Elf Atochem S.a.

Georges Lacote

Rene Bertocchio

Christophe Verge

Patrick Lambert

The invention relates to a continuous process for the preparation of perfluoroalkyl iodides by thermal telomerization, in the gas phase, of tetrafluoroethylene with pentafluoroethyl iodide or heptafluoroisopropyl iodide in a tubular reactor. To improve the selectivity for a telomer of the desired extent, the telomers of lesser extent are recycled to at least one point in the reactor, which is situated between one-twentieth and three-quarters the length of the tube.

Synthesis of perfluoroalkyl iodides

The invention relates to a continuous process for the preparation of perfluoroalkyl iodides containing from 4 to 12 carbon atoms by thermal telomerization of tetrafluoroethylene by pentafluoroethyl iodide or heptafluoroisopropyl iodide in a tubular reactor. According to the invention, 30 to 75% of the tetrafluoroethylene is supplied at the head of the reactor; the remainder is introduced at a point in the reactor located between the 2/5 and 3/4 of the length of the tube. The proportion of undesirable heavy telomers is reduced in this way.

Growing community of inventors

Chauffailles, France

Georges Lacote