JPS63139154A - Production of perfluorotrialkylamine - Google Patents

Abstract

PURPOSE:To obtain a compound useful as a test bath medium for electronic parts heating medium for gas-phase soldering, etc., in high yield, by fluorinating a trialkylamine or a partially fluorinated trialkylamine with a fluorine gas at a specific temperature. CONSTITUTION:A trialkylamine or a partially fluorinated trialkylamine is fluorinated with a fluorine gas at 110-180 deg.C, preferably 120-150 deg.C to give the aimed substance. Optionally neutralization reaction and distillation are carried out. When fluorination is carried out by the use of a high valence metal lic fluoride, a partially fluorinated trialkylamine having the number ratio of H/F of <=1/8, especially <=1/10 is obtained. When this compound is used as a raw material, existence of incomplete fluorinated substance is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing perfluorotrialkylamines in high yield by fluorination using fluorine gas.

(Prior art and problems to be solved by the invention) Perfluoro organic compounds in which all hydrogen atoms in organic compounds are replaced with fluorine atoms are generally chemically stable, have high dielectric strength, and high thermal conductivity. It has properties such as low surface tension, high oxygen solubility, non-flammability, non-toxicity and odor. For this reason, perfluorinated organic compounds are used as test heating media for electronic components, heating media for vapor phase soldering, insulating coolants for electronic equipment, oxygen carriers for artificial blood, working fluids for heat pumps, and the like.

Among the above uses, perfluorotrialkylamines are particularly useful as test heating media for electronic parts.

The compound is suitable for vapor phase soldering, as a heating medium, as an irrigation fluid for organs, etc. Methods for producing this perfluorotrialkylamine include an electrolytic fluorination method using hydrogen fluoride (U.S. Patent No. 2,519,983) and a fluorination method using fluorine gas (Organic Fluorine Chemistry, written by Atsushi Sakai). Gihodo, published December 1, 1970, p. 135) is known. The former electrolytic fluorination method has a relatively good yield of perfluorotrialkylamine, but the latter fluorination method using fluorine gas produces a large amount of decomposition products of perfluorotrialkyl 7 amine, As a result, the yield of perfluorotrialkyl 7mine was only 1
It was about 0%.

(Problems to be Solved by the Invention) The present inventors have proposed a method for obtaining perfluorotrialkylamine in high yield by a fluorination method using fluorine gas using triflukylamine or partially fluorinated triflukylamine as a raw material. I've done a lot of research. As a result, the perfluorinated (perfluory) IJ alkylamine yield is
The present invention was completed based on the discovery that the fluorination reaction temperature largely depends on the reaction temperature and that perfluorotrialkylamines can be obtained in high yield only within a specific narrow temperature range.

That is, the present invention is a method for producing perfluorotrialkylamine, which is characterized by fluorinating trialkylamine or partially fluorinated trialkyl-7mine using fluorine gas at a temperature range of 110 to 180°C.

In the present invention, trialkyl 7 used as a raw material
Any known min may be used without any restriction. For example, trimethylamine.

Examples include triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, trioctylamine, dipentylbutylamine, dintylpropylamine, and the like. In particular, the trialkylamine preferably used in the present invention has 4 to 2 carbon atoms.
4, and further 10 to 18 compounds.

As a raw material in the present invention, a partially fluorinated triflukylamine in which the hydrogen atoms of the above-mentioned trialkylamine are partially substituted with fluorine atoms can also be used. If fluorination does not proceed completely, incompletely fluorinated products remain in the PerfluoropMJ flukylamine.

This underfluorinated product causes serious problems when perfluorotrialkylamines are used in various applications. Therefore, it is preferable to separate the incompletely fluorinated product from the perfluorotrialkylamine, but separation by distillation has been extremely difficult. In the present invention, the above-described partially fluorinated trialkylamine has a ratio of hydrogen atoms to fluorine atoms (H/F) of 1/8 or less, particularly 1/1.
When a compound with a fluorinated fluoride content of 0 or less is used, it is possible to suppress the residual amount of incompletely fluorinated substances to an extremely low level. Furthermore, since the incompletely fluorinated product is fluorinated to become perfluorotrialkylamine, the desired perfluorotrialkylamine can be obtained in high yield. However, the above-mentioned ratio of hydrogen atoms to fluorine atoms is an average value of all partially fluorinated triflukylamines, which are a collection of individual partially fluorinated triflukylamines having various ratios.

As a method for obtaining partially fluorinated trialkylamine,
Known fluorination methods are employed without any restriction. especially,
Fluorination methods using high valence metal fluorides are preferred. The fluorination method using a high-valent metal fluoride will be specifically described as follows.

Examples of high-valent metal fluorides include cobalt trifluoride, potassium tetrafluoride, scissors difluoride, manganese trifluoride, cerium tetrafluoride, lead tetrafluoride, and antimony pentafluoride. Among these, cobalt trifluoride, potassium tetrafluorocobaltate, silver difluoride, and manganese trifluoride are preferably used.

On the other hand, as a raw material for fluorination, the above-mentioned trialkyl-7mine, a halogenated trialkyl-7mine partially substituted with a fluorine atom or a chlorine atom, or an unsaturated bond obtained by dehydrogenation of a trialkylamine is used. Amines are used.

The reaction to obtain a partially fluorinated trialkylamine by contacting a high-valent metal fluoride with the above-mentioned raw materials can be carried out in either a liquid phase or a gas phase. In the case of a liquid phase, a diluting solvent or dispersant that is stable to high-valent fluorides is usually used in order to ensure sufficient stirring and control the reaction temperature. Generally, it is more convenient to carry out the reaction in the gas phase because the fluorination reaction proceeds more easily. The raw material is supplied to the reactor alone or in the presence of a high-valent metal fluoride and an inert gas, such as nitrogen or helium. It is preferable to spread the high-valent metal heptadide into a thin layer or stir it in the reactor in order to improve contact with the raw materials. The reaction temperature is usually 1
The temperature is selected from the range of 00 to 400°C. The reaction shifts the high valence metal fluoride to a low valence metal fluoride. If the fluorination ability decreases as a result, it can be regenerated by reaction with fluorine gas at high temperatures. Typically, the fluorinated product and hydrogen heptadide are collected separately from inert gases in a cold trap. Thereafter, if necessary, hydrogen fluoride is removed by operations such as neutralization, and the product is separated and purified by distillation or other methods.

As a method for obtaining the above-mentioned partially fluorinated trialkyl 7mine with a specific ratio of the number of hydrogen atoms to fluorine atoms, there is a method of appropriately selecting the conditions for fluorination with the above-mentioned high-valent fluoride, or a method of appropriately selecting the conditions of fluorination with the above-mentioned fluorine Examples include methods for purifying partially fluorinated trialkylamine obtained by chemical reaction.

When fluorinating by the method of the present invention, it is preferable to use a perfluorotrialkylamine corresponding to the raw material as a reaction medium rather than using the raw material alone. The amount of perfluorotrialkylamine used as a reaction medium is not particularly limited, but it is in the range of 40 to 600 parts by weight, more preferably 70 to 400 parts by weight, of perfluoro)IJ alkyl 7 amine per 100 parts by weight of the raw material. It is preferable. As mentioned above, when partially fluorinated trialkylamine is used as a raw material, perfluorotrialkyl 7 co-produced when obtaining partially fluorinated trialkylamine
Min can be used directly as a reaction medium.

The greatest feature of the present invention is that the fluorination reaction of the above-described trialkylamine or partially fluorinated trialkylamine with fluorine gas is carried out at a temperature of 110 to 180°C, preferably 120°C.
The point is to carry out the process at a temperature of ~150°C. When the temperature of the fluorination reaction is less than 110°C, the fluorination reaction hardly progresses. On the other hand, if the temperature of the fluorination reaction exceeds 180°C, a large amount of decomposed products of the target barfluorinated riflkylamine are produced. However, by increasing the reaction temperature to 110°C or higher, the fluorination reaction progresses rapidly, and by suppressing the reaction temperature to 180°C or lower,
The present inventors have discovered that the decomposition of the target per-7-fluorotriflukylamine is significantly suppressed. Therefore, by setting the reaction temperature to 110 to 180°C, the desired perfluorotri-7-rukyl-7mine fluorination with fluorine gas of the present invention can be achieved using known methods except for employing the above-mentioned reaction temperature. It can be used without any restrictions. Fluorination can be carried out in either a gas phase reaction or a liquid phase reaction, but as mentioned above, a liquid phase reaction using perfluorotrialkyl 7mine as a liquid medium is preferable to achieve the desired perfluorotrifluorination in high yield. This is preferred because an alkylamine can be obtained.

When carrying out a liquid phase reaction, it is preferable to adopt the following method in order to improve the contact between the raw material trialkylamine or partially fluorinated triflukylamine and fluorine gas. The raw material is brought into contact with fluorine gas while stirring.

(2) Blowing fluorine gas into the raw material.

(3) Bringing the raw material and fluorine gas into contact with each other in countercurrent flow.

(4) The raw material is brought into contact with fluorine gas in the form of droplets.

In this case, nickel or nickel alloys are used to increase the efficiency of contact. Other metal particles.

It is preferable to use Raschig rings, wire mesh, etc. as the filler.

Fluorine gas is used in excess of the theoretical amount required to replace all hydrogen atoms contained in the raw material with fluorine atoms. When the raw material is triflukylamine, the raw material 100
The fluorine gas is usually used in an amount of 600 to 3,500 parts by weight. Fluorine gas can be used as it is or diluted to about several percent with an inert gas such as nitrogen, helium, or neon. Although the reaction pressure is sufficient around normal pressure, it may be pressurized. The reaction time is also not particularly limited, but is usually selected from the range of 1 to 30 hours. In the fluorination reaction, copper or copper coated with gold or silver can also be used as a catalyst in the form of a mesh or particles. The fluorination reaction can also be promoted by irradiating light with a wavelength of 200 to 600 wavelengths.

After the fluorination reaction using fluorine gas, a neutralization reaction or distillation is performed, if necessary, in order to remove hydrogen fluoride contained in the product and to increase the purity of the desired perfluorotrialkylamine.

(Effects) According to the method of the present invention, perfluoro) IJ alkyl 7mine can be obtained in extremely high yield by a fluorination method using fluorine gas. Moreover, first, a partially fluorinated trialkyl 7mine with a ratio of hydrogen atoms to fluorine atoms (H/F) of 1/8 or less was obtained by a fluorination method using a high-valent metal fluoride. When used as a raw material in the present invention, there is no residual incomplete fluoride (
, perfluorotriflukylamine can be obtained in high yield. Therefore, the method of the present invention is an extremely useful method for industrially obtaining perfluorotrialkylamine.

(Examples) Examples and comparative examples are shown below to explain the present invention in more detail, but the present invention is not limited to these examples.

Example 1 Tributylamine 25.9 and perfluorotributylamine 85.9 were mixed with a stirrer inside and a reflux condenser (-6
A mixed gas of fluorine gas and nitrogen gas (1:3 molar ratio) was introduced from the bottom of the reactor while stirring.
was fed at a rate of 400 d/min (room temperature) for 35 hours. During this time, the temperature of the reactor was maintained at 125° C. using an oil bath. The amount of liquid recovered after the reaction was 136 g.

Analysis revealed that the liquid contained 11.2.9 underfluorinated compounds and a perfluorotributylamine content of 10.
It turned out to be 3.59. The analysis was performed using gas chromatography (GC-8A manufactured by Shimadzu Corporation; the column was a capillary column FS-25 m in length x 0.251 N in diameter coated with silicone 0V-215 manufactured by Gascro Kogyo ■).
WCOT, column temperature 35°C), gas chromatography-mass spectrometry, gas croftography-infrared spectroscopy 9-element analysis.

The tests were conducted using diethylamine.

Example 2 Four types of trialkylamines shown in Table 1 were fluorinated with cobalt trifluoride. Length 110 crn, inner diameter 10 with stirrer, filled with cobalt trifluoride of 37 mm
A CIR nickel reactor was used, and vaporized trialkylamine was supplied from the end of the reactor together with nitrogen gas. The reaction product and hydrogen fluoride flowing out of the reactor were condensed in a cooling trap and separated from nitrogen gas. The reaction conditions are shown in Table 1. After the reaction, only nitrogen gas was flowed for an additional 2 hours to recover the products in the reactor. The reaction product, hydrogen fluoride, and the fluorinated product were neutralized, followed by washing with water and drying. A simple distillation was then performed to separate out high-boiling compounds and some partially fluorinated organic compounds with high hydrogen content.

The amounts and compositions of the fluorinated products thus obtained are shown in Table 1. The analysis was carried out in the same manner as in Example 1. However, the column temperature for gas chromatography is 27°C and 65°C when the raw material trialkyl 7mine is tripropylamine, tripentylamine, and trioctylamine, respectively.
The temperature was 125°C.

Next, the product obtained by fluorination of cobalt trifluoride was fluorinated with fluorine gas using a reflux condenser (-
A reactor made of nickel fuel (inner diameter 3 cm, height 25 CIn) filled with a nickel Raschig ring (inner diameter 3 cm, height 25 CIn)
This was done using A mixed gas of fluorine gas and nitrogen gas was blown into the reactor from the bottom under the conditions shown in Table 1. The reaction temperature was controlled using an oil bath. After neutralizing and removing hydrogen fluoride produced by the reaction, the fluorinated product was recovered. The amounts and analysis results are shown in Table 1.

In both cases no underfluorinated compounds were present. In the case of tripentylamine, further distillation was performed to obtain perfluorotripentylamine 311 with a purity of 96%.

Comparative Examples 1 and 2 Using tributylamine as a raw material, fluorination with cobalt trifluoride and post-treatment were performed in exactly the same manner as in Example 2. Fluorination of the obtained product with fluorine gas was carried out in the same manner as in Example 2 except that the reaction temperature was 100 ° C. and 190 ° C. After neutralizing the generated hydrogen fluoride,
The fluorinated products were collected and analyzed. The results are shown in Table 2.

Example 3 Tripentylamine was fluorinated in the same manner as in Example 2/I63 except that potassium tetrafluoride (fval)ff was used in place of cobalt trifluoride in Example 243.

The obtained fluorinated product was subjected to precision distillation to obtain a product containing partially fluorinated triflukyl 7mine (H/F' (number ratio) = 0.10) as the main component (64% by weight). 18 of this.
For 0.9 (I), and this 18, 0 # Ic
For (II) containing 20.9% perfluorotripentylamine, 14% was added in the same manner as in Example 243.
Fluorination with fluorine gas was performed at 5°C, and then hydrogen fluoride was neutralized. The results obtained for these cases are shown in Table 3.

Claims (1)

[Claims] A method for producing perfluorotrialkylamine, which comprises fluorinating trialkylamine or partially fluorinated trialkylamine using fluorine gas at a temperature range of 110 to 180°C.