JPH02108652A - Treatment of quaternary onium salt - Google Patents

Abstract

PURPOSE:To easily obtain the subject compound at a low cost by using thiocyanate ion, contacting an aqueous phase containing said ion with an organic phase hardly miscible with water containing a quaternary onium salt of a fluorine-containing carboxylic acid and successively contacting the organic phase with an aqueous phase containing a water-soluble oxidizing agent. CONSTITUTION:The objective compound is produced by contacting (A) an aqueous phase containing thiocyanate ion with (B) an organic phase hardly miscible with water containing a fluorine-containing carboxylic acid quaternary onium salt of formula (A is N or P; R1, R2, R3 and R4 are substituted or unsubstituted hydrocarbon group; the total number of carbon atoms of R1-R4 is >=8 per one onium ion; R1-R4 may be linked together to form a heterocyclic group; R1-R4 may contain other onium ion; RfCO2<-> is 2-15C polyfluorocarboxylic acid anion) to form a thiocyanic acid quaternary onium salt in the organic phase, transferring RfCO2<-> into the aqueous phase and contacting the above organic phase containing the onium salt with (C) an aqueous solution containing a water-soluble oxidizing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for treating quaternary onium salts.

More specifically, the present invention relates to a method for separating RfCO□O from a quaternary onium salt represented by general formula [I] and producing a quaternary onium salt with easy ion exchange.

[Conventional technology]

Utilization technology of O quaternary onium salt.

Quaternary onium salts are useful substances that are used as phase transfer catalysts and extractants for various anions from an aqueous phase by utilizing their ion exchange ability.

However, when the present inventor tried to utilize quaternary onium salts in the field of fluorine chemistry, the quaternary onium cation R+RzRJJ in general formula (1) was discovered.

[hereinafter abbreviated as QO] and the polyfluorocarboxylic acid anion RfCOρ in general formula (1) [hereinafter simply 1lf
cO! o] forms an extremely stable ion pair in a hydrophobic organic solvent, and it has been found that it is generally difficult to ion-exchange this RfCOρ with other anions.

Therefore, RfCO! In extraction methods and phase transfer catalytic reactions in which a quaternary onium salt represented by OQΦ is formed, RrcopqQ cannot be used repeatedly as it is, so it is necessary to exchange RfCOρ with an anion that can be easily exchanged by some method. be.

For example, in the following fields, there is a need to develop a technology for converting quaternary onium salts represented by general formula (1) into quaternary onium salts that are easier to ion exchange.

■ Recovery of polyfluorocarboxylic acid.

Polyfluorocarboxylic acid is a useful substance used in fluorosurfactants, solvents, etc., and is also very expensive, so an effective recovery method is desired, but no excellent recovery method has been found at present. do not have.

As mentioned above, it has been confirmed that polyfluorocarboxylic acid anions form extremely stable ion pairs with ρ in the organic phase. When brought into contact with the organic phase, the polyfluorocarboxylic acid anion can be easily extracted into the organic phase as a counter ion of QO.

However, at present, there is no known effective method to remove the polyfluorocarboxylic acid anion from the stable ion pair of QO and the polyfluorocarboxylic acid anion to regenerate a quaternary onium salt that is easy to ion exchange. When attempting to recover polyfluorocarboxylic acid ions using a quaternary onium salt, a complicated and costly treatment method has to be adopted, which is economically disadvantageous.

Conventional techniques for recovering polyfluorocarboxylic acids from aqueous media using quaternary onium salts include, for example,
A method for recovering fluoroalkanoic acid used as a surfactant from an aqueous medium used in the polymerization of fluoroolefins is disclosed in JP-A-61-246142.

An example of the operation in this case is as follows.

(i) adding hexadecyltrimethylammonium chloride to an aqueous solution containing ammonium perfluorooctanoate, (ii) extracting the produced hexadecyltrimethylammonium perfluorooctanoate with dichloromethane, and (ii) removing dichloromethane. A 50-layer capped χ sulfuric acid aqueous solution is added to the resulting salt, and distillation is performed to distill out the mutual fluorooctanoic acid. Obtain pure perfluorooctanoic acid by distillation.

The above method for recovering fluoroalkanoic acid requires complicated operations, and the quaternary onium salt is mixed in a highly concentrated sulfuric acid aqueous solution for 100 min.
It is necessary to treat at a high temperature of .degree. C. or higher for a long time, and decomposition of the quaternary onium cation moiety is unavoidable, so it cannot be said to be an industrially advantageous method.

On the other hand, if an effective treatment method for stable ion pairs between QO and polyfluorocarboxylic acid anions can be found, a very economical process for recovering polyfluorocarboxylic acids using quaternary onium salts will become possible. Conceivable.

■ Catalyst regeneration in phase transfer catalytic reactions.

In a phase transfer catalytic reaction using a quaternary onium salt as a catalyst, in the case of a reaction in which RfCOρ is produced as a main product or by-product, a stable ion pair Rrcopo
(Because Dh< is formed, the ion exchange ability of the catalyst decreases, and the activity of the phase transfer catalytic reaction is suppressed.

Even in such cases, in order to economically carry out the phase transfer catalytic reaction by effectively using QO, it is necessary to replace the quaternary onium salt with reduced activity with a quaternary onium salt with easy ion exchange and high activity. It is desired to develop an economical method to regenerate onium salts.

Conversion to a quaternary onium salt that facilitates O ion exchange.

Conventionally, the following method has been known as a method for converting a quaternary onium salt that forms a stable ion pair into a quaternary onium salt that facilitates ion exchange.

(a) Brands trQ
n) method (A, ``Ion pair extraction method (Preparative Jon Pa1r E)'' by Brändström.
xtraction) J pp. 139-148, Ap
otekarsocieteten/l1assle,
Lake+Wedel, Sweden, 1974): (Reaction formula) % Formula % - Uses toxic (CI+ 30) zso□.

・Operations are complicated as the solvent must be replaced after each reaction.

-Strict reaction conditions (high temperature, long time).

(b) Silver oxide (AgzO) method (written by W. T. Ford).

Journal of American Chemical Society (Journal of American Ch.
5ociety) 95.7381. (
1973)) :(Reaction formula) %Formula% ・Ag and O are expensive and it is not a practical method.

The conventionally known methods (a) and (b) as described above are as follows:
All of these methods have problems such as complicated operations and high processing costs, and cannot be said to be economical methods.

[Problem to be solved by the invention]

As shown above, RfC
The technology of separating O□O and converting it into a quaternary onium salt that can be easily ion-exchanged is important in fields such as phase transfer catalytic reactions and extraction, but no excellent method has been known so far.

(Means for Solving the Problems) The present inventors efficiently separated RfCOρ from the quaternary onium salt represented by the general formula (1) under mild conditions, and prepared a quaternary onium salt with easy ion exchange. As a result of intensive studies to find a method for converting the oxidation into a class onium salt, a treatment method using thiocyanate ions was discovered, and the present invention was completed.

That is, the present invention provides [(a), general formula [I]: RfC
O□O〇8R+RzR4 ・ ・ ・
・ ・ (1) (However, A represents an N or P atom.

R1, RZ, R3 and R4 represent substituted or unsubstituted hydrocarbon groups. The total number of carbons in R1, RZ, R:l and R4 is at least 8 per onium ion. Rlh, R3 and R4 may be linked to each other to form a heterocycle, or R+, Rz, lh or R4 may contain another onium ion.

RfCO,G represents a polyfluorocarboxylic acid anion having 2 to 15 carbon atoms. ) A water-immiscible organic phase containing a quaternary onium salt of a fluorine-containing carboxylic acid represented by RfCO! is simultaneously formed in the organic phase! A method for treating a quaternary onium salt, which comprises transferring G to an aqueous phase, and (g) contacting the organic phase containing the quaternary onium salt of thiocyanate with an aqueous solution containing a water-soluble oxidizing agent. It concerns J.

In the above case, the present inventors first converted RfCO□ from R r Co zOQO forming a stable ion pair.
A method of separating O was investigated. However, Rfc
Since o and ooO form an extremely stable ion pair, even when ion exchange was attempted between RfCO□0 and 01ρ, c+O, etc., almost no exchange occurred.

Therefore, as a result of further intensive studies on various methods, the present inventors surprisingly found that when an organic phase containing RfCOρρ was brought into contact with an aqueous phase containing thiocyanate ion SCρ, the RfCOteQo used in the present invention It was found that RfCOρ easily exchanges ions with SCρ.

As a result, a quaternary onium thiocyanate salt is formed in the organic phase, and since l1fCO□0 is transferred to the aqueous phase, RfCOρ can be easily recovered from the aqueous phase.

Furthermore, the quaternary onium thiocyanate salt produced in the organic phase forms a very stable ion pair, and as it is, it is difficult to exchange it with various anions in the aqueous phase. Therefore, the present inventors conducted intensive studies to find a method for converting the quaternary onium salt of thiocyanate in the organic phase into an active quaternary onium salt that can be easily exchanged with ions. When the organic phase containing the 5CNe is brought into contact with the aqueous phase containing the water-soluble oxidizing agent, 5CNe is easily decomposed under mild conditions, and as a result, the organic phase contains active quaternary onium that can be easily ion-exchanged with various anions. It was discovered that salts are formed, and the present invention was completed.

As described above, in order to carry out the present invention, it is only necessary to carry out the two-phase reaction of the organic phase and the aqueous phase twice, and the active quaternary onium salt produced by the treatment method of the present invention is The organic phase can be used repeatedly for phase transfer catalytic reactions and ion extraction as it is.

Furthermore, according to the method of the present invention, 1? fcOρ can be easily recovered. Therefore, by employing the method of the present invention, a simple and economical separation process or phase transfer catalytic reaction process becomes possible.

The present invention will be explained in more detail below.

In the method of the present invention, a hydrophobic quaternary onium cation represented by general formula (II) is used.

1? ,I? , RlR, ^O-...-(II) (However,
(n) In the formula, ^ represents an N or P atom, R,, R1, R
, and R4 represent a hydrocarbon group, which may be substituted with a substituent that is stable under the reaction conditions of the present invention.) The type and length of this hydrocarbon group depend on the It is appropriately selected depending on the solvent, purpose of use, etc. Examples of the type of hydrocarbon group include an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, an aralkyl group, an alkenylal group, and particularly preferably an alkyl group, an aryl group, an aralkyl group, etc. is used.

In addition, the lengths of the hydrocarbon groups are R+, Rz, Rs and R
The total number of carbon atoms contained in 4 is at least 8 per onium ion, usually in the range of 8 to 70, preferably in the range of 10 to 50, particularly preferably 12 to 50. The range is 40.

The inert substituents that can be substituted on the above hydrocarbon groups are limited depending on the reaction conditions, but halogens, acyl groups, ether groups, ester groups, nitrile groups, alkoxyl groups, etc. are usually used. .

R+, Rz, Rs and R4 may be linked to each other to form a heterocycle, or R+, Rz, R3 or R
4 may contain other onium ions.

Examples of the hydrophobic quaternary onium cation represented by general formula (n) include tetra-n-propylammonium ion, tetra-n-butylammonium ion, streamy octylmethylammonium ion, and tetra-n-propylammonium ion. -Octylammonium ion, tetra-n-decylammonium ion, cetyltrimethylammonium ion, tri-n-decylmethylammonium ion, benzyltrimethylammonium ion, benzyltriethylammonium ion, cetylbenzyldimethylammonium ion, cetylpyridinium ion, tododecylpyridinium ion , phenyltrimethylammonium ion, phenyltriethylammonium ion, N-benzylpicolinium ion, pentamethonium ion, hexamethonium ion, and other quaternary ammonium ions; or tetra-n-butylphosphonium ion, tri-n-octylethylphosphonium ion, tri-n-octylmethylphosphonium ion, cetyltriethylphosphonium ion, cetyltri-n-butylphosphonium ion, n-butyltriphenylphosphonium ion, n-amyltriphenylphosphonium ion, n-hexyltriphenylphosphonium ion, n
Examples include quaternary phosphonium ions such as -hebutyltriphenylphosphonium ion, methyltriphenylphosphonium ion, benzyltriphenylphosphonium ion, and tetraphenylphosphonium ion.

As RfCOρ in the quaternary onium salt represented by the general formula (1) used in the present invention, a polyfluorocarboxylic acid anion having 2 to 15 carbon atoms is used.

The above-mentioned polyfluorocarboxylic acid anion refers to a carboxylic acid anion in which a plurality of hydrogen atoms are substituted with fluorine, and preferably a fluorine-substituted carboxylic acid anion in which the number of fluorine atoms is equal to the number of hydrogen atoms. However, it may contain substituents that are stable under the operating conditions of the present invention, such as halogen atoms other than fluorine and ether groups.

Furthermore, among the polyfluorocarboxylic acid anions, those in which at least one fluorine atom is bonded to the carbon bonded to the carbonyl group are particularly preferred.

The number of carbon atoms in the polyfluorocarboxylic acid anion used in the present invention ranges from 2 to 15, preferably from 2 to 12.

Specific examples of polyfluorocarboxylic acid anions include trifluoroacetic acid, 2,3,3.3-tetrafluoropropionic acid, 2,2,3.3-tetrafluoropropionic acid, and 2-chloro-2,3,3 , 3-tetrafluoropropionic acid, pentafluoropropionic acid, perfluorovaleric acid, the following general formula [■]: Z-Rf-COJ ...... (I[I) (However,
llf is a perfluorinated linear or branched alkylene group having 5 to 10 carbon atoms, and Z is hydrogen, fluorine or chlorine. ), a long-chain polyfluorocarboxylic acid represented by perfluorooctanoic acid, which is commonly used as a fluorine anionic surfactant, and perfluoro-2-methyl-3-oxa-
perfluoroether carboxylic acids represented by hexanoic acid, aromatic carboxylic acids substituted with perfluoroalkyl groups, or perfluoroalkylene groups;
Examples include, but are not limited to, anions such as nuclear fluorinated aromatic carboxylic acids represented by pentafluorobenzoic acid.

In addition, in the quaternary onium salt to which the method of the present invention is applied,
Even if anions other than RfCO□O are included,
Since most of it is ion-exchanged with thiocyanate ions at the same time as RfCOρ, this does not pose a particular problem.

The poorly water-miscible organic phase used in the present invention has the general formula (
It contains a quaternary onium salt represented by 1) and forms a phase different from the aqueous phase, and usually consists of a quaternary onium salt and an organic solvent that is poorly miscible with water. In some cases, the main component may be a liquid quaternary onium salt.

Fl miscible with water for the organic phase used in the process of the invention! Examples of iN media include, for example, n-hexane, n-
- Aliphatic hydrocarbons such as octane and n-decane; Alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and decalin; Aromatic hydrocarbons such as benzene, toluene, and xylene; Diisopropyl ether, di-n-butyl ether Ethers such as; chlorinated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene; 1,2-dichloro-1,1,
2,2-tetrafluoroethane, fluorotrichloromethane, 1,1.2trichloro-1,2,2-)lifluoroethane, 1. L2゜Chlorofluorocarbons such as 2-tetrachloro-1,2-difluoroethane; perfluorocyclobutane, perfluorodimethylcyclobutane, perfluorohexane, perfluorooctane, perfluorodecane, 1,3-di(trifluoroacetate) Examples include, but are not limited to, fluorocarbons such as benzene and hexafluorobenzene; or mixed solvents thereof.

When selecting an organic solvent, consider the solubility of the quaternary onium salt, its phase separation from the aqueous phase, the proposed temperature at which the method of the present invention is carried out, and the actual use of the active onium salt obtained by the treatment method of the present invention. An appropriate solvent is selected in consideration of the conditions used for the phase transfer catalytic reaction and extraction.

Among the above solvents, chlorinated hydrocarbons are RfCO20Q
It is excellent in that the solubility of Q is high. In addition, fluorine-containing solvents are excellent in that they have good phase separation from the aqueous phase and have high solubility for fluorine-based reaction substrates and products when used as phase transfer catalysts.

The ion source of thiocyanate ions used in the method of the present invention is not particularly limited as long as it forms thiocyanate ions in an aqueous solution, and various water-soluble thiocyanates may be used. Ru.

Examples of water-soluble thiocyanates include alkali metal salts such as sodium thiocyanate and potassium thiocyanate; alkaline earth metal salts such as calcium thiocyanate and barium thiocyanate; zinc thiocyanate, iron thiocyanate, and thiocyanate. Examples include, but are not limited to, ammonium acid.

However, in consideration of price, availability, etc., sodium thiocyanate, potassium thiocyanate, and ammonium thiocyanate, which are used in large quantities industrially, are advantageous as thiocyanate ion sources.

There are no particular restrictions on the molar ratio of the quaternary onium salt RfCOzoQO (RfCOzoQO) and SCp used in the method of the present invention.

However, if the molar ratio of scρ/RfCOρ00 is less than 1, complete exchange of RfCOz○ is not possible, so if you want to exchange virtually all of the scρ/RfCOpQO, The molar ratio needs to be 1 or more.

In practice, the molar ratio of SCρ/RfCOρQO is usually 0.5<SCρ/RfCOρ[+C
D<20171 range, preferably 0.8<5CNO
/RfCOρQo〈10) Range power used.

1? As a reaction method for the organic phase containing fcoρQ(E) and the aqueous phase containing 5CNO, any of the Haunch method, half-flow method, and flow method, which are commonly used as two-liquid reaction methods, can be used. However, industrially, a flow method that allows continuous operation is advantageous, and in particular, a flow method using a countercurrent multistage catalytic reaction system is advantageous in that the amount of SCp used relative to RfCOρQO can be reduced.

As the countercurrent multistage reaction apparatus, mixer settlers, rotating disk extractors, perforated plate extraction towers, stirring extraction towers, etc., which are commonly used in extraction operations, etc. can be used as they are.

The temperature at which the organic phase containing RfCOρρ and the aqueous phase containing SCp are reacted may be around room temperature and is not particularly limited; however, if the temperature is too low, the ion exchange rate may become slow or the aqueous phase or may cause problems such as freezing,
Furthermore, if the temperature is too high, evaporation of the i8 medium will become a problem. Therefore, a temperature between -10°C and 100°C is usually chosen, preferably between -5°C and 80°C. Conventionally, the method of decomposing SCp was to use sodium hypochlorite in water? Although decomposition of 5C)10 in -7JI is known, an example of decomposition of SCp in a hydrophobic solvent was not known to the extent investigated by the present inventors.

However, the inventors' studies surprisingly revealed that
Although various water-soluble oxidizing agents including sodium hypochlorite contain quaternary onium thiocyanate in a phase different from the aqueous phase, that is, in an organic phase that is poorly miscible with water, It has been found that quaternary onium thiocyanate can be efficiently decomposed.

As the water-soluble oxidizing agent used in the present invention, various oxidizing agents that react with thiocyanate ions to decompose the thiocyanate ion structure are used. Examples include hypochlorites such as sodium hypochlorite, potassium hypochlorite, and calcium hypochlorite; chlorates such as sodium chlorate; chlorine including hypochlorous acid and chlorine water; Peroxide-based oxidizing agents such as hydrogen peroxide and t-butyl hydroperoxide; Nitric acid-based oxidizing agents such as nitric acid, nitrous acid, and sodium nitrate, or persulfuric acid-based oxidizing agents such as sodium persulfate. Examples include, but are not limited to, agents.

Among these water-soluble oxidizing agents, inorganic oxidizing agents are superior in that they are easy to handle and leave little residue in the organic phase. Among them, chlorine-based oxidizing agents, especially hypochlorites such as sodium hypochlorite, are easy to obtain and are excellent in terms of safety, operability, and reactivity, and the method of the present invention I am passing through.

Furthermore, polyfluorocarboxylic acid ion RfCO□0 represented by general formula [1] may coexist in the aqueous solution containing the water-soluble oxidizing agent used in the present invention. In such a case, Rf
Extraction of CO20 into the organic phase takes place.

In the method of the present invention, there is no particular restriction on the molar ratio of the water-soluble oxidizing agent to be reacted and the quaternary onium thiocyanate salt in the organic phase, but in order to sufficiently decompose 5CNO, it is necessary to It is preferable to use a molar ratio of oxidizing agent/quaternary onium thiocyanate of 2 or more.

In practice, in consideration of economic efficiency, reaction efficiency, etc., the molar ratio of water-soluble oxidizing agent/quaternary onium thiocyanate is usually in the range of 2 to 20, preferably in the range of 3 to 15. be done.

As a reaction method of the organic phase containing the quaternary onium thiocyanate salt and the aqueous phase containing the water-soluble oxidizing agent, the above-mentioned I? f
A method completely similar to the reaction method of the organic phase containing COρQO and the aqueous phase containing SCρ can be used.

The temperature for reacting the organic phase containing the quaternary onium thiocyanate with the aqueous phase containing the water-soluble oxidizing agent may be around room temperature and is not particularly limited, but if the temperature is too low, the reaction rate will be slow. If the temperature is too high, problems such as evaporation of the solvent may occur. Therefore, usually -10'C to 10
Temperatures between 0'C and preferably between -5°C and 60°C
A temperature between is chosen.

〔Effect of the invention〕

By employing the method for treating quaternary onium salts of the present invention, simple and economical separation processes and phase transfer catalytic reaction processes that utilize the properties of quaternary onium salts become possible.

〔Example〕

The present invention will be specifically explained below using Examples and Comparative Examples, but the present invention is not limited thereto.

In the table below, the trioctylmethylammonium thiocyanate salt used is abbreviated as TCA.

Example 1 Tri-n-octylmethylammonium chloride (hereinafter abbreviated as TOMAC) 4.0 g (10 m
1,1,2-trichloro-1,2 containing mol)
, 2-1-lifluoroethane (hereinafter abbreviated as !-113) dissolved tfj, 100 ml, and sodium trifluoroacetate (CF.

100 rrdl of an aqueous solution containing 2.04 g (15 mmol) of C0Ja) was charged into an eggplant flask with an internal volume of 500 al equipped with a stirring bar, and stirred at 30 °C for 1 hour.
The mixture was vigorously stirred for 0 minutes.

Thereafter, stirring was stopped and the mixture was allowed to stand to allow phase separation between the organic phase and the aqueous phase. When the contents of the organic phase were analyzed by infrared absorption spectroscopy and 19F-NMR spectroscopy, it was found that the chlorine ions in the TOMAC used at the beginning were almost total Ic.
It was found that CF3COρ (○ represents tri-ro-octylmethylammonium cation) was formed by exchanging with F and Co□O ions.

Infrared absorption spectrum ν0. . : 1695C+1-' (CF, CO2)
νゎ-M: 2940cm-'(ρ)"F-N
MR spectrum Cf: 87 ppm C hexafluorobenzene standard) (CFzC(ho) Example 2 CF3C0pQ"10+11 +m obtained in Example 1
1.62 g (20 w m
100 ml of an aqueous solution containing
Stirred at °C for 10 minutes. Thereafter, stirring was stopped and the mixture was allowed to stand to allow phase separation between the organic phase and the aqueous phase. When the contents in the organic phase were analyzed by infrared absorption spectroscopy and F-NMR spectroscopy, it was found that the initially used cp, copo (
It was found that 91% of CF, CO, C) in E) was converted to SCρ.

Infrared absorption spectrum ν6. . : 1695cm-' (residual CF, COρQ
G)) νscs: 2050cm-' (SCNO
) c-,: 2940cm-'(GO)' ”F
-NMR spectrum cL,: 87 ppm+ (hexafluorobenzene standard) (Residual cFicOzOQQ) Comparative Example 1 In the same manner as in Example 2, sodium thiocyanate 20
*20mmol of sodium chloride instead of mol
CFsCOρ0 was treated using ChC (hCI
Almost no conversion from Q(E) to QG)CIO was observed.

Example 3 Column diameter 40a with 10 stages of stirring chambers partitioned by perforated plates
An ion exchange reaction between CF2C0ρ00 in the organic phase and Na5CN in the aqueous phase was carried out using a +aΦ jacketed multistage countercurrent extraction column.

The same CF as in Example 2, the F-113 solution of CoρQO,
CF2C Na5CN aqueous solution at jacket temperature 15°C
0ρ00) and Na5C110 in a countercurrent flow so that the molar ratio was 1:1.5, CF in the organic phase,
Almost all of the CF3CO□O in the CO□OQ glaze was converted to 5CNQ.

Example 4 Trioctylmethylammonium thiocyanate salt 1h
F-113 solution containing 100 mol and an aqueous solution containing 1N sodium chlorite were prepared by changing the molar ratio of trioctylmethylammonium thiocyanate and sodium hypochlorite, and using a stirring bar. The mixture was filled into a 300 d eggplant flask and stirred vigorously for 10 minutes at a bath temperature of 20''C.

Thereafter, stirring was stopped and the mixture was allowed to stand to allow phase separation between the organic phase and the aqueous phase. As a result of analyzing the contents in the organic phase by infrared absorption spectroscopy, decomposition of 5CN(E) in trioctylmethylammonium thiocyanate salt as shown in Table 1 was confirmed.

It was confirmed by 'H-NMR spectrum that 00 in the organic phase was not decomposed at all in this operation. Also,
No 5C11O was present in the aqueous phase.

When the same operation as in Example 1 was carried out using the organic phase obtained in Experiment No. 4 in Table 1 below in place of the F-113i9 solution in Q10, the quaternary ammonium salt in the organic phase was was almost converted to CF This indicates that an active quaternary ammonium salt, which is easily ion-exchanged like C1O, was formed.

Comparative Example 2 Trioctylmethylammonium thiocyanate salt 10m
F-113?8 liquid 1001a1 containing mol and an aqueous solution ioo R1 containing 50 s mol of sodium chloride,
Although the mixture was stirred in the same manner as in Example 4, the SCN○ of trioctylmethylammonium thiocyanate in the organic phase hardly decreased.

Table 1 By touching CF 3CF! COpQo,
CF3Cl1ICOρQOOyohiCF zCFCICO
A zC'[1O(7)F113/8 solution was obtained.

These F-113 solutions were treated in the same manner as in Example 3,
Na5CN water? When treated with Solution B, prco2ooo was converted to trioctylmethylammonium thiocyanate with the results shown in Table 2 below.

Table 2 Example 5 In the same manner as in Example 1, 0 (Jio's F-113 solution and aqueous solutions of various fluorine-containing sodium carboxylates were applied.) Example 6 In the same manner as in Example 5, except that F-113 Using carbon tetrachloride instead of Na5CN/RfCOzO
Under the conditions of QO molar ratio 2.0 instead of 1.5, CPs
(CFt)□C(h OQo, CFi (Ch) 4
COρQO1Ch(Ch)aCotOρ, H+Ch +
? Coρmouth O1 and Chcptcpzocp (cp,
)copo(i), an attempt was made to convert it to trioctylmethylammonium thiocyanate, and the results shown in Table 3 below were obtained.

Table 3 Example 7 In the same manner as in Example 4, decomposition of 5CIIO in trioctylmethylammonium thiocyanate was attempted using various other water-soluble oxidizing agents instead of sodium hypochlorite. However, the oxidizing agent concentration is 2N, and the molar ratio of oxidizing agent/trioctylmethylammonium thiocyanate is 1
O1 stirring was performed at 30°C for 20 minutes.

The results are shown in Table 4 below, and all water-soluble oxidants effectively decomposed 5CNO.

In addition, all of the quaternary ammonium salts in the organic phase obtained by this treatment showed good CF3C0p extraction ability, as in the case of Example 4, and active quaternary ammonium salts that are easily ion-exchanged. It shows that it was formed.

Table 4 In addition, as in the case of Example 4, all of the quaternary ammonium salts in the organic phase obtained by this treatment showed good cp and coto extractability, and active quaternary ammonium salts that were easy to ion exchange. This indicates that a class ammonium salt was formed.

Example 8 In the same manner as in Example 7, but using F- as the organic solvent.
Using carbon tetrachloride instead of 113, attempts were made to decompose 5CNO in trioctylmethylammonium thiocyanate using various water-soluble oxidizing agents.

However, the molar ratio of oxidizing agent/trioctylmethylammonium thiocyanate salt and stirring time (oxidation treatment time) were performed under the conditions shown in Table 5 below.

The results are shown in Table 5 below, and all water-soluble oxidants effectively decomposed 5CN-.

Example 9 Aqueous solution prepared by adding concentrated hydrochloric acid to PI (2,8) Table 5 Various onium salts were converted in the same manner as in Example 5.However, Example 5 Dichloroethane was used instead of F-113 used as an organic solvent in
Also, instead of various RfCO□Qρ, CFsCOzO
”N(n-Bu)4,CP,Co,QIE)N(n-o
ct) a, CF3CO1α”NEtz (CHzPh)
, CF, co, α-(n-Decyl)4, CF, Co
ρEP(n-oct)Je, CPiCOzcXDPP
h:+(C1lzPh), CFiCOρ"P(n-B
Various onium salts such as u) and the like were used.

When these dichloroethane solutions of various onium trifluoroacetate salts were treated with an aqueous Na5CN solution in the same manner as in Example 3, conversion to onium thiocyanate salts was performed with the results shown in Table 6 below. .

Furthermore, when dichloroethane solutions of various onium thiocyanate salts obtained by this method were treated with an aqueous sodium hypochlorite solution under the same conditions as in Example 7, thiocyanate ion was Completely separated.

Table 6 Example 10 Using the same method as in Example 4, but using a 0.3N aqueous sodium persulfate solution instead of a 1N aqueous sodium hypochlorite solution, and using sodium persulfate/trithiocyanate. The molar ratio of octylmethylammonium salt is 3
．． 5C in trioctylmethylammonium thiocyanate salt by stirring for 30 minutes at a bath temperature of 40°C.
When an attempt was made to decompose NQ, 73% of 5CNO was decomposed.

Claims (1)

[Claims] (1), (a), General formula [I]: RfCO_2^■^■AR_1R_2R_3R_4...
... [I] (However, A represents N or P atom. R_1, R_2, R_3 and R_4 represent substituted or unsubstituted hydrocarbon groups. R_1, R_2, R_3 and R_
The total number of carbons in 4 is at least 8 per onium ion. R_1, R_2, R_3 and R_4 may be linked to each other to form a heterocycle, or R_
1, R_2, R_3 or R_4 may contain other onium ions. RfCO_2^■ represents a polyfluorocarboxylic acid anion having 2 to 15 carbon atoms. ) A water-immiscible organic phase containing a fluorine-containing carboxylic acid quaternary onium salt represented by (b) contacting the organic phase containing the quaternary onium thiocyanate with an aqueous solution containing a water-soluble oxidizing agent; How to treat quaternary onium salts.