Daikin Industries, Ltd.

Takeomi Hirasaka

Takuya Ichida

Yuuki Matsuda

Yoshinori Tanaka

Kazuyoshi Ichihara

Takuji Kume

Tomoo Shimada

The present invention provides a novel method for producing a mixture of fluoroalkyl iodides with high production efficiency, the method enabling the production of a desired fluoroalkyl iodide with high selectivity. Specifically, the present invention provides a method for producing a mixture of fluoroalkyl iodides represented by formula (I):R(CFCF)I&#x2003;&#x2003;(I)(wherein Rrepresents a fluoroalkyl group having 1 to 10 carbon atoms, and n is an integer indicating a degree of polymerization), the degree of polymerization n being m or more (m is an integer of 2 or more) by telomerization in metal catalyst-containing reactors, the method including:

Method for producing mixture of fluoroalkyl iodides

A novel process for producing a fluoroalkyl iodide telomer is provided, which is able to obtain a fluoroalkyl iodide telomer having a desired chain length, efficiently. A fluoroalkyl iodide represented by the general formula RfI (wherein Rf is a Cfluoroalkyl group) and tetrafluoroethylene are used as a telogen and a taxogen, respectively. These compounds are supplied to a distillation apparatus. In a reaction zone located in an intermediate part of the distillation apparatus, the compounds are subjected to a telomerization reaction in the presence of a metal catalyst with heating to generate a fluoroalkyl iodide telomer represented by the general formula Rf(CFCF)I (wherein Rf is the same as defined above and n is an integer of 1-4). Thereafter, a fraction comprising the fluoroalkyl iodide telomer is separated by distillation.

Process for producing fluoroalkyl iodide telomer

There is provided a method for separating and collecting at least alcohol with a high purity from an azeotropic mixture of olefin and alcohol. The method conducts the following steps: an azeotropic mixture crystallization step of subjecting an azeotropic mixture of alcohol and olefin represented by the formula: RfCH&#x2550;CH[wherein Rf represents a linear perfluoroalkyl group having 1 to 10 carbon atoms] to a crystallization procedure to separate the mixture into an olefin portion having a higher olefin concentration than that of the original azeotropic mixture and an alcohol portion having a higher alcohol concentration than that of the original azeotropic mixture; and an alcohol purification step of subjecting the separated alcohol portion to either a crystallization procedure or a distillation procedure to separate the alcohol portion into a low-alcohol portion having a lower alcohol concentration than that of the original alcohol portion and a high-alcohol portion having a higher alcohol concentration than that of the original alcohol portion, and thereby collecting alcohol as the high-alcohol portion.

Method for separation of olefin-alcohol azeotropic mixture

In a first sulfation step, 2-perfluoroalkylethyl iodide is brought into contact with fuming sulfuric acid to obtain a reaction mixture comprising 2-perfluoroalkylethyl sulfate and bis(2-perfluoroalkylethyl)sulfate. Then, in a first hydrolysis step, 2-perfluoroalkylethyl sulfate produced in the first sulfation step is hydrolyzed to obtain a reaction mixture comprising 2-perfluoroalkylethyl alcohol. In a second sulfation step, bis(2-perfluoroalkylethyl)sulfate produced in the first sulfation step is brought into contact with fuming sulfuric acid to obtain a reaction mixture comprising 2-perfluoroalkylethyl sulfate. Then, in a second hydrolysis step, 2-perfluoroalkylethyl sulfate produced in the second sulfation step is hydrolyzed to obtain a reaction mixture comprising 2-perfluoroalkylethyl alcohol. According to such procedures, 2-perfluoroalkylethyl alcohol can be obtained in a high yield.

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Osaka, Japan

Takeomi Hirasaka