JP4184767B2 - Process for producing bicyclo [2.2.1] heptenes - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a method for producing bicyclo [2.2.1] heptenes. More specifically, the present invention relates to bicyclo [2 .2] useful as a functional monomer or a base oil production raw material for a traction drive fluid. 2.1] A method for efficiently producing heptenes.
[0002]
[Prior art]
The traction CVT (continuously variable transmission) for automobiles can be mounted from large vehicles to small vehicles, and it will be the mainstream of future automatic transmissions as a comfortable transmission with good fuel efficiency, sharp acceleration, and no shift shock. It is predicted. This CVT has a high traction coefficient at high temperature (about 140 ° C) for power transmission, and has excellent performance with low viscosity at low temperature (about -40 ° C) for low temperature startability. Oil is needed.
[0003]
The high temperature traction coefficient and the low temperature viscosity are contradictory performances, and excellent traction oil base oils in which the contradictory performances are compatible at a high level are disclosed (for example, Patent Document 1 and Patent Documents). 2). Moreover, these patent documents include 2-methylene-3-methylbicyclo [2.2.1] heptane and 2,3-dimethylbicyclo [2.2.1] hept-2 as intermediates of the above base oil. -En and others are disclosed. As one of the precursors of the above intermediate, bicyclo [2.2.1] heptenes such as 5,6-dimethylbicyclo [2.2.1] hept-2-ene can be considered, and the bicyclo [2. 2.1] A method for obtaining heptenes with high efficiency is desired.
On the other hand, cyclopentadiene and 2-butene are subjected to Diels-Alder reaction to obtain 5,6-dimethylbicyclo [2.2.1] hept-2-ene, which is isomerized to give 2-methylene-3. -A method for producing methylbicyclo [2.2.1] heptane and 2,3-dimethylbicyclo [2.2.1] hept-2-ene is disclosed (for example, see Patent Document 3). Furthermore, in the first half of the Diels-Alder reaction, the acyclic olefin having 3 or 4 carbon atoms or cyclopentadiene is reacted in the gas phase or supercritical conditions, thereby increasing the bicyclo [2.2.1] heptenes. A manufacturing method that can be obtained with a selectivity is also disclosed (for example, see Patent Document 4).
[0004]
However, in these methods, a heavy product produced as a by-product is precipitated in the reactor, and further, polymerization proceeds (heavy), causing the reactor to become dirty and clogged. In some cases, continuous operation may be hindered, and the conversion rate of cyclopentadiene is not high enough to be sufficiently satisfied, and there is room for improvement.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 7-103387 [Patent Document 2]
JP 2000-17280 A [Patent Document 3]
JP 2001-226296 A [Patent Document 4]
JP-A-2002-114714 gazette
[Problems to be solved by the invention]
Under such circumstances, the present invention provides a conversion rate of the raw material cyclopentadiene in the production of bicyclo [2.2.1] heptenes useful as a base oil production raw material for functional monomers and traction drive fluids. An object of the present invention is to provide a method capable of improving the selectivity of the target compound, suppressing precipitation of heavy components in the reaction system, and further increasing the weight of the reaction apparatus, and enabling a long-term continuous operation of the reaction apparatus. is there.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have achieved the object by adding a solvent and carrying out the reaction under the condition that the reaction field density becomes a liquid phase of a certain value or more. I found out that I could do it. The present invention has been completed based on such findings.
That is, the present invention
(1) 2-butene and cyclopentadiene by Diels-Alder reaction of 5,6-dimethyl-bicyclo [2.2. 1] Upon producing hept-2-ene, was added the solvent, temperature 200 ° C. or higher, the pressure 5,6-dimethylbicyclo is characterized in that the reaction is carried out under the conditions of a liquid phase of 4 MPa · G or more , a molar ratio of 2-butene / cyclopentadiene of 5 to 15 and a reaction field density of 100 kg / m ³ or more. [2.2. 1] hept-2-ene the method of manufacturing,
(2) reaction field, the reaction is carried out at above the critical temperature and critical pressure on the supercritical state to become the conditions of mixture above (1), wherein the 5,6-dimethyl-bicyclo [2.2. 1] hept -2 A process for producing en ,
(3) The 5,6-description described in (1) or (2) above, wherein the solvent is at least one selected from an aliphatic hydrocarbon solvent, an alicyclic hydrocarbon solvent, and an aromatic hydrocarbon solvent. dimethyl bicyclo [2.2. 1] hept-2-ene the method of manufacturing,
(4) Temperature 200 to 350 ° C., above (1) to carry out the reaction under a pressure 4 ~20 MPa · G, (2 ) or (3) wherein the 5,6-dimethyl-bicyclo [2.2. 1] hept -2-ene production method,
Is to provide.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
In the method for producing bicyclo [2.2.1] heptenes according to the present invention, a dicycloalder reaction of a cycloolefin having 3 or 4 carbon atoms with cyclopentadiene is performed to produce bicyclo [2.2.1] heptenes. To manufacture. In this reaction, examples of the acyclic olefin having 3 or 4 carbon atoms used as one of the raw materials include propylene, 1-butene and 2-butene. Among these, 2-butene is particularly preferable. As this 2-butene, either a cis isomer or a trans isomer may be used, or a mixture thereof may be used. Hereinafter, a case where the acyclic olefin is 2-butene will be described as an example.
For cyclopentadiene, which is the other raw material, cyclopentadiene itself may be used, but Diels-Alder reaction is performed while dicyclopentadiene or tricyclopentadiene is charged into the reactor and cyclopentadiene is generated by thermal decomposition. May be.
[0009]
Although there is no restriction | limiting in particular about the usage-amount of the said 2-butene and cyclopentadiene, It is preferable that 2-butene is excess from a theoretical value, ie, 2-butene / cyclopentadiene molar ratio exceeds 1. When the molar ratio is 1 or less, many heavy by-products are easily generated. A preferable value of the molar ratio is in the range of 2 to 30, and a range of 5 to 15 is particularly preferable. If this molar ratio is less than 2, the selectivity of the target substance tends to be low, while if it exceeds 30, the volume of the reactor becomes too large, which is not preferable in terms of economy.
In the present invention, a solvent is used. As the solvent, a hydrocarbon solvent or an aprotic organic solvent can be used, but an aliphatic hydrocarbon solvent, an alicyclic hydrocarbon solvent, and an aromatic hydrocarbon solvent are preferable.
[0010]
Here, as an aliphatic hydrocarbon solvent, a C6-C30 linear or branched hydrocarbon compound is mentioned, for example. Examples of the alicyclic hydrocarbon solvent include cyclohexane, decalin, and hydrocarbon compounds having 6 to 15 carbon atoms in which an alkyl group is introduced. Furthermore, examples of the aromatic hydrocarbon solvent include hydrocarbon compounds having an aromatic ring having 6 to 15 carbon atoms such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, and tetralin.
These solvents may be used singly or in combination of two or more. The addition amount is not particularly limited as long as it is an amount capable of maintaining a liquid phase or a supercritical state under the temperature and pressure conditions during the reaction, but the mass ratio of solvent / 2-butene is 0.2. Is preferably in the range of 10 to 10, particularly preferably in the range of 0.5 to 5. If the mass ratio is less than 0.2, the conversion rate of cyclopentadiene may be low. On the other hand, if the mass ratio exceeds 10, the volume of the reactor becomes too large, which is not preferable in terms of economy.
[0011]
In the present invention, it is necessary to carry out the reaction under the condition that the solvent is added and the density of the reaction field becomes a liquid phase of 100 kg / m ³ or more. If the density is less than 100 kg / m ³ , precipitation and polymerization in the heavy reactor proceed, and continuous operation cannot be performed due to blockage or the like, and the object of the present invention cannot be achieved. The preferable density of the reaction field is in the range of 100 to 600 kg / m ³ , and particularly preferably in the range of 200 to 600 kg / m ³ . Therefore, the reaction temperature and the reaction pressure are selected under the conditions for maintaining the liquid phase, but the conditions in the supercritical state above the critical temperature of the mixture and above the critical pressure can be selected.
A preferable reaction temperature in the Diels-Alder reaction of 2-butene and cyclopentadiene is selected in the range of 180 to 450 ° C. If the reaction temperature is less than 180 ° C., a large amount of dicyclopentadiene will be present, and the yield of the target substance may be reduced. On the other hand, if the reaction temperature exceeds 450 ° C., the amount of heavy by-products will increase. This will cause a decrease in yield. A more preferable reaction temperature is selected in the range of 200 to 350 ° C.
[0012]
The reaction pressure is not particularly limited as long as it is a pressure capable of maintaining a liquid phase with a reaction field density of 100 kg / m ³ or more at the above reaction temperature, or a pressure higher than the critical pressure of the mixture. -The range of G is suitable. The critical pressure of 2-butene is 4 MPa · G. If it is less than 4 MPa · G, a gas phase is generated. On the other hand, if it exceeds 20 MPa · G, the pressure resistance of the reactor becomes too high, which is not preferable in terms of economy.
The reaction method may be any method such as a continuous flow method or a batch method, but the continuous flow method is preferable from the viewpoint of productivity. When this continuous flow type is adopted, it may be a tube type (single tube, multi-tube, empty column, packed column can be used) or a stirring tank type. In the case of a tube-type continuous flow reaction, LHSV (liquid hourly space velocity) is usually in the range of 0.1 to 20 h ⁻¹ , preferably 0.5 to 10 h ⁻¹ . If this LHSV is less than 0.5 h ⁻¹ , the residence time becomes too long and heavy by-products increase and the selectivity of the target product decreases, while if it exceeds 10 h ⁻¹ , the residence time becomes too short. , The conversion rate of cyclopentadiene is lowered, which is not preferable in terms of economy.
[0013]
Japanese Patent Laid-Open No. 2002-114714 discloses that the Diels-Alder reaction is carried out at a high temperature (220 to 350 ° C.) and a low pressure (1 to 4 MPa · G). The component has a low solubility in the gas phase and precipitates in the reactor, and easily causes contamination in the reactor. When the deposited heavy material is exposed to a high temperature in the reactor, it causes further heaviness (polymerization) and eventually causes the reactor to be clogged. In addition, the critical pressure of 2-butene is 4 MPa · G as described above, and a pressure of 4 MPa · G or more is required to bring the reactor into a supercritical state. Further, in the system without addition of solvent, the reaction temperature is considerably higher than the critical temperature of 2-butene (160 ° C.), so that the density in the reactor is the gas phase even when the pressure is higher than the critical pressure (supercritical state). In the same manner as in the gas phase, precipitation of heavy by-products and clogging of the reactor due to polymerization occur.
When a solvent is added and the liquid phase or supercritical state (near the critical point) is maintained under reaction temperature conditions, the by-product heavy components are discharged from the reactor in a state dissolved in the liquid phase or supercritical phase. Therefore, precipitation and polymerization in the reactor are unlikely to occur, and contamination and blockage of the reactor can be avoided. Furthermore, by increasing the pressure of the reaction system, the conversion rate of cyclopentadiene is improved, and by adding a solvent, the concentration of cyclopentadiene in the reactor is decreased, thereby causing a by-product involving cyclopentadiene (tricyclopentadiene). Etc.) and the one-pass yield is improved.
[0014]
When the acyclic olefin is 2-butene, 5,6-dimethylbicyclo [2.2.1] hept-2-ene is obtained as the target compound bicyclo [2.2.1] heptenes. When the acyclic olefin is 1-butene, 5-ethylbicyclo [2.2.1] hept-2-ene is obtained, and when propylene is used, 5-methylbicyclo [2.2.1] is obtained. ] Hept-2-ene is obtained.
[0015]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Example 1
A continuous flow experiment was conducted using a stainless steel flow-type pressurized reaction tube (empty column) having an inner diameter of 12 mm and a length of 40 cm.
Dicyclopentadiene 57.8 g (cyclopentadiene conversion 0.87 mol), mixed 2-butene (trans isomer / cis isomer = 62/38) 489.6 g (8.73 mol) and p-diethylbenzene 491 as a solvent in a raw material tank .6 g was charged to prepare a raw material mixture (2-blanc / cyclopentadiene molar ratio = 5, solvent / 2-butene mass ratio = 1).
The raw material mixture was continuously supplied to a tubular reactor adjusted to 290 ° C. and 9 MPa · G through a 200 ° C. preheating tube at 160 mL / h using a metering pump. At this time, 1 / LHSV was 0.23 h.
The reaction solution was returned to normal pressure via a pressure regulating valve, and then gas-liquid separation was performed in a receiver kept at 50 ° C. After reaching the steady state, the liquid phase was sampled as it was, while the gas phase was sampled after the entire amount was liquefied at -10 ° C. Both phases were analyzed using gas chromatography. As a result, the conversion was 44.0% based on cyclopentadiene, and the selectivity for 5,6-dimethylbicyclo [2.2.1] hept-2-ene was 83.4. %, And the yield was 36.7%.
[0016]
Example 2
In Example 1, it implemented like Example 1 except having changed the supply speed | rate of the raw material mixture into 50 mL / h (1 / LHSV = 0.74h). As a result, the cyclopentadiene conversion rate was 60.1%, 5,6-dimethylbicyclo [2.2.1] hept-2-ene selectivity was 77.3%, and the yield was 46.4%.
Example 3
In Example 1, it implemented like Example 1 except having used tetralin instead of p-diethylbenzene as a solvent. As a result, the cyclopentadiene conversion rate was 45.0%, the 5,6-dimethylbicyclo [2.2.1] hept-2-ene yield was 79.3%, and the yield was 35.7%.
Under this condition, continuous operation for about 100 hours was performed. After completion of the experiment, the reactor was opened, and no precipitate or polymer was found in the reactor.
[0017]
Comparative Example 1
Using a stainless steel flow-type pressurized reaction tube with an inner diameter of 20 mm and a length of 1000 mm, 1 / GHSV (1 / gas hourly space velocity) is 0.1 h under the conditions of 300 ° C. and 3 MPa · G. The same mixed 2-butene and dicyclopentadiene as in Example 1 were fed so that the 2-butene / cyclopentadiene molar ratio was 10. As a result, the conversion was 23.5% based on cyclopentadiene, the selectivity of 5,6-dimethylbicyclo [2.2.1] hept-2-ene was 67.6%, and the yield was 15.9%. It was.
Immediately after the start of operation, ΔP began to attach to the reactor, and continuous operation became impossible in about 24 hours. As a result of opening the reactor, a large amount of black polymer was produced in the reactor, and it was confirmed that the increase in ΔP was caused by the production of a polymer.
Comparative Example 2
Using a multi-tube continuous flow apparatus equipped with 10 tubes with an inner diameter of 24.9 mm and a length of 2000 mm, the same as in Example 1 was performed so that 1 / LHSV was 2 h under the conditions of 270 ° C. and 3 MPa · G. Mixed 2-butene and dicyclopentadiene were fed so that the 2-butene / cyclopentadiene molar ratio was 10. As a result, the 1-pass yield was as low as about 5%.
Several hours after the start of continuous operation, ΔP of the reactor increased, and continuous operation became impossible in one day. As a result of opening the reactor, a large amount of polymer was produced in the reactor.
[0018]
Example 4
Using a multi-tube continuous flow apparatus equipped with 10 tubes having an inner diameter of 24.9 mm and a length of 2000 mm, 1 / LHSV is 1 h under the conditions of 230 ° C. and 5.5 MPa · G. A similar mixture of 2-butene and dicyclopentadiene has a 2-butene / cyclopentadiene molar ratio of 10 and diethylbenzene (o, m, p-form mixture) as a solvent has a mass ratio of 1 to 2-butene. Supplied to. As a result, the yield of 1 pass was about 21.0%.
After 8 days of continuous operation, the reactor was inspected for opening. As a result, no precipitate or polymer was formed in the reactor.
[0019]
【The invention's effect】
According to the present invention, in the production of bicyclo [2.2.1] heptenes useful as a base oil production raw material for functional monomers and traction drive fluids, the conversion rate of the raw material cyclopentadiene and the selectivity of the target compound In addition, the precipitation of heavy components in the reaction system and further increase in the weight can be suppressed, and the reactor can be operated continuously for a long time.

Claims (4)

2-butene and cyclopentadiene by Diels-Alder reaction of 5,6-dimethyl-bicyclo [2.2. 1] Upon producing hept-2-ene, it was added the solvent, temperature 200 ° C. or higher, pressure 4 MPa-G As described above , the reaction is carried out under the condition that the liquid phase is such that the molar ratio of 2-butene / cyclopentadiene is 5 to 15 and the density of the reaction field is 100 g / m ³ or more, 5,6-dimethylbicyclo [ 2 . 2.1] hept-2-ene manufacturing method. Reaction field, the reaction is carried out at above the critical temperature and critical pressure on the supercritical state condition: mixture according to claim 1 5,6-dimethyl bicyclo according [2.2. 1] hept-2-ene manufacturing Method. Solvent, aliphatic hydrocarbon solvent is at least one selected from alicyclic hydrocarbon solvents and aromatic hydrocarbon solvents according to claim 1 or 2, wherein the 5,6-dimethyl-bicyclo [2.2 [ 1 ] A method for producing hept-2-ene . Temperature 200 to 350 ° C., 5,6-dimethyl bicyclo according to claim 1, wherein the reaction is carried out under a pressure 4 ~20 MPa · G [2. 2. 1] hept-2-ene manufacturing method.