Elf Atochem S.a.

Produits Chimiques Ugine Kuhlmann

Institut Francais Du Pe'trole

Arkema Inc.

P C U K Produits Chimiques Ugine Kuhlmann

D'elf Atochem S.a.

Atochem, Gaz De France

Rene Bertocchio

Andre Lantz

Louis Foulletier

Eric Lacroix

Georges Lacote

Patrick Lambert

Bertrand Collier

Jacques Cheron

Sylvain Perdrieux

Christophe Verge

Laurent Wendlinger

Laurence Rolland

Daniel Roland

Eric Deslandes

Process for drying wet F32, which comprises placing a stream of the said F32 in continuous contact with a feed stock of a composition comprising a molecular sieve chosen from a 3A type sieve, at a temperature of between 5 and 78&#xb0; C. and at a pressure of between 0.5 and 25 atm.

Process for drying difluoromethane

A process for the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115). The F125-F115 mixture to be purified is subjected to an extractive distillation, the extractant being a C.sub.5 -C.sub.8 perfluoroalkyl halide.

Process for the purification of pentafluoroethane by extractive

To remove the olefinic impurities from a hydrochlorofluoroethane of formula: CF.sub.3 --CHClX (X=H, F, or Cl), it is subjected to a photochlorination stage.

Process for purification of hydrochlorofluoroethanes

A process for the purification of 1-chloro-1,2,2,2-tetrafluoroethane (F124) containing 1,2-dichlorotetrafluoroethane (F114) and/or 1,1-dichlorotetrafluoroethane (F114a). The F124 to be purified is subjected to extractive distillation, the extractant being chosen from C.sub.5 -C.sub.8 aliphatic or cycloaliphatic hydrocarbons and C.sub.4 -C.sub.8 perfluoroalkyl halides.

Purification of chlorotetraflouroethane by extractive distillation

1,1,1,3,3-Pentachlorobutane, whose fluorination leads to 1,1,1,3,3-pentafluorobutane, is prepared with high yield and selectivity by addition of carbon tetrachloride to 2-chloropropene in the presence of a copper salt and an amine.

Preparation of 1,1,1,3,3-pentachlorobutane and

To remove the traces of chlorotrifluoroethylene (F1113) which are present in a pentafluoroethane (F125), the F125 is passed through a bed of active carbon.

Purification of pentafluroethane

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

To remove the traces of chlorofluoromethane present in a difluoromethane, the difluoromethane to be purified is passed over a 13X molecular sieve at a temperature of at least 60.degree. C. The sieve can be regenerated by washing with the aid of a solution of sodium or potassium carbonate and heating to high temperature under inert atmosphere or in vacuum.

Process for the purification of difluoromethane

In order to stabilize 1,1-dichloro-1-fluoroethane containing traces of vinylidene chloride, at least one ethylenic hydrocarbon containing at least 4 carbon atoms is added thereto.

Stabilization of 1,1-dichloro-1-fluoroethane

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.

The invention relates to compositions which contain a chlorofluorinated ether and at least one solvent, and their use in thermal absorption apparatus for the generation of heat or cold. In the compositions according to the invention, the chlorofluorinated ether is 1-difluoromethoxy-1,1,2-trifluoro-2-chloroethane (enflurane: CF.sub.2 H-O-CF.sub.2 CHFCl) and the solvent is selected among aromatic esters and .omega.,.omega.'-dialkylated polyoxyethylene glycols. The present invention can be particularly applied in the heating and refrigeration areas using absorption systems such as, for example, heat pumps.

Compositions based on chlorofluorinated ether and solvent and their

Perfluoroalkyl amine oxides of the following formula: ##STR1## where C.sub.n F.sub.2n+1 is a straight or branched perfluorinated chain, n is a whole number from 1 to 20, a is a whole number from 2 to 10, p is a whole number from 0 to 10, R.sub.1 is either a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms, and R.sub.2 and R.sub.3 are alkyl radicals having 1 to 6 carbon atoms, and the use of the amine oxides as surface active agents particularly in fire extinguishing compositions.

Perfluoroalkylamine oxides and use of these products in fire

A fluorinated sulphobetaine compound of the general formula ##STR1## wherein R.sub.F represents a straight-chained or branched perfluorinated aliphatic chain C.sub.n F.sub.2n+1 (n being an integer between 1 and 20), a is an integer between 0 and 10, X is CO or SO.sub.2, p is an integer between 0 and 10, R.sub.1 is a hydrogen atom or an alkyl group containing 1 to 6 carbon atoms, R.sub.2 and R.sub.3 are each alkyl radicals containing 1 to 6 carbon atoms, and Z is a bivalent organic group; and fire extinguishing compositions comprising such fluorinated sulphobetaine compounds.

Fluorinated sulphobetaines and compositions containing the same

Aqueous fire-extinguishing compositions comprising a mixture of (1) a nonionic surface-active agent, (2) a amphoteric surface active agent and (3) a fluorinated cationic surface active agent containing as a part of the molecule an aromatic radical.

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Vourles par Vernaison, France

Rene Bertocchio