JPS58131976A - Preparation of hexafluoro-1,2-epoxypropane - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as a monomer for the preparation of a fluorine-contained polymer and as an intermediate of perfluorovinyl ether, under mild conditions, in high yield, by reacting hexafluoropropene with an aqueous solution of a hypochlorous acid salt in the presence of a specific surface active agent and a water-insoluble organic solvent. CONSTITUTION:The titled compound is prepared by reacting hexafluoropropene with an aqueous solution of a hypochlorous acid salt in a water-insoluble organic solvent such as benzene, carbon tetrachloride, etc. in the presence of a surface active agent comprising anionic, nonionic or amphoteric surface active agents having the group of formulaI(n is >=2) (for anionic or nonionic surface active agent) or the group of formula II (for nonionic surface active agent) or their mixture. EFFECT:The solvent and the surface active agent can be recovered easily, and their consumptions are saved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing hexafluoro-1,2-epoxypropane, more specifically, a method for producing hexafluoro-1,2-epoxypropane from hexafluoropropene and an aqueous hypochlorite solution. Relating to a method of manufacturing.

Hexafluoro-1,2-epoxypropane is a conventionally known compound and has various useful uses. For example, it is used as a low polymer in heat-resistant liquids, as an intermediate for laryll perfluorovinyl ether, or as a monomer for fluorine-containing polymers.

Hitherto, various methods have been known for producing hexafluoro-1,2-epoxypropane, and these methods are usually carried out using hexafluoropropene as a raw material and acting on it with an oxidizing agent.

However, for example, a liquid phase method using hydrogen peroxide as an oxidizing agent has difficulty in treating the waste liquid, and a gas phase method using oxygen has the disadvantage that a considerable amount of decomposition products are generated.

Furthermore, the liquid phase method using an organic peroxide or the anodic oxidation method involves operational risks and complicated equipment.

Furthermore, there is also a method of reacting hexafluoropropene and hypochlorite salt in the presence of an aprotic solvent, which gives a good yield under mild conditions (1°P, Kolenk
o et al., 1zvestiya Akademii Nau
k.

USSR, 11. pp. 2509-2512, November 1979
Month). However, this production method uses acetonitrile and diglyme as aprotic solvents to carry out the reaction, and these solvents have high solubility in hypochlorite aqueous solutions and are difficult to recover from waste liquid. It is difficult to reuse the materials. In addition, these solvents react with hypochlorite and are gradually degraded and consumed, resulting in excessive consumption of hypochlorite. As described above, the known manufacturing method using hypochlorite has the advantage of being able to use inexpensive sodium hypochlorite, etc., so it was unsuitable as an industrial manufacturing method. .

The present inventors conducted intensive research to solve the above-mentioned problems regarding the method using hypochlorite. The present inventors have discovered that by conducting the reaction in the presence of an organic solvent, the solvent and surfactant can be easily recovered, the amount consumed is small, and a good yield can be achieved under mild conditions, and the present invention has been completed.

That is, the present invention combines hexafluoropropene and an aqueous hypochlorite solution into (a)(1)-(cl12Ct(2o
) a nonionic surfactant having an anionic or amine oxide group having an n-group (where n is 2 or more), or (+il) an amphoteric surfactant; and (b) a water-insoluble organic solvent. Hexafluoro-
A method for producing 1,2-epoxypropane is provided.

However, according to the method of the present invention, the waste liquid after the reaction undergoes phase separation from the solvent by standing still, and the elution of water-insoluble solvents and surfactants into the aqueous phase is extremely small, so it can be easily disposed of. can. On the other hand, water-insoluble solvents and surfactants hardly dissolve into the aqueous phase and do not change in quality, so they can be recycled and reused. Furthermore, the reaction according to the method of the present invention proceeds under mild conditions and the desired product can be obtained in high yield, making it extremely useful industrially.

In the method of the present invention, the reaction is carried out using an aqueous hypochlorite solution in the presence of a specific surfactant and a water-insoluble organic solvent.

As the hypochlorite, alkali metal salts and alkaline earth metal salts can be used, and sodium salts and potassium salts are particularly preferred. The amount of hypochlorite used in the reaction may be a stoichiometric amount to an excess amount relative to hexafluoro-propene. Although it is preferable that the concentration of the hypochlorite aqueous solution be high, it is usually 1 to 20% by weight.

The surfactant used in the method of the present invention refers to not only those commonly commercially available as surfactants, but also compounds having any of the following properties.

(+) soluble in at least one phase of the liquid system, (1
1) Molecules of the compound have as a constituent a group that is insoluble in the dissolved phase of the liquid system, (iiD a monomolecular film in which the molecules or ions of the chemical compound are oriented at the interface of the liquid system. (iv) In the case of a solution, the equilibrium concentration at the interface or greater than the equilibrium concentration of the entire solution; (v) When the overall concentration of the solution exceeds a certain value, aggregates of molecules or ions called micelles are formed. form, (v
l) Has any of the following functions: detergency, foam-forming ability, wetting ability, emulsifying ability, solubilizing ability, and dispersing ability.

The specific surfactants used in the method of the present invention include anionic, nonionic, and amphoteric surfactants;
Alternatively, they can be used in combination, and anionic, nonionic, or a mixture of both is particularly preferred. However, these surfactants have -(C112CH20)n- group [where n is 2 or more] (in the case of anionic or nonionic surfactants), or N-,0 group ( (in the case of nonionic surfactants). It was experimentally confirmed that these groups promote the reaction with hypochlorite tohexafluoropropene in cooperation with a water-insoluble organic solvent.

Typical examples of such surfactants include those having the following general formula (unless otherwise specified, n is 2 to 100, k is an alkyl group having 6 to 30 carbon atoms, and M is hydrogen). , alkali metal or organic amine residues such as triethanolamine residues or ammonium residues, n, m, p mean different overlap numbers depending on the compound)
: (l means 2 or 3) RO(CH2CH20). 503M (P is an integer of 1 to 5) 1 [RO(CH2CH20). +P-(OMI.

(X is 1.2 or 3, y is 3-x, M is hydrogen, sodium, potassium or morpholino (however, at least one means something other than hydrogen) (x, y and M are all the same as above) R-0-(CH2CH2O)□H (P is an integer from 1 to 5) C) 13
L t t 3C ■ 0 (CH2CH20). OCR CHO(CH2Cf(20)nOCR CHO(CH2C1120)nH CHO(CH2CH20) nH ■ CFlo(CH2CH20)nH Naw CHO(CH2CH20)nH ■ CH20(C1126H20)□H kCOO(C1120H2 0)nH/(CH2CH20)n[I RN \(.14°.H2o).□ RN, 0 2 (R1o and 2 are alkyl groups having 1 to 5 carbon atoms)
H3k.

2 (R1 and R2 are both the same as above) CH2C11
The amount of the 20H surfactant used is not particularly limited. The reaction rate increases as the amount used increases, but approaches a constant reaction rate determined by the type of activator. Generally, 0.1 to 10 weight percent of the hypochlorite aqueous solution is preferred. 0,1
If it is less than 10% by weight, it is meaningless in terms of industrial production.
There is no increase in the reaction rate with increasing amount, even if the weight % is exceeded.

As the solvent, a water-insoluble organic solvent is used.

In the method of the present invention, the reaction hardly proceeds in the presence of the surfactant alone and requires the presence of a water-insoluble organic solvent. It is necessary that the solvent is liquid at the reaction temperature, that it is hydrolyzed as much as possible in the presence of an alkali, and that it is as free from the oxidizing action of hypochlorite as possible. Such solvents generally include saturated aliphatic hydrocarbons, aromatic hydrocarbons, and halogen-substituted products thereof, such as benzene, toluene, xylene, chlorobenzene, dichlorobenzene, trifluorotrichloroethane, liquid paraffin, hexane, There are no particular limitations on the amounts of pensitrifluoride, P-chlorohencytrifluoride, and the four-term solvent used, and it is generally preferred that they be used in an amount of 1 to 30% based on the aqueous hypochlorite solution. If it is less than 1% by volume, it is meaningless in terms of industrial production, and if it exceeds 30% by volume, it is not economically desirable.

The reaction between hexafluoropropene and hypochlorite can be carried out in various ways, for example by adding hexafluoropropene to a mixture of an aqueous hypochlorite solution and a solvent, or vice versa. An aqueous hypochlorite solution may be added to the fluoropropene mixture system. Furthermore, since hypochlorite is easily generated by reacting chlorine with an aqueous caustic alkali solution, the reaction may be carried out by simultaneously adding hexafluoropropene and chlorine to a mixture of an aqueous caustic alkaline solution and a solvent. .

The reaction temperature is -20 to 40°C, preferably -10 to 3°C.
0°C is adopted. This is because when the temperature is lower than -20°C, the hypochlorite aqueous solution solidifies, whereas when the temperature exceeds 40°C, the hypochlorite becomes unstable.

The pH during the reaction is 9 or higher, preferably 10 or higher. This is for the convenience of pH adjustment since hypochlorite is unstable in acidic conditions.

A high reaction pressure is preferred, but usually atmospheric pressure or slightly increased pressure, for example 10 atmospheres or less, is employed.

The present invention will now be described in more detail with reference to Examples.

Example 1 Sodium hypochlorite was added to a sealed 300 m4 round bottom flask equipped with a stirrer, a gas inlet, a thermometer and a reflux condenser cooled to -78°C with dry cold methanol. Aqueous solution (10% available chlorine) 200
, e and 20 me of 30 wt % potassium hydroxide aqueous gauze were added, and chlorobenzene (CH2C[(20
). -〇 (average of n is 8) Prepare 1.0y.

Hexafluoropropene (hereinafter abbreviated as RFP) 16.
Charge 0y and start the reaction. During the reaction, the temperature inside the flask is maintained at -5 to 0°C. After 240 minutes, the generated gas was reduced to 178
Collect in a trap at °C (150y). As a result of analyzing the recovered gas by gas chromatography, it was found that hexafluoro-1,2-epoxypropane (HFPO) was 26.0
The mol% and )l F P were 74.0 mol%.

Examples 2 to 32 The results shown in Table 1 were obtained by the same operations as in Example 1, except that the raw materials and reagents shown in Table 1 were used and the conditions shown in the table were used.

In addition, in the table, P-chloro B TF means P-chloropene citrifluoride, the value of n in +CH2CH2O+o means the average value, and surfactant A means / \.

Procedural Amendment (Self-restraint March 13, 1980 Examiner of the Patent Office 1 Indication of Case 1982 Patent Application No. 013945 2 Title of Invention Process for Producing Hexafluoro-1,2-Epoxypropane 3
, Relationship with the case of the person making the amendment Patent applicant address 8611'l 1-1, Kita-ku, Osaka City, Osaka Prefecture] 12
No. 39 New Hankyu Building Name (285) Daikin Industries, Ltd. Representative Yama 1) Park 4, Agent 5, Date of amendment order Motto 7, Oral statement for amendment (1) Page 13 of the specification, 4 lines from the bottom, `` (The average of +1 is 8
)"a? Correct as r (average of n is 8.3)J.

that's all

Claims (1)

[Claims] (1) Hexafluoropropene and hypochlorite aqueous solution, (a) m+CH2cH2o+, an anionic or nonionic surfactant having a group (however, n is 2 or more), (11) amine oxide nonionic surfactants having groups, or (iiD amphoteric surfactants, and (b
) A method for producing hexafluoro-1,2-epoxypropane, which comprises reacting in the presence of a water-insoluble organic solvent.