Novel technology for preparing pentafluoroethyl iodide by one-step method

Abstract

A technology for preparing pentafluoroethyl iodide by a one-step method. By the adoption of a multiple-stage tower reactor series connection process flow (N is greater than or equal to 2 upon the process requirements), an iodine pentafluoride solution, a gas mixture of perfluoroalkyl sulfonyl fluoride and fluorine nitrogen and tetrafluoroethene respectively enter into the multiple-stage tower reactor from two ends and countercurrently flow for reaction. The invention has the following advantages: fluorine gas, iodine and tetrafluoroethene are used as raw materials to react so as to synthesize pentafluoroethyl iodide in one step; the newborn iodine pentafluoride in the invention has high activity and can perform a mild reaction at the temperature of 60-65 DEG C; the catalyst perfluoroalkyl sulfonyl fluoride can be used as a catalyst and a surfactant to raise the reaction rate and the yield; two iodine-eroded grooves and a tail gas absorbing tower cooperate and are alternatively used to make the reaction continuously automated; unreacted fluorine gas can be adsorbed by active alumina and then recovered and reused; the technological equipment and parts, which are made from regular steel, undergo a pock-free electroless nickel plating treatment and a fluorine passivation treatment, so as to prevent the damage of corrosive chemicals to the equipment, reduce the investment cost and benefit for industrialization.

Description

technical field [0001] The invention belongs to a technique for preparing pentafluoroiodoethane in a one-step method, and specifically relates to a process using iodine, fluorine gas and tetrafluoroethylene as raw materials and iodine pentafluoride as a solvent under a perfluoroalkylsulfonyl fluoride atmosphere. Continuous gas-liquid countercurrent reaction in a multi-stage reaction tower. Background technique [0002] Pentafluoroiodoethane is an important raw material for the synthesis of perfluoroalkyl iodides. It is mainly used as an initial telogen for the production of perfluoroalkyl iodides, and can also be used for the production of fluorine-containing fine chemicals such as fluorine-containing pharmaceutical intermediates. Perfluoroalkyl iodide, a downstream product of pentafluoroiodoethane, has a wide range of uses as an intermediate in the synthesis reaction, such as fluorine-containing surfactants, fluorine finishing agents, etc., which are widely used. With the i...

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Problems solved by technology

But this method has obvious disadvantages: 1,2-diiodotetrafluoroethane (CF 2 ICF 2 1), iodine pentafluoride, hydrogen fluoride, etc. are all toxic substances, and the toxicity of 1,2-diiodotetrafluoroethane is not yet clear at home and abroad, and acute inhalation belongs to the highly toxic category, and operation protection is more important

The selectivity and yield of this method are not easy to control, and its carrier uses activated carbon, which has the problem of easy oxidation or carbon deposition of the catalyst carrier, which is not conducive to industrial production

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