The manufacture method of fluoroalkyl iodide

Abstract

The present invention provides a novel preparation method of fluoroalkyl iodile, which can prepare fluoroalkyl iodile with high selection rate, and furthermore a small-size reactor can be used and excellent production efficiency is obtained. Particularly the invention provides the preparation method of the fluoroalkyl iodile, which is characterized in that: in a reactor, telomerization between fluoroalkyl iodile which is used as telogen and is represented by a formula (I) and tetrafluoroethylene that is used as backbone material is caused for preparing the fluoroalkyl iodile represented by the formula (II). In the RfI formula (I), Rf is a fluoroalkyl of which the number of carbon atoms is 1-6. In the Rf-(CF2CF2)n-I formula (II), Rf is same with that in the formula (I), and n is an integer selected from 1-4. Reaction solution in the reactor is extrated and is fed from an ejector inlet on the reactor to the inner part of the ejector. When the reaction solution passes through the ejector, gas which contains tetrafluoroethylene in the reactor is sucked from the suction port of the ejector to the inner part of the ejector. Mixture of the reaction solution and the gas which comprises tetrafluoroethylene is sprayed from the outlet of the ejector into the reactor, thereby causing reaction between the fluoroalkyl iodile represented by the formula (I) and tetrafluoroethylene.

Description

technical field [0001] The present invention relates to a method for producing fluoroalkyl iodides. Background technique [0002] Conventionally, there is known a method for producing fluoroalkyl iodides by telomerization. [0003] In such a telomerization reaction, 1-iodoperfluoroethane (C 2 f 5 I) A fluoroalkyl iodide is produced by stepwise reaction with tetrafluoroethylene as a main chain (for example, refer to Patent Document 1). [0004] In such a method, 1-iodoperfluoroethane (C 2 f 5 I) The reaction liquid obtained by reacting with tetrafluoroethylene exists as a liquid phase, and tetrafluoroethylene is supplied in a gas phase adjacent to the liquid to further promote the production of fluoroalkyl iodides. [0005] Although this production method is also an excellent production method, since the telomerization reaction is a gas-liquid reaction, there is a problem that the reaction rate decreases when the contact efficiency between the gas phase and the liquid ph...

AI Technical Summary

Problems solved by technology

[0005] Although this production method is also an excellent production method, since the telomerization reaction is a gas-liquid reaction, when the contact efficiency between the gas phase and the liquid phase is low, there is a problem that the reaction rate decreases

When the reaction speed decreased, a stepwise reaction took place in the reactor due to a long residence time, and the chain length of the obtained fluoroalkyl iodide became longer, thus, there was, for example, 1-iodoperfluorohexane (C 6 f 13 I, degree of polymerization n=2), 1-iodoperfluorooctane (C 8 f 17 I, the degree of polymerization n=3) etc., the problem that the selectivity of the desired fluoroalkyl iodides with a degree of polymerization n of 2 or more decreases

[0006] In addition, in order to ensure a predetermined throughput, the gas-liquid contact area must be increased to improve the contact efficiency between the gas phase and the liquid phase, and there is a problem that the equipment of the reactor must be increased.

Therefore, the above-mentioned production method cannot be said to be a method capable of satisfying industrial requirements.

Images