the EdTCD production process.

That is, in the method of the present invention, EdTCD
At least 1% by mass of by-products having a higher boiling point is discarded outside the reaction system. The remaining high-boiling by-products are recycled to the reactor. That is, the amount circulated to the reactor is 1 to
99% by mass. If the amount is less than 1% by mass, no improvement in the effective yield of the raw material can be expected, and if it exceeds 99% by mass, heavy substances accumulate. Heavy materialization is a process in which cyclopentadiene is added by a Diels-Alder reaction, and an increase in heavy materials means that DCPD and / or CP
The effective yield of D decreases. Preferably, a constant amount of heavy matter is always circulating. However, the rate of formation of heavy matter varies depending on the raw material composition, reaction temperature, space velocity,
In addition, since heavy substances also change due to recycle use, the amount to be discharged out of the system may be determined in consideration of these.

For example, assuming that the amount of heavy matter generated is A for all the new raw materials 1 in one reaction, and when the entire amount of A is reused, A + xA (x Is the rate of change of the heavy material). Therefore, in order to always have a certain amount (= A) of heavy matter,
It is necessary to discharge xA out of the system. However, x changes depending on the temperature of the reactor, the residence time, and the composition of heavy substances. In obtaining x, a reaction is performed at a predetermined temperature and a predetermined space velocity with a 1 + A composition, and
It can be obtained by dividing by. In this way, the standard of the emission amount may be determined. It is to be noted that it is not preferable to dispose of the heavy material normally because the entire amount of the heavy material cannot be effectively used. However,
As described above, the heavy material may be further heavier by heating in the reactor, and the polymer obtained by such further heavier has an insoluble and infusible property. Therefore, the reactor may be closed. Therefore, in order to prevent reactor clogging, at an arbitrary frequency as appropriate during continuous operation,
All heavy materials can be discarded. Such proper disposal of the entire amount of heavy substances is performed by once completely discarding the production of cyclopentadiene tetramer in the circulating heavy substance composition, and then resuming continuous operation again. It is preferable that

In the present invention, a hydrocarbon solvent can be used as a reaction solvent. In addition to benzene, toluene, and xylene, a branched aliphatic hydrocarbon or an alicyclic hydrocarbon is preferably used in terms of high safety to the environment and the human body and high solubility. Specifically, cyclopentane, cyclohexane, ethylcyclopentane, dimethylcyclopentane, methylcyclohexane,
Normal hexane, normal heptane, 2-methylhexane, 3-methylhexane, 3-ethylpentane, 2,
3-dimethylpentane, 3,3-dimethylpentane, normal octane, methylheptane, dimethylhexane,
2,2,3-trimethylpentane, 2,2,4-trimethylpentane, alkylated gasoline, normal decane and the like. Alkylated gasoline as used herein refers to a product obtained by alkylating isobutane with butene using a (super) strong acid such as zirconia sulfate, sulfuric acid, or hydrogen fluoride as a catalyst. Of the alkylated products, trimethylpentane is a main component. It is a fraction to be made. By using these solvents, a condition in which substantially no gas phase is present is achieved at a lower pressure, whereby the yield of the target substance, ethylidenetetracyclododecene, can be improved. The weight ratio between these hydrocarbon solvents and EBH is arbitrary,
It is preferable to use EBH / hydrocarbon solvent = 0.1 to 10 (molar ratio).

In this reaction, an antioxidant and a polymerization inhibitor can be appropriately added to the reaction raw materials. For example, phenolic compounds such as hydroquinone, 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 4-methoxyphenol, N, N-dimethylhydroxylamine, N, N- A hydroxylamine compound such as diethylhydroxylamine is preferably added. The addition amount is usually in the range of 10 to 10000 ppm, preferably 50 to 5000 ppm, based on the total amount of the reaction raw materials supplied into the reactor. Of course, it can be similarly added to ethylidenetetracyclododecene as a product. In this way, the target substance, ethylidenetetracyclododecene, can be efficiently produced by effectively utilizing the raw materials.

[0018]

The present invention will be described below with reference to examples. (Example 1) Continuous production of ethylidenetetracyclododecene was performed using the apparatus shown in FIG. The EBH and DCPD were continuously introduced into the reactor 4 from the EBH tank 1 and the DCPD tank 2 via the transfer pump 3 so that the molar ratio of EBH and DCPD was 8: 1. The reaction temperature was 250 ° C., and the reaction pressure was 2 MPa. The EBH purity in the tank was 9
9.6%, DCPD purity was 94.7%. As a continuous operation, the space velocity was 2 h ⁻¹ and the temperature in the reactor 4 was 250 ° C. The reaction pressure was 2 MPa.
After the reaction, the reaction mixture was transferred to the first distillation column 5. The first distillation column had 20 theoretical plates, and a fraction containing EBH was recovered from the top of the column at 20 kPa. This recovered liquid was continuously mixed with the raw material DCPD and newly supplied EBH through the EBH recovery / circulation line 8 and sent to the reactor 4 from the transfer pump 3 for reuse as a raw material. In this case, the sum of the EBH to be recycled and the EBH to be newly supplied and D
The molar ratio with CPD is adjusted to be 8: 1.
The reaction mixture withdrawn from the bottom of the first distillation column 5 is transferred to the second distillation column 6, where dicyclopentadiene and methyltetrahydroindene are separated from the top of the column, and the mixed mixture withdrawn from the bottom of the column. The liquid was sent to the third distillation column 7, where ethylidenetetracyclododecene was distilled from the top. EdTCD obtained from the bottom of the third distillation column
50% of the by-product fraction having a higher boiling point than that is sent to the transfer pump 3 through the heavy matter circulation line 9 and introduced into the reactor 4;
The remainder was discharged from the waste line 10 to the outside of the system. In the above operation, a stable continuous operation could be performed for 250 days or more without any change over time without disposing the entire bottom liquid of the third distillation column. As a result, the purity was 97.2%.
Was obtained, and the yield of ethylidenetetracyclododecene was 73% (based on charged dicyclopentadiene). (Comparative Example 1) The third distillation column 7 without using the waste line 10
Was carried out in the same manner as in Example 1 except that the entire amount of the heavy liquid obtained from the bottom of the above was circulated to the reactor 4. After the reaction starts 2
After a lapse of days, CPD tetramer was found in the heavy liquid obtained from the bottom of the circulating third distillation column 7, and the amount gradually increased. Therefore, the operation was stopped four days after the start of the reaction. When the operation was stopped, ethylidenetetracyclododecene having a purity of 97.1% was obtained, and the yield of ethylidenetetracyclododecene was 62% (based on charged dicyclopentadiene).

[0019]

According to the method of the present invention, at least 1% by mass of the heavy product of the reaction product is discarded outside the reaction system,
By recycling the remaining part to the reaction step, heavy substances can be effectively used to efficiently produce ethylidenetetracyclododecene, and furthermore, the target substance ethylidenetetracyclododecene can be produced stably and continuously. be able to.

[Brief description of the drawings]

FIG. 1 is a process chart showing one embodiment of a continuous production method in the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 EBH tank 2 DCPD tank 3 Transfer pump 4 Reactor 5 1st distillation tower (EBH separation tower) 6 2nd distillation tower 7 3rd distillation tower (ethylidene tetracyclododecene separation tower) 8 EBH recovery and circulation line 9 Heavy materials Circulation line 10 Waste line

Claims (1)

[Claims] 1. A method for continuously producing ethylidenetetracyclododecene represented by the following formula [II], comprising the following steps (1) to (3): (1) The following formula [I]
And supplying 5-ethylidene-2-norbornene and cyclopentadiene and / or dicyclopentadiene to a reactor to react them to obtain a reaction mixture containing ethylidenetetracyclododecene represented by the following formula [II]. Embedded image (2) a step of separating and recovering ethylidenetetracyclododecene from the reaction mixture, and (3) discarding at least 1% by mass of the remaining heavy matter in the step (2) outside the reaction system,
Circulating the remaining heavy matter to the reactor of step (1).