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Патент USA US3041327

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Unired ?it-ates Parent
El
2
3,041,317
Hugh Harper Gibbs, Vienna, W. Va., and Richard Nor
FLUOROCAREON SULFONYL FLUQRL‘DES
man Griffin, Wilmington, Del., assiguors to E. I. du
Pont de Nemours and Company, Wilmington, Del., a
corporation of Delaware
3,0413 1 7
Patented June 26, 1962
'
~
No Drawing. Filed May 2, 1960, Ser. No. 25,859
13 Claims. (Cl. 260-733)
?uorinated solvent if desired. Suitable ?uorinated sol
vents are inert, liquid per?uorinated hydrocarbons, such
as per?uoromethylcyclohexane, per?uorodimethylcyclo
butane, ,per?uorooctane, per?uorobenzene, etc.
In accordance with the present invention, it was further
found that ?uoroalkyl sulfonyl ?uorides containing a hy-.
drogen in the a-position could be dehydro?uorinated to
?uoroalkenyl sulfonyl ?uorides in substantial yields and
at high conversions when a catalyst is employed which is.
The present invention relates to ‘the preparation of novel 10 a physical mixture of chromium oxide and an alkali metal '
?uorocarbon sulfonyl ?uorides, and, more particularly, to
chloride, particularly potassium chloride. The use of
the preparation of novel ?uoroalkenyl sulfonyl ?uorides
either catalyst component alone in the process described
and their polymerization to high molecular weight resins.
fails to result in the formation of the desired product or
The polymerization of ethylenically unsaturated ?uori
gives rise to only very small and insigni?cant quantities
nated hydrocarbons has been well established in the art. .
of the unsaturated sulfonyl ?uoride.
A number of highly useful polymeric products, such as
The formation of‘ the ?uoroalkenyl sulfonyl ?uoride is‘
polytetra?uoroethylene, have been developed from ?uoro
generally carried out by a process which comprises pass:
carbon’ monomers. However, practically no addition
ing the hydro?uoroalkyl sulfonyl ?uoride in vaporized
polymers derived from ?uorocarbon monomers which
form over‘ the catalyst bed and recovering the product
contain functional groups are known. The present inven 20 from a cold trap by distillation. The temperature of the
tion is directed to the formation of such products and to
reaction zone should be between 450 and 650° C. and is
a method for their preparation.
preferably between 490 and 530° C. If‘ desired, the
It is, therefore, an object of the present invention to
starting material may be passed through the bed by.
provide novel ?uorocarbon monomers containing func
means of an inert carrier gas, such as nitrogen or the
tional groups. It is another object of the present inven 25 process may be operated at reduced pressure so as to
tion to provide novel ?uorocarbon addition polymers con
create a pressure drop. In general, the process is gov-.
taining functional side-chains. A further object of the
erned by conditions established for solid phase gas reac:
present invention is to provide novel ?uorocarbon mono
tions.
mers and polymers containing sulfonyl side-groups. Still
The a-hydro?uoroalkyl sulfonyl ?uorides employed in
another object of the present invention is to provide a 30 the present invention as starting materials are obtained‘
method for the preparation of ?uorocarbon monomers
from the reaction of ?uoroole?ns and sulfur trioxide re.
containing functional groups. Other objects will become
apparent hereinafter.
The objects of the present invention are accomplished
by the formation of ?uoroalkenyl sulfonyl ?uorides hav
ing the general formula RfCF-TCFSOZF, where Rf is a
?uorine, per?uoroalkyl or an omega-hydroper?uoroalkyl
radical, which can be polymerized with a ?uorinated
ethylene, i.e., a ?uoroethylene, to result in the formation
of high molecular weight sulfonyl ?uoride side-chain con
taining polymers. The ?uoroalkenyl sulfonyl ?uorides are
sulting in the formation of the following sultone
which readily rearranges and hydrolyzes on contact with
water, and decarboxylates to give the desired a-hydro
?uoroalkyl sulfonyl ?uoride. A suitable method of pre
paring the hydro?uoroalkyl sulfonyl ?uoride is'as follows:
150 g. of the per?uoroole?n and 40 g. of freshly distilled
prepared by a process which comprises contacting a
?uoroalkyl sulfonyl ?uoride having the general formula "
RfCF2—CFHSO2‘F, wherein Rf is a ?uorine, a per?uoro
sulfur trioxide are reacted in a 300 ml. vessel under
catalyst consisting of a mixture of an alkali-metal chloride
and chromium oxide at a temperature of 450 to 650° C.
which the temperature is slowly increased to re?ux tem
and recovering a ?uoroalkenyl sulfonyl ?uoride having
the general formula RfCF=CFSO2F wherein Rf has the
sulfonyl ?uoride is distilled out of the re?uxed mixture.
Suitable starting materials are formed from such ?uoro~
ole?ns as hexa?uoropropylene, per?uorobutene-l, per
autogenous pressure at 150° C. for 2 hours; the resulting
sultone is isolated by distillation; 20 g. of the sultone is
alkyl or an omega-hydroper?uoroalkyl radical with a 45 then reacted with 1.6 g. of water in a reaction zone in
same meaning as above.
It was found that the novel ?uoroalkenyl sulfonyl ?uo
rides of the present invention polymerize with ?uorinated
ethylenes to form functional side-chain containing poly
peratures of the reaction mixture. The hydro?uoroalkyl
?uoropentene-l, per?uorohepteue-l, per?uorododecene-l,
omega - hydroper?uorohexene-l,
omega-hydroper?uoro
octene-l, and include a-hydroper?uoroethyl sulfonyl ?uo
mers. Suitable ?uorinated ethylenes which form copoly
ride, a-hydroper?uoropropyl sulfonyl ?uoride, ot-hydroper
mers with ?uoroalkenyl sulfonyl ?uorides are vinyl ?uo 55 ?uorobutyl sulfonyl ?uoride, a-hydroper?uorohexyl sul
ride, vinylidene ?uoride, tri?uoroethylene, chlorotri?uorov
ethylene and tetra?uoroethylene. The polymers of the
present invention are prepared by polymerization tech
niques developed for nonaqueous homo- and copolymer
izations of ?uorinated ethylenes, particularly those em
ployed for tetra?uoroethylene, which have been published
in the literature and are thus not described herein in any
great detail. Generally, the polymers of the present
fonyl ?uoride, l,S-dihydroper?uoropentyl sulfonyl ?uo
ride and 1,7-dihydroper?uoroheptyl sulfonyl ?uoride,
among others. The preferred monomers of the present
invention contain from 2 to 10 carbon atoms.
-
The catalyst employed in the formation of the ?uoro
alkenyl sulfonyl ?uoride comprises a physical mixture of
an valkali metal chloride and chromium oxide.
The cata
lyst is obtained by such methods as tumbling alkali metal
invention are obtained by the polymerization of a mixture
chloride in pellet form with ?nely divided chromium ox
ofthe ?uorinated ethylene, such as tetra?uoroethylene, 65 ide. A more homogeneous mixture" of the two compo
and the ?uoroalkenyl sulfonyl ?uoride in the presence of
nents is, of course, equally active. The ratio of the cata
a free radical initiator, preferably a per?uorocarbon per~
lyst components is not critical. However, in general,
oxide or an azo compound, at a temperature of 0° to
ratios of 1:1 of alkali metal chloride to chromium oxide
200° C., and pressures varying from atmospheric pres 70 varying to where only trace quantities of chromium ox
sure to pressures of 200 and more atmospheres. The
ide are employed,‘ are particularly suitable. ‘Only very
polymerization may be carried out in the presence of a
short contact times between 0.001 and 1 second are nec
3,041,317
.
£3
_It is apparent that the example illustrated merely repre
essary to e?ect the catalytic reaction of the present in
vention.
sents one embodiment of the present invention.
,
The present invention is further illustrated by the fol
Various
modi?cations and substitutions of the illustrated procedure
lowing example:
within the frame of the invention described will occur to
A horizontal “Vycor” borosilicate glass furnacetube
those skilled in the art, such modi?cations and equiva
15 in. long and having an CD. of l in, was ?lled ‘for a
lencies having been established in the art.
The polymers of the present invention serve many pur
poses. The polymers may be employed as thermoplastic
length of 12 in. with potassium chloride pellets admixed
with 0.1 weight percent of chromium oxide. The re
action tube was placed in an electric tube furnace, heated
resins in a manner that polytetra?uoroethylene is em
to 506m 509° C. and reduced in pressure to 20 to 40 10 ployed. However, a particular utilility of the polymer
comprises its use as an ion exchange resin after hydrolysis
mm. Hg. Through a valve, 3.6 g. of 2,2,2,l-tetra?uoro
ethyl sulfonyl ?uoride was injected into the tube. The
low pressure caused the vaporization of the liquid starting
,7
material and its passage over the hot catalyst bed. The ‘
effluent from the reaction tube was condensed in a ves~
cations involving highly corrosive solutions.
sel maintained at liquid nitrogen temperatures. Tri?uoro
vinyl sulfonyl ?uoride was obtained by distillation from
the condensed product. The conversion of the tetra?uo
roethyl sulfonyl ?uoride was 51% per single pass and
We claim:
1. A ?uoroalkenyl sulfonyl ?uoride having the gen
eral formula
the tn'?uorovinyl sulfonyl ?uoride was obtained in a yield
of 61% based on recovered'starting material.
wherein R; is a radical of the class consisting of ?uorine,
per?uoroalkyl ‘and ,ornega-hydroperfluoroalkyl radicals,
The run was repeated using chromium oxide as the
sole catalyst at a temperature of 500 to 513° C. and a
pressure of 10 mm. Hg.
of the sulfonyl ?uoride group to the sulfonic acid group.
The chemical inertness of the ?uorocarbon polymer chain
makes these polymers suitable for ion exchange appli
said alkyl radicals containing {from 1 to 8 carbon atoms.
2. Tri?uorovinyl sulfonyl ?uoride.
3. Per?uoropropenyl sulfonyl ?uoride.
4. Per?uorobutenyl sulfonyl ?uoride.
A yield of less than 2% of the
tri?uorovinyl sulfonyl ?uoride was obtained. Using po
tassium chloride in a 15 in. nickel tube at a temperature
of 508 to 517° C. and a pressure of 25 to 35 mm. Hg, no
5. A normally solid copolymer of a ?uoroethylene and
a ?uoroalkenyl sulfonyl ?uoride haw'ng the general for
tri?uorovinyl sulfonyl ?uoride was formed.
Potassium chloride was replaced by sodium chloride in
mula
the described two component catalyst and substantially
wherein R1; is a radical selected from the class consisting
‘ identical results were obtained.
The tn'?uorovinyl sulfonyl ?uoride isolated was found
of ?uorine, per?uoroalkyl and omega-hydroper?uoro
to have a boiling point at atmospheric pressure of 51.8
alkyl radicals, said alkyl radicals containing from 1 to 8
to 522° CJand a refractive index of nD25‘4=1.32367_._
carbon ‘atoms, said copolymer being characterized by sul
Infrared scan showed absorption at 5.68 microns, indica 35 fonyl groups in the infrared spectrum of the copolymer.
tive of the tri?uorovinyl group; absorption at 6.85 and
6. The copolymer of claim 5 wherein the ?uoroethylene
8.25 microns, indicative of the sulfur dioxide groups; and
is tetra?uoroethylene.
absorption at 7.35, 8, and 9.2 microns, indicative of the
carbon-?uoride bonds.
.‘7. A normally solid copolymer of tetra?uoroethylene
and tri?uorovinyl sulfonyl ?uoride, said copolymer being
Nuclear magnetic resonance was
also consistent with the structure of tri?uorovinyl sul 40 characterized by sulfonyl groups in the infrared spectrum
fonyl ?uoride.
Polymerization of tri?uorovinyl sulfonyl ?uoride was
accomplished by the ‘following procedure. Into a 330
of the copolymer.
8. A process for the preparation of ?uoroalkenyl sul
fonyl ?uoride which comprises contacting a ?uoroalkyl
ml. stainless steel pressure vessel was charged 49 ml. of
sulfonyl ?uoride having the general formula
45
per?uorodimethyl cyclobutane, 1 ml. of tri?uorovinyl sul
fonyl ?uoride, 20 g. or tetra?uoroethylene and 0.5g. of
per?uoromethyl peroxide as the catalyst. The reaction
wherein Rf is a member of the class consisting of ?uorine,
vessel was heated to 150° C. and agitated for one hour
per?uoroalkyl and omega-hydroper?uoroalkyl radicals,
under autogenous pressure. There was isolated from the
said alkyl radicals containing from 1 to 8 carbon atoms,
reaction mixture 10 g. of a copolymer of tetra?uoroethyl 50 with a catalyst comprising a mixture of an alkali metal
ene and tri?uorovinyl sulfonyl ?uoride. The dried co
chloride and a chromium oxide, at a temperature of 450
polymer was a white powder which could be compression
to 650° C., and recovering a ?uoroalkenyl sulfonyl ?uo
molded into solid shapes by preforming at room tem
ride having the general formula
perature and sintering the preform at 317° C. The in
frared spectrum showed the presence of sulfonyl ?uoride 55
wherein RE is as de?ned above.
groups in the polymer.
‘
9. The process as set forth in claim 8 wherein R; is
Similar results are obtained when, instead of the tetra
?uoroethyl sulfonyl ?uoride, a-hydroper?uoropropyl
sulfonyl ?uoride, u-hydroper?uorobutyl sulfonyl ?uoride,
?uorine.
per?uoromethyl.
a-hydroper?uoroheptyl sulfonyl ?uoride and 1,6-dihydro
per?uorohexyl sulfonyl ?uoride are employed in the syn
thesis process to result in the formation of per?uoropro
11. The process as set ‘forth in claim 8 wherein R; is
penyl sulfonyl ?uoride, per?uorobutenyl sulfonyl ?uoride,
per?uoroheptenyl sulfonyl ?uoride and 6-hydroper?uoro
hexenyl sulfonyl ?uoride; said compounds similarly form
sulfonyl ?uoride containing copolymers ‘with tetrafluoro
ethylene when employed in the illustrated polymerization
‘
10. The process as set forth in claim 8 wherein Rf is
65
per?uoroethyl.
12. The process as set forth
4-hydroper?uorobutyl.
in claim 8 wherein Rf is
13. The process as set ‘forth in claim 8 wherein the
alkali metal chloride is potassium chloride.
procedure. The resulting copolymers are similar to the
References Cited in the ?le of this patent
copolymer df tetra?uoroethylene and tri?uorovinyl sul
UNITED STATES PATENTS
fonyl ?uoride, although the temperature required for sin
tering of the copolymer decreases as the number of car
bon atoms in the comonomer increases.
2,884,452
2,950,317
Scherer _____________ __ Apr. 28, 1959
Brown ______________ __ Aug. 23, 1960
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