JPH0236155A - Method for treating fluorinated product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a method for heat-treating a fluorinated product 1 containing a perfluorotrialkylamine obtained by fluorination of a trialkylamine at a certain temperature. This invention relates to a method for obtaining a perfluorotrialkylamine that generates less hydrogen fluoride.

[Prior art and problems to be solved by the invention] Retaperfluorotrialkylamines obtained by fluorination of trialkylamines are chemically stable, have high thermal conductivity, are nonflammable, and are nontoxic. Therefore, it is used as a medium for reliability testing of electronic components, a medium for direct cooling of electronic devices, and a heating medium for vapor phase soldering. However, since perfluorotrialkylamine is used as a heat medium for vapor phase soldering, there is a problem in that hydrogen fluoride is generated when it is heated to its boiling point to vaporize it or when it is irradiated with ultraviolet rays. The amount of hydrogen fluoride generated during heating is large at the beginning of heating, and then gradually decreases, but once it has decreased to a certain point, it no longer decreases even if heating at the boiling point is continued for a long time. Hydrogen fluoride is highly corrosive, so even a small amount of hydrogen fluoride can cause damage to electronic components and corrosion of equipment materials.Therefore, a perfluorotrialkylamine that does not generate hydrogen fluoride has been desired.

[Means to solve the problem]

Therefore, the present inventors conducted intensive research with the aim of obtaining a perfluorotrialkylamine that does not generate hydrogen fluoride even when heated to the boiling point and can be suitably used as a heat medium for vapor phase soldering. I have continued to do so. As a result, the inventors discovered that the above object can be achieved by heat-treating a fluorinated product obtained by fluorination of trialkylamine in a specific temperature range, and completed the present invention.

That is, the present invention provides a fluorinated product characterized by heating a fluorinated product containing a perfluorotrialkylamine obtained by fluorination of a trialkylamine to a temperature satisfying the following formula 1. This is a processing method.

As the trialkylamine that can be used in the present invention, any known trialkylamine can be used without any restriction. Generally, when perfluorotrialkylamine obtained by fluorination is used as a medium for direct cooling of electronic equipment or as a heating medium for vapor phase soldering, it is necessary to use trialkylamine to maintain the boiling point at an appropriate value. Carbon number is 4-21. Furthermore, it is preferable that it is 9-18. Specific examples of trialkylamines preferably used in the present invention include tripropylamine, dipropylbutylamine, propyldibutylamine, tributylamine, dibutylpentylamine, and butyldipentylamine.

Dibutylethylamine, tripentylamine.

These include dibentylhexylamine, pentyldihexylamine, dipentylmethylamine, trihexylamine, and the like.

As a method for fluorinating the above-mentioned trialkylamine,
Any known fluorination method capable of producing Perflu 40 trial bovine luamine can be employed without limitation. For example, direct fluorination method using fluorine gas.

An electrolytic fluorination method, a fluorination method using a high-valent metal fluoride, or a fluorination method that is an appropriate combination of these methods is preferably employed.

In the present invention, the fluorinated product thus obtained,
Preferably, the fluorinated product, which has been further purified by neutralization, distillation or other known methods, is subjected to heating. The heating temperature is a temperature that satisfies the following formula: %. If the temperature is lower than the above-mentioned lower limit temperature, the problem of hydrogen fluoride generation cannot be solved, and if it is higher than the lower limit temperature, the perfluorotrialkylamine may be decomposed, which is not preferable. From the viewpoint of reducing the generation of hydrogen fluoride and preventing the decomposition of perfluorotrialkylamine, the heating temperature is determined by the following formula (%) [Here, T and N are the same as in the above formula. ] is preferably within the temperature range.

For example, when the object of heat treatment is a fluorinated product containing perfluorotripentylamine, the heating temperature is
Must be in the range of 240-420℃, 270-3
Preferably, the temperature is in the range of 80°C.

The heating time is not particularly limited, and is usually selected from a range of several seconds to several hours.

The heating method is not particularly limited, and the fluorinated product to be treated may be heated in a liquid state using a pressure vessel;
The fluorinated product to be treated may be vaporized and heated in a gaseous state (the atmosphere at the time of heating is not particularly limited, and N2
Heating may be performed in an inert atmosphere using gas, Ar gas, or the like, or may be heated in an oxidizing atmosphere using air or the like.

〔effect〕

When a fluorinated product containing perfluorotrialkylamine obtained by fluorination of trialkylamine is heated directly to the boiling point or irradiated with ultraviolet rays, hydrogen fluoride is generated. Hydrogen heptadide continues to be generated even if time passes. However, the fluorinated product heat-treated by the method of the present invention hardly generates hydrogen fluoride even when heated to the boiling point or irradiated with light. Although the reason for this is not clear, the present inventors speculate as follows. That is, the fluorinated product obtained by fluorination of trialkylamine contains not only perfluorotrialkylamine but also incompletely fluorinated products, and when the fluorinated product is heated to the boiling point, this incompletely fluorinated product is removed. Fluorinated substances are decomposed to generate hydrogen fluoride, but most of the incompletely fluorinated substances are decomposed by heat treatment according to the method of the present invention, and therefore the generation of hydrogen fluoride is thought to be reduced.

When the fluorinated product contains a perfluorinated alkylamine having an alkyl group having 5 or more carbon atoms in its molecule, perfluoroinbutene, a toxic compound, is generated by heating at the boiling point. By performing heat treatment using this method, this occurrence can be completely prevented.

Since the fluorinated product treated by the method of the present invention hardly generates hydrogen heptadide, it can be suitably used as a heating medium for vapor phase soldering materials, and can also be used as a testing medium for electronic components and for electronic equipment. It can also be used as an insulating coolant, etc.

〔Example〕

EXAMPLES Examples and comparative examples are listed below to further specifically explain the present invention, but the present invention is not limited to these examples.

Example 1 Electrolytic fluorination was carried out using anhydrous 7-hydrofluoric acid and tripentylamine as raw materials and using a nickel electrolytic bath (electrode area 10 d, current 20 A, capacity 3.51 While continuously supplying anhydrous hydrofluoric acid and tripentylamine, the produced fluoride was intermittently extracted from the bottom of the electrolytic cell.
A fluorinated product mainly consisting of perfluorotripentylamine was obtained by dehydrofluorination by refluxing for 120 hours in an equal volume mixture of a 1% by weight aqueous solution of caustic soda and diisobutylamine, washing with water, and then distilling. .

The obtained fluorinated product 200.9 was placed in a 400ml container.
The sample was placed in a US autoclave, and after creating an inert atmosphere with nitrogen gas, it was heat-treated under the conditions shown in Table 1. Note that when the heat treatment was performed at 300°C, the pressure inside the container was 45.

The heat-treated fluorinated product 100F was placed in a 200 m eggplant-shaped flask equipped with a reflux device at the top, and the liquid was heated under atmospheric pressure for 5 hours. S made me scared. The liquid temperature was 215°C. During this time, nitrogen gas was blown into the liquid at a flow rate of 80 lLt/m, and the generated hydrogen fluoride was
It was absorbed into a 1 mo1/l aqueous potassium hydroxide solution.

By measuring the fluorine ion concentration contained in this potassium hydroxide aqueous solution with an ion chromato analyzer (manufactured by Yokogawa Hokushin Electric, model IC100), the amount of hydrogen heptadium generated was determined, and the amount of hydrogen fluoride generated per unit weight of the fluorinated product was determined. The amount generated was converted to mg-(HF)/Y-(fluorinated product)].The results are shown in Table 1.This value was calculated as
This will be referred to as the amount of hydrogen tsuride generated.

For comparison, Table 1 also shows the results of heating outside the temperature range of the present invention. In addition, comparative example/Wh2 to Bird 4
is heat-treated at the boiling point (215° C.) under atmospheric pressure. Further, Comparative Example No. 5 shows the results of determining the amount of hydrogen fluoride generated during boiling without heat treatment.

In addition, in the measurement of the amount of hydrogen heptadide generated during boiling in Example A3 and Comparative Example M5 in Table 1, the concentration of perfluoroinbutene contained in the nitrogen gas 3 hours after the start of the measurement was detected by electron capture detection. When measured with an equipped gas chromatograph (Yanagimoto Sosakusho, G-2800EN), Example/
In the case of I&3, it was below the detection limit @ (o, oox sir), and in the case of Comparative Example No. 5, it was 0905.

Further, 6 g of the fluorinated product obtained under the heat treatment conditions of Example A3 in Table 1 and 6 I of the fluorinated product before heat treatment were placed in a 1 cm square transparent quartz cell, and an ultraviolet irradiator (manufactured by Ushio Inc. [JSH -250D, 200,000LX) were used to simultaneously irradiate two ultraviolet rays. When each quartz cell was observed after 24 hours, no changes were observed in the quartz cell containing the heat-treated fluorinated product;
The quartz cell containing the fluorinated product before heat treatment became cloudy due to the generation of hydrogen heptadide.

Example 2 Electrolytic fluorination and post-treatment were carried out in the same manner as in Example 1, except that tributylamine was used as the reaction raw material, to obtain a fluorinated product mainly consisting of perfluorotributylamine.

When this was heat-treated at 270°C for 7 hours using the same equipment as in Example 1, the recovery rate was 9% and 6%, and the amount of hydrogen heptadide generated during boiling was 0.1 mg-(HF)/kg-(sulfur heptadide). reaction products) were as follows.

Example 3 Electrolytic fluorination and post-treatment were carried out in the same manner as in Example 1 except that trihexylamine was used as a reaction raw material to obtain a fluorinated product mainly consisting of perfluorotrihexylamine. This was heated at 330°C in an atmosphere using air.
When the mixture was heat-treated for 7 hours, the recovery rate was 9% and 7%, and the amount of hydrogen fluoride generated during boiling was 0.1119-(HF)/Y-(fluorinated product).

Claims (1)

[Claims] (1) The fluorinated product containing perfluorotrialkylamine obtained by fluorination of trialkylamine is expressed using the following formula: 14N+30≦T≦420 [where, T=temperature (°C), N=total of trialkylamine] A method for treating a fluorinated product, characterized by heating it to a temperature that satisfies [carbon number].