Process for preparing perhaloethers from perhaloolefins and new perhaloethers so obtained

A process for preparing perhaloethers from perhaloolefins by reacting at least one fluorooxy compound R.sub.x --OF, wherein R.sub.x is a perhaloalkyl radical, with a perfluoroolefin in a liquid phase, optionally containing an organic solvent inert to the perfluoroolefin, while maintaining the temperature of the liquid phase in the range of -30.degree. to -120.degree. C. The process includes continuously feeding to the liquid phase a stream of an inert gas and a gaseous stream of the fluorooxy compound.

DESCRIPTION OF THE INVENTION 
The present invention relates to a process for preparing perhaloether 
compounds starting from perhaloolefins. 
In particular, the present invention relates to a process for preparing 
perhalomonoethers and perhalopolyethers having defined structure and 
molecular weight, by reacting at least a perhaloolefin with at least a 
fluoroxy compound. The invention relates al so to new perhaloethers 
obtained by the and said process. 
The obtained compounds are used in particular in the fields of the electric 
insulating liquids, of the lubricants and of the heat transmission means. 
Processes for preparing fluorinated polyethers by fluorination of 
substrates or of hydrogenated polymers and rupture of the polymeric chain 
are known in the art (U.S. Pat. No. 4,523,039). This type of process 
involves long operative times, of the order of a few days, to obtain a 
complete fluorination. 
On the other hand it is known (U.S. Pat. No. 3,962,348) to obtain 
perfluoropolyether from fluoroolefins and hydrogenated polyols and 
subsequent electrofluorination. Also in this case the process requires 
very long reaction times and, in addition, the use of HF involves several 
technological, safety problems etc. 
There are known processes for preparing mixtures of perfluoropolyethers of 
undefined molecular weights and determinable as average molecular weight 
of the terms contained in the mixtures, on the basis of the ethereal units 
present in the chains, by photo-oxidation or polymerization of 
perfluoroolefins. In this case too the processes in question are 
complicate and at any rate alien to the one which is the object of the 
present invention. 
Lastly, it is known how to prepare perfluoromonoethers by addition reaction 
of CF.sub.3 OF on olefins, carried out for example by using stoichiometric 
amounts of the reactants at low temperatures and in the presence of 
ultraviolet light (U.S. Pat. Nos. 4,077,857 and 4,149,016), or in the gas 
phase at high temperatures (from 20.degree. to 175.degree. C.) (Int. J. 
Chem. Kinet. 1984, 1612, 103-115). There are obtained, following 
modalities different from the ones forming the object of the present 
invention, exclusively monoethereal addition products other than the ones 
being the object of the present invention. 
It is known too (J. Org. Chem. 1985, 50, 3698-3701) that the use of complex 
oxidative mixtures consisting of perfluoroacylipofluorites in combination 
with mono- and bis-fluoroxy compounds, produced in situ in an aqueous 
medium, and utilized as liquids under pressure as starters for the 
polymerization of perfluorinated monomers, leads to the obtaining solid 
polymeric materials having a very high molecular weight. 
The Applicant has now surprisingly found a simple and economic method for 
preparing perhaloethers endowed with defined structure and molecular 
weight, which is not affected by the drawbacks illustrated in connection 
with the above-discussed prior art. 
It was found, in fact, that by reacting a perhalomonoolefin with a fluoroxy 
compound, better defined hereinafter, in certain temperature and dilution 
conditions in an inert gas,it is possible to obtain perhaloether compounds 
exhibiting a strictly delimited structure and molecular weight. 
A portion of said perhaloether compounds is per se new and represents a 
further surprising feature of the intrinsic novelty of the process Object 
of the present invention. 
Thus, it is an object of the present invention to provide a simple and 
economic process for preparing perhaloethers (mono- and poly-ethers) with 
ether end groups, having a structure and molecular weight selectively 
restricted falling within the defined limits of a low oligomerization. 
Another object is to provide the abovesaid perhaloethers in the form of a 
mixture useful in the above cited fields. 
Lastly, still another object is to provide "per se" new perhaloethers or 
mixtures thereof. 
These and still further objects, which will be better apparent to those 
skilled in the art from the following description, are achieved, according 
to the present invention, by means of a process for preparing 
perhaloethers, which is characterized in that at least a perhalomonoolefin 
is reacted with at least a fluoroxy compound R.sub.x --OF, wherein R.sub.x 
represents a straight or branched perhaloalkyl radical containing from 1 
to 10 carbon atoms, at a temperature not higher than 20.degree. C., in the 
presence of a gas which is inert to the reaction conditions. 
In the present specification, fluoroxy compound R.sub.x --OF will be also 
referred to as "starter". 
Furthermore, the term "perhalomonoolefin" defines monoolefins, in which all 
the hydrogen atoms have been substituted by atoms of chlorine and 
fluorine, or of fluorine. 
As regards fluoroxy compound R.sub.x --OF, the halogen component can be Cl, 
F, Br, I, preferably it is selected from F and Cl or F. 
Accordingly, it is possible to use all the perhalomonoolefins compatible 
with the above-described process. 
For illustrative purposes, and in consideration of the applicative purposes 
of the obtained products, there are usually utilized one or more 
perfluorinated and/or fluorochlorinated perhalomonolefins and/or mixtures 
thereof selected from perfluoromonoolefins, fluorochloromonoolefins, 
perfluoroalkylvinylethers and mixtures thereof, defined as follows: 
1) one or more perfluoromonoolefins; 
2) a fluorochloromonoolefin in combination with a perfluoroalkylvinylether 
and/or another perfluoromonoolefin; 
3) one or more perfluoroalkylvinylethers; 
4) a perfluoromonoolefin in combination with a perfluoroalkylvinylether. 
Preferably, fluoroxy compound R.sub.x --OF contains from 1 to 3 carbon 
atoms furthermore, the halogen component is selected from chlorine and 
fluorine, even better, it consists of fluorine. 
As regards the perhalomonoolefins, they preferably contain from 2 to 6 
carbon atoms, the halogen component of which being selected, as mentioned 
hereinbefore, from a mixture of F and Cl, or F. 
It resulted to be advantageous to use, among the perfluoromonoolefins, 
perfluoropropene and tetrafluoroethylene and, among the 
fluorochloromonoolefins, chlorotrifluoroethylene and 
1,2-dichloro-difluoroethylene. Last, as regards the 
perfluoroalkylvinylethers, they are corresponding to the following formula 
: 
EQU CF.sub.2 =CF--O--R.sub.F 
wherein R.sub.F represents a straight or branched perfluoroalkyl radical 
containing from 1 to 10 and preferably from 1 to 3 carbon atoms, such as 
perfluoromethylvinylether, perfluoroethylvinylether or 
perfluoropropylvinylether. 
According to a preferred embodiment, the process of the present invention 
is carried out in a liquid phase, which consists of an inert organic 
medium and/or of one or more perhalomonoolefins, with a gaseous stream 
consisting of the starter or of the starter mixture, an inert gas stream 
and, optionally, a gaseous or liquid stream consisting of the 
perhalomonolefinic reactant or of mixtures thereof, the last-mentioned 
stream being always present, if the liquid phase does not contain 
perhalomonoolefins prior to the reaction starting. 
Preferably, the inert gas is fed to the liquid phase in admixture with the 
gaseous stream consisting of the starter or of its mixtures, in determined 
quantitative ratios, and it is preferably selected from nitrogen, helium, 
argon, CF.sub.4 and C.sub.2 F.sub.6 and mixtures thereof. 
The inert organic solvent medium, when used, consists of a straight or 
cyclic fluorocarbon or chlorofluorocarbon. CFCl.sub.3 ; CF.sub.2 Cl.sub.2 
; c.C.sub.4 F.sub.8 ; CF.sub.3 --CF.sub.2 C.sub.1 ; CF.sub.2 Cl.sub.1 
--CFCl.sub.2 and CF.sub.2 Cl.sub.1 --CF.sub.2 Cl.sub.1 have proved to be 
suitable solvents. 
Preferably, the liquid phase is composed of one or more perhalomonoolefins. 
The starter R.sub.x --OF or its mixtures can be utilized in association 
with minor amounts of starter fluorine ranging from 1 to 30% by mols, 
preferably from 5 to 20% by mols with respect to R.sub.x --OF. 
Analogous results are obtainable also by operating in a fully gaseous 
phase. 
The ether products, in which A.dbd.B.dbd.F in formulas II-IV, as defined 
hereinafter, can be selectively obtained also by using only elemental 
fluorine diluted with the inert gas, in the same conditions as already 
described. 
As mentioned before, the reaction temperature shall be lower than 
20.degree. C., and exactly: the minimum temperature at which the liquid 
phase is maintained during the reaction shall be such that the component 
or components of said phase remain in the liquid state. The reaction 
temperature can range, on the whole, from -120.degree. C. to +20.degree. 
C., approximately, and usually it is maintained approximately from 
-100.degree. C. to -30.degree. C. The total pressure is generally 
maintained around the ambient values (about 1 atmosphere). 
The gaseous volume ratio of the starter or starters to the inert gas can 
vary over a wide range, for example from 0.01 to 5. 
The concentration of the perhalomonoolefin or of its mixtures in the liquid 
phase usually ranges from 0.01 to 10 moles/liter of total liquid phase, 
higher values being allowable up to the molar concentration of the 
perhalomonoolefin and mixtures thereof in the pure state. 
The feeding of the starter or of its mixtures in the gas phase is adjusted 
in such a way as to keep its flowrate rate ranging from 0.01 to 5 moles 
per hour per one liter of liquid phase and usually it ranges from 0.05 to 
2 moles per hour per liter of liquid phase. 
When tetrafluoroethylene is utilized as a perhalomonoolefin, this is 
preferably fed in the gaseous state by bubbling it into the liquid phase 
of the solvent and/or of another liquid perhaloolefin. 
At the end of the adjusted reaction time, which is usually comprised 
between approximately 2 and 20 hours, the perhaloether products, which are 
obtained, in mixture, are separated by distillation from the unreacted 
perhaloolefin monomer or monomers and from the solvent, if any. In such 
manner, mixtures of perhaloether products are obtained, which have the 
appearance of colorless transparent liquids. 
A further separation of the components or of narrower cuts of 
mixtures,starting from the mixtures of the obtained perhaloether 
products,can be carried out by fractionated distillation, 
gas-chromatographic techniques, etc., thereby obtaining products or 
product cuts having a narrow range, for example, of the boiling points or 
an analogous boiling point (isomeric mixtures, etc.). 
The reaction can be conducted in a completely continuous manner, by 
continuously withdrawing a liquid phase portion from the reactor, 
subjecting said portion to distillation and recycling the solvent, if any, 
and the unreacted monomer or monomers and separating the reaction product. 
As mentioned before, the reaction product consists of a mixture of 
monoperhaloethers or of perhalopolyethers and optionally of minor amounts 
of perhaloalkanes, depending on the type of the starting perhalomonoolefin 
or of mixtures thereof and depending on the utilized starter or starters. 
Said mixtures, in most of cases, can be used directly without further 
separation treatments, etc. 
Hereinafter are described in particular a few embodiments of the process 
object of the present invention and the obtained products or mixtures 
thereof, a few of said products being new "per se" and are intended for 
being included in the scope of the present invention. 
I) When a perfluoromonoolefin having at least three carbon atoms and, as a 
starter, a fluoroxy compound R.sub.x --OF either alone or associated with 
elemental fluorine are used, the obtained products have the following 
formula: 
##STR1## 
wherein A is like or different from B and consists of R.sub.x O; R.sub.y 
O; R.sub.y ;F; 
R.sub.f represents a straight or branched perfluoroalkyl radical containing 
from 1 to 10 carbon atoms and preferably from 1 to 3 carbon atoms; 
R.sub.y represents a straight or branched perhaloalkyl radical containing 
at least 1 carbon atom less than R.sub.x, and 1 is 1 or 2; 
R.sub.f preferably represents CF.sub.3 and R.sub.y =CF.sub.3 or --CF.sub.2 
--CF.sub.3. 
The products having formula I, in which 1=2 and A and B are not R.sub.y or 
F simultaneously, are new "per se". 
In particular, when the starting perhalomonoolefin is perfluoropropene 
alone and the starter consists of a fluoroxy compound as defined above 
either alone or in admixture with fluorine, the following products are 
obtained, in which M represents the monomeric unit derived from 
perfluoropropene: 
EQU F--(M).sub.1 --F (A) 
EQU R.sub.x O--(M).sub.1 --F (B) 
EQU R.sub.x O--(M).sub.1 --OR.sub.x (C) 
EQU R.sub.y --(M).sub.1 --F (D) 
EQU R.sub.y --(M).sub.1 --OR.sub.x (E) 
EQU R.sub.y O--(M).sub.1 --F (F) 
EQU R.sub.x O--(M).sub.1 --OR.sub.y (G) 
EQU R.sub.y --(M).sub.1 --R.sub.y (H) 
wherein R.sub.x and R.sub.y are the same as defined above. The products B, 
C, E, F and G for 1=2 are new "per se". 
In the case under examination, the starting perfluoromonoolefin is 
perfluoropropene and the monomeric unit M represents, therefore, a 
diradical 
##STR2## 
wherefore to products A-H, for example to product (B) for 1=1, two 
specific isomeric products correspond, which have respectively the 
formulas: 
##STR3## 
and furthermore for 1=2, all the combinations between the isomeric 
monomeric units are possible, wherefore, for example, always in the case 
of the product of formula (B), four specific products having the following 
formulas can be present: 
##STR4## 
When the abovesaid reaction is carried out with elemental F.sub.2 only, the 
perfluoroalkane products (A), known "per se", where 1=1 and 2, are 
selectively obtained. 
The obtained perhaloether mixtures can contain, generally in little 
amounts, also products different from the ones indicated, for example due 
to the re-arrangement of the monomeric unit or units, under such reaction 
conditions as to promote local exothermicities. 
For example, when it is operated with perfluoropropene alone or in 
combination, monomeric units of the type 
##STR5## 
can be present. 
Therefore, when perfluoropropene is reacted, as above mentioned, with 
CF.sub.3 OF and with elemental F.sub.2, the mixture A-H of the obtained 
products is composed in particular of: 
______________________________________ 
CF.sub.3 --CF(CF.sub.3)--CF.sub.3 
(1) 1 = 1 
CF.sub.3 --CF.sub.2 --CF.sub.2 --CF.sub.3 
(2) 1 = 1 
CF.sub.3 --CF.sub.2 --CF(CF.sub.3)--CF.sub.3 
(3) 1 = 1 
CF.sub.3 --CF.sub.2 --CF.sub.2 --CF.sub.2 --CF.sub.3 
(4) 1 = 1 
CF.sub.3 O--CF(CF.sub.3)--CF.sub.3 
(5) 1 = 1 
CF.sub.3 O--CF.sub.2 --CF.sub.2 --CF.sub.3 
(6) 1 = 1 
CF.sub.3 --CF(CF.sub.3)--CF(CF.sub.3)--CF.sub.3 
(7) 1 = 1 
CF.sub.3 --CF(CF.sub.3)--CF.sub.2 --CF.sub.2 --CF.sub.3 
(8) 1 = 1 
CF.sub.3 (CF.sub.2).sub.4 CF.sub.3 
(9) 1 = 2 
CF.sub.3 --CF(CF.sub.3)--(CF.sub.2).sub.3 CF.sub.3 
(10) 1 = 2 
CF.sub.3 --(CF.sub.2).sub.2 --C(CF.sub.3).sub.3 
(11) 1 = 2 
CF.sub.3 O--(CF.sub.2).sub.3 --CF(CF.sub.3).sub.2 
(12) 1 = 2 
CF.sub.3 O--CF.sub.2 --CF(CF.sub.3)--CF(CF.sub.3)--CF.sub.3 
(13) 1 = 2 
CF.sub.3 O--CF(CF.sub.3)--CF.sub.2 --CF(CF.sub.3)--CF.sub.3 
(14) 1 = 2 
CF.sub.3 O--CF.sub.2 CF(CF.sub.3)--(CF.sub.2).sub.2 --CF.sub.3 
(15) 1 = 2 
CF.sub.3 O--CF(CF.sub.3)--(CF.sub.2).sub.3 CF.sub.3 
(16) 1 = 2 
CF.sub.3 O--(CF.sub.2).sub.6 --CF.sub.3 
(17) 1 = 2 
CF.sub.3 O--CF.sub.2 --CF(CF.sub.3)--CF(CF.sub.3)--CF.sub.2 --OCF.sub.3 
(18) 1 = 2 
CF.sub.3 O--CF.sub.2 --CF(CF.sub.3)--CF.sub.2 --CF(CF.sub.3)--OCF.sub.3 
(19) 1 = 2 
CF.sub.3 O--CF(CF.sub.3)--CF.sub.2).sub.2 --CF(CF.sub.3)--OCF.sub.3 
(20) 1 = 2 
CF.sub.3 O--CF(CF.sub.3)--(CF.sub.2).sub.4 --OCF.sub.3 
(21) 1 = 2 
______________________________________ 
Products (11), (12) and (21) are characterized by a re-arrangement of the 
monomeric unit and the products from (12) to (21), belonging to series 
A-H, are "per se" new. 
Furthermore, the dimeric products (1=2) can represent up to 90% and above 
of the obtained products, of which the mono- and bis-ether products can 
represent even more than 60%. 
When the abovesaid reaction is conducted at rather high temperatures, for 
example at about -30.degree. C., with a high CF.sub.3 OF/inert gas volume 
ratio, for example .gtoreq.5 ether products, prevailingly consisting of 
products (12), (13), (17), (18), (20) and (21), are present in the 
mixture. 
Conversely, when the abovesaid volume ratio is of about 0.25, the ether 
products present in the mixture prevailingly consist of products (13)-(16) 
and (18)-(20). 
When perfluoropropene is reacted with C.sub.2 F.sub.5 OF or with a mixture 
of C.sub.2 F.sub.5 OF and elemental fluorine, the mixture of the obtained 
products is almost exclusively composed of: 
______________________________________ 
CF.sub.3 --CF(CF.sub.3)--CF(CF.sub.3)--CF.sub.3 
(7) 1 = 2 
CF.sub.3 --CF(CF.sub.3)--CF.sub.2 --CF.sub.2 --CF.sub.3 
(8) 1 = 2 
CF.sub.3 --(CF.sub.2).sub.4 --CF.sub.3 
(9) 1 = 2 
CF.sub.3 --CF(CF.sub.3)--(CF.sub.2).sub.3 --CF.sub.3 
(10) 1 = 2 
C.sub.2 F.sub.5 --O--CF(CF.sub.3).sub.2 
(1A) 1 = 1 
C.sub.2 F.sub.5 O--CF.sub.2 --CF.sub.2 --CF.sub.3 
(2A) 1 = 1 
CF.sub.3 O--CF.sub.2 --CF(CF.sub.3)--(CF.sub.2).sub.2 --CF.sub.3 
(3A) 1 = 2 
CF.sub.3 O--CF(CF.sub.3)--(CF.sub.2).sub.3 --CF.sub.3 
(4A) 1 = 2 
C.sub.2 F.sub.5 O--(CF.sub.2).sub.3 --CF(CF.sub.3).sub.2 
(5A) 1 = 2 
C.sub.2 F.sub.5 O--CF(CF.sub.3)--CF.sub.2 --CF(CF.sub.3).sub.2 
(6A) 1 = 2 
C.sub.2 F.sub.5 O--CF.sub.2 CF(CF.sub.3)--CF(CF.sub.3).sub.2 
(7A) 1 = 2 
C.sub.2 F.sub.5 O--CF.sub.2 CF(CF.sub.3)--(CF.sub.2).sub.2 --CF.sub.3 
(8A) 1 = 2 
C.sub.2 F.sub.5 O--CF(CF.sub.3)--(CF.sub.2).sub.3 --CF.sub.3 
(9A) 1 = 2 
C.sub.2 F.sub.5 O--CF.sub.2 CF(CF.sub.3)--CF(CF.sub.3)CF.sub.2 CF.sub.3 
(10A) 1 = 2 
C.sub.2 F.sub.5 O--CF.sub.2 --CF(CF.sub.3)--CF.sub.2 --CF(CF.sub.3).sub.2 
(11A) 1 = 2 
C.sub.2 F.sub.5 O--CF(CF.sub.3)--(CF.sub.2).sub.2 --CF(CF.sub.3).sub.2 
(12A) 1 = 2 
C.sub.2 F.sub.5 O--CF(CF.sub.3)--CF.sub.2 --CF(CF.sub.3)--CF.sub.2 
--CF.sub.3 (13A) 1 = 2 
C.sub.2 F.sub.5 O--CF.sub.2 CF(CF.sub.3)--CF.sub.2 --CF(CF.sub.3)--OC.sub. 
2 F.sub.5 (14A) 1 = 2 
C.sub.2 F.sub.5 O--CF.sub.2 --CF(CF.sub.3)--CF(CF.sub.3)--CF.sub.2 
--OC.sub.2 F.sub.5 (15A) 1 = 2 
C.sub.2 F.sub.5 O--CF(CF.sub.3)--CF.sub.2).sub.2 --CF(CF.sub.3)--OC.sub.2 
F.sub.5 (16A) 1 = 2 
______________________________________ 
The products from (3A) to (16A) are new "per se". 
Product (5A) derives from a re-arrangement of the monomeric unit. 
(II) When a perfluoroalkylvinylether having formula: 
EQU R.sub.f --O--CF=CF.sub.2 
wherein R.sub.f is the same as defined hereinbefore, is used as a starting 
monoolefin, the resulting products have the general formula: 
##STR6## 
wherein R.sub.f represents a perfluoroalkyl radical containing from 1 to 
10 and preferably from 1 to 3 carbon atoms, as defined before, and m=1 or 
2. 
The products having formula II where m=2 are "per se" new. 
When a perfluoroalkylvinylether alone is used as a starting 
perfluoromonoolefin and a fluoroxy compound either alone or in admixture 
with elemental fluorine is used as a starter, the following products, 
wherein letter N represents the monomeric unit, are obtained: 
EQU F--(N).sub.m --F (A') 
EQU R.sub.x O--(N).sub.m --F (B') 
EQU R.sub.x O--(N).sub.m --OR.sub.x (C') 
EQU R.sub.y --(N).sub.m --F (D') 
EQU R.sub.y --(N).sub.m --OR.sub.x (E') 
EQU R.sub.y O--(N).sub.m --F (F') 
EQU R.sub.x O--(N).sub.m--OR.sub.y (G') 
EQU R.sub.y --(N).sub.m --R.sub.y (H') 
wherein R.sub.x, R.sub.y are the same as defined hereinbefore. 
In the indicated formulae of products A'-H', (N) represents a diradical 
##STR7## 
so that, analogously with what discussed above in relation to the reaction 
with perfluoropropene, two specific products correspond to each formula 
A'-H' where m=1, and four specific products correspond to each formula 
A'-H' where m=2. 
When it is operated with perfluoroalkylvinylethers alone or in combination, 
monomeric units, caused by a re-arrangement, of the type 
##STR8## 
wherein R.sub.f is the same as defined before, can be present. 
When the abovesaid reaction is carried out with elemental fluorine, only 
the ether products of formula (A'), where m=1 and 2, are obtained. 
When perfluoromethylvinylether CF.sub.3 O--CF.dbd.CF.sub.2 is reacted with 
CF.sub.3 OF either alone or in admixture with elemental F.sub.2, the 
mixture of the obtained products is almost exclusively composed of: 
______________________________________ 
CF.sub.3 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.3 
(1a) m = 2 
CF.sub.3 --CF(OCF.sub.3)--CF.sub.2 --CF.sub.2 --OCF.sub.3 
(2a) m = 2 
CF.sub.3 O--(CF.sub.2).sub.4 --OCF.sub.3 
(3a) m = 2 
CF.sub.3 O--CF(OCF.sub.3)--CF.sub.3 
(4a) m = 1 
CF.sub.3 O--CF.sub.2 --CF.sub.2 --OCF.sub.3 
(5a) m = 1 
CF.sub.3 O--CF(OCF.sub.3)--CF.sub.2 --CF(OCF.sub.3)--CF.sub.3 
(6a) m = 2 
CF.sub.3 O--CF(OCF.sub.3)--(CF.sub.2).sub.3 --OCF.sub.3 
(7a) m = 2 
CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.3 
(8a) m = 2 
CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--(CF.sub.2).sub.2 --OCF.sub.3 
(9a) m = 2 
CF.sub.3 O--CF(OCF.sub.3)--CF.sub.2 --CF(OCF.sub.3)--CF.sub.2 --OCF.sub.3 
(10a) m = 2 
CF.sub.3 O--CF(OCF.sub.3)--(CF.sub.2).sub.2 --CF(OCF.sub.3)--OCF.sub.3 
(11a) m = 2 
CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.2 --OCF.sub.3 
(12a) m = 2 
______________________________________ 
These products,with the exception of (5a), are new "per se". 
When perfluoromethylvinylether is reacted with C.sub.2 F.sub.5 OF alone or 
in admixture with elemental fluorine, the mixture of the obtained products 
is composed of: 
______________________________________ 
CF.sub.3 --CF(OCF.sub.3)--CF.sub.3 
(5) m = 1 
CF.sub.3 --CF.sub.2 --CF.sub.2 --O--CF.sub.3 
(6) m = 1 
C.sub.2 F.sub.5 O--CF(OCF.sub.3)--CF.sub.3 
(3c) m = 1 
C.sub.2 F.sub.5 O--(CF.sub.2).sub.2 OCF.sub.3 
(4c) m = 1 
CF.sub.3 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.3 
(1a) m = 2 
CF.sub.3 --CF(OCF.sub.3)--(CF.sub.2).sub.2 --OCF.sub.3 
(2a) m = 2 
CF.sub.3 O(CF.sub.2).sub.4 --OCF.sub.3 
(3a) m = 2 
C.sub.2 F.sub.5 O--CF.sub.2 --CF(OCF.sub.3)CF.sub.3 
(5c) m = 2 
C.sub.2 F.sub.5 O--CF(OCF.sub.3)--CF.sub.2 --CF.sub.3 
(6c) m = 2 
CF.sub.3 --CF(OCF.sub.3)--(CF.sub.2).sub.3 --OCF.sub.3 
(7c) m = 2 
CF.sub.3 --CF(OCF.sub.3)--CF.sub.2 --CF(OCF.sub.3)--CF.sub.3 
(8c) m = 2 
CF.sub.3 --CF.sub.2 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.3 
(9c) m = 2 
CF.sub.3 --CF.sub.2 --CF(OCF.sub.3)--CF.sub.2 --CF.sub.2 --O--CF.sub.3 
(10c) m = 2 
C.sub.2 F.sub.5 O--CF(OCF.sub.3)--(CF.sub.2).sub.3--OCF.sub.3 
(11c) m = 2 
C.sub.2 F.sub.5 O--CF(OCF.sub.3)--CF.sub.2 --CF(OCF.sub.3)--CF.sub.3 
(12c) m = 2 
C.sub.2 F.sub.5 O--CF.sub.2 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.3 
(13c) m = 2 
C.sub.2 F.sub.5 O--CF.sub.2 --CF(OCF.sub.3)--(CF.sub.2).sub.2 --OCF.sub.3 
(14c) m = 2 
C.sub.2 F.sub.5 O--CF(OCF.sub.3)--CF.sub.2 --CF(OCF.sub.3)--CF.sub.2 
--O--C.sub.2 F.sub.5 (15c) m = 2 
C.sub.2 F.sub.5 O--CF(OCF.sub.3)--(CF.sub.2).sub.2 --CF(OCF.sub.3)--O--C.s 
ub.2 F.sub.5 (16c) m = 2 
C.sub.2 F.sub.5 O--CF.sub.2 --CF(OCF.sub.3)--CF(OCF.sub.3)--CF.sub.2 
--O--C.sub.2 F.sub.5 (17c) m = 2 
C.sub.2 F.sub.5 --C(CF.sub.3)(OCF.sub.3)--CF(CF.sub.3)--OCF.sub.3 
(18c) m = 2 
CF.sub.3 CF(OCF.sub.3)--CF(OC.sub.2 F.sub.5)--CF.sub.2 --OCF.sub.3 
(19c) m = 2 
______________________________________ 
The products, with the exception of (5), (6), (14c), are new "per se". 
Products (18c) and (19c) are characterized by a re-arrangement in the 
monomeric unit. 
When perfluoropropylvinylether is reacted with C.sub.2 F.sub.5 OF alone or 
in admixture with elemental fluorine, in the product mixture the following 
new products are present: 
EQU C.sub.3 F.sub.7 --O--CF(CF.sub.3)--O--C.sub.2 F.sub.5 ( 1d) 
EQU C.sub.3 F.sub.7 --O--CF.sub.2 --CF.sub.2 --O--C.sub.2 F.sub.5( 2d) 
EQU C.sub.3 F.sub.7 --O--CF(CF.sub.3)--CF(CF.sub.3)--O--C.sub.3 F.sub.7( 3d) 
EQU C.sub.3 F.sub.7 --O--CF(CF.sub.3)--CF.sub.2 --CF.sub.2 --O--C.sub.3 
F.sub.7( 4d) 
EQU C.sub.3 F.sub.7 --O--(CF.sub.2).sub.4 --O--C.sub.3 F.sub.7 ( 5d) 
EQU C.sub.2 F.sub.5 OCF.sub.2 CF(OC.sub.3 F.sub.7)(CF.sub.2).sub.2 OC.sub.3 
F.sub.7 ( 6d) 
EQU C.sub.2 F.sub.5 OCF(OC.sub.3 F.sub.7)(CF.sub.2).sub.3 OC.sub.3 F.sub.7( 7d) 
When perfluoroethylvinylether C.sub.2 F.sub.5 --O--CF.dbd.CF.sub.2 is 
reacted with CF.sub.3 OF, the resulting mixture prevailingly contains the 
following new products: 
EQU CF.sub.3 --CF(OC.sub.2 F.sub.5)--CF(OC.sub.2 F.sub.5)--CF.sub.3( 1b) 
EQU CF.sub.3 --CF(OC.sub.2 F.sub.5)--(CF.sub.2).sub.2 --OC.sub.2 F.sub.5( 2b) 
EQU C.sub.2 F.sub.5 O--(CF.sub.2).sub.4 --OC.sub.2 F.sub.5 ( 3b) 
besides (14c), (15c), (16c) and (17c). 
The new products (1a), (2a) and (3a); (1b), (2b) and (3b; (1c), (2c) and 
(3c); (3d), (4d) and (5d), have been furthermore selectively obtained by 
reacting the respective perfluoroalkylvinylethers with elemental fluorine. 
III) When a mixture of a perfluoroalkylvinylether and a perfluoroolefin is 
utilized as starting monoolefins, the products of formula: 
##STR9## 
are obtained, wherein A, B and R.sub.f are the same as defined 
hereinbefore, 
m is 0, 1, 2; 1=0, 1, 2 such that m+1=2, 
x represents a fluorine atom or a radical R.sub.f, 
with R.sub.f being the same as defined before. Preferably, x=F or CF.sub.3. 
The products with m=1=1 are new "per se". 
Analogously with what has been considered before, the monomeric units are 
enchained with one another according to any possible combinations. 
When the abovesaid mixture consists of R.sub.f O--CF.dbd.CF.sub.2 and 
perfluoropropene, the following new products are obtained, in which M 
represents the perfluoropropene monomeric unit and N the one of R.sub.f 
O--CF.dbd.CF.sub.2 : 
EQU F(M)(N)F (A") 
EQU R.sub.x O(M)(N)F (B") 
EQU R.sub.x O(M)(N)OR.sub.x (C") 
EQU R.sub.y (M)(N)F (D") 
EQU R.sub.y (M)(N)OR.sub.x (E") 
EQU R.sub.y O(M)(N)F (F") 
EQU R.sub.x O(M)(N)OR.sub.y (G") 
EQU R.sub.y (M)(N)R.sub.y (H") 
besides the products A-H and A'-H'. 
When CF.sub.3 --O--CF.dbd.CF.sub.2 is reacted with perfluoropropene by 
using CF.sub.3 OF either alone or in combination with elemental fluorine, 
the resulting mixture contains, besides the new compounds (1a), (2a), 
(3a), (13), (15), (16), (19), the new compounds: 
EQU CF.sub.3 O--CF.sub.2 --CF.sub.2 --CF(CF.sub.3).sub.2 ( 1e) 
EQU CF.sub.3 O--(CF.sub.2).sub.4 CF.sub.3 ( 2e) 
EQU CF.sub.3 O--CF(CF.sub.3)--(CF.sub.2).sub.2 --CF.sub.3 ( 3e) 
EQU CF.sub.3 O--CF(CF.sub.3)--CF(CF.sub.3)--CF.sub.3 ( 4e) 
EQU CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CF.sub.2 --CF.sub.2 --CF.sub.3( 4e) 
EQU CF.sub.3 O--CF(OCF.sub.3)--CF.sub.2 --CF(CF.sub.3).sub.2 ( 6e) 
EQU CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CF.sub.2 --CF(CF.sub.3)--OCF.sub.3( 
7e) 
EQU CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CF(CF.sub.3)--CF.sub.2 --OCF.sub.3( 
8e) 
When CF.sub.3 O--CF.dbd.CF.sub.2 is reacted with tetrafluoroethylene by 
using CF3OF either alone or in combination with elemental fluorine, the 
resulting mixture contains the new compounds (1a), (2a), (3a), (7a), (9a) 
and 
EQU CF.sub.3 O--CF(CF.sub.3)--CF.sub.2 --CF.sub.3 ( 1f) 
EQU CF.sub.3 O--(CF.sub.2).sub.3 --CF.sub.3 ( 2f) 
EQU CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CF.sub.2 --CF.sub.3 ( 3f) 
EQU CF.sub.3 O--CF(OCF.sub.3)--(CF.sub.2).sub.3 CF.sub.3 ( 4f) 
EQU CF.sub.3 O(CF.sub.2).sub.4 OCF.sub.3 ( 5f) 
EQU CF.sub.3 O(CF.sub.2).sub.2 --CF(CF.sub.3)OCF.sub.3 ( 6f) 
The new products (1f), (2f), (1e), (2e), (3e), (4e) are selectively 
obtained also by reacting the above-said mixtures with elemental fluorine. 
(IV) When a mixture of a perfluoroalkylvinylether and a chlorofluoroolefin 
selected from CFCl.dbd.CFCl and CF.sub.2 =CFCl is utilized as starting 
monoolefins, the products of formula: 
##STR10## 
are obtained, wherein A, B and R.sub.f are the same as defined before and 
m=0, 1, 2; 
n=0, 1, 2 so that m+n=2; represents an atom of F or Cl. 
The products with m=n=1 are new "per se". 
Analogously with what has been discussed before, the monomeric units are 
enchained with each other according to any possible combinations. 
When the abovesaid mixture is composed of R.sub.f OCF.dbd.CF.sub.2 and 
CFCl.dbd.CFCl, the following new products are obtained, in which N 
represents the monomeric unit of R.sub.f --O--CF.dbd.CF.sub.2 and L the 
one of CFCl.dbd.CFCl: 
EQU F(N)(L)F (A'") 
EQU R.sub.x O(N)(L)F (B'") 
EQU R.sub.x O(N)(L)OR.sub.x (C'") 
EQU R.sub.y (N)(L)F (D'") 
EQU R.sub.y (N)(L)OR.sub.x (E'") 
EQU R.sub.y O(N)(L)F (F'") 
EQU R.sub.x O(N)(L)OR.sub.y (G'") 
EQU R.sub.y (N)(L)R.sub.y (H'") 
besides products A'-H'. 
When CF.sub.3 O--CF.dbd.CF.sub.2 is reacted with CFCl.dbd.CFCl using 
CF.sub.3 OF alone or in combination with fluorine, the mixture of obtained 
products contains the following new products (1a), (2a), (3a) and 
EQU CF.sub.3 --CF(OCF.sub.3)--CFCl--CF.sub.2 Cl (1g) 
EQU CF.sub.3 O--(CF.sub.2).sub.2 --CFCl--CF.sub.2 Cl (2g) 
EQU CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CFCl--CF.sub.2 Cl (3g) 
EQU CF.sub.3 O--CF.sub.2 --CF(OCF.sub.3)--CFCl--CFCl--OCF.sub.3( 4g) 
EQU CF.sub.3 O--CF(OCF3)--CF.sub.2 --(CFCl).sub.2 --OCF.sub.3 ( 5g) 
When in the abovesaid reaction CF.sub.2 .dbd.CFCl is used as a 
chlorofluoroolefin, the mixture of obtained products contains the 
following new products (1a), (2a), (3a) and 
EQU CF.sub.3 O--CF(CF.sub.3)--CFCl--CF.sub.3 ( 1h) 
EQU CF.sub.3 O--(CF.sub.2).sub.2 --CFCl--CF.sub.3 ( 2h) 
EQU CF.sub.3 O--(CF.sub.2).sub.2 --CF.sub.2 --CF.sub.2 Cl (3h) 
EQU CF.sub.3 O--CF(CF.sub.3)--CF.sub.2 --CF.sub.2 Cl (4h) 
EQU CF.sub.3 O--CF(CF.sub.3)--CFCl--CF.sub.2 --OCF.sub.3 ( 5h) 
EQU CF.sub.3 O(CF.sub.2).sub.2 --CFCl--CF.sub.2 --OCF.sub.3 ( 6h) 
Products (1g), (2g), (1h)-(4n) were also obtained selectively by reacting 
the abovesaid mixtures of olefins with elemental fluorine. 
The process forming the object of the present invention permits to achieve 
several advantages, which can be briefly indicated as the possibility of 
obtaining perhaloethers having defined structure and molecular weight, by 
means of a simple and flexible process, operating on the concerned 
parameters,such as the choice of the perhalomonoolefin and of the fluoroxy 
starter compound, in a single reaction step. 
The art has not offered so far such a possibility. 
The perhalogenated products which contain fluorine and chlorine, prepared 
by means of the process of the present invention,have an important 
applicative field as electric insulating materials, lubricants and heat 
transmission media. 
The perfluorinated ethers of the invention are compounds, which are well 
known for their exceptional thermal stability, thermooxidative stability 
and stability to chemical agents as well as for their uninflammability 
properties and are utilizable in very different sectors and under 
extremely severe operative conditions. 
The perfluoropolyethers known in the art generally consist of mixtures of 
products, from which it is difficult to obtain the individual compounds. 
Reference should be made in this connection to British Patent No. 
1,226,566. The perfluoropolyethers of the present invention are generally 
obtainable as isomeric mixtures of compounds having their boiling points 
in a very narrow temperature range. 
The perfluoropolyethers of the invention are particularly useful as fluids 
for the testing in electronics, for example for the leak testing, thermal 
shock testing, hot spot location, dew point determination and the like. 
The polyethers containing bromine and/or iodine atoms are utilized as 
intermediates for the preparation of functionalized derivatives.

EXAMPLES 
The following examples are given for merely illustrative purposes and are 
not to be regarded as limitative of any possible embodiment of the 
process. 
Example 1 
218 g of C.sub.3 F.sub.6 were condensed in a glass reactor having a volume 
of 500 ml, equipped with a stirrer, thermometer, gas feeding pipes 
reaching the reactor bottom, and with cooler with a liquid at -78.degree. 
C. connected to the atmosphere. Subsequently, while maintaining an outer 
cooling such as to keep the inner temperature at -40.degree. C., a flow of 
2.0 Nl/h of CF.sub.3 OF and 1 Nl/h of N.sub.2 was fed during 14 hours by 
bubbling into the liquid phase. 
260 g of a rough reaction product were obtained, from which, after having 
distilled off the unreacted C.sub.3 F.sub.6 and the volatile by-products, 
52 g of a limpid and colorless liquid were obtained, which, analyzed by 
means of gas mass in electronic impact with 1% SP-1100 column and FT-NMR 
spectrometry for .sup.19 F, resulted to be composed of products 1 to 21, 
the content of dimeric 12 to 21) (1=2) monoether (12-17) and bisether 
(18-21) products, thereof determined by gas--chromatography, amounted to 
about 55% by weight of the mixture the bisether dimers/monoether dimers 
weight ratio being of 1 to 2. 
The dimeric monoether products (12-17) have boiling point in the 
temperature range of -91.degree..+-.2.degree. C. at atmospheric pressure. 
The dimeric bisether products have boiling point in the temperature range 
of -121.degree..+-.2.degree. C. 
Ether products (12), (17) and (21) were present in traces. 
Example 2 
Example 1 was repeated according to the same modalities, using 2.8 Nl/h of 
CF.sub.3 OF diluted with 0.5 Nl/h of N.sub.2 bubbled into 186 g of C.sub.3 
F.sub.6 maintained at -40.degree. C. 
The products obtained,after removal of C.sub.3 F.sub.6, were the same as in 
example 1. The ether terms (12), (13), (17), (18) and (21) represented 
about 90% of the dimeric ether products obtained. The ether terms (12), 
(17) and (21) were characterized by a re-arrangement of the monomeric 
unit. 
Example 3 
By operating according to the modalities described in example 1, a flow of 
1 Nl/h of C.sub.2 F.sub.5 OF and 0.2 Nl/h of F.sub.2 diluted with 5 Nl/h 
of N.sub.2 was bubbled for 11.5 hours into 233 g of C.sub.3 F.sub.6 kept 
in liquid phase at -48.degree. C. 
There were obtained 214 g of a rough reaction mixture which, after C.sub.3 
F.sub.6 removal, was analyzed by means of gas-chromatography, gas-mass and 
.sup.19 F NMR; it resulted to be composed of products 1A to 16A. Products 
3A to 16A represented about 20% of the mixture. The dimeric monoether 
products (3A-13A) were in a weight ratio of about 1:1 with respect to the 
dimeric bisether products (14A-16A). 
Example 4 
Into a steel AISI 316 tubular reactor having an inside diameter of 1/8 inch 
and a length of 1 m, equipped with a circulating-liquid cooling jacket, 
maintained at -10.degree. C. and downstream connected with a trap 
maintained at -80.degree. C., a flow of 2 Nl/h of gaseous C.sub.3 F.sub.6 
diluted with 10 Nl/h of N.sub.2 and a flow of 1 Nl/h of CF.sub.3 OF 
diluted with 10 Nl/h of N.sub.2 were simultaneously and separately fed 
during 2 hours by means of a two-way inlet connection. 
The resulting reaction products leaving the reactor and condensed in the 
trap, after removal of C.sub.3 F.sub.6, of the perfluoroalkane dimers and 
of the monomeric monoethers (1=1), were analyzed by means of the 
above-cited techniques; they resulted to be composed of dimeric monoethers 
and diethers (12)-(21), the weight ratio being 5:1. 
Example 5 
By operating according to the procedure described in example 1, 1 Nl/h of 
CF.sub.3 OF diluted with 3 Nl/h of N.sub.2 was bubbled into 230 g of 
C.sub.3 F.sub.6 in the liquid state at -60.degree. C. and was reacted for 
19 hours. 
After removal of C.sub.3 F.sub.6 and of the other products which had formed 
(1-11), the dimeric monoethers and diethers (1=2) were in a ratio of about 
1:1. 
Example 6 
By operating according to the procedure described in example 1, a flow of 1 
Nl/h of CF.sub.3 OF diluted with 5 Nl/h of N.sub.2 was bubbled for 6 hours 
into 200 g of CF.sub.3 O--CF.dbd.CF.sub.2 kept in the liquid state at 
-60.degree. C. 
190 g of a rough reaction mixture were obtained, from which, by means of 
distillation, 45 g of ether products consisting of (1a)-(12a) were 
recovered. 
Example 7 
Example 6 was repeated,by bubbling for 12 hours a flow of 1 Nl/h of F 
diluted with 50 Nl/h of N.sub.2, into 186 g of CF.sub.3 O--OF.dbd.CF.sub.2 
maintained at -97.degree. C. 
185 g of, a rough reaction mixture were obtained, from which, after removal 
of the unreacted CF.sub.3 O--CF.dbd.CF.sub.2 and of the volatile 
by.-products, 81 g of dimeric bis ether products (1a), (2a) and (3a), 
which boil at about 60.degree. C..+-.2.degree. C., were obtained. 
Example 8 
By operating according to the modalities of example 1, after bubbling a 
flow of 1.5 Nl/h of C.sub.2 F.sub.5 OF diluted with 7.5 Nl/h of N.sub.2 
into 200 g of CF.sub.3 O--CF.dbd.CF.sub.2 in the liquid state at 
-50.degree. C. during 6 hours 200 g of a rough reaction mixture were 
obtained, from which, by distillation, 58 g of ether products were 
recovered; these products, subjected to the analyses, resulted to be 
composed of products (1a), (2a), (3a), (5), (6) and from (3c) to (19c) in 
the following weight ratio: tetraethers/triethers/diethers=1/3/6.5. 
Products (18c) and (19c) were present in little amounts. 
Example 9 
By operating according to the modalities described in example 1, after 
bubbling of 0.75 Nl/h of C.sub.2 F.sub.5 OF and of 0.75 Nl/h of F.sub.2 
diluted with 60 Nl/h of N.sub.2 into 112 g of C.sub.3 F.sub.7 
--O--CF.dbd.CF.sub.2 in the liquid state at -50.degree. C., during 5 
hours, 127.5 g of a rough reaction mixture were obtained, which was 
composed for 65% of products (1d)-(7d) and in which the products (3d)-(5d) 
represented 20%. 
Example 10 
Example 9 was repeated by bubbling a flow of 1 Nl/h of F.sub.2 diluted with 
70 Nl/h of N.sub.2 during 6 hours into 178 g of C.sub.3 F.sub.7 
--O--CF.dbd.CF.sub.2 in the liquid state at -75.degree. C.: 177 g of a 
rough reaction product were obtained, from which, by distillation, 65 g of 
his-ether products (1d), (2d) and (3d), which boil at about 120.degree. 
C..+-.2.degree. C., were separated. 
Example 11 
By operating according to the modalities described in example 1, after 
bubbling a flow of 1 Nl/h of CF.sub.3 OF diluted with 3 Nl/h of N.sub.2, 
during 6 hours, into 200 g of C.sub.2 F.sub.5 --O--CF.dbd.CF.sub.2 in the 
liquid state at -60.degree. C., after removal of the unreacted monomer and 
of the volatile by-products, a mixture was obtained containing bisether 
products (1b)-(3b) and (14c)-(17c). 
Example 12 
By operating according to the modalities described in example 1, after 
bubbling, during 3 hours, a flow of 1 Nl/h of F.sub.2 diluted with 50 Nl/h 
of N.sub.2 into 225 g of liquid C.sub.2 F.sub.5 O--CF.dbd.CF.sub.2 
maintained at -75.degree. C., 180 g of a rough reaction product were 
obtained, which consisted by 66% of dimeric diethers (1), (2b) and (3b), 
which boil at about 98.degree. C..+-.2.degree. C. 
Example 13 
By operating according to the modalities described in example 1,after 
bubbling, during 6 hours, a flow of 2 Nl/h of CF.sub.3 OF diluted with 5 
Nl/h of N.sub.2 into a liquid phase maintained at -60.degree. C. and 
composed of 115 g of CF.sub.3 O--CF.dbd.CF.sub.2 and of 105 g of C.sub.3 
F.sub.6, after removal of the unreacted monomers and of the volatile 
by-products, a mixture was obtained containing products (1a)-(3a), (13), 
(15), (16), (19) and (1e)-(8e). 
Example 14 
Example 13 was repeated by bubbling, for 6 hours, a flow of 1.5 Nl/h of 
F.sub.2 diluted with 50 Nl/h of N.sub.2 into 116.2 g of CF.sub.3 
O--CF.dbd.CF.sub.2 and 105 g of C.sub.3 F.sub.6 at -100.degree. C.; after 
removal of the unreacted monomers and of the volatile by-products, 74 g of 
products consisting of (1a)-(3a) (63.5%), (7)-(9) (11.4%) and (1e)-(4e) 
(24.7%) were obtained. 
Example 15 
By operating according to the modalities described in example 1, after 
bubbling, during 5 hour, a flow of 1 Nl/h of CF.sub.3 OF diluted with 3 
Nl/h of N.sub.2 and, simultaneously but separately, a flow of 3 Nl/h of 
gaseous C.sub.2 F.sub.4 into 106 g of liquid CF.sub.3 O--CF.dbd.CF.sub.2 
maintained at -75.degree. C., after removal of the unreacted monomers and 
of the volatile by-products, a mixture containing products (1a)-(13a), 
(7a), (9a) and (1f)-(6f) was obtained. 
Example 16 
Example 15 was repeated by bubbling, during 5 hours, a flow of 1 Nl/h of 
F.sub.2 diluted with 50 Nl/h of N.sub.2 into the same liquid phase at 
-100.degree. C. with the same flow of C.sub.2 F.sub.4 ; after the 
separation, 31.5 g of dimeric products consisting by 52% of (1f) and (2f) 
and by 48% of (1a)-(3a) were obtained. 
Example 17 
By operating according to the modalities described in example 1 and after 
bubbling for 5 hours 1.5 Nl/h of CF.sub.3 OF diluted with 2 Nl/h of 
N.sub.2 into liquid 55 g of CF.sub.3 O--CF.dbd.CF.sub.2 and 42 g of 
CFCl.dbd.CFCl maintained at -65.degree. C., after removal of the unreacted 
monomers and of the volatile by-products, a mixture was obtained, which 
contained products (1a)-(3a) and (1g)-(5g). 
Example 18 
Example 17 was repeated by bubbling, during 5 hours, a flow of 1.5 Nl/h of 
F.sub.2 diluted with 80 Nl/h of N.sub.2 into the same liquid phase at 
-100.degree. C., there were obtained by distillation 43.4 g of dimeric 
products consisting by 28% of products (1a)-(3a), by 26% of products (3g) 
and by 46% of products (1g) and (2g). 
Example 19 
By operating according to the modalities described in example 1 and after 
bubbling, during 5 hours, 1.2 Nl/h of CF.sub.3 OF diluted with 3 Nl/h of 
N.sub.2 into liquid 80 g of CF.sub.3 O--CF.dbd.CF.sub.2 and 
57 g of CF.sub.2 .dbd.CFCl maintained at -70.degree. C., after removal of 
the unreacted monomers, a mixture was obtained containing products (1 
h)-(6 h) besides (1a)-(3a). 
Example 20 
Example 19 was repeated by bubbling, during 5 hours a flow of 1.2 Nl/h of 
F.sub.2 diluted with 60 Nl/h of N.sub.2 into the same liquid phase 
maintained at -100.degree. C. there were obtained, after separation, 
products (1a)-(3a) and (1 h)-(4 h), the latter products representing 41% 
of the obtained mixture. 
Example 21 
By operating according to the modalities described in example 1 and after 
bubbling, during 14 hours, 0.5 Nl/h of CF.sub.3 OF diluted with 2 Nl/h of 
N.sub.2 into a liquid phase consisting of 50 g of CF.sub.2 Cl --CF.sub.2 
Cl and of 54.7 g of C.sub.3 F.sub.6, there were obtained, after removal of 
the volatile by-products, 8.5 g of a product consisting of (5)-(10), 
(13)-(16) and (18)-(20). 
Although the invention has been described in conjunction with specific 
embodiments, it is evident that many alternatives and variations willl be 
apparent to those skilled in the art in light of the foregoing 
description. Accordingly, the invention is intended to embrace all of the 
alternatives and varations that will fall eithin the spirit and scope of 
the appended claims. The above references are hereby incorporated by 
reference.