JPH03294236A - Production of branched perfluorononane - Google Patents

Abstract

PURPOSE:To advantageously obtain the subject compound without any complicatedness in operation by circulating hexafluoropropene trimer through a reactor-a packed column-the reactor and simultaneously unreacted fluorine gas is discharged from the filling tower in fluorinating hexafluoropropene trimer. CONSTITUTION:Hexafluoropropene trimer is fluorinated to produce branched perfluoronanone especially useful as a coolant or an insulator of a high-tension electric part material such as an ultrahigh pressure transformer as having excellent resistance to chemical agent, resistance to heat and electrical insulating properties. In said process, said trimer is circulated through a reactor-a packed column-the reactor and simultaneously fluorine gas used in fluorinating reaction is discharged from the packed column to afford the aimed compound at a high reaction rate even in using a diluted fluorine gas without complicatedness in operation. Besides, the contact of said trimer and the fluorine gas in the filling tower is preferably performed in a countercurrent method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing branched perfluorononane. More specifically, the present invention relates to a method for producing branched perfluorononane by fluorinating a hexafluoropropene trimer.

[Conventional technology]

A method of producing branched perfluorononane by fluorinating hexafluoropropene trimer (perfluorononene) is known. However, each of the conventionally proposed methods has the following problems.

Japanese Patent Publication No. 58-49526: A method in which hexafluoropropene trimer is reacted with undiluted elemental fluorine in the absence of an inert solvent in a liquid phase, and the fluorine gas is used undiluted. Instead, it is blown into fine bubbles, so a device is needed to make the bubbles fine. Also, the reaction speed is slow.

According to the example, a reaction time of 44.88 hours is required to produce 1 mole of perfluorononane.

Japanese Patent Publication No. 63-2537: Fluorine gas is introduced while raising the reaction temperature in the range of 0 to 110°C, and the reaction temperature is 10°C or lower until the reaction rate of the raw material hexafluoropropene trimer is at least 30 mol%. This is a method of reacting to a final temperature of 160°C or higher, which not only requires a device to cool the reactor at the initial stage of the reaction, but also requires detailed operations to raise the temperature in one step. and, if not so manipulated, give very low yields.

[Problem to be solved by the invention]

The purpose of the present invention is to overcome these problems seen in the prior art, and to achieve a fast reaction rate even when diluted fluorine gas is used when fluorinating hexafluoropropene trimer with fluorine gas, and to facilitate the fluorination reaction. An object of the present invention is to provide a method for producing branched perfluorononane that does not require any operational complexity.

[Means to solve the problem]

The purpose of the present invention is to circulate the hexafluoropropene trimer from reactor to packed column to reactor when fluorinating hexafluoropropene trimer to produce branched perfluorononane, and to This is accomplished by a method in which unreacted fluorine gas used in the reaction is discharged from a packed column.

When carrying out this reaction, a reaction apparatus equipped with a packed column above the reactor is used. The material for the packed tower should be one that has sufficient resistance to fluorine gas, such as SU.
S, Monel, Hastelloy, etc. are preferably used, but
Glass, iron, etc. are also used when there is little moisture in the system. In addition, the packing material to be filled in the packed tower may be any commonly used packing material such as Raschig rings, Dickson backings, Helipacks, etc., as long as it is sufficiently resistant to fluorine gas. can be used.

In the reaction, first, a raw material hexafluoropropene trimer is charged into a reactor, and bubbling with nitrogen gas or the like is performed. After that, using the 511 ring pump, the raw material 3
The mass is fed into a packed column and returned to one reactor, and so on. During this time, the temperature of the reactor was kept at about 10-110°C.
Fluorine gas diluted with fluorine gas or nitrogen gas to a concentration of about 5% or more is blown into the raw material trimer while preferably maintaining the temperature at about 20 to 100°C.

The raw material trimer is circulated between the reactor, the packed column, and the reactor, and in the packed column, it is brought into contact with fluorine gas for the fluorination reaction. Although this contact may be carried out in co-current flow, it is preferably carried out in counter-current flow, and the unreacted fluorine gas used in the fluorination reaction is discharged from the packed column.

In the case of the countercurrent method, the raw material trimer accompanied by some fluorine gas is sent from the upper part of the packed tower, and most of the fluorine gas is sent from the reactor to the lower part of the packed tower as the packing material. are brought into contact in a countercurrent manner in a packed column filled with

The fluorination reaction is carried out in one reactor and packed column, but the introduction rate (flow rate) of fluorine gas introduced into the reactor
can be appropriately selected, and the reaction rate can be increased by increasing the introduction rate. can also be enhanced.

〔Effect of the invention〕

When hexafluoropropene trimer is fluorinated to produce branched perfluorononane, diluted fluorine gas is used by circulating the hexafluoropropene trimer from reactor to packed column to reactor. It is possible to produce perfluorononane, which has a high reaction rate and does not require any operational complexity, simply by adding the step of circulating it through a packed column during the fluorination reaction.

The branched perfluorononane obtained has excellent chemical resistance and heat resistance, and has high electrical insulation properties and high thermal conductivity, so it is particularly useful for high-voltage electrical components such as ultra-high voltage transformers. Used as a refrigerant, insulator, etc. Furthermore, it is also used as a liquid for various tests of high-voltage electrical parts and as an unused column active liquid for vPS.

〔Example〕

Next, the present invention will be explained with reference to examples.

Example A glass packed column (SUS403 Dixon backing packed with 6M/M, diameter 50 mm) was placed above the reactor equipped with a thermometer, a gas inlet pipe, and an outlet for a circulation pump.

height 500mm). This packed tower has a Y-shaped pipe above it, and a condenser on one side.
The other side is each equipped with an introduction pipe for the circulating liquid from the reactor.

Into such a reactor, 2 kg (4.44 mol) of hexafluoropropene trimer as a raw material was charged, and after nitrogen gas bubbling, the raw trimer was fed at a flow rate of 9 Q/min using a circulation pump. , from the outlet for the circulation pump of the reactor to the circulation flow introduction pipe of the packed tower, and circulated through the packed tower to the reactor.

During this period, while maintaining the temperature of one reactor at 30°C, fluorine gas diluted to a concentration of 20% with nitrogen gas was supplied at a rate of 500 m/min.
After completion of one reaction in which the diluted fluorine gas was blown into the raw material trimer at a flow rate of Q and was allowed to react for 33.5 hours while being discharged from the condenser of the packed column, the fluorine gas was removed by bubbling nitrogen gas.

Gas chromatography analysis of the 2.17 kg of residual liquid revealed that it contained 96.5% perfluorononane, corresponding to a yield of 96.6%. Also.

The reaction time required to produce 1 mole of perfluorononane was 7.8 hours.

Comparative Example In the example, fluorine gas diluted to 20% with nitrogen gas was fed at a rate of 5 oons (3 amounts of raw material at a flow rate of l) per minute while maintaining the temperature of the reactor at 30°C without circulation to the packed column. When reacting for 33.5 hours while blowing diluted fluorine gas into the body and discharging diluted fluorine gas from a condenser attached to the reactor, the perfluorononane content in the residual liquid (2.18 kg) was 23.8%. , the yield is 23.9
It was g. Also, what is the reaction time required to produce 1 mole of perfluorononane?

It was 31.5 hours.

Claims (1)

[Claims] 1. When producing branched perfluorononane by fluorinating a hexafluoropropene trimer, the hexafluoropropene trimer is circulated between a reactor, a packed column, and a reactor, and A method for producing branched perfluorononane, which comprises discharging unreacted fluorine gas used in a fluorination reaction from a packed column. 2. The method for producing branched perfluorononane according to claim 1, wherein the contact between the hexafluoropropene trimer and the fluorine gas in the packed column is carried out by a countercurrent method.