JPH0283339A - Production of diene oligomer - Google Patents

Abstract

PURPOSE:To obtain an oligomer from a diene monomer in liquid phase in the presence of a complex catalyst in high yield while preventing the highly polymerizing reaction by evaporating the diene monomer during the reaction, thereby controlling the reaction temperature by the latent heat of evaporation. CONSTITUTION:A diene compound such as butadiene and isoprene is made to react in a liquid phase in the presence of a complex catalyst (preferably a Ti-based catalyst) to obtain an oligomer (e.g., octatriene, cyclooctadiene or methyloctatriene). The reaction temperature is controlled with the latent heat of evaporation absorbed by evaporating the diene compound during the reaction. The evaporated reaction mixture composed mainly of the diene monomer is condensed by cooling with air or water and returned to the reaction chamber. Since the cooling capability is increased by increasing the molar fraction of the diene monomer in the reaction system, it is preferable to perform the reaction by using the reaction solvent as little as possible or without using the solvent.

Description

[Detailed Description of the Invention] [Background of the Invention] Industrial Field of Application The present invention is directed to the oligomerization of dienes such as butadiene and isoprene in the presence of a complex catalyst to produce di- and trimers of dienes. Regarding how to.

BACKGROUND OF THE INVENTION Conventionally, oligomerization of conjugated dienes has been carried out by placing a complex catalyst, a solvent, and dienes as monomers in an autoclave, and reacting them as described in, for example, Japanese Patent Publication No. 60-59216. The heat generated during autoclaving has been removed simply by passing water through the jacket of the autoclave body from the outside.

However, in these methods, attempts are made to increase the amount of catalyst to accelerate the reaction rate and shorten the production time, or to reduce the amount of solvent and increase the amount of dienes as monomers to increase the production amount per batch. If an attempt was made to increase the reaction heat, the reaction heat was often so large that the cooling capacity could not keep up, resulting in a dangerous rise in the reaction temperature and pressure. In addition, an increase in reaction temperature leads to high polymerization of dienes and products,
As a result, not only is the yield of the diene oligomer, which is the original target compound, extremely reduced, but the reaction tank is also contaminated with highly viscous polymers, which may cause catalyst poisoning in the next production and cause high-density build-up on the walls. Due to the adhesion of polymers, the thermal conductivity deteriorates, causing problems in heat removal.

[Summary of the invention] The present invention aims to solve these problems,
The present invention provides a method for producing diene oligomers in which the reaction temperature can be easily controlled and at a high yield.

Summary: The present invention is a method for producing oligomers from diene monomers in the presence of a complex catalyst in a liquid phase, mainly by vaporizing diene monomers during the polymerization reaction and controlling the reaction temperature using the latent heat of vaporization. It is a characteristic feature.

Effects According to the present invention, the reaction temperature can be easily controlled,
Moreover, diene oligomers can be produced in high yield. Furthermore, the present invention can also provide a method for solvent-free low polymerization of diene oligomers that does not require a reaction solvent.

[Detailed description of the invention Codiene monomer and its oligomer The diene monomer to which the production method of the present invention can be applied refers to a diene having 4 to 12 carbon atoms, and specific examples include:
butadiene, isopre, piperylene, 1,3-hexadiene, 1,3-octadiene, 1,3-dodecadiene,
5-methyl-1,3-hexadiene, 6-ethyl-1,
Examples include 3-octadiene. Particularly preferred for the production method of the invention are dienes having 4 to 5 carbon atoms, such as butadiene, isoprene, piperylene.

The dienes to which the present invention is applicable are not limited to conjugated dienes,
Any material capable of diene polymerization may be used.

Therefore, for example, butadiene includes not only 1,3-butadiene but also 1,2-butadiene.

Furthermore, the diene oligomer that can be produced by the method of the present invention is a dimer or mer of the above-mentioned dienes, preferably a whole of 2 or 3.

Specific examples of diene oligomers that can be produced by the present invention include the following.

Octatriene, dodecatetraene, hexadecapentenes, cyclooctadiene (COD), cyclododecatriene (CDT) etc. derived from butadiene, dimethyloctatriene, trimethyldodecatetraene, dimethyloctatriene derived from isoprene, etc. diene (DMCOD), trimethylchlordodecatriene (T
MCDT), octatriene derived from piperylene, DMCODSTMCDT, etc.

Furthermore, the diene oligomer that can be produced by the present invention is
It may be obtained by copolymerizing multiple diene monomers, such as methyloctatriene, dimethyldodecatetraene, methylcyclooctadiene, methylcyclododecatriene, dimethylcyclododecatriene, etc. obtained from butadiene and isoprene. Examples include co-dimers and trimers of .

Catalyst and Solvent As the complex catalyst that can be used in the method of the present invention, known catalysts used in the production of diene oligomers by diene polymerization can be used. Specific examples of this complex catalyst include:
Ti-based catalyst (Japanese Patent Publication No. 487628, Japanese Patent Publication No. 48-
19304, Japanese Patent Publication No. 49-4456, Japanese Patent Publication No. 49-4215, Japanese Patent Publication No. 33957-1982, Japanese Patent Publication No. 37186-1986, Japanese Patent Publication No. 60592.
16), Nl-based catalyst (Japanese Patent Publication No. 38-168)
82 Publication, Special Publication No. 43-22975, Special Publication No. 4
9-56950, JP 49-56951, JP 50-31138, JP 50-939
No. 41, JP-A-51-68504, JP-A-Sho 5
1-98242 etc.), Fe-based catalyst (Bull
, Chem, Soc, Jpn, 391357
(1966), etc.), Zr-based contact vX, (Bull,
Chem, Soc, Jpn, 422303 (1
909), Japanese Patent Publication No. 48-30603, Japanese Patent Application Publication No. 1973
-29403, Japanese Patent Publication No. 53-5642, US Pat. No. 4,071,575, etc.), Pd-based catalysts (Bull, Chem, Soc, Jpn, etc.).

461300 (1973), diary 88130B (1
967), JP-A No. 52-23006, JP-A-Sho 5
3-98907, etc.). Among these, the present invention is particularly effective for Ti-based catalysts which have extremely high initial activity and therefore generate intense heat in the initial stage.

The diene oligomerization reaction of the present invention can be carried out in a suitable reaction solvent. The solvent used can be appropriately selected from among suitable solvent systems depending on the diene monomer and the type of catalyst used. The amount of solvent can be 20% by weight or less, preferably 10% by weight or less based on the diene monomer.

However, in the present invention, as described later, it is also possible to carry out the polymerization reaction without using a solvent, and the use of a solvent is not necessarily essential in the present invention.

Specific examples of solvents that can be used in the present invention include benzene,
Examples include aromatic solvents such as toluene and xylene, and paraffinic solvents such as hexane and heptane. Furthermore, the generated diene oligomer also substantially functions as a solvent.

Reaction and Reaction Apparatus The diene polymerization reaction of the present invention is the same as the known low polymerization reaction of dienes, except for the modifications described below and the accompanying modifications to the reaction apparatus. Regarding the oligomerization of known dienes, please refer to the basics and reviews, for example, Journal of the Society of Organic Synthetic Chemistry, 41 (2) 154 (
1983) etc. may be referred to.

The diene polymerization reaction of dienes of the present invention is carried out by placing the dienes as monomers, a reaction catalyst, and if necessary a solvent in a reaction tank. Generally, the diene polymerization reaction is an exothermic reaction, so in order to make the reaction proceed steadily,
It is necessary to remove the generated heat to prevent the reaction temperature from rising and to stably maintain the reaction temperature at a desired value.

In the present invention, the heat of the polymerization reaction is removed by utilizing the latent heat of vaporization of the reaction mixture, mainly diene as a monomer. That is, a reaction mixture consisting of unreacted diene monomer, generated diene oligomer, and optionally a solvent is present in the reaction tank.
In the present invention, the reaction mixture is vaporized by the heat of polymerization reaction, and at that time, the amount of heat equivalent to the latent heat of vaporization of the reaction mixture is removed from the reaction mixture. This is used to remove the reaction heat and control the reaction temperature. It is something to do.

In particular, since the boiling point of the diene monomer in the reaction mixture is relatively low compared to that of other reaction mixtures, it is mainly this diene monomer that is vaporized by the generated polymerization reaction heat, and during vaporization, this diene monomer is An amount of heat equivalent to the latent heat of vaporization of the monomer can be removed from the reaction mixture.

The vaporized reaction mixture, consisting primarily of diene monomer, will then typically be cooled, condensed, and returned to the reactor to participate in the reaction. The cooling means in the present invention is not particularly limited as long as it is a heat exchanger that can at least condense the vaporized diene monomer, but an air-cooled or water-cooled condenser is preferably used.

The reaction temperature is automatically controlled as the reaction progresses. In other words, when the reaction is not very violent, the heat generation is not that large, and as a result, the amount of vaporization of the reaction mixture is corresponding to the heat generation.On the other hand, when the reaction proceeds violently, the heat generation increases, but as a result, , the reaction mixture becomes actively vaporized, and the amount of heat corresponding to the amount of heat generated is removed. As described above, in the production method of the present invention, reaction heat is automatically removed depending on the reaction state.

Furthermore, as an aid to controlling the reaction temperature, it may be useful to control the amount of this reaction mixture fed to the cooling means and/or the amount of cooled condensate returned to the reaction vessel. This control means is usually preferably implemented by a valve or the like. It is also possible to control the reaction temperature by adjusting the cooling efficiency of the cooling means, for example, by adjusting the amount of water passed through a water-cooled condenser.

Furthermore, the reaction can be carried out at a desired temperature by reducing or increasing the pressure in the reaction system so that the boiling point of the diene as a monomer becomes a desired temperature. For example, TMC
When producing DT, the temperature is desirably 50°C or lower, and according to Mizuyoshi, it is possible to control the temperature to 45°C or lower.

As described above, in the present invention, the reaction heat can be removed depending on the reaction situation, so that the reaction can be controlled more easily and stably than in the past. Furthermore, the present invention
Attempts to increase production per batch by increasing the amount of catalyst to speed up the reaction rate, or reducing the amount of solvent and increasing the amount of dienes as monomers, which cannot be achieved using conventional cooling methods. It can effectively cope with such modifications. The amount of catalyst is lXl0 per mole of conjugated diene.
'~lXl0-1 mol transition metal catalyst, preferably 1x1
02 molar transition metal catalyst.

The use of the production method of the present invention is particularly effective because monomers such as titanium-based catalysts have extremely high reaction activity at relatively low temperatures, such as around room temperature, and have a short catalyst life. This is the case when the reaction must be completed in a short time by feeding all at once. When the reaction must proceed at such a relatively low temperature (for example, about 40°C), it is necessary to pass water through the autoclave jacket of the reaction tank as in the past, or to install an inner coil in the reaction tank. If the temperature difference between the reaction system and the cooling water was small, temperature control would be difficult. On the other hand, according to the present invention, even in such a case, it is possible to allow the reaction to proceed stably at a desired temperature.

Furthermore, in the production method of the present invention, since the reaction temperature can be stably controlled to a desired value, side reactions such as high diene polymerization can be effectively prevented. Therefore, it is possible to solve the conventional problems such as contamination of the reaction tank and poisoning of the catalyst due to highly viscous polymers.

In addition, the heat removal ability in the production method of the present invention increases as the zero mole fraction of diene monomer in the reaction system increases. It can be said that it is preferable from the viewpoint of removing the heat of the polymerization reaction to carry out the polymerization reaction without the reaction. Furthermore, since the amount of monomer per batch increases, it is also advantageous in that production efficiency per batch can be improved.

In addition, in the conventional diene polymerization method, a high-pressure reactor was essential to ensure safety even in the event of a runaway reaction, but in the production method of the present invention, a low-pressure reactor (5 kg/cd
(G and below) reactors can be used.

Therefore, a specific example of the reaction apparatus used in the production method of the present invention is as shown in FIG. In FIG. 1, 1 is a catalyst preparation tank, 2 is a reaction tank, and 3 is a condenser (overhead condenser).

The polymerization reaction of the present invention can be explained using FIG. 1 as described above. First, a catalyst and, if necessary, a solvent are put into a catalyst preparation tank 1, stirred and adjusted, and then put into a reaction tank 2.

Then, dienes are put into the reaction tank 2 and stirred to start the reaction. Unreacted diene monomer is mainly vaporized by reaction heat generated as the reaction progresses. The vaporized diene monomer enters the overhead condenser 3 via valve 6, where it is cooled and condensed. The condensed diene monomer passes through valve 6 again and enters reaction tank 2.
return to the reaction. This series of vaporization, cooling, and condensation cycles of the diene monomer removes the heat of reaction from the reaction mixture in the reactor, allowing control of the reaction temperature.

〔Example〕

Example 1 In a 150 g reactor as shown in FIG.
21 g of titanium tetrachloride, 181 g of ethylaluminum sesquichloride, and 8.5 g of dimethyl sulfoxide were added, and after stirring and mixing with a stirring blade 9, this was introduced into the reaction tank 2. Then dehydrated and degassed Butadiene 76
kg was put into the reaction tank. After pressurizing with nitrogen, the temperature was raised while stirring with a stirring blade 10, and the temperature inside the reaction tank was maintained at 40° C. by valve control of the overhead condenser, and the reaction was carried out for 3 hours.

After cooling, the reaction crude liquid taken out from the reaction tank valve 8 was analyzed by gas chromatography. As a result, the reaction rate of butadiene was 98.6%, and the reaction rate of butadiene was 98.6%.
) was obtained in an amount of 68.7 kg, with a yield of 90.4%.

Comparative Example 1 Same as Example 1 except that toluene was changed to 20 liters, butadiene was changed to 60 kg, the valve 6 of the overhead condenser was closed, and cooling was performed by passing water through the water jacket 4 (approximately 20°C). and the reaction was carried out.

After the reaction started, the reaction temperature became uncontrollable and the reaction temperature decreased to about 1
At 80 °C, the pressure rose to 12-3 kg/ca.

After cooling, the reaction crude liquid was analyzed, and the reaction rate of butadiene was 99.4%, and 17.2 kg of CDT was obtained, with a yield of 2.
It was 8.6%. Furthermore, the viscosity of the crude liquid was high, and high polymerization occurred. The reaction tank was dyed with this highly polymerized product, and had to be washed before the next reaction.

Example 2 In a reaction apparatus as shown in FIG. 1, 0.5 liters of toluene, 15 mL of titanium tetrachloride, 4.4'-dichlorobenzophenone 34, were added to the catalyst adjustment tank 1 under nitrogen gas.
g1 and 5.4 g of dimethyl sulfoxide were added to the 150-liter reaction tank 2 while stirring. Next, put 85 kg of dehydrated and degassed isoprene into reaction tank 2, mix and stir, and then add 145 g of diethyl aluminum chloride.
was added and the temperature was raised. After the temperature reached 40° C., the valve 6 of the overhead condenser 3 was opened, the reaction temperature was controlled by the latent heat of vaporization of isoprene, and the reaction was carried out for 3 hours.

After cooling, the crude reaction solution was analyzed, and the isoprene reaction rate was 98.3%, and trimethylcyclododecatriene (TM
CDT) was obtained in an amount of 56.1 kg, and the yield was 66.0%.

Comparative Example 2 The temperature was raised to 40°C in the same manner as in Example 2, except that the valve 6 to the overhead condenser 3 was closed, an inner coil was installed in the reaction tank, and the amount of toluene was changed to 20 liters and 70 kg of isoprene. The reaction was carried out. The reaction temperature was controlled by passing water through the jacket and inner coil, but the reaction heat could not be removed and the reaction temperature was 18.
At 0°C, the pressure rose to about 10 kg/c-.

After cooling, the reaction crude liquid was extracted and analyzed, and the reaction rate of isoprene was 99.7%, and TMCDT was 17.7k.
The yield was 25.396 g. Further, a high polymer of isoprene adhered to the reaction tank 2, and the next reaction could not be carried out unless it was cleaned.

Example 3 In the same manner as in Example 1, toluene 1. After introducing 6 kg of nickel acetylacetonate, 252 g of nickel acetylacetonate, 450 g of cresyl phosphite, 228 g of l-ethylaluminium, and 76 kg of butadiene into reaction tank 1, nitrogen was pressurized.
The reaction was carried out by raising the temperature to 95°C.

Open valve 6 to overhead condenser 3;
The reaction was carried out at 95° C. for 5 hours while controlling the reaction temperature. After the reaction was completed, it was cooled and the crude reaction liquid was analyzed.
The reaction rate of butadiene was 981%, and 69.4 kg of cyclooctadiene (COD) was obtained, with a yield of 91.396.
Met.

Example 4 In the same manner as in Example 1, 2 liters of toluene, 328 g of nickel acetylacetonate, 107 g of pentaerythritol phosphite, 29 g of ethylaluminum
After introducing 6 g of isoprene and 85 kg of isoprene into reaction tank 1, nitrogen pressure was applied, and the temperature was raised to 95° C. to cause a reaction. The reaction heat was controlled by an overhead condenser 3, and the reaction was carried out for 5 hours.

After cooling, the reaction crude liquid was analyzed, and the reaction rate of isoprene was 97.6%, and T M CD T was 46.6 kg.
The yield was 54.8%.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a reaction apparatus suitable for carrying out the production method of the present invention. DESCRIPTION OF SYMBOLS 1... Catalyst adjustment tank, 2... Reaction tank, 3... Condenser (overhead condenser), 4... Water passage jacket, 5... Catalyst adjustment tank valve, 6... Condenser valve , 7... Water passage jacket valve, 8... Reaction tank valve, 9... Catalyst adjustment tank stirring blade, 10... Reaction tank stirring blade.

Claims (1)

[Claims] 1. A method for producing oligomers from diene monomers in the presence of a complex catalyst in a liquid phase, which is mainly characterized by vaporizing the diene monomer during the polymerization reaction and controlling the reaction temperature using the latent heat of vaporization. Method for producing diene oligomers.