Hoechst Aktiengesellschaft

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Konrad Von Werner

Anton Probst

Alfons Gisser

Wolfgang Knoblauch

Reinhard Albert Sulzbach

Klaus Raab

Wilfried Becker

Heiner Debrodt

Joachim Naumann

Linyang Zhang

Werner Fub

Martin Winter

The safety of secondary lithium cells is remarkedly enhanced when partially fluorinated ethers of the formulae

Fluorine-containing solvents for lithium batteries having increased

The selectivity of copper as the catalyst for the reaction of short-chain perfluoroalkyl iodides with tetrafluoroethylene is increased if a further transition metal is employed as a cocatalyst.

Metal-catalyzed preparation of perfluoroalkyl iodide telomers

The toxic perfluoro-2-methyl-2-pentene can be removed from perfluoro-4-methyl-2-pentene by treating the mixture with lower alkanols, the toxic isomer being converted into high boiling-point compounds which can be easily removed. The high-purity perfluoro-4-methyl-2-pentene so obtained is suitable as a substitute for chlorofluorocarbons.

High-purity perfluoro-4-methyl-2-pentene and its preparation and use

A mixture of isomers of the formula C.sub.6 F.sup.12, which contains at least 80% by weight of the trans isomer of perfluoro-4-methyl-2-pentene and at most 3% by weight of perfluoro-2-methyl-2-pentene, is suitable as a cooling and insulating medium and can be used as a substitute 1,1,2-trichloro-1,2,2-trifluoroethane.

Perfluoroisohexene as a cooling and insulating medium

Process for the preparation of hexafluoropropene dimers having a high proportion of perfluoro-(4-methyl-2-pentene) The dimerization of hexafluoropropene produces almost exclusively dimers having a high content of perfluoro-(4-methyl-2-pentene) if the dimerization is carried out in an aprotic solvent in the presence of an adduct of an amine, which contains no NH groups, and a metal fluoride.

Process for the preparation of hexafluoropropene dimers having a high

Oligomers of fluorinated olefins

The present invention provides a process for the photochemical production of compounds of the general formula:

Process for the photochemical production of halogen compounds

The halogenotetrafluoropropionic acid 3-iodotetrafluoropropionic acid of the formula ICF.sub.2 CF.sub.2 COOH, it is prepared by reacting iodine, tetrafluoroethylene and ethylene in a one-pot reaction under specific conditions, reacting the resulting compound ICF.sub.2 CF.sub.2 CH.sub.2 CH.sub.2 I with a base in order to eliminate hydrogen iodide and oxidizing the compound ICF.sub.2 CF.sub.2 --CH.dbd.CH.sub.2 thus obtained to give 3-iodotetrafluoropropionic acid. The halogenotetrafluoropropionic acid is an advantageous starting compound for the preparation of valuable unsaturated compounds containing functional groups.

Process for the preparation of halogenotetrafluoropropionic acid

A process is described for the preparation of the title compounds from the corresponding iodine-containing compounds by reaction with bromide or chloride ions present as salts, in a dipolar aprotic solvent, in the presence of a metal complex compound which contains chromium, nickel, cobalt or rhodium as the central atom and contains, per central atom, 1, 2 or 3 bromine or chlorine atoms and at least one additional phosphorus-containing ligand, at 20.degree. to 140.degree. C. Good yields are obtained in this way without the difficulties associated with the known procedure using elemental halogens at elevated temperatures. The compounds prepared can be used in the medical sector and as liquids resistant to high temperatures.

Process for the preparation of extensively fluorinated aliphatic

New processes for the preparation of 2-iodo-perfluoro-2-methyl-butane and the corresponding -pentane are described. In one process, perfluoro-2-methyl-2-butene or the corresponding -pentene is reacted in an amount of at least 5 mol with a mixture of 2 mol of iodine and 1 mol of iodine pentafluoride in the presence of more than 1 mol of at least one fluoride of a metal of group I of the periodic table of the elements under the autogenous pressure of the reaction mixture at 170.degree. to 220.degree. C. for 2 to 30 hours. In another process, the same perfluoroolefins are reacted, as the starting substances, with iodine and an alkali metal fluoride in the presence of at least 1 mol of a soluble silver salt per mole of the perfluorinated olefin at 20.degree. to 100.degree. C. for 0.5 to 10 hours. After working up by distillation, the pure iodoperfluoroalkanes are obtained. They are suitable for numerous reactions, but in particular as a packing for lasers.

2-iodo-perfluoro-2-methylalkanes, processes for their preparation and

A process is described for the preparation of perfluorocarboxylic acids by oxidizing perfluoroalkylalkenes with permanganate in aqueous solution, catalytic amounts of at least one quaternary ammonium salt containing alkyl and/or arylalkyl groups being added. It is possible by these means to prepare even perfluorocarboxylic acids having a fairly long chain in a high state of purity in a readily controllable reaction and in a good space-time yield.

Process for the preparation of perfluorocarboxylic acids

Stable aqueous, colloidal dispersions, having a high shear stability, of copolymers of tetrafluoroethylene and ethylene, which may also contain at least one further comonomer, are described. Such dispersions are prepared in the presence of a mixture of perfluorooctanoic acid and perfluorononanoic or perfluorodecanoic acids or salts thereof.

Stable, aqueous, colloidal dispersions of copolymers of the

A process is described for preparing fluoroalkyl-substituted iodoalkanes by reacting a fluorinated alkyl iodide with a substituted or unsubstituted alkene under heat in the presence of a catalyst. The catalyst is at least one metal which, in the periodic table of the elements, has one of the atomic numbers 24 to 30, 42 to 48 or 74 to 79 and is in finely divided form. The products of the process according to the invention are addition compounds of the fluorinated alkyl iodide with the substituted or unsubstituted alkene and, in known processes, can be used as useful intermediates for preparing fluorine-containing polymers, textile finishes, fire-extinguishing agents or surfactants.

Process for preparing fluoroalkyl-substituted iodoalkanes

A process is described for the preparation of 2-alkenyl 1,1,2-trifluoro-2-halogenoethyl ethers by reacting optionally substituted allyl alcohols with fluoroolefins in the presence of an alkali metal hydroxide as catalyst, in which the reaction is carried out by intimately mixing the reactants with an N,N-dialkylcarboxylic acid amide. The said ethers are suitable as intermediate products for the preparation of addition products by the addition of alcohols, primary or secondary amines or R.sub.3 SiH compounds, and are also suitable as comonomers for fluorine-containing copolymers.

Process for the preparation of 2-alkenyl 1,1,2-trifluoro-2-halogenoethyl

Saturated perfluoroalkane-1-carboxylic acids having 6 to 14 C atoms are prepared by reacting the corresponding 1-iodoperfluoroalkanes at temperatures of 100.degree. to 180.degree. C. with fuming sulfuric acid containing 15 to 45% by weight of dissolved sulfur trioxide. The two liquid phases which are formed are separated. The lighter phase is mixed with 0.3 to 6% of its weight of water and is distilled at a pressure of 0.3 to 100 kPa. The heavier phase is mixed with 0.7 to 1.5 moles of water per mole of sulfur trioxide employed and is cooled to 0.degree. to +30.degree. C. and the precipitated iodine is filtered off. After the addition of sulfur trioxide, the liquid filtrate can be re-used. Perfluoroalkan-1-oic acids are obtained in a high state of purity and the bulk of the iodine is recovered in the elementary form.

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Halsbach, Germany

Konrad Von Werner