JPH02115155A - Production of 2,5-dimethylhexanedinitrile - Google Patents

Abstract

PURPOSE:To obtain the title compound in high current efficiency and in high efficiency by using an electroconductive substance containing an inorganic salt and a quaternary ammonium salt as a supporting electrolyte and dimerizing methacrylonitrile through electrolytic reduction in an emulsion base having a specific composition by a single electrolytic cell. CONSTITUTION:Methacrylonitrile is electrolytically reduced in an emulsion base having 0.05-0.30, especially 0.10-0.2 volume ratio of oil phase, 20-90wt.%, especially 30-80wt.% methacrylonitrile concentration in the oil phase, 1.0-20.0wt.%, especially 2-10wt.% concentration of the compound shown by the formula in a water phase and pH5-10 in the water phase at 45-65 deg.C temperature of electrolyte and 5-40Angstrom current density per 1dm<2> cathode surface in the presence of an electroconductive substance comprising an inorganic salt containing a phosphate and a compound shown by the formula [R<1>-R<4> are alkyl or aralkyl (sum of carbons is 10-25); X is acid group; n is integer corresponding to ion valence of X] to give the aimed compound.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to the production of 2,5-dimethylhexane dinitrile (hereinafter abbreviated as DMADN) by electroreductive dimerization of methacrylonitrile (hereinafter abbreviated as MAN). ), and in particular, a method for continuously carrying out the same.

DMADN is important as a raw material for agricultural chemicals, medicines, synthetic fibers, synthetic resins, etc. In particular, its hydrogenated product, 2,5-dimethyl-1,6-hexa/diamine, is used as a raw material for transparent nylon. In addition, hexahydro-3,6-dimethyl-1H-azepine, which is a permeation product obtained by hydrogenation, extraction, and ammonia, has recently become particularly important as a raw material for carbamate-based drugs.

(Prior art) Conventionally, DMAD by electrolytic reduction dimerization of batch-type MAN
The following method is known as a method for producing N.

) A method of electrolytic reduction using sodium hydroxide as an electrolytic supporting salt and graphite, zinc, tin, and copper as cathodes in an aqueous solution.

(A,,P,Tom4xor,L,V,Kaa
bak and S,L.

Varsharskii, Zh, 0bahch,
Khjm-+ 33 (9) + (21y A method of electrolytic reduction using traethylammonium para-toluenesulfur electrolyte and mercury as a cathode in a water-dimethylformamide mixed solvent.

C.M., M., Ba1zer and J.D., and
erson, J.

Electrochemical Soc, +111
(2)+223-26 (1964), and U.S. Pat. No. 3,193.481 (1965)), but (I)
The method of 12. shows the maximum yield even under a graphite cathode.
Only 9% selectivity and 0.6% current efficiency were obtained, and it is stated in the document (1) above that DMADN was not generated with tin and copper cathodes. A major problem is low current efficiency. Since method (2) uses mercury as a cathode, it is extremely problematic in terms of pollution prevention as an industrial production method.

In addition, (1) and (21) both methods are batch reactions and are not suitable for industrial production on a certain scale.
A continuous method for producing N was unknown.

On the other hand, as an industrial method for producing adiponitrile by electroreductive dimerization of acrylonitrile, which is a similar compound of MAN, a method that does not use a mercury cathode is generally carried out. However, even though electrolytic reduction is the same, the yield of the reduced 2 product differs greatly depending on the structure of the starting nitrile, and the conversion of simple techniques does not give good results. That is, due to the presence of its methyl group, MAN
Since it is significantly different from acrylonitrile in water solubility, electronic state, degree of steric hindrance, etc., its reaction behavior is different from that of acrylonitrile.

Incidentally, when the present inventors attempted electrolysis of MAN under the conditions normally adopted for electrolytic reduction of acrylonitrile to 2ft, as is clear from Comparative Example 6, DMA
It was found that almost no DN was generated, making it unsuitable for practical use.

Furthermore, JP-A-59-219485, JP-A-60-
Publication No. 50190 solves the above-mentioned problems and proposes a technology that can be industrialized.

That is, MAN'5c-NoshiroR1-itchR3yO (in the formula, R1, R2, R31R'lr
The alkyl group having 4 or less carbon atoms, ρ, represents at least one counter anion selected from the group consisting of a monoalkyl sulfate anion, an aromatic sulfonate anion, a hexafluoride anion, a phosphate anion, and a perchlorate anion. ) in an aprotic polar solvent in the presence of a quaternary ammonium salt represented by: lead, steel, zinc, carbon, titanium,
It is characterized by electrolytic reduction dimerization using a cathode whose main component is at least one element selected from the group of
We have obtained high reaction results of more than %.

The feature of this technology is that dimethyl sulfoxide or dimethyl formamide as an aprotic solvent is added to the catholyte to achieve selectivity and current efficiency at an industrial level. It makes things uniform and at the same time exhibits a remarkable solvent effect.

Furthermore, in JP-A No. 60-52587, the recovery rate of starting materials, solvents, and quaternary ammonium salts from a homogeneous catholyte is
In addition, a method for isolating the desired raw material has been proposed.

(Problems to be Solved by the Invention) However, if the processes proposed in the three JP-A-Sho publications mentioned above are operated continuously for a long time, the aprotic solvent used gradually decomposes and accumulates. At the same time, the performance of electrolytic reactions deteriorated, and at the same time, the operations of recovering raw materials, solvents, and quaternary ammonium salts from a homogeneous catholyte and isolating products became increasingly difficult, especially for quaternary ammonium salts. The problem has arisen that collection is getting worse.

(Ninth Means to Solve the Problems) As a result of intensive study on industrialization technology that can solve the above problems, the inventors of the present invention have developed a method for producing quaternary ammonium salts, which are bulky to some extent, using a membraneless electrolytic cell. It can be industrialized by using a supporting electrolyte that contains it and setting a specific electrolyte composition in an aqueous emulsion system! D that can be operated continuously and stably for a long time while achieving good reaction results and suppressing hydrogen generation.
We have discovered a method for manufacturing MADN.

That is, the present invention uses a single MAN made of lead or a lead alloy, cadmium as a cathode, and iron or an iron alloy as an anode.
In a 1LM bath, in the presence of an electrically conductive substance consisting of an inorganic salt containing a phosphate and a quaternary ammonium represented by the general formula, in the state of an aqueous emulsion, and the volume ratio of the oil phase in the aqueous emulsion 'k0. 05 to 0.60, the concentration of MAN in the oil phase to 20 to 9 Q wt%, the concentration of quaternary ammonium salt in the water phase to 1.0 to 20, and the concentration of - This is a method for producing DMADN, characterized in that electrolytic reduction is carried out at a concentration of 5 to 10.

The present invention will be explained below.

The essence of the present invention is to perform the electrolytic reaction in a single-chamber electrolyzer, and the objective cannot be achieved simply by achieving high current efficiency and high yield; it suppresses hydrogen generation and generates an explosive mixed gas. This can only be achieved by preventing this and being able to operate continuously and stably for a long period of time.

For this purpose, a conductive substance containing an inorganic salt and a quaternary ammonium salt is used as a supporting electrolyte, and in an aqueous emulsion state, the ratio of the oil phase and water phase in the aqueous emulsion, the concentration of MAN in the oil phase, and the water It is necessary to combine the six features of setting the concentration of the quaternary ammonium salt in the phase to a specific value.

In the present invention, it is necessary to carry out this reaction in an aqueous emulsion state, that is, in a heterogeneous phase consisting of an aqueous phase and an oil phase.

The oil phase cap ratio of the electrolyte emulsion in method 2 of the present invention is preferably in the range of 0.05 to 0.60, more preferably 0.05 to 0.60 from the viewpoint of separation and recovery of the generated DMADN and stable maintenance of the electrolyte composition. .10 to 0.2.

The aqueous phase of the aqueous emulsion mainly contains electrically conductive substances, including phosphates and quaternary ammonium salts, which influence -, especially phosphates. In order to adjust F)1 in the aqueous layer to 5-10, it is necessary to adjust the phosphate, that is, the alkali metal salt of phosphoric acid, t-pl (5 to 10). To do this, phosphoric acid or dihydrogen phosphate must be neutralized with alkali, or alkali metal hydroxide or phosphoric acid-hydrogen salt must be neutralized with phosphoric acid. If it comes off, the by-products of MAN will increase.

As the inorganic salt used in the present invention, it is preferable to mainly use a phosphate or a mixture of a phosphate and a borate.

Electrode wear is reduced, especially when a mixture of phosphate and borate is used. Of course, sulfates and carbonates may be included, and organic residues such as p-1 luenesulfonic acid and ethyl sulfate can also be used together as anions.

The cations of the inorganic salt used in the present invention include, for example, alkali metal cations such as sodium, potassium, lithium, cesium and rubidium, and ammonium ions, with sodium and potassium being preferred for economical reasons.

There are no particular restrictions on the amount of inorganic salt to be used as long as the electrical resistance of the emulsion is not extremely low and electrolysis can be carried out smoothly, and the concentration in the aqueous phase is usually in the range of 1 to 30% by weight. It is used like this.

The degree of effectiveness of the quaternary ammonium salt used in the present invention varies depending on the type of food. It is preferable to use a quaternary ammonium salt having a total number of carbon atoms of 10 or more and 25 or less in the general formula described below. When it is less than 10 and more than 25, current efficiency and reaction yield decrease.

As mentioned above, the quaternary ammonium salt has the general formula (RA in the formula
, B2, R3 and R4 are the same or different alkyl groups or aralkyl groups, and the total number of carbon atoms in these groups is 10 to 25, or is an acid group,
n is an integer and corresponds to the valence of the ion of X. ) is a compound represented by As for this quaternary ammonium salt, it is generally preferable that RA, R2, R, 3 and R' are selected from the group consisting of methyl group, ethyl group, propyl group, butyl group, and amyl group and are alkyl groups. ,
Among them, at least 6 of R1, R2, R3 and R4
It is particularly preferable that each group is an alkyl group having 6 or more carbon atoms. As such, for example, tetra (n or 5
80)-propyl, tetra(n or iso)-butyl, tetra(n or 18o)-amyl, ethyltripropyl, ethyltributyl, ammonium salts of ethylpropyldibutyl, and the like.

As the counter anion X (same as shown in -Noshiro) of the quaternary ammonium salt, for example, phosphate ion, sulfate ion, halogen ion, etc. are used, and among these, phosphate ion is preferable.

Sulfate ions, halogen ions, and the like are undesirable because they cause a slight decrease in reaction yield and current efficiency, and halogen ions increase electrode wear.

The amount of quaternary ammonium salt in the aqueous phase is 1% by weight or more from the viewpoint of improving the electrolytic reaction M, performance, suppressing hydrogen generation, and improving the anticorrosion effect of the electrode. However, if the amount is too large, the electrical resistance of the electrolyte will increase and the amount of dissolution into the cocoon oil phase will also increase, leading to problems such as increased loss during recovery, so it is preferably 20 wt% or less. Preferably it's Vi2~i [1wt].

The concentration of MAN in the oil phase of the aqueous emulsion particularly affects the electrolytic reaction performance, and in order to achieve high electrolytic reaction performance that can be industrialized, a concentration of 20 to 9 Qwt% is required, preferably 30 Qwt%. ~80 wt%. If the methacrylic concentration is less than 20 wt%, not only will the electrolytic reaction result be poor, but hydrogen will also be generated intensely.
More than t%? Remer production increases.

The cathode material used in the present invention is lead, an alloy containing lead as a main component, cadmium, etc., but it does not cause pollution problems, has sufficient mechanical strength, and can be used in a bipolar filter press type battery case. It is preferable to use lead or a lead alloy containing lead as a main component, which can continue stable operation for a long period of time even when used for. Examples of lead alloys include hard lead containing antimony and lead-tin alloys.

The anode material used in the present invention is iron or an iron alloy containing iron as a main component. Examples of the iron alloy include carbon steel, nickel-containing steel, and stainless steel.

The electrolytic cell used in the present invention is a single-chamber electrolytic cell using the anode and cathode described above. Examples of the single electrolytic cell include a filter press type and a tank type, but the filter press type is preferred from an industrial perspective. To explain in detail about the filter press type, a cathode plate and an anode plate are opposed in parallel, and there is a polypropylene plate between the two electrodes that defines the electrode spacing, and the electrolyte flows through the center of this polypropylene plate. The conductive area of the electrode is determined by the size of the opening, and the electrode spacing is determined by the thickness of the plate.

The temperature of the electrolytic solution in the electrolytic cell during electrolysis may be at or above the precipitation point of the alkali metal salt, but is usually 20 to 75°C, preferably 30 to 70°C, and more preferably 45 to 65°C.

The current density during electrolysis is usually 0.05 to 70 A1, preferably 1 to 50 A1, and more preferably 5 to 40 A1 per cathode surface i dm2.

In the present invention, the distance between the cathode and the anode in the electrolytic cell is
The distance is usually 0.1 to 5n, preferably 1 to 3 distances.

In addition, the electrolyte is usually 0.1 to 4 times per electrode between the electrodes of this container.
sec, preferably at a speed of 0.5 to 2.5 m/sec.

In the method of the present invention, it is necessary to treat the electrolyte in order to suppress hydrogen generation at the cathode. For example, there are methods in which a free sequestering agent such as ethylenediaminetetraacetate is included in the electrolyte and brought into contact with the cathode surface, a method in which triethanolamine is added, and a method in which the electrolyte is extracted and treated with an ion exchange resin or a chelate resin. . Among these, a preferable method is to extract the electrolyte, use an ion exchange resin,
This is a method of treatment with a chelate resin, and the most preferred method is a method of treatment with a chelate resin.

An embodiment of the method of the present invention will be described based on the drawings. 1
is a filter press type non-diaphragm electrolytic cell, 2 is an absorption tower for raw material MAN, and 3 is an electrolyte tank. The electrolytic reaction solution is circulated between the absorption tower 2 and the electrolytic cell 1, and after undergoing an electrolytic reduction reaction in the electrolytic cell 1, it is converted into raw material MAN,
An aqueous emulsion of an oil phase containing the product DMADN and an aqueous phase containing quaternary ammonium salts and inorganic salts and oxygen generated at the anode return to the absorption tower 2. In the absorption tower 2, a purified aqueous phase is supplied from the upper part, MAN as a raw material is absorbed into the aqueous phase, and oxygen not containing MAN is barged from A to the outside.

The electrolyte supplied from the absorption tower 2 to the electrolytic cell 1 is extracted.
The electrolyte is circulated between the electrolyte tank 3 and the absorption tower 2 (11). Furthermore, a part of the electrolyte supplied from the absorption tower 2 to the electrolytic cell 1 is extracted and sent to the raw material MAN stripper tower 4. In the MAN stripper tower 4, MAN, by-product urinbutyronitrile (hereinafter abbreviated as IBN), and a part of water are extracted from the upper part, and the remaining liquid is extracted from the lower part and sent to an emulsion breaker. 8. In the emulsion breaker 8, the aqueous emulsion is separated into an oil phase and an aqueous phase, and the oil phase is sent to the next DMADN refining step C.
MADN is isolated. The aqueous phase is sent to the chelate resin tower 9, where heavy metal ions mainly consisting of iron are removed and purified, and then O/I-cycled into the electrolyte tank 2. Some of them are M
It is supplied to the upper part of the AN absorption tower 2. The mixed liquid extracted from the upper part of the MAN stripper column 4 is supplied to a decanter 5 and separated into an oil and water phase. Oil phase is IBN stripper 6
The raw material MAN is extracted from the upper part of the MAN
It is collected in the absorption tower 2, and the by-product IBN is extracted from the lower part. The aqueous phase in the lower part of the decanter 5 is supplied to the water stripper 7, and raw material MAN is extracted from the upper part of the decanter.
'The water is collected into the M liquid tank 3, and the water is extracted from the lower part. The refining process of the raw material MAN and the product DMADN to be consumed, and the quaternary ammonium salt etc. which are partially dissolved in the oil phase and extracted are supplied from B.

(Effect of the invention) The advantages of the present invention are listed below.

1) Using specific inorganic salts and quaternary ammonium salts as supporting solutes, setting the solution composition to specific conditions in an aqueous emulsion state, and using conventionally used cathode chambers and anode chambers. DMADN can be obtained with extremely high current efficiency and excellent selectivity by electrolytic reduction in an equipment-simplified single-chamber electrolyzer that does not require a separate 'electrolytic cell and an anolyte.

2) Separation of the product is easy. In other words, the emulsion that has left the electrolytic tank can be easily removed by simply allowing it to stand still.
It can be easily divided into an oil phase mainly composed of MAN as a raw material and DMADN as a product, and an aqueous phase mainly composed of water and a conductive substance. The product can be easily isolated and purified by removing only this oil phase and distilling it. In this distillation, there is no need to distill and recover multiple solvents as in a homogeneous system, and the utility costs are extremely low. After the electrolytic solution is separated into two phases, the aqueous phase can be subjected to subsequent electrolysis as it is after some treatment.

3) The conductive material lx, which is the supporting electrolyte, can be easily separated and recovered. That is, as mentioned in 2) above, the oil phase and the water phase can be easily separated, and the permissive substance in this oil phase can be separated and recovered very easily by extraction with water.

4) It is possible to operate continuously and stably for a long period of time.

Thus, the present invention provides MAN7fr:ll (dereduction 2
This is of great significance in that it provides a very advantageous industrial production method for quantifying and producing DMADN.

(Examples) Examples will be shown below to further specifically explain the present invention. However, the flow efficiency of 11 was determined by the following formula on the assumption that 1 mole of DMADN or IBN was generated based on the amount of electricity of 2 Faradays.

"LvJ represents the flow linear velocity on the pole surface, and the selectivity was determined by the following formula.

Example 1 A single-chamber electrolyzer uses a lead alloy with a current-carrying surface of 1 crn x 90 crIL as the cathode, and uses nickel-containing steel with the same current-carrying surface as the anode, with a spacer placed between the cathode and the anode, with a gap of 2 ml. A friend to keep. Two of these single-chamber electrolytic cells were connected in series. The hot liquid contains 10 volumes of oil phase and 90 volumes of oil phase.
The composition of the aqueous phase is MAN approximately 0.62iit and ethyltributylammonium salt 5.0%. t%, potassium phosphate approximately 131%
, about 6% potassium borate DMADN O, 6% by weight
and an aqueous solution containing some IBN, p) with phosphoric acid.
Adjusted to 17.7. The oil phase is in solubility equilibrium with the aqueous solution, and its composition is approximately 75% MAR, DMA
Approximately 15i% DN and other IBN water.

This emulsion is transferred from the electrolyte tank to a current-carrying surface at a linear speed of 1.
Supply and circulation to a single chamber electrolytic cell at a rate of 577 L/sec,
Electrolysis was performed at a current density of 15 A/dm and 255°C. At the same time as electricity is turned on, a portion of the electrolyte is continuously drawn out from the electrolyte tank and sent to a decanter, where it is separated into an oil phase and an aqueous phase. The produced DMADN and by-products are extracted from the decanter as an oil phase. A portion of the aqueous phase is extracted and passed through a resin column filled with chelate resin, and the passed solution returns to the electrolyte tank and is circulated to the electrolytic cell. The amount of liquid passed is approximately 8 cr-
/A・HR.

MAN and water were continuously added so as to maintain the above-mentioned hot liquid composition X, and ethyltributylammonium salt dissolved in the oil phase and extracted was added at any time.

As a result of carrying out electrolysis in this manner for 170 hours, the hydrogen contained in the generated gas was 0.10 vot% at the end of the electrolysis, and stable operation was possible without any wear on the cathode. 'The IL flow efficiency is 57%, and the consumption MAN-based DMADN selection system is 69%.

Examples 2-9 A single-chamber electrolyzer uses a lead alloy with a 1 cm x 90α current-carrying surface as the cathode, a carbon steel with the same current-carrying surface as the anode, and a spacer T device between the cathode and the anode. 1
．． A distance of 5 m was maintained. Two of these single-chamber electrolytic cells were connected in series. The electrolytic solution forms an emulsion with the composition shown in Table 1, consisting of an oil phase and an aqueous phase, and the concentration of potassium phosphate in the aqueous phase is approximately 16=x%, and the concentration of potassium borate is approximately 3%. Ta. Concentration of ethyltributylammonium salt and -
The details are shown in Table 1.

This emulsion is transferred from the electrolyte tank to a current-carrying surface at a linear speed of 1.
Electrolysis was carried out at the temperature shown in Table 1 with a current density of 20 A/dm by circulating the supply to a single-chamber electrolyzer at a current density of 5 m/sec. A portion was extracted and sent to a decanter to separate it into an oil phase and an aqueous phase.The raw DMADN and by-products were extracted from the decanter as this oil phase.A portion of the aqueous phase was extracted and packed with chelate resin. The liquid is passed through the resin tower, and the liquid is returned to the electrolyte tank and circulated to the battery tank.

To maintain the above electrolyte composition, MAN and water were continuously added, and after being dissolved in the oil phase and extracted, ethyltributylammonium salt was added as needed.

As a result of performing electrolysis for 50 hours in this manner, the hydrogen contained in the generated gas was 0.10 volts at the end of electrolysis, and stable operation was possible. The current efficiency is shown in Table 1.

Example 10 Electrolysis was carried out in the same manner as in Example 2, except that the cathode was replaced with a lead alloy and a cadmium plate was used. The results are shown in Table 1.

Example 11 A single-chamber electrolyzer uses a conductive surface, a lead alloy with a tiv of 92 dm2 as the cathode, a decarbonized W4 with the same current-conducting area as the anode, and a spacer placed between the cathode and the anode.
．． Continuous electrolysis was carried out in the following process as shown in the drawings using a device having two pairs of battery containers kept at an interval of 5 m.

The electrolyte composition was maintained within the range of the open method in which the electrolytic reaction was carried out. The volume ratio of the oil phase is 0.1-0.15, the MAN concentration in the oil phase is 40-45%, the IBM concentration is 6-8%, and the ethylbutylammonium salt concentration in the water phase is 4.5-5.0-i%, the concentration of potassium phosphate is 12
~13 weight ratio, concentration of potassium borate is 2.5-3.0
Weight i%, - was in the range of 7.5 to 8.0.

The reaction conditions were as follows. The linear velocity inside the battery case is 1
．． 5 m/sec, electrolytic cell input pressure U 1.3 to 1.41 V/G
%Equivalent pressure is 0.2~0.3kg/(), current density is 20
A/dm2@, the solution temperature was maintained at 55° C. at the outlet of the cell. 'ai decomposition thermal liquid ring volume is 7 m''/Hr,
The raw material MAN was continuously supplied to the feed fjk8 at a rate of 9/Hr, and the insufficient water and ethyltributylammonium salt were added as needed to maintain the electrolyte composition within the above range while analyzing the electrolyte composition.

As a result of continuous electrolysis for 383 hours as described above, the hydrogen contained in the generated gas was 0.1 to i, Qvot%.
The iron ion concentration in the electrolyte aqueous phase can be maintained within the range of 15
The lead ion concentration could be maintained at 8 to 15 ppm, the voltage could be maintained at 8.4 to 8.6 V, and the cathode could be operated stably with almost no consumption. The average current efficiency over all time for DMADN was 55%, and the selectivity of consumed MAN pace was 62%.

Comparative example: Current-carrying area of both anode and cathode was 2.23 dm” (25 m
The anode chamber and the cathode chamber are partitioned by a cation exchange membrane obtained by sulfonating divinylbenzene-styrene-butadiene copolymer with a thickness of 1, using lead from ``892 Dragon'', and a spacer made of polyethylene. A filter press type container was used in which the distance between the membrane and the electrode was maintained at 2 mm.

For the anolyte, 600 roy of a 10% sulfuric acid aqueous solution was used, and approximately 609 y of pure water was continuously added per 1 Faraday (F) of the current-carrying lid to maintain the sulfuric acid concentration at 103 % of the lid. Oxygen generated from the anode passes through cooling water for a length of 500 s + m.
It was dissipated into the atmosphere through the Zimroth. As the catholyte, MAN 8.2 ]<% by volume, DMA, DN 11.8
m%, Nato2ethylammonium #L salt 8.71
℃m%, water 69.2 specie% mixture 3,0 [10,!
l' was used. Keep the catholyte at a temperature of 50-55℃,
Circulating stirring at LVl, 077L/sec, anolyte also at L
While performing #i ring stirring at V 1-Orn/sec, the MAN concentration of the entire catholyte was 8 ± 1 mk%, the tetraethylammonium concentration was 9 ± 1% by weight, and the water concentration of the entire catholyte was 70 ± 51% by mass. Adjust the extraction sweetness, feed 1ltl, and current density to 6OA to maintain
/ dm” and operated continuously for 24 hours. DMA
Both the current efficiency and selectivity of DN were below 10.

[Brief explanation of the drawing]

The drawing is an example of a block flowchart of a continuous process according to the present invention. Patent applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] Methacrylonitrile is used in a single electrolytic cell consisting of lead or a lead alloy, cadmium as a cathode, and iron or an iron alloy as an anode, and an inorganic salt containing a phosphate and a general formula ▲ mathematical formula, chemical formula, table. etc. ▼ [In the formula, R^1, R^2, R^3 and R^4 are the same or different alkyl groups or aralkyl groups, and the total number of carbon atoms in these groups is 10 to 25. Yes, X
is an acid group, and n is an integer corresponding to the ionic valence of X. ] In the presence of an electrically conductive substance consisting of quaternary ammonium represented by the formula, in an aqueous emulsion state, and the volume ratio of the oil phase in the aqueous emulsion is set to 0.05 to 0.30, methacrylonitrile in the oil phase is The concentration of is set to 20 to 90 wt%,
The concentration of quaternary ammonium salt in the aqueous phase was set to 1.0 to 20.
A method for producing 2,5-dimethylhexane dinitrile, which is characterized by carrying out electrolytic reduction at a pH of 5 to 10 in the aqueous phase.