U.S. patent application number 11/420413 was filed with the patent office on 2007-02-01 for recovery of fluorinated carboxylic acid from adsorbent particles.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to Richard M. Flynn, Klaus Hintzer, Michael Jurgens, Harald Kaspar, Herbert Koenigsmann, Kai Helmut Lochhaas, Andreas R. Maurer, George G. I. Moore, Jay F. Schulz, Werner Schwertfeger, Tilman Zipplies.
Application Number | 20070025902 11/420413 |
Document ID | / |
Family ID | 37662436 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070025902 |
Kind Code |
A1 |
Hintzer; Klaus ; et
al. |
February 1, 2007 |
RECOVERY OF FLUORINATED CARBOXYLIC ACID FROM ADSORBENT
PARTICLES
Abstract
A process for the recovery of fluorinated carboxylic acid or
derivative thereof from adsorbent particles on which fluorinated
carboxylic acid or a salt thereof is adsorbed. The process includes
contacting the adsorbent particles with a liquid composition
capable of removing at least part of the fluorinated carboxylic
acid or salt thereof from the adsorbent particles. The fluorinated
carboxylic acid or salt thereof is selected from the group
consisting of fluorinated carboxylic acids or salts thereof that
correspond to the general formula:
[R.sub.fO-L-COO.sup.-].sub.iX.sup.i+ (I) wherein L represents a
linear partially or fully fluorinated alkylene group or an
aliphatic hydrocarbon group, R.sub.f represents a linear partially
or fully fluorinated aliphatic group or a linear partially or fully
fluorinated aliphatic group interrupted with one or more oxygen
atoms, X.sup.i- represents a cation having the valence i and i is
1, 2 or 3.
Inventors: |
Hintzer; Klaus; (Kastl,
DE) ; Jurgens; Michael; (Neuoetting, DE) ;
Kaspar; Harald; (Burgkirchen, DE) ; Koenigsmann;
Herbert; (Burgkirchen, DE) ; Lochhaas; Kai
Helmut; (Neuoetting, DE) ; Maurer; Andreas R.;
(Langenneufnach, DE) ; Schwertfeger; Werner;
(Altoetting, DE) ; Zipplies; Tilman; (Burghausen,
DE) ; Moore; George G. I.; (Afton, MN) ;
Schulz; Jay F.; (Inver Grove Heights, MN) ; Flynn;
Richard M.; (Mahtomedi, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
37662436 |
Appl. No.: |
11/420413 |
Filed: |
May 25, 2006 |
Current U.S.
Class: |
423/240S |
Current CPC
Class: |
C08L 27/12 20130101;
C08L 27/12 20130101; C08L 2666/22 20130101; C08L 71/02 20130101;
Y02C 20/30 20130101 |
Class at
Publication: |
423/240.00S |
International
Class: |
B01D 53/70 20060101
B01D053/70 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2005 |
GB |
0525978.3 |
Nov 24, 2005 |
GB |
0523853.0 |
Jul 15, 2005 |
GB |
0514398.7 |
Jul 15, 2005 |
GB |
0514387.0 |
Claims
1. A process comprising recovery of fluorinated carboxylic acid or
derivative thereof from adsorbent particles on which fluorinated
carboxylic acid or a salt thereof is adsorbed, by contacting said
adsorbent particles with a liquid composition capable of removing
at least part of said fluorinated carboxylic acid or salt thereof
from said adsorbent particles, wherein said fluorinated carboxylic
acid or salt thereof is selected from the group consisting of
fluorinated carboxylic acids or salts thereof that correspond to
the general formula: [R.sub.f--O-L-COO.sup.-].sub.iX.sup.i+ wherein
L represents a linear partially or fully fluorinated alkylene group
or an aliphatic hydrocarbon group, R.sub.f represents a linear
partially or fully fluorinated aliphatic group or a linear
partially or fully fluorinated aliphatic group interrupted with one
or more oxygen atoms, X.sup.i+ represents a cation having the
valence i and i is 1, 2 or 3.
2. A process according to claim 1 wherein said liquid composition
is capable of dissolving said fluorinated carboxylic acid or a salt
thereof.
3. A process according to claim 1 wherein said liquid composition
is capable of converting said fluorinated carboxylic acid or salt
thereof into a corresponding ester and wherein said ester is
removed by distillation from a mixture of adsorbent particles and
said liquid composition.
4. A process according to claim 1 wherein said adsorbent particles
are selected from the group consisting of anion exchange resin,
active carbon, alumina, celites, clay and zeolites.
5. A process according to claim 3 wherein said liquid composition
comprises an alcohol.
6. A process according to claim 5 wherein liquid composition
further comprises an acid.
7. A process according to claim 2 wherein said liquid composition
comprises an alkaline solution.
8. A process according to claim 7 wherein the liquid composition
comprises an organic solvent and a base selected from the group
consisting of ammonia, alkali hydroxides and mixtures thereof.
9. A process according to claim 1 wherein said adsorbent particles
comprise an anion exchange resin and wherein said liquid
composition comprises an ammonium salt dissolved in an organic
solvent.
10. A process according to claim 1 wherein the anion of said
fluorinated carboxylic acids or salts thereof have a molecular
weight of not more than 1000 g/mol.
11. A process according to claim 1 wherein the anion of said
fluorinated carboxylic acids or salts thereof have a molecular
weight of not more than 500 g/mol.
12. A process according to claim 1 wherein the fluorinated
carboxylic acid or salt thereof when administered to rat shows a
renal recovery rate of at least 50% of the administered amount, 96
hours after administration and wherein the renal half-life
(T.sub.1/2) is not more than 30 hours.
13. A process according to claim 1 wherein the fluorinated
carboxylic acid or salts are selected from fluorinated carboxylic
acid or salts of which any fluorinated aliphatic portion has not
more than 3 carbon atoms.
14. A process according to claim 1 wherein L in said formula is
selected from the group consisting of linear perfluorinated
alkylene groups having 1 to 6 carbon atoms, linear partially
fluorinated alkylene groups having 1 to 6 carbon atoms having not
more than 2 hydrogen atoms and aliphatic hydrocarbon groups having
1 to 6 carbon atoms.
15. A process according to claim 1 wherein R.sub.f is selected from
the group consisting of linear perfluorinated aliphatic groups
having 1 to 6 carbon atoms; linear perfluorinated aliphatic groups
interrupted with one or more oxygen atoms of which alkylene groups
between oxygen atoms have not more than 6 carbon atoms and wherein
the terminal alkyl group has not more than 6 carbon atoms; linear
partially fluorinated aliphatic groups having 1 to 6 carbon atoms
and not more than 2 hydrogen atoms and linear partially fluorinated
aliphatic groups interrupted with one or more oxygen atoms and
which have not more than 2 hydrogen atoms.
16. A process according to claim 1 wherein L is selected from the
group consisting of --(CF.sub.2).sub.g-- wherein g is 1, 2, 3, 4, 5
or 6; --CFH--(CF.sub.2).sub.h-- wherein h is 0, 1, 2, 3, 4 or 5;
--CF.sub.2--CFH--(CF.sub.2).sub.d-- wherein d is 0, 1, 2, 3 or 4;
--CH.sub.2--(CF.sub.2).sub.h-- wherein h is 1, 2, 3 or 4; and
--(CH.sub.2).sub.c-- wherein c is 1, 2, 3 or 4.
17. A process according to claim 1 wherein R.sub.f corresponds to
the following formula:
R.sub.f.sup.1--[OR.sub.f.sup.2].sub.p--[OR.sub.f.sup.3].sub.q--
(II) wherein R.sub.f.sup.1 is a perfluorinated linear aliphatic
group of 1 to 6 carbon atoms, R.sub.f.sup.2 and R.sub.f.sup.3 each
independently represents a linear perfluorinated alkylene of 1, 2,
3 or 4 carbon atoms and p and q each independently represent a
value of 0 to 4 and wherein the sum of p and q is at least 1.
18. A process according to claim 1 wherein R.sub.f corresponds to
the following formula: R.sup.7.sub.f--(O).sub.t--CFH--CF.sub.2--
(III) wherein t is 0 or 1 and R.sup.7.sub.f represents a linear
partially or fully fluorinated aliphatic group optionally
interrupted with one or more oxygen atoms.
19. A process according to claim 1 wherein R.sub.f corresponds to
the formula: R.sub.f.sup.8--(OCF.sub.2).sub.a-- (IV) wherein a is
an integer of 1 to 6 and R.sub.f.sup.8 is a linear partially
fluorinated aliphatic group or a linear fully fluorinated aliphatic
group having 1, 2, 3 or 4 carbon atoms.
20. A process according to claim 1 wherein R.sub.f corresponds to
the formula: R.sub.f.sup.9--O--(CF.sub.2).sub.b-- (V) wherein b is
an integer of 1 to 6, preferably 1, 2, 3 or 4 and R.sub.f.sup.9 is
a linear partially fluorinated aliphatic group or a linear fully
fluorinated aliphatic group having 1, 2, 3 or 4 carbon atoms.
21. A process according to claim 1 wherein the fluorinated
carboxylic acid corresponds to the following formula:
[R.sub.f.sup.a--(O).sub.t--CHF--(CF.sub.2).sub.n--COO.sup.-].sub.iX.sup.i-
+ (VI) wherein R.sub.f.sup.a represents a linear partially or fully
fluorinated aliphatic group optionally interrupted with one or more
oxygen atoms, t is 0 or 1 and n is 0 or 1, X.sup.i+ represents a
cation having a valence i and i is 1, 2 or 3, with the proviso that
when t is 0, the R.sub.f.sup.a contains at least one ether oxygen
atom.
22. A process according to claim 1 wherein the fluorinated
carboxylic acid corresponds to the following formula:
R.sub.f.sup.b--(O).sub.t--CFH--CF.sub.2--O--R-G (VII) wherein
R.sub.f.sup.b represents a linear partially or fully fluorinated
aliphatic group optionally interrupted with one or more oxygen
atoms, R is an aliphatic hydrocarbon group, G represents a
carboxylic acid or salt thereof, t is 0 or 1.
23. A process according to claim 1 wherein the fluorinated
carboxylic acid corresponds to one of the following formulas:
R.sub.f.sup.c--(OCF.sub.2).sub.u--O--(CF.sub.2).sub.v-AC (VIII)
wherein u is an integer of 1 to 6, v is an integer of 1 to 6,
R.sub.f.sup.c represents a linear perfluorinated aliphatic group of
1, 2, 3 or 4 carbon atoms and AC represents a carboxylic acid group
or salt thereof, and
R.sub.f.sup.c--O--(CF.sub.2).sub.y--O-L.sup.1-AC (IX) wherein y has
a value of 1, 2, 3, 4, 5 or 6, L.sup.1 represents a linear
perfluorinated alkylene of 1, 2, 3, 4, 5 or 6 carbon atoms or a
partially fluorinated alkylene having 1 to 6 carbon atoms and 1 or
2 hydrogen atoms, R.sub.f.sup.c is as defined in above formula
(VIII) and AC represents a carboxylic acid group or salt
thereof.
24. A process according to claim 1 wherein the fluorinated
carboxylic acid or salt thereof is selected from the group
consisting of C.sub.3F.sub.7--O--CHF--COOH
CF.sub.3--O--CF.sub.2CF.sub.2--CF.sub.2--O--CHF--COOH
CF.sub.3CF.sub.2CF.sub.2--O--CF.sub.2CF.sub.2--CF.sub.2--O--CHF--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--O--CHF--COOH
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CHF--COOH
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CHF--COOH
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CHF--COOH
CF.sub.3--O--CHF--CF.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--COOH
CF.sub.3--CF.sub.2--O--CHF--CF.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--COOH
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--C-
OOH
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.-
2--COOH CF.sub.3--O--CF.sub.2--CHF--COOH
C.sub.3F.sub.7--O--CF.sub.2--CHF--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--COOH
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--COOH
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--C-
OOH
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CH-
F--COOH CF.sub.3--O--CF.sub.2--CHF--CF.sub.2--COOH
C.sub.2F.sub.5--O--CF.sub.2--CHF--CF.sub.2--COOH
C.sub.3F.sub.7--O--CF.sub.2--CHF--CF.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--CF.sub.2--CO-
OH
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--CF.sub-
.2--COOH
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.-
2--CHF--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--C-
F.sub.2--COOH CF.sub.3--O--CHF--CF.sub.2--O--CH.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--O--CH.sub.2--
-COOH C.sub.3F.sub.7--O--CHF--CF.sub.2--O--CH.sub.2--COOH
C.sub.3F.sub.7--O--CHF--CF.sub.2--O--CH.sub.2--CH.sub.2--COOH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--OCH.sub.2COOH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--OCH.su-
b.2COOH C.sub.3F.sub.7--O--CF.sub.2--CHF--CF.sub.2--OCH.sub.2COOH
CF.sub.3--CHF--CF.sub.2--O--CH.sub.2COOH
C.sub.3F.sub.7--CF.sub.2--CHF--CF.sub.2--OCH.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--O--CH.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CH.s-
ub.2--COOH C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CH.sub.2--COOH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CH.sub.2--CH.sub.2--COOH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CF.sub.2--OCH.sub.2CO-
OH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CF.sub.2-
--OCH.sub.2COOH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--CF.sub.2--OCH.sub.2COOH
C.sub.4F.sub.9--O--CH.sub.2--COOH
C.sub.4F.sub.9--O--CH.sub.2--CH.sub.2--COOH
C.sub.3F.sub.7--O--CH.sub.2COOH C.sub.6F.sub.13--OCH.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--COOH
C.sub.2F.sub.5--O--CF.sub.2--CF.sub.2--COOH
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--COOH
C.sub.4F.sub.9--O--CF.sub.2--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2).sub.1--O--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2--CF.sub.2).sub.1--O--CF.sub.2--COOH
C.sub.2F.sub.5--(O--CF.sub.2--CF.sub.2).sub.1--O--CF.sub.2--COOH
C.sub.2F.sub.5--(O--CF.sub.2--CF.sub.2).sub.2--O--CF.sub.2--COOH
CF.sub.3--(O--CF.sub.2--CF.sub.2).sub.2--O--CF.sub.2--COOH
C.sub.3F.sub.7--O--CF.sub.2--COOH
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--COOH
CF.sub.3CFH--O--(CF.sub.2).sub.3--COOH
CF.sub.3CFH--O--(CF.sub.2).sub.5--COOH
CF.sub.3--CF.sub.2--O--(CF.sub.2).sub.3COOH
CF.sub.3--CF.sub.2--O--(CF.sub.2).sub.5COOH and salts of any of
these fluorinated carboxylic acids.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority to Great Britain
Application No. 0525978.3, filed on Dec. 21, 2005; Great Britain
Application No. 0523853.0, filed on Nov. 24, 2005; Great Britain
Application No. 0514398.7, filed on Jul. 15, 2005; and Great
Britain Application No. 0514387.0 filed on Jul. 15, 2005, all of
which are herein incorporated by reference in their entirety.
[0002] The present invention relates to the recovery of fluorinated
carboxylic acids and derivatives thereof from adsorbent
particles.
[0003] Polymerization of fluoroolefins to manufacture
fluoropolymers, i.e. polymers having a fluorinated backbone, is
often performed in aqueous media. In one such process referred to
as emulsion polymerization, fluorinated carboxylic acids are
typically used as surfactants in the aqueous media. Examples of
these fluorosurfactants include the perfluorinated alkanecarboxylic
acids having 7 to 10 carbon atoms, in particular perfluorooctanoic
acid (PFOA). These acids are generally used in the salt form,
preferably as ammonium salts. Fluoropolymerization to make
"granular fluoropolymer" is also done in aqueous media in a process
sometimes referred to as suspension polymerization, though with
less fluorosurfactant (or none) than is used in dispersion
polymerization. For a discussion of the processes, see
"Tetrafluoroethylene Polymers" in the Encyclopedia of Polymer
Science and Engineering, John Wiley & Sons, New York, 1989,
Vol. 16, p. 580.
[0004] Because of its expense and to avoid undesirable release in
the environment, the fluorosurfactant used in the polymerization
processes is typically removed from the dispersions and waste
streams generated in the manufacturing of the fluoropolymer,
including waste waters and exhaust gas. An effective and frequently
used method involves adsorbing the fluorosurfactant to adsorbent
particles such as activated carbon and anion exchange resins. Such
processes have been described in EP 1514848, EP 1093441, EP 1084097
and WO 2005/082785. Following the adsorption to the adsorbent
particles, the fluorosurfactant is typically recovered there from
using an eluting liquid as disclosed in for example EP 0014431,
EP1069078, U.S. Pat. No. 6,642,415, EP 1323677 and U.S. Pat. No.
3,882,153.
[0005] These processes are typically practiced for recovering
perfluorooctanoic acid or salts thereof, which is the most widely
used surfactant in making fluoropolymers through aqueous emulsion
polymerization. Unfortunately, these surfactants are eliminated
only slowly from the body of living organisms and they hence show
an undesirably high bioaccumulation. Notwithstanding the fact that
these surfactants are recovered from the adsorbent particles, these
processes themselves are disadvantages because operators of these
processes may come into contact with the surfactants or derivatives
thereof and hence special measures are typically necessary to avoid
such contact or to at least minimize exposure of the operators to
these compounds.
[0006] There was therefore a desire to find alternative surfactants
that can be used in the making of fluoropolymer in aqueous emulsion
polymerization and that can be recovered from adsorbent particles.
It was in particular desirable to find alternative surfactants that
eliminate faster from the body of living organisms and that thus
have lower bioaccumulation than perfluorooctanoic acid or salts
thereof.
[0007] In accordance with one aspect of the present invention,
there is provided a process comprising recovery of fluorinated
carboxylic acid or derivative thereof from adsorbent particles on
which fluorinated carboxylic acid or a salt thereof is adsorbed, by
contacting said adsorbent particles with a liquid composition
capable of removing at least part of said fluorinated carboxylic
acid or salt thereof from said adsorbent particles, wherein said
fluorinated carboxylic acid or salt thereof is selected from the
group consisting of fluorinated carboxylic acids or salts thereof
that correspond to the general formula:
[R.sub.fO-L-COO.sup.-].sub.iX.sup.i+ (I) wherein L represents a
linear partially or fully fluorinated alkylene group or an
aliphatic hydrocarbon group, R.sub.f represents a linear partially
or fully fluorinated aliphatic group or a linear partially or fully
fluorinated aliphatic group interrupted with one or more oxygen
atoms, X.sup.i- represents a cation having the valence i and i is
1, 2 or 3.
[0008] It has been found that the fluorinated carboxylic acids or
salts thereof according to formula (I) are suitable for making
fluoropolymers by aqueous emulsion polymerization. These compounds
can be removed from dispersions and waste streams by adsorbing them
on adsorbent particles. They can furthermore be recovered from
these adsorbent particles using a liquid composition capable of
removing at least part of said fluorinated carboxylic acid or salt
thereof from said adsorbent particles so that the fluorinated
carboxylic acid can be re-used (after possible further
purification) in the polymerization of fluorinated monomers. The
fluorinated carboxylic acids or salts thereof typically have lower
bioaccumulation than perfluorooctanoic acids or salts thereof and
hence the elution process according to the invention provides
advantages for the operators involved with the process.
[0009] By the term `liquid composition capable of removing at least
part of said fluorinated carboxylic acid or salt thereof from said
adsorbent particles` is meant a liquid that is capable of
dissolving and/or desorbing the fluorinated carboxylic acid and/or
its salt or that alternatively converts the fluorinated carboxylic
acid or salt into a derivative such as an ester that may be
recovered from the mixture of adsorbent particles and the liquid.
For sake of convenience, the liquid composition capable of removing
at least part of said fluorinated carboxylic acid or salt thereof
from said adsorbent particles will hereinafter be referred to as
eluting liquid.
[0010] Fluorinated Carboxylic Acid
[0011] For the sake of convenience, the term `fluorinated
carboxylic acid` is hereinafter used to indicate the free acid as
well as salts thereof. The fluorinated carboxylic acid used in the
process of the invention corresponds to formula (I) above.
Generally, the fluorinated carboxylic acid will be a low molecular
weight compound, for example a compound having a molecular weight
for the anion part of the compound of not more than 1000 g/mol,
typically not more than 600 g/mol and in particular embodiments,
the anion of the fluorinated carboxylic acid may have a molecular
weight of not more than 500 g/mol.
[0012] Particularly preferred fluorinated carboxylic acids are
those that when administered to rats show a recovery of at least
45%, for example at least 50% of the administered amount after 96
hours via renal elimination and that have a renal elimination
half-life of not more than 35 hours, for example of not more than
30 hours in rats as tested according to the method set forth in the
examples. Generally, fluorinated carboxylic acids in which each of
the fluorinated aliphatic moieties in the compound have not more
than 3 carbon atoms fulfill the aforementioned conditions of renal
recovery and half-life. Thus, preferred compounds are those in
which any fluorinated alkylene groups have not more than 3 carbon
atoms and in which a fluorinated alkyl group of the compound has
not more than 3 carbon atoms.
[0013] In the above formula (I), L represents a linking group. In
one embodiment, the linking group can be a linear partially or
fully fluorinated alkylene. Fully fluorinated alkylene groups
include alkylene groups that consist of only carbon and fluorine
atoms whereas partially fluorinated alkylene groups may
additionally contain hydrogen. Generally, a partially fluorinated
alkylene group should not contain more than 2 hydrogen atoms so as
to be highly fluorinated and be non-telogenic or at least have
minimal telogenic effects. Examples of fully fluorinated alkylene
groups include linear perfluorinated alkylenes that have from 1 to
6 carbon atoms, for example linear perfluorinated alkylene groups
of 1, 2, 3, 4 or 5 carbon atoms.
[0014] Examples of linear partially fluorinated alkylene groups
include those that have from 1 to 6 carbon atoms. In a particular
embodiment the linear partially fluorinated alkylene linking group
has 1, 2, 3, 4, 5 or 6 carbon atoms and has only 1 or 2 hydrogen
atoms. When the partially fluorinated alkylene group has 2 hydrogen
atoms, they may be attached to the same carbon atom or they can be
attached to different carbon atoms. When they are attached to
different carbon atoms, such carbon atoms can be adjacent to each
other or not. Also, in a particular embodiment, a carbon atom
having 1 or 2 hydrogen atoms may be adjacent the ether oxygen atom
to which the linking group is attached or adjacent the carboxylic
group to which the linking group is attached at its other end.
[0015] In a further embodiment, the linking group L is an aliphatic
hydrocarbon group. Examples of aliphatic hydrocarbon groups include
linear, branched or cyclic aliphatic groups. Particular examples of
aliphatic groups include linear or branched alkylene groups of 1 to
4 carbon atoms such as for example methylene or ethylene.
[0016] Particular examples of linking groups L may be selected from
the following:
[0017] --(CF.sub.2).sub.g-- wherein g is 1, 2, 3, 4, 5 or 6;
[0018] --CFH--(CF.sub.2).sub.h-- wherein h is 0, 1, 2, 3, 4 or
5;
[0019] --CF.sub.2--CFH--(CF.sub.2).sub.d-- wherein d is 0, 1, 2, 3
or 4;
[0020] --CH.sub.2--(CF.sub.2).sub.h-- wherein h is 1, 2, 3 or
4;
[0021] --(CH.sub.2).sub.c-- wherein c is 1, 2, 3 or 4;
[0022] In the above examples, the left side of the formula of the
linking group is the site where the linking group is connected to
the ether oxygen in formula (I).
[0023] The R.sub.f group in formula (I) represents a linear
partially or fully fluorinated aliphatic group or a linear
partially or fully fluorinated aliphatic group interrupted with one
or more oxygen atoms. In one embodiment, R.sub.f is a linear
perfluorinated aliphatic group having 1 to 6 carbon atoms,
preferably having 1, 2, 3 or 4 carbon atoms. According to another
embodiment R.sub.f is a linear perfluorinated aliphatic group
interrupted with one or more oxygen atoms of which the alkylene
groups between oxygen atoms have not more than 4 or 6 carbon atoms,
for example 3 or less carbon atoms and wherein the terminal alkyl
group has not more than 4 or 6 carbon atoms, for example 3 or less
carbon atoms. According to a still further embodiment, R.sub.f is a
linear partially fluorinated aliphatic group having 1 to 6 carbon
atoms and not more than 2 hydrogen atoms or a linear partially
fluorinated aliphatic group interrupted with one or more oxygen
atoms and which has not more than 2 hydrogen atoms. In the latter
embodiment, it will generally be preferred that any perfluorinated
alkylene moiety has not more than 4 or 6 carbon atoms and any
terminal perfluorinated alkyl group, likewise preferably should not
have more than 6 carbon atoms, for example not more than 4 carbon
atoms. A particular example of a partially fluorinated aliphatic
group R.sub.f is CF.sub.3CFH--.
[0024] In a particular embodiment, R.sub.f may correspond to the
following formula:
R.sub.f.sup.1--[OR.sub.f.sup.2].sub.p--[OR.sub.f.sup.3].sub.q--
(II)
[0025] wherein R.sub.f.sup.1 is a perfluorinated linear aliphatic
group of 1 to 6 carbon atoms (for example 3 or less), R.sub.f.sup.2
and R.sub.f.sup.3 each independently represents a linear
perfluorinated alkylene of 1, 2, 3 or 4 carbon atoms and p and q
each independently represent a value of 0 to 4 and wherein the sum
of p and q is at least 1.
[0026] In another embodiment, R.sub.f may correspond to the
following formula: R.sup.7.sub.f--(O).sub.t--CFH--CF.sub.2--
(III)
[0027] wherein t is 0 or 1 and R.sup.7.sub.f represents a linear
partially or fully fluorinated aliphatic group optionally
interrupted with one or more oxygen atoms. Typically R.sup.7.sub.f
does not contain perfluorinated aliphatic moieties of more than 4
or 6 carbon atoms. For example, in one embodiment, R.sup.7.sub.f is
a perfluorinated linear aliphatic group of 1 to 6 carbon atoms. In
another embodiment, R.sup.7.sub.f is a group corresponding to above
formula (II).
[0028] In yet a further embodiment, R.sub.f may correspond to the
following formula: R.sub.f.sup.1--(OCF.sub.2).sub.a-- (IV)
[0029] wherein a is an integer of 1 to 6 and R.sub.f.sup.8 is a
linear partially fluorinated aliphatic group or a linear fully
fluorinated aliphatic group having 1, 2, 3 or 4 carbon atoms. When
R.sub.f.sup.8 is a partially fluorinated aliphatic group, the
number of carbon atoms preferably is between 1 and 6 and the number
of hydrogen atoms in the partially fluorinated aliphatic groups is
preferably 1 or 2.
[0030] In a still further embodiment, R.sub.f may correspond to the
following formula: R.sub.f.sup.9--O--(CF.sub.2).sub.b-- (V)
[0031] wherein b is an integer of 1 to 6, preferably 1, 2, 3 or 4
and R.sub.f.sup.9 is a linear partially fluorinated aliphatic group
or a linear fully fluorinated aliphatic group having 1, 2, 3 or 4
carbon atoms. When R.sub.f.sup.9 is a partially fluorinated
aliphatic group, the number of carbon atoms preferably is between 1
and 6 and the number of hydrogen atoms in the partially fluorinated
groups is preferably 1 or 2.
[0032] In a particular embodiment of the present invention, the
fluorinated carboxylic acid corresponds to the following formula:
[R.sub.f.sup.a--(O).sub.t--CHF--(CF.sub.2).sub.n--COO.sup.-].sub.iX.sup.i-
+ (VI)
[0033] wherein R.sub.f.sup.a represents a linear partially or fully
fluorinated aliphatic group optionally interrupted with one or more
oxygen atoms, t is 0 or 1 and n is 0 or 1, X.sup.i+ represents a
cation having a valence i and i is 1, 2 or 3, with the proviso that
when t is 0, the R.sub.f.sup.a contains at least one ether oxygen
atom.
[0034] In a particular aspect of this embodiment, the R.sub.f.sup.a
is selected from the group consisting of linear perfluorinated
aliphatic groups of 1 to 6 carbon atoms, preferably having 1 to 4
carbon atoms, perfluorinated groups of the formula
R.sub.f.sup.1--[OR.sub.f.sup.2].sub.p--[OR.sub.f.sup.3].sub.q--
wherein R.sub.f.sup.1 is a linear perfluorinated aliphatic group of
1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, R.sub.f.sup.2
and R.sub.f.sup.3 each independently represents a linear
perfluorinated alkylene of 1, 2, 3 or 4 carbon atoms and p and q
each independently represent a value of 0 to 4 and wherein the sum
of p and q is at least 1 and perfluorinated groups of the formula
R.sub.f.sup.4--[OR.sub.f.sup.5].sub.k--[OR.sub.f.sup.6].sub.m--O--CF.sub.-
2-- wherein R.sub.f.sup.4 is a linear perfluorinated aliphatic
group of 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms,
R.sub.f.sup.5 and R.sub.f.sup.6 each independently represents a
linear perfluorinated alkylene of 1, 2, 3 or 4 carbon atoms and k
and m each independently represent a value of 0 to 4.
[0035] Fluorinated carboxylic acid of formula (VI) can be derived
from fluorinated olefins of the general formula:
R.sup.a.sub.f--(O).sub.t--CF.dbd.CF.sub.2 (VIa)
[0036] wherein R.sup.a.sub.f and t are as defined above. Compounds
according to formula (VIa) are well known in the art and include
fluorinated olefins such as perfluorinated alkyl vinyl compounds,
vinyl ethers in particular perfluorovinyl ethers and allyl ethers,
in particular perfluorinated allyl ethers.
[0037] Fluorinated carboxylic acids according to formula (VI)
wherein n is 0 can be prepared by reacting a fluorinated olefin of
formula (VIa) with a base. The reaction is generally carried out in
aqueous media. An organic solvent may be added to improve the
solubility of the fluorinated olefin. Examples of organic solvents
include glyme, tetrahydrofuran (THF) and acetonitrile. Additionally
or alternatively a phase transfer catalyst may be used. As a base,
use can be made of for example ammonia, alkali and earth alkali
hydroxides. Without intending to be bound by any theory, it is
believed, that the reaction proceeds according to the following
sequence when ammonia is used as a base:
R.sub.f--(O).sub.t--CF.dbd.CF.sub.2+NH.sub.3+H.sub.2O.fwdarw.R.sub.f--(O)-
.sub.t--CHF--COONH.sub.4+NH.sub.4F
[0038] The reaction is generally carried out between 0 and
200.degree. C., for example between 20-150.degree. C. and at a
pressure between about 1 bar up to about 20 bar. For further
purification, the obtained salts can be distilled via the free acid
or by first converting the acid into an ester derivative and then
distilling the ester derivative followed by hydolysis of the ester
to obtain the purified acid or salt thereof.
[0039] Fluorinated carboxylic acids of formula (VI) wherein n is 0
can also be prepared by reacting a fluorinated olefin of formula
(VIa) with a hydrocarbon alcohol in an alkaline medium and then
decomposing the resulting ether in acidic conditions thereby
forming the corresponding carboxylic acid. Suitable hydrocarbon
alcohols include aliphatic alcohols such as lower alkanols having 1
to 4 carbon atoms. Specific examples include methanol, ethanol and
butanol including t-butanol. The reaction of the fluorinated olefin
with the alcohol in an alkaline medium may be carried out as
described in "Furin et al., Bull Korean Chem. Soc. 20, 220 (1999)".
The reaction product of this reaction is an ether derivative of the
fluorinated olefin. This resulting ether can be decomposed under
acidic conditions as described in "D. C. England, J. Org. Chem. 49,
4007 (1984)" to yield the corresponding carboxylic acid or salt
thereof.
[0040] To prepare fluorinated carboxylic acids of formula (VI)
wherein n is 1, a free radical reaction of the fluorinated olefin
of formula (VIa) with methanol may be carried out followed by an
oxidation of the resulting reaction product. The free radical
reaction is typically carried out using a free radical initiator as
is typically used in a free radical polymerization reaction.
Examples of suitable free radical initiators include persulfates
such as for example ammonium persulfate. Detailed conditions of the
free radical reaction of the fluorinated carboxylic acid with an
alcohol can be found in "S. V. Sokolov et al., Zh. Vses. Khim Obsh
24, 656 (1979)". The resulting alcohol derivative of the
fluorinated olefin can be chemically oxidized with an oxidizing
agent to the corresponding carboxylic acid. Examples of oxidizing
agents include for example potassium permanganate, chromium (VI)
oxide, RuO.sub.4 or OsO.sub.4 optionally in the presence of NaOCl,
nitric acid/iron catalyst, dinitrogen tetroxide. Typically the
oxidation is carried out in acidic or basic conditions at a
temperature between 10 and 100.degree. C. In addition to chemical
oxidation, electrochemical oxidation may be used as well.
[0041] In another embodiment, the fluorinated carboxylic acid
corresponds to the following formula:
R.sub.f.sup.b--(O).sub.t--CFH--CF.sub.2--O--R-G (VII)
[0042] wherein R.sub.f.sup.b represents a linear partially or fully
fluorinated aliphatic group optionally interrupted with one or more
oxygen atoms, R is an aliphatic hydrocarbon group, G represents a
carboxylic acid or salt thereof, t is 0 or 1. Particular examples
for R include a methylene group or an ethylene group.
[0043] In a particular aspect of this embodiment, the R.sub.f.sup.b
is selected from the group consisting of linear perfluorinated
aliphatic groups of 1 to 6 carbon atoms, preferably having 1 to 4
carbon atoms, perfluorinated groups of the formula
R.sub.f.sup.1--[OR.sub.f.sup.2].sub.p--[OR.sub.f.sup.3].sub.q--
wherein R.sub.f.sup.1 is a linear perfluorinated aliphatic group of
1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, R.sub.f.sup.2
and R.sub.f.sup.3 each independently represents a linear
perfluorinated alkylene of 1, 2, 3 or 4 carbon atoms and p and q
each independently represent a value of 0 to 4 and wherein the sum
of p and q is at least 1 and perfluorinated groups of the formula
R.sub.f.sup.4--[OR.sub.f.sup.5].sub.k--[OR.sub.f.sup.6].sub.m--O--CF.sub.-
2-- wherein R.sub.f.sup.4 is a linear perfluorinated aliphatic
group of 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms,
R.sub.f.sup.5 and R.sub.f.sup.6 each independently represents a
linear perfluorinated alkylene of 1, 2, 3 or 4 carbon atoms and k
and m each independently represent a value of 0 to 4.
[0044] Fluorinated carboxylic acids according to formula (VII) may
be prepared through the preparation of an intermediate of formula
(VIIa): R.sub.f.sup.b--(O).sub.t--CFH--CF.sub.2--O--R-Z
[0045] wherein R.sub.f.sup.b, t and R have the same meaning as
defined above. Z represents a carboxylic acid ester or a
carboxylamide.
[0046] The intermediate compound according to formula (VIIa) can be
prepared by reacting a fluorinated olefin of the general formula
(VIa) with an organic compound of the formula HO--R-Z (VIIb)
[0047] wherein Z and R are as defined above. Compounds according to
formula (VIIb) are well known in the art and/or are commercially
available. The reaction of compound (VIa) with compound (VIIb) is
typically carried out in the presence of a base although it is also
possible to carry out the reaction under acidic or neutral
conditions. Suitable bases include carbonates such as potassium
carbonate, sodium carbonate and lithium carbonate, hydroxides,
alkoholates etc. The amount of base used may vary widely. For
example a catalytic amount may be used. Generally the amount of
base used will be about at least 1 or 2% by weight based on the
amount of reactant of formula (VIIb). In a particular embodiment,
the amount of base can be upto 2 times the molar amount of the
reactant of formula (VIIb). The reaction is typically carried out
in an aprotic solvent such as for example, tetrahydrofuran,
acetonitrile, glyme, diglyme etc. Further suitable aprotic solvents
are disclosed in DE 3828063. The reaction is typically carried out
a temperature between 0 and 200.degree. C., for example between 10
and 150.degree. C. The reaction is generally carried out at an
ambient pressure (1 bar) or up to 20 bar. Following the reaction,
the resulting compound may be isolated and purified by
distillation.
[0048] The fluorinated carboxylic acids of formula (VII) can be
readily prepared by hydrolyzing the intermediate compound of
formula (VIIa) above. In formula (VIIa) above, Z represents a
carboxylic acid ester or a carboxylamide. Typically a carboxylic
acid ester is used. In one embodiment, the ester can be an
aliphatic ester, e.g. an alkyl ester in which the number of carbon
atoms in the alkyl group are from 1 to 4. Hydrolysis of the
intermediate compound may be carried out under acidic or basic
conditions and is generally carried out in an alcoholic acidic or
basic solution of the intermediate compound. Alternatively the
intermediate compound may be hydrolysed in an acidic or basic
solution of other water miscible organic solvents such as ketones,
ethers etc. Typically, a basic alcoholic solution is used such as
for example a methanol or ethanol solution containing an alkali
metal hydroxide as the base. Typically the hydrolysis is carried
out at room temperature but it is also possible to use elevated
temperatures of for example up to the boiling point of the
solution.
[0049] Alternatively, the fluorinated surfactant may be prepared by
reacting the fluorinated olefin of formula (VIa) above with a
hydroxy substituted carboxylic acid or salt thereof.
[0050] Thus, in accordance with this embodiment the fluorinated
olefin of formula (VIa) is reacted with a compound of the formula:
HO--R-G (VIc)
[0051] wherein G is a carboxylic acid group or salt thereof and R
is as defined above. The reaction of a fluorinated olefin of
formula (VIa) with a hydroxy compound or formula (VIIc) can be
carried out under the same conditions described above for the
reaction with compounds of formula (VIIb).
[0052] In a still further embodiment, the fluorinated carboxylic
acid corresponds to one of the following formulas:
R.sub.f.sup.c--(OCF.sub.2).sub.u--O--(CF.sub.2).sub.v-AC (VIII)
[0053] wherein u is an integer of 1 to 6, v is an integer of 1 to
6, R.sub.f.sup.c represents a linear perfluorinated aliphatic group
of 1, 2, 3 or 4 carbon atoms and AC represents a carboxylic acid
group or salt thereof, and
R.sub.f.sup.c--O--(CF.sub.2).sub.y--O-L.sup.1-AC (IX)
[0054] wherein y has a value of 1, 2, 3, 4, 5 or 6, L.sup.1
represents a linear perfluorinated alkylene of 1, 2, 3, 4, 5 or 6
carbon atoms or a linear partially fluorinated alkylene having 1 to
6 carbon atoms and 1 or 2 hydrogen atoms, R.sub.f.sup.c is as
defined in above formula (VIII) and AC represents a carboxylic acid
group or salt thereof. A particular example for L.sup.1 includes a
group of the formula --CFH--. Particular compounds according to
formula (IX) include those wherein R.sub.f.sup.c represents
CF.sub.3CFH--. Such groups can be obtained from decarboxylation of
--CF(CF.sub.3)COOX groups (X is a cation) in the presence of a
protic substance as described in JOC 34, 1841 (1969).
[0055] Fluorinated carboxylic acids of formula (VIII) are
commercially available from Anles Ltd., St. Petersburg, Russia.
These compounds may be prepared for example as described by Ershov
and Popova in Fluorine Notes 4(11), 2002. Also, these fluorinated
carboxylic acids typically form as byproducts in the manufacturing
of hexafluoropropylene oxide by direct oxidation of
hexafluoropropylene.
[0056] Fluorinated carboxylic acids according to formula (IX) can
be derived from reactants that are also used in the manufacturing
of fluorinated vinyl ethers as described in U.S. Pat. No.
6,255,536.
[0057] In another embodiment acid fluorides of formula (X) are
reacted with a metal fluoride like KF or CsF: R.sub.f.sup.g--COF
(X)
[0058] wherein R.sub.f.sup.g is a partially or perfluorinated
linear aliphatic chain optionally interrupted with one or more
oxygen atoms. This reaction results in an alkoxylate that can be
further reacted with a carboxylic acid derivative of formula (XI)
Y--(CH.sub.2).sub.n-Q (XI)
[0059] wherein Y represents a leaving group like iodide, bromide,
chloride, mesylate, tosylate and the like, n is an integer from 1
to 3, and Q represents a carboxyl acid group or a lower alkyl
ester. The reaction results in fluorinated carboxylic acid
derivatives of formula (XII)
R.sub.f.sup.g--CF.sub.2--O--(CH.sub.2).sub.nQ (XII)
[0060] with R.sub.f.sup.g n, and Q having the same meaning as
above. The corresponding salts can be obtained by
saponification.
[0061] In yet a further embodiment the fluorinated carboxylic acids
correspond to formula (XIII)
CF.sub.3--CF.sub.2--O--R.sub.f.sup.h--COOX (XIII)
[0062] with R.sub.f.sup.h representing a linear partially or fully
fluorinated linear carbon chain of 1 to 8 carbon atoms optionally
interrupted with one or more oxygen atoms, for example a
perfluorinated linear aliphatic group of 1 to 6 carbon atoms, for
example 1, 2, 3 or 4 carbon atoms and X is a monovalent cation.
Compounds of this formula can be made by conversion of diacid
difluorides of formula (XIV) in the presence of e.g. antimony
pentafluoride. FOC--CF(CF.sub.3)--O--R.sub.f.sup.h--COF (XIV)
[0063] This conversion may be carried out at elevated temperature
according to the method described in U.S. Pat. No. 3,555,100
resulting preferably in the decarbonylation of the secondary COF
group. The resulting mono acid fluoride can be converted to the
corresponding salt using well known methods.
[0064] Fluorinated carboxylic acids having a --O--CF.sub.2--COOX
group can be obtained from the corresponding vinyl ethers
--O--CF.dbd.CF.sub.2. Reaction of the vinyl ether with oxygen
according to U.S. Pat. No. 4,987,254 results in acid fluorides
carrying a --O--CF.sub.2COF group which can be readily converted to
the corresponding acid or salt.
[0065] Specific examples of compounds according to formula (I)
include the following:
R.sub.f--O--CHF--COOH
[0066] C.sub.3F.sub.7--O--CHF--COOH
[0067] CF.sub.3--O--CF.sub.2CF.sub.2--CF.sub.2--O--CHF--COOH
[0068]
CF.sub.3CF.sub.2CF.sub.2--O--CF.sub.2CF.sub.2--CF.sub.2--O--CHF--C-
OOH
[0069] CF.sub.3--O--CF.sub.2--CF.sub.2--O--CHF--COOH
[0070]
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CHF--COOH
[0071]
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CHF--COOH
[0072]
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CHF--COOH
R.sub.f--O--CHF--CF.sub.2--COOH
[0073] CF.sub.3--O--CHF--CF.sub.2--COOH
[0074] CF.sub.3--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--COOH
[0075] CF.sub.3--CF.sub.2--O--CHF--CF.sub.2--COOH
[0076]
CF.sub.3--O--CF.sub.2--F.sub.2--CF.sub.2--O--CHF--CF.sub.2--COOH
[0077]
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--CO-
OH
[0078]
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CHF--CF.s-
ub.2--COOH
[0079]
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CHF--CF.s-
ub.2--COOH
R.sub.f--O--CF.sub.2--CHFCOOH
[0080] CF.sub.3--O--CF.sub.2--CHF--COOH
[0081] C.sub.3F.sub.7--O--CF.sub.2--CHF--COOH
[0082]
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--COOH
[0083]
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--CO-
OH
[0084]
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--
-CHF--COOH
[0085]
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CF.sub.2--
-CHF--COOH
R.sub.f--O--CF.sub.2--CHF--CF.sub.2COOH
[0086] CF.sub.3--O--CF.sub.2--CHF--CF.sub.2--COOH
[0087] C.sub.2F.sub.5--O--CF.sub.2--CHF--CF.sub.2--COOH
[0088] C.sub.3F.sub.7--O--CF.sub.2--CHF--CF.sub.2--COOH
[0089]
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--CF.su-
b.2--COOH
[0090]
CF.sub.3--O--CF.sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CHF--CF-
.sub.2--COOH
[0091]
CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--CF.sub.2--O--CF.sub.2--
-CHF--CF.sub.2--COOH
[0092]
CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--CF.sub.2--O--CF.sub.2--
-CHF--CF.sub.2--COOH
R.sub.f--(O).sub.m--CHF--CF.sub.2--O--(CH.sub.2).sub.n--COOH n=1,2
or 3; m=0 or 1
[0093] CF.sub.3--O--CHF--CF.sub.2--O--CH.sub.2--COOH
[0094]
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--O--CH-
.sub.2--COOH
[0095] C.sub.3F.sub.7--O--CHF--CF.sub.2--O--CH.sub.2--COOH
[0096]
C.sub.3F.sub.7--O--CHF--CF.sub.2--O--CH.sub.2--CH.sub.2--COOH
[0097]
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--OCH.sub.2-
COOH
[0098]
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--
-OCH.sub.2COOH
[0099]
C.sub.3F.sub.7--O--CF.sub.2--CHF--CF.sub.2--OCH.sub.2COOH
[0100] CF.sub.3--CHF--CF.sub.2--O--CH.sub.2COOH
[0101] C.sub.3F.sub.7--CF.sub.2--CHF--CF.sub.2--OCH.sub.2--COOH
[0102] CF.sub.3--O--CF.sub.2--CF.sub.2--O--CH.sub.2--COOH
[0103]
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--CF.sub.2---
O--CH.sub.2--COOH
[0104] C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CH.sub.2--COOH
[0105]
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CH.sub.2--CH.sub.2--COOH
[0106]
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--O--CF.sub.2--CF.sub.2--OCH.-
sub.2COOH
[0107]
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2-CF.su-
b.2--OCH.sub.2COOH
[0108]
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--CF.sub.2--OCH.sub.2COOH
[0109] C.sub.4F.sub.9--O--CH.sub.2--COOH
[0110] C.sub.4F.sub.9--O--CH.sub.2--CH.sub.2--COOH
[0111] C.sub.3F.sub.7--O--CH.sub.2COOH
[0112] C.sub.6F.sub.13--OCH.sub.2--COOH
R.sub.f--O--CF.sub.2--CF.sub.2--COOH
[0113] CF.sub.3--O--CF.sub.2--CF.sub.2--COOH
[0114] C.sub.2F.sub.5--O--CF.sub.2--CF.sub.2--COOH
[0115] C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--COOH
[0116] C.sub.4F.sub.9--O--CF.sub.2--CF.sub.2--COOH
R.sub.f--(O--CF.sub.2).sub.u--O--CF.sub.2--COOH with u being as
defined above
[0117] CF.sub.3--(O--CF.sub.2).sub.3--O--CF.sub.2--COOH
[0118] CF.sub.3--(O--CF.sub.2).sub.2--O--CF.sub.2--COOH
[0119] CF.sub.3--(O--CF.sub.2).sub.1--O--CF.sub.2--COOH
R.sub.f--(O--CF.sub.2--CF.sub.2).sub.k--O--CF.sub.2--COOH with k
being 1, 2 or 3
[0120]
CF.sub.3--(O--CF.sub.2--CF.sub.2).sub.1--O--CF.sub.2--COOH
[0121]
C.sub.2F.sub.5--(O--CF.sub.2--CF.sub.2).sub.1--O--CF.sub.2--COOH
[0122]
C.sub.3F.sub.7--(O--CF.sub.2--CF.sub.2).sub.1--O--CF.sub.2--COOH
[0123]
C.sub.4F.sub.9--(O--CF.sub.2--CF.sub.2).sub.1--O--CF.sub.2--COOH
[0124]
C.sub.2F.sub.5--(O--CF.sub.2--CF.sub.2).sub.2--O--CF.sub.2--COOH
[0125]
CF.sub.3--(O--CF.sub.2--CF.sub.2).sub.2--O--CF.sub.2--COOH
[0126]
C.sub.3F.sub.7--(O--CF.sub.2--CF.sub.2).sub.2--O--CF.sub.2--COOH
[0127]
C.sub.4F.sub.9--(O--CF.sub.2--CF.sub.2).sub.2--O--CF.sub.2--COOH
R.sub.f--O--CF.sub.2--COOH
[0128] C.sub.3F.sub.7--O--CF.sub.2--COOH
[0129]
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CF.sub.2--COOH
CF.sub.3--CHF--O--(CF.sub.2).sub.o--COOH with o being an integer of
1, 2, 3, 4, 5 or 6
[0130] CF.sub.3CFH--O--(CF.sub.2).sub.3--COOH
[0131] CF.sub.3CFH--O--(CF.sub.2).sub.5--COOH
CF.sub.3--CF.sub.2--O--(CF.sub.2).sub.o--COOH with o being as
above
[0132] CF.sub.3--CF.sub.2--O--(CF.sub.2).sub.3COOH
[0133] CF.sub.3--CF.sub.2--O--(CF.sub.2).sub.5COOH
[0134] In the above generic formulas, R.sub.f has the meaning as
defined above in respect of generic formula (I). It is understood
that while the above list of compounds only lists the acids, the
corresponding salts, in particular the NH.sub.4.sup.+, potassium,
sodium or lithium salts can equally be used.
[0135] Adsorbent Particles
[0136] By the term `absorbent particles` in connection with the
present invention is meant particles that are capable of physically
adsorbing the fluorinated carboxylic acid or salt thereof by
whatever mechanism of physical adsorption including but not limited
to ionic interactions causing physical adsorption. Accordingly, the
term `adsorbent particles` include ion exchange resins, which
typically bind fluorinated carboxylic acids, which have ionic
groups, as a result of an ion exchange process although the
adsorption to the exchange resin may also occur by a physical
adsorption process other than the ion exchange process.
[0137] Suitable adsorbent particles further include activated
carbon, silica gel, clays and zeolites. Conveniently used are
activated carbon particles. The shape of the adsorbent particles is
not particularly critical. For example, the adsorbent particles may
have a plate shape, can be spherical, cylindrical or they can be
rods. Also, adsorbent particles having a variety of different
shapes may be used as a mixture. The size of the adsorbent
particles is typically between 0.05 mm and 20 mm, generally between
0.1 and 10 mm. A practical range is between 0.5 and 5 mm. The
adsorbent particles typically adsorb the fluorinated carboxylic
acid on their surface and it will thus generally be preferred to
optimize the specific surface area of the particles, i.e. the
amount of surface per unit of weight. Typically, the specific
surface area of the adsorbent particles will be between 10 and 5000
m.sup.2/g, generally between 100 and 3000 m.sup.2/g with a
practical range being from 300 to 2000 m.sup.2/g.
[0138] Additionally, anion exchange resin particles can be used as
adsorbent particles. Examples of anion exchange resin that can be
used to adsorb a fluorinated carboxylic acid include strong, medium
strong as well as weak basic anion exchange resins. The terms
strong, medium strong and weak basic anion exchange resin are
defined in "Encyclopedia of Polymer Science and Engineering", John
Wiley & Sons, 1985, Volume 8, page 347 and "Kirk-Othmer", John
Wiley & Sons, 3.sup.rd edition, Volume 13, page 687. Strong
basic anion exchange resin typically contain quaternary ammonium
groups, medium strong resins usually have tertiary amine groups and
weak basic resins usually have secondary amines as the anion
exchange functions. Examples of anion exchange resins that are
commercially available for use in this invention include
AMBERLITE.RTM. IRA-402, AMBERJET.RTM. 4200, AMBERLITE.RTM. IRA-67
and AMBERLITE.RTM. IRA-92 all available from Rohm & Haas,
PUROLITE.RTM. A845 (Purolite GmbH) and LEWATIT.RTM. MP-500 (Bayer
AG).
[0139] Eluting Liquid
[0140] The fluorinated carboxylic acids that are adsorbed on an
adsorbent particle may be recovered therefrom by eluting the loaded
adsorbent particles with an eluting liquid capable of desorbing
and/or dissolving the fluorinated carboxylic acid or a derivative
thereof. The nature and composition of the eluting liquid typically
depends on the nature of the adsorbent particles to which the
fluorinated carboxylic acid is adsorbed and typically includes an
organic solvent. Also, the recovery or elution of the adsorbent
particles may be practiced over a wide range of temperature. For
example, in one embodiment, the recovery is practiced at ambient
temperature, i.e. between 10 and 35.degree. C. In another
embodiment, the recovery may be carried out at elevated temperature
of for example 40.degree. C. or more up to in certain embodiments
the boiling point of the eluting liquid.
[0141] In one embodiment, the fluorinated carboxylic acid may be
recovered from strongly, medium strong or weak basic anion exchange
resin particles. The terms strong, medium strong and weak basic
anion exchange resin are defined in "Encyclopedia of Polymer
Science and Engineering", John Wiley & Sons, 1985, volume 8,
page 347 and "Kirk-Othmer", John Wiley & Sons, 3.sup.rd
edition, Volume 13, page 687. Strong basic anion exchange resins
typically contain quaternary ammonium groups, medium strong resins
usually have tertiary amine groups and weak basic resins usually
have secondary amines as the anion exchange functions.
[0142] Suitable eluting liquids for eluting the fluorinated
carboxylic acids from basic anion exchange resin particles include
a mixture of a mineral acid and a water miscible organic solvent.
Suitable mineral acids are all those the anions of which confer a
salt form upon the anion exchanger (anion form) which is
appropriate to the further adsorption of fluorinated emulsifying
acids. Under the conditions of elution their oxidation strength
should generally be so low that the anion exchanger will not be
damaged oxidatively. Mineral acids that can be used include, for
example ortho-, meta-, and diphosphoric acid, nitric acid and
preferably hydrochloric acid and sulfuric acid.
[0143] Suitable organic solvents include polar organic solvents
such as alcohols, aliphatic or aromatic ethers, nitrites, amides,
sulfoxides, ketones and carboxylic acid esters. Preferred solvents
include those that are substantially miscible with water, i.e.
miscible to at least 40% by volume when mixing equal volumes, or
solvents that are completely miscible with water. Solvents of this
type are especially aliphatic alcohols having from 1 to 4 carbon
atoms, preferably methanol and ethanol, as well as mono- and
dimethyl ethers and mono- and diethyl ethers of ethylene glycol or
of the corresponding monoethers of polyglycols having a chain
length up to that of decaethylene glycol. It is likewise possible
to use mixtures of the aforesaid solvents.
[0144] A typical eluting liquid may be prepared from the mineral
acid and the organic solvent to be used the acid concentration of
which, calculated on the total mixture, is adjusted in the range of
from 0.5 to 10 N, preferably 0.5 to 2 N. In said mixture the
proportion of mineral acid (including the water portion) to solvent
ranges from 1:0.25 to 1:20, preferably 1:3 to 1:10 parts by
volume.
[0145] For a quantitative elution of the adsorbed fluorinated
carboxylic acids 50 to 500 and preferably 100 to 225 parts by
volume, calculated on 100 parts of anion exchanger matrix, of the
mixture of mineral acid and organic solvent is typically used.
[0146] When the elution is terminated the eluate generally
separates into two layers of which the lower layer having the
higher specific gravity contains approximately the entire amount of
fluorinated carboxylic acid. The lower layer may be neutralized
with dilute, usually 2 N sodium hydroxide solution and the
fluorinated carboxylic acid is typically precipitated in compact
form and easy to separate by adding the neutralized phase while
stirring to dilute hydrochloric acid.
[0147] In another embodiment, the eluting mixture for the elution
of fluorinated carboxylic acid adsorbed to an anion exchange resin
comprises a) water, b) a compound of the formula M-X in which M is
an alkali metal or alkyl ammonium ion, and X is hydroxyl, fluoride
or chloride, and c) at least one organic solvent capable of
dissolving the other components a) and b) and thus provides a
sufficient quantity of anions X for the elution of the fluorinated
carboxylic acid from the anion exchanger resin.
[0148] In a particular aspect of this embodiment, the eluting
liquid has the following composition: [0149] a) from 15 to 40% of
water, [0150] b) from 1 to 10 of the compound M-A, and [0151] c)
from 60 to 70% of the solvent.
[0152] In another aspect, the eluting mixture has the following
composition:
[0153] a) from 18 to 35% of water,
[0154] b) from 2 to 8% of M-A, and
[0155] c) from 60 to 70% of solvent.
[0156] Useful solvents include those mentioned above. Suitable
cations M include lithium, sodium, potassium, tetramethylammonium
and tetraethylammonium, and the preferred anion A is hydroxyl.
[0157] In yet a further embodiment, the fluorinated carboxylic acid
may be recovered from a strongly basic anion exchange resin using
an eluting liquid comprising an ammonium salt and a water miscible
organic solvent. The ammonium salt is typically one that
corresponds to the general formula: (NH.sub.4).sub.nA
[0158] wherein A represents an anion other than OH.sup.- and n
equals the valence of A. Examples of anions A include inorganic as
well as organic anions. Particular examples of inorganic anions
include halogen or halogen containing inorganic anions such as for
example F.sup.-, Cl.sup.-, Br.sup.-, I.sup.-, ClO.sub.4.sup.-,
phosphates, sulfates, sulfonates, carbonates including
HCO.sub.3.sup.- and CO.sub.3.sup.2-. Examples of organic anions
include in particular carboxylic anions such as for example
HCOO.sup.- and CH.sub.3COO.sup.-.
[0159] The amount of ammonium salt in the eluting liquid will
generally depend on the nature of the anion exchange resin and the
amount of fluorinated carboxylic acid adsorbed on the anion
exchange resin and/or the percentage of recovery that is desired. A
suitable amount of ammonium salt is generally at least 0.1% by
weight. According to a particular embodiment, the amount of
ammonium salt is between 0.1 and 5% by weight based on the total
weight of the composition used for eluting the exchange resin.
[0160] The eluting composition further includes a water-miscible
solvent. By `water miscible solvent` is generally meant an organic
solvent that has solubility in water of at least 5% by weight, for
example at least 10% by weight or at least 20% by weight. Suitable
water-miscible solvents are typically polar solvents including for
example alcohols, ketones, ethers and mixtures thereof Particular
examples of solvents include lower alkanols having between 1 and 6
carbon atoms such as for example methanol, ethanol and propanol;
glycols, mono- and dialkyl ethers or monoglycol and diglycol
wherein the alkyl groups have between 1 and 4 carbon atoms; ketones
such as acetone and methyl ethyl ketone. The amount of water
miscible organic may vary widely but should generally be enough to
dissolve the ammonium salt. The amount of water-miscible organic
solvent is generally at least 50% by weight of the total weight of
the eluting composition. Exemplary ranges are 50 to 99.9% by
weight, or between 60 and 90% by weight or between 90 and 98% by
weight.
[0161] The eluting liquid comprising the ammonium salt and a
water-miscible solvent may contain further components that may aid
in the recovery of the fluorinated carboxylic acid from the anion
exchange resin. In one particular embodiment, the eluting
composition further comprises water. Water may for example be used
in the eluting composition in an amount of up to 45% by weight, for
example in an amount of 0.1 to 40% by weight or in amount between 1
and 15% by weight or in an amount between 4 and 10% by weight.
[0162] A further component that may be present in the eluting
liquid is a base. Suitable bases that may be used are alkali metal
hydroxides such as for example sodium hydroxide and potassium
hydroxide. Other bases that may be used include earth alkali metal
hydroxides, aluminium hydroxide or alcoholates such as for example
sodium methylate. When present, the amount of base included in the
composition is generally up to about 5% by weight. An exemplary
range is from 0.1 to 5% or from 0.5 to 2% by weight.
[0163] Further eluting liquids include those disclosed in U.S. Pat.
No. 6,642,415 and EP 1,323,677. The latter discloses eluting
liquids comprising an alkaline mixture of water and an organic
solvent. An aqueous ammonia solution as disclosed in U.S. Pat. No.
3,882,153 may also be used.
[0164] According to a further embodiment, the fluorinated
carboxylic acid may be recovered by mixing the adsorbent particles
(e.g. ion exchange resin or activated carbon) with an alcohol and
optionally an acid. The mixture is then generally heated to cause
esterification of the fluorinated carboxylic acid with the alcohol
so as to form an ester derivative of the fluorinated carboxylic
acid. The so obtained mixture may then be distilled to form a
distillate comprising the ester derivative followed by separation
of the ester derivative from the distillate. Generally, the eluting
liquid will also comprise water.
[0165] Suitable alcohols that may be used include in particular
lower aliphatic alcohols having 1 to 5 carbon atoms such as
methanol, ethanol and propanol. However aromatic alcohols may be
used as well. Additionally, the alcohol may be added under the form
of a precursor of the alcohol. Such a precursor should however form
an alcohol under the conditions used to cause the esterification.
Suitable precursors of the alcohol may include compounds such as
ketals that readily form a corresponding alcohol under the acidic
conditions existing in the eluting liquid or mixture thereof with
the adsorbent particles. The acid used with the eluting fluid is
preferably an inorganic acid but the use of organic acids is not
excluded. Also, the acid is preferably a strong acid such as for
example sulphuric acid, hydrochloric acid, phosphoric acid or
nitric acid. The amount and nature of the acid used is typically
such that a pH of less than 4, preferably not more than 3 and more
preferably not more than 2 is attained in the mixture of eluting
liquid and adsorbent particles.
[0166] Depending on the amount of water present in the distillate
the ester derivative may separate out as a separate phase,
typically the lower phase, from the distillate. Thus the ester
derivative can be easily separated from the distillate and the
remainder of the distillate can be re-introduced into the mixture
being distilled. Such a circulating regeneration process thus
allows a convenient regeneration of the adsorbent particles with a
minimal amount of eluting fluid being needed. The received ester
can be further purified by distilllation and is then converted to
the fluorinated acid salt by saponification typically with ammonia.
The eluated purified fluorinated carboxylic acid salt will
typically have a purity sufficient to allow use of the compound in
emulsion polymerization of fluorinated monomers. The adsorbent
particles can be regenerated several times before their efficiency
drops below an uneconomical level at which point the adsorbent
particles need to be disposed of.
[0167] Following their recovery, the fluorinated carboxylic acids
can be purified to the desired high purity enabling re-use of the
fluorinated carboxylic acid in an aqueous emulsion polymerization.
A suitable purification method is disclosed in U.S. Pat. No.
5,312,935. Herein the liberated and dewatered carboxylic acids are
treated with oxidants like dichromates, peroxodisulfates or
permanganates at a temperature of about 60.degree. C. to the
boiling point of the mixture. The pure product is then isolated by
crystallization e.g. at low temperature or preferably by
distillation if desired under reduced pressure. Alternatively, the
method of WO 2004/031141 may be used.
EXAMPLES
[0168] Test Method:
[0169] Content of Fluorinated Carboxylic Acid
[0170] The amount of fluorinated carboxylic acid in aqueous
solution was determined by conversion of the fluorinated emulsifier
into the methyl ester followed by an analysis with gas
chromatography (head space) using methyl ester of perfluorodecanoic
acid as an internal standard. The detection limit was about 10
ppm.
[0171] Particle Size
[0172] The latex particle size determination was conducted by means
of dynamic light scattering with a Malvern Zetazizer 1000 HAS in
accordance to ISO/DIS 13321. Prior to the measurements, the polymer
latexes as yielded from the polymerizations were diluted with 0.001
mol/L KCl-solution, the measurement temperature was 25.degree. C.
in all cases. The reported average is the Z-average particle
diameter. [0173] SSG: Standard specific gravity was measured
according ASTM 4894-04 [0174] Solid Content: Determination of solid
content was done by subjecting the latex sample to a temperature up
to 250.degree. C. for 30 min.
[0175] Polymerization of Fluorinated Monomers (Fluoroolefin) Using
a Fluorinated Carboxylic Acid
[0176] The polymerization experiments were performed in a 40 l
kettle equipped with an impeller agitator and a baffle. The kettle
was charged with 30 l of deionized water and set to 35.degree. C.;
the kettle was evacuated repeatedly to remove oxygen; Agitation
speed was set to 165 rpm. The oxygen free kettle was charged with
70 mmol fluorinated emulsifier (unless specified differently) as
listed in table 3 and the following materials were added: 0.5 ml of
a solution containing 40 mg of copper sulphate penta hydrate and 1
mg of conc. sulphuric acid; 15 g of a 25 w-% of aqueous ammonia
solution and 5.6 g of
CF.sub.3CF.sub.2CF.sub.2--O--CF(CF.sub.3)--CF.sub.2--O--CF.dbd.CF.sub.2
(PPVE-2). Finally the reactor was pressurized with
tetrafluoroethylene (TFE) to 0.2 MPa and 47 g of
hexafluoropropylene (HFP) were added. The kettle was then set to
1.5 MPa using TFE and 100 ml of an aqueous initiator solution
containing 140 mg of sodium disulfite followed by 100 ml of a
solution containing 340 mg of ammonium peroxodisulfate was pumped
into the reactor. The beginning of the polymerization is indicated
by a pressure drop. During polymerization the pressure was
maintained at 1.5 MPa by feeding TFE continuously. After 3.2 kg of
TFE had been added, the monomer valve was closed and the pressure
was released. The characteristics of the obtained polymer latices
are summarized in table 3.
[0177] 1000 ml of this polymer dispersion were coagulated by adding
20 ml hydrochloric acid under agitation. The coagulated material
was agglomerated with gasoline and washed repeatedly. The
agglomerated polymer was dried overnight at 200.degree. C. in a
vacuum oven; test data are given in table 3. TABLE-US-00001 TABLE 1
Emulsifiers used: C.sub.7F.sub.15COONH.sub.4 Comparative example
C-1 ##STR1## Comparative example C-2 ##STR2## Comparative example
C-3 CF.sub.3--O--(CF.sub.2).sub.3--O--CF.sub.2--COONH.sub.4
Compound 1 CF.sub.3--OCF.sub.2--O--CF.sub.2--COONH.sub.4 Compound 2
CF.sub.3--OCF.sub.2--OCF.sub.2--OCF.sub.2--COONH.sub.4 Compound 3
CF.sub.3--(OCF.sub.2).sub.3--OCF.sub.2--COONH.sub.4 Compound 4
C.sub.3F.sub.7--O--CF.sub.2--COONH.sub.4 Compound 5
CF.sub.3--O--CF.sub.2--CF.sub.2--COONH.sub.4 Compound 6
C.sub.2F.sub.5--O--CF.sub.2--CF.sub.2--COONH.sub.4 Compound 7
C.sub.3F.sub.7--O--CF.sub.2--CF.sub.2--COONH.sub.4 Compound 8
C.sub.4F.sub.9--O--CF.sub.2--CF.sub.2--COONH.sub.4 Compound 9
C.sub.2F.sub.5--O--CF.sub.2--CF.sub.2--O--CF.sub.2--COONH.sub.4
Compound 10
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--CF.sub.2--COONH.sub.4
Compound 11
CF.sub.3--O--CF.sub.2--CF.sub.2--CF.sub.2--O--CHF--COONH.sub.4
Compound 12 C.sub.3F.sub.7--O--CFH--CF.sub.2COONH.sub.4 Compound 13
CF.sub.3--CFH--O--(CF.sub.2).sub.5--COONH.sub.4 Compound 14
CF.sub.3--CFH--O--(CF.sub.2).sub.3--COONH.sub.4 Compound 15
C.sub.3F.sub.7--O--CFH--CF.sub.2--O--CH.sub.2--COONH.sub.4 Compound
16 C.sub.3F.sub.7--O--CFH--COONH.sub.4 Compound 17
Preparation of compound 1:
CF.sub.3OCF.sub.2CF.sub.2CF.sub.2OCF.sub.2COONH.sub.4
[0178] Oxidation of perfluorinated vinyl ethers with oxygen in the
presence of SbF.sub.5 was carried out as described in U.S. Pat. No.
4,987,254. The initially formed acid fluorides were esterified with
methanol and purified by distillation. The distilled esters were
converted to the corresponding ammonium salts by saponification
with aqueous ammonia. A dry flask equipped with a magnetic stirrer
bar, thermometer, dry ice reflux condenser, dropping funnel, and
gas inlet tube was charged with 5 g of graphite. The flask was
flushed with nitrogen and 332 g of
CF.sub.3OCF.sub.2CF.sub.2CF.sub.2OCF.dbd.CF.sub.2 were added at
room temperature. 2.6 g of SbF.sub.5 was added via the dropping
funnel and oxygen was charged to the flask at ambient pressure. An
exothermic reaction indicated the oxidation. Total reaction time
was 14 h. After the first hour 2.6 g and after 7 hours 3.5 g of
SbF.sub.5 were added. Esterification was achieved by slow addition
of 50 g of methanol to the reaction mixture. The resulting ester
was isolated from the batch by flash distillation after addition of
300 g water and 50 g methanol. The distillate formed two phases.
The lower phase was separated and the upper phase retuned to the
flask. 310 g of lower phase were collected. GC analysis showed a
content of 52% of
CF.sub.3OCF.sub.2CF.sub.2CF.sub.2OCF.sub.2COOCH.sub.3. Purification
via fractionated distillation resulted in 144 g pure ester with a
boiling point of 51.degree. C. at 52 mbar.
CF.sub.3OCF.sub.2CF.sub.2COOCH.sub.3 was isolated as by product.
Saponification of the ester with aqueous ammonia at 60-80.degree.
C. and removal of methanol by distillation resulted in an aqueous
solution of CF.sub.3OCF.sub.2CF.sub.2CF.sub.2OCF.sub.2COONH.sub.4.
All structures were confirmed by F-NMR spectra.
Preparation of compound 5:
CF.sub.3CF.sub.2CF.sub.2OCF.sub.2COONH.sub.4
[0179] Using the procedures described in U.S. Pat. No. 4,987,254,
CF.sub.3CF.sub.2CF.sub.2OCF.dbd.CF.sub.2 was converted to
CF.sub.3CF.sub.2CF.sub.2OCF.sub.2COOCH.sub.3 (bp 102-104.degree.
C.). Saponification with aqueous ammonia and removal of methanol by
distillation resulted in an aqueous solution of
CF.sub.3CF.sub.2CF.sub.2OCF.sub.2COONH.sub.4. Structures were
confirmed by F-NMR spectra.
Preparation of compound 17:
CF.sub.3CF.sub.2CF.sub.2OCHFCOONH.sub.4
[0180] A 2 liter glass flask equipped with a mechanical stirrer,
thermometer and reflux condenser (-80.degree. C.) is used. Heating
of the flask is provided by an electric heating mantle. The
conversion is carried out as a one pot reaction. 275 g
perfluoropropyl vinyl ether (PPVE), 280 g KOH, 602 g water, 151 g
t-butanol, and 10 g methyl trioctyl ammonium chloride are placed in
the flask. The three phase mixture is subjected to vigorous
stirring. After initial heating a moderate exothermic reaction
occours. Mixing is continued for nine hours. During this time the
internal temperature adjusts to 27-33.degree. C. Mixing is stopped
when the exothermic reaction ceases. The reaction mixture forms two
layers. The low temperature reflux condenser is replaced by a
standard reflux condenser. Sulfuric acid (392 g) is slowly added
without external cooling. The batch is heated to reflux. Unreacted
PPVE is vented. At about 80.degree. C. internal temperature gas
begins to evolve. Heating is continued until the gas evolution has
ceased. At this time the internal temperature reaches 101.degree.
C. The batch is cooled to RT and the reflux condenser is replaced
by a distillation device. No column is used. 110 g methanol is
added to the batch and distillation is started.
[0181] The condensed vapors form two layers. The lower layer is
separated and the upper layer is returned to the flask.
Distillation is stopped when no more lower phase is formed. In
total, 234 g of lower phase are collected. Fractionation of the
lower phase yields 167 g of C.sub.3F.sub.7OCHFCOOCH.sub.3 with a
boiling point of 120-122.degree. C. at ambient pressure. Calculated
yield: 59% based on total PPVE used; 70% based on converted PPVE.
The ester is converted to the ammonium salt by reaction with
aqueous ammonia. Methanol is removed by fractionated distillation.
The resulting aqueous solution is used as an emulsifier in the
polymerization of fluorinated olefins.
Preparation of compound 12:
CF.sub.3OCF.sub.2CF.sub.2CF.sub.2OCHFCOONH.sub.4
[0182] A glass flask equipped with a reflux condenser, thermometer,
and magnetic stirrer was used. Perfluoromethoxy propyl vinyl ether
(498 g), t-butanol (149 g), water (1007 g), potassium hydroxide
(280 g), and methyl trioctyl ammonium chloride (10 g) were added to
the flask. The resulting two phase mixture was heated to reflux for
16 hours under vigorous stirring. The mixture was cooled to room
temperature and sulphuric acid (588 g) was added. The two phase
mixture was heated again under vigorous stirring. At about
70.degree. C. gas began to evolve. Heating was continued until the
gas evolution ceased. The reflux condenser was replaced by a
distillation device which allowed the separation of a lower phase
while returning the upper phase to the flask. Methanol (150 g) was
added and the mixture was heated for distillation. Distillation was
carried out at ambient pressure without any intent for
rectification. The condensed vapors separated into two phases. The
lower phase was collected and the upper phase was returned to the
flask. Distillation was continued until no more lower phase
separated from the condensate. The combined crude ester (493 g) was
purified by fractionated distillation, resulting in 401 g
CF.sub.3O(CF.sub.2).sub.3OCHFCOOCH.sub.3 with a boiling point of 51
to 52.degree. C./ 22 mbar. This corresponds to a yield of 78%,
based on vinyl ether used.
[0183] The ester was converted to the ammonium salt by heating with
aqueous ammonia and removal of methanol by fractionated
distillation.
[0184] Alternatively, the previous reaction was repeated but 36 g
of an aqueous solution containing 11 g of
CF.sub.3O(CF.sub.2).sub.3OCHFCOONH.sub.4 was used as phase transfer
catalyst instead of methyl trioctyl ammonium chloride. The mixture
was slowly heated to 70.degree. C. internal temperature. Total
reaction time was 26 hours. Work up was carried out as described
above. 438 g of distilled CF.sub.3O(CF.sub.2).sub.3OCHFCOOCH.sub.3
was received. This corresponds to a yield of 83% (calculation
includes the amount of phase transfer catalyst). The conversion to
the ammonium salt was carried out as above.
Preparation of compound 13:
C.sub.3F.sub.7OCHFCF.sub.2COONH.sub.4
a. Preparation of
CF.sub.3CF.sub.2CF.sub.2OCHFCF.sub.2CH.sub.2OH
[0185] In a 2 liter glass flask equipped with a stirrer,
thermometer, reflux condenser, and dropping funnel were placed 1008
g methanol, 266 g perfluoropropyl vinyl ether, and 9.2 g of
Rongalit.RTM. (sodium hydroxymethyl sulfinate). The reaction
mixture was heated to reflux, resulting in an internal temperature
of 29.degree. C. 7.1 g t-butyl hydroperoxide (70% in water) is
added in aliquots during a 9 h time frame. The internal temperature
reached 52.degree. C. at the end. The reaction mixture showed a
single liquid phase and some solids. The liquid was analyzed by GC
and indicated a content of 223 g of
C.sub.3F.sub.7OCHFCF.sub.2CH.sub.2OH which corresponded to a yield
of 75%.
[0186] Distillation of the reaction mixture resulted in 171 g of
product (bp 54.degree. C./23 mbar) corresponding to an isolated
yield of 57%.
b. Preparation of C.sub.3F.sub.7OCHFCF.sub.2COONH.sub.4
[0187] A 2 liter glass flask equipped with a thermometer, reflux
condenser, dropping funnel and stirrer was used. 674 g water, 136 g
KMnO4, and 38 g NaOH are placed in the flask. 169 g
C.sub.3F.sub.7OCHFCF.sub.2CH.sub.2OH were added to the well stirred
mixture via the dropping funnel. The temperature is held below
50.degree. C. Residual permanganate was destroyed by addition of a
small amount of methanol. The resulting slurry was filtered to
remove the MnO.sub.2. After washing the filter cake with water, the
combined filtrate was transferred to a distillation apparatus and
acidified with 65 g of sulfuric acid. 100 g methanol was added and
a flash distillation was started. The distillate formed two layers.
The lower layer was separated and the upper layer returned to the
distillation pot. In total 182 g lower layer were collected.
Fractionation of the crude ester resulted in 137 g of
C.sub.3F.sub.7OCHFCF.sub.2COOCH.sub.3 with a boiling point of
55-56.degree. C./52 mbar. This corresponds to a yield of 77%.
[0188] The ester was converted to the ammonium salt by
saponification with aqueous ammonia and subsequent removal of
methanol by distillation.
Preparation of compound 11:
CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2COONH.sub.4
a. Preparation of
CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2CH.sub.2OH
[0189] Using equipment similar to the described above, 255 g of
perfluoromethoxypropyl vinyl ether and 730 g methanol were
converted with Rongalit and t-butylhydroperoxide as radical source.
Reaction temperature started at 47.degree. C. and reached
64.degree. C. at the end. Work up by distillation yielded 166 g of
pure CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2CH.sub.2OH with a boiling
point of 60-61.degree. C./20 mbar. This corresponds to a yield of
59%.
b. Preparation of
CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2COONH.sub.4
[0190] A 2 liter glass flask equipped with a thermometer, reflux
condenser, dropping funnel and stirrer was used. 159 g of
CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2CH.sub.2OH, 520 g water, and
100 g sulfuric acid were added to the flask. 190 g KMnO4 were added
manually to the liquid over a period of 2 hours while stirring. The
reaction temperature increased to 95.degree. C. over time. After a
post reaction time of two hours, an aqueous solution of sodium
bisulfite was added until a clear solution was formed. 100 g of
methanol and in total 400 g of 50% aqueous sulphuric acid were
added. Flash distillation of the reaction mixture resulted in a two
phase distillate. Fractionation of the lower phase (120 g) gave
85.5 g of CF.sub.3O(CF.sub.2).sub.3OCHFCF.sub.2COOCH.sub.3 (bp
34-35.degree. C./6 mbar; yield 50%).
[0191] The ester was converted to the ammonium salt by
saponification with aqueous ammonia and subsequent removal of
methanol by distillation.
Preparation of Compound 6
[0192] CH.sub.3--O--CF.sub.2--CF.sub.2--COOCH.sub.3 was fluorinated
as described in WO 01/46116; the acid fluoride
CF.sub.3--O--CF.sub.2--CF.sub.2--COF was then converted into the
methylester. The distilled ester was converted into the
ammonia-salt as described above.
Preparation of compound 14:
CF.sub.3--CFH--O--(CF.sub.2).sub.5COONH.sub.4
[0193] A sample of diacid fluoride,
FCOCF(CF.sub.3)--O--(CF.sub.2).sub.5COF (500 g, 1.1 mol) prepared
from the hexafluoropropylene oxide (HFPO) coupling of
perfluoroadipoyl fluoride as described in U.S. Pub. No.
2004/0116742 and was added over 2 hours to a stirred slurry of
sodium carbonate (500 g, 4.7 mol) in 500 g of diglyme at 85.degree.
C. to make the disalt. The reaction liberated CO.sub.2 gas.
Distilled water (25 g, 1.4 mol) was added at 85.degree. C. The
mixture was heated up to 168.degree. C. with CO.sub.2 off-gassing
and held for 30 minutes. Reaction was cooled down and sulphuric
acid (350 g, 3.6 mol) in 1100 g of water was added to make the
reaction mixture acidic. Bottom phase was washed with 400 g of 50%
sulfuric acid and vacuum distilled to give
CF.sub.3--CFH--O--(CF.sub.2).sub.5COOH 426 g, 1.0 mol for a 95%
yield having a boiling point of 132-135.degree. C./15 mm. This was
followed by the addition of 46 g NaOH in 63 g of water. Dried salts
in vacuum oven at 112.degree. C./15 mm Hg to give 386 g of slight
yellow sticky solids. To the salt was added sulphuric acid and the
lower fluorochemical phase was vacuum distilled. The previous
process was repeated two more times to yield a colorless acid. The
surfactant CF.sub.3--CFH--O--(CF.sub.2).sub.5COONH.sub.4 having a
melting point of 159-165.degree. C. was made quantitatively from
the reaction of 200 g of acid reacted with excess ammonium
hydroxide and dried.
Preparation of Compound 15:
CF.sub.3--CFH--O(CF.sub.2).sub.3COONH.sub.4
[0194] A sample of diacid fluoride,
FCOCF(CF.sub.3)--O--(CF.sub.2).sub.3COF (503 g, 1.4 mol) prepared
from the HFPO coupling of perfluorosuccinyl fluoride as described
in U.S. Pub. No. 2004/0116742 and was added over 2 hours to a
stirred slurry of sodium carbonate (387 g, 3.7 mol) in 650 g of
diglyme at 78.degree. C. to make the disalt. The reaction liberated
CO.sub.2 gas. Distilled water (35 g, 1.9 mol) was added at
85.degree. C. The mixture was heated up to 165.degree. C. with
CO.sub.2 off-gassing and held for 30 minutes. Reaction was cooled
down and sulphuric acid (250 g, 2.6 mol) in 1250 g of water was
added to make the reaction mixture acidic. To the bottom phase was
added 60 g NaOH in 60 g of water. Dried the salt in vacuum oven at
112.degree. C./15 mm and recovered 450 g. To the salt was added 300
g of 50% sulphuric acid and the lower fluorochemical phase was
washed once with 200 g of 50% sulphuric acid. Vacuum distillation
gave CF.sub.3--CFH--O--(CF.sub.2).sub.3COOH (400 g, 1.3 mol) for a
95% yield having a boiling point of 111.degree. C./15 mm Hg. The
acid was treated with caustic followed by sulphuric acid and vacuum
distilled. This was repeated a second time to yield a colorless
acid. The surfactant CF.sub.3--CFH--O--(CF.sub.2).sub.3COONH.sub.4
having a melting point of 64-68.degree. C. was made quantitatively
from the reaction of 208 g of acid reacted with excess ammonium
hydroxide and dried.
Preparation of compound C-3
[0195] Conversion of
CF.sub.3CF.sub.2CF.sub.2OCF(CF.sub.3)CF.sub.2OCF.dbd.CF.sub.2 to
CF.sub.3CF.sub.2CF.sub.2OCF(CF.sub.3)CF.sub.2OCF.sub.2COOCH.sub.3
(bp 91-92.degree. C. at 133 mbar) was carried described in U.S.
Pat. No. 4,987,254. The ester was reacted with aqueous ammonia and
methanol was removed by distillation resulting in
CF.sub.3CF.sub.2CF.sub.2OCF(CF.sub.3)CF.sub.2OCF.sub.2COONH.sub.4.
All structures were confirmed by F-NMR spectra. Due to an isomer
content in the vinyl ether, an isomer with the structure
CF.sub.3CF.sub.2CF.sub.2OCF.sub.2CF(CF.sub.3)OCF.sub.2COOX
(X.dbd.CH.sub.3, NH.sub.4) was found.
Preparation of compound 16:
C.sub.3F.sub.7--O--C.sub.2HF.sub.3--O--CH.sub.2--COONH.sub.4
[0196] A mixture of 320 ml Tetrahydrofurane, 40 g Hydroxy acetic
methylester and 188 g PPVE is cooled to 0.degree. C., 27 g
KOH-powder are added in small portions--during the addition of KOH,
the reaction mixture heats up to 60.degree. C. After the addition
of KOH, the whole reaction mixture is agitated for 6 h at
25.degree. C. The precipitated salt is separated by filtration,
dissolved in 300 ml water and then treated with 57 g
H.sub.2SO.sub.4 (conc). The resulting mixture separates in two
layers; the lower phase is
C.sub.3F.sub.7--O--C.sub.2HF.sub.3--O--CH.sub.2--COOH, 86 g (56%).
The distilled acid (bp. 125.degree. C., 20 mbar) is neutralized
with 25% aqueous ammonia solution to provide a 30% solution in
water.
[0197] Compounds 2, 3, 4 were prepared from the corresponding
carboxylic acids (purchased from Anles Ltd. St. Petersburg, Russia)
by neutralizing with aqueous ammonia.
[0198] Compounds 7, 8, 10 were prepared from the corresponding
carboxylic acid fluorides (.about.COF) [purchased from Exfluor,
Round Rock, Tex., USA]. The acid fluorides were converted by
addition of methanol to the methylester. The distillated
methylester were saponified with aqueous ammonia at 60-80.degree.
C. and methanol is removed by distillation.
[0199] Compound C-2 was prepared as described in U.S. Pat. No.
6,703,520 (column 7).
[0200] Determination of Bio-Accumulation
[0201] The perfluorinated and partially fluorinated carboxylates
were evaluated for urinary clearance using a pharmacokinetic study
in rats. The goal was to measure the total amount of parent
compound eliminated via urinary output and estimate the rate of
elimination. The study was approved by the IACUC (Institutional
Animal Care and Use Committees) and was performed in 3M Company's
AAALAC (Association for Assessment and Accreditation of Laboratory
Animal Care)--accredited facility.
[0202] The study utilized male Sprague Dawley rats, 6 to 8 weeks of
age, and approximately 200 to 250 g body weight at study onset. The
test compounds of table 2 were administered at a dose of 73 micro
Moles per kg body weight in rats (N=3 animals per tested compound).
All test compounds were prepared in sterile deionized water and
given to rats via oral gavage. After test compounds administration,
the rats were housed individually in metabolism cages for urine
collection: 0 to 6 hours, 6 to 24 hours, 24 to 48 hours and 72 to
96 hours. Animals were observed throughout the study for clinical
signs of toxicity. Gross necropsy was performed at the termination
of each study (96 hours post-dose) with sera and liver samples
being retained from each animal.
[0203] The concentration of the parent compound or metabolites
thereof were quantitatively measured via fluorine NMR on each urine
sample for each animal at each time point based on internally added
standards.
[0204] The bioaccumulation data obtained in accordance with the
above test are reported in table 2 below. TABLE-US-00002 TABLE 2 %
Recovery Compound-related T1/2 (h) (96 h) Effects C-1 .about.550 6
Hepatomegaly C-2 29 40 Hepatomegaly C-3 95 5 Hepatomegaly Compound
1 10 73 -- Compound 2 12 96 -- Compound 3 12 100 -- Compound 4 15
50 -- Compound 5 11 97 -- Compound 6 11 100 -- Compound 7 10 100 --
Compound 8 12 82 -- Compound 9 31 42 Hepatomegaly Compound 10 10 99
-- Compound 11 12 84 -- Compound 12 11 95 Compound 13 11 94 --
Compound 14 24 32 Hepatomegaly Compound 15 8 95 -- Compound 16 13*
65* -- *No parent compound observed in the urine. T1/2 and %
recovery are based on elimination of the major metabolite
--C.sub.3F.sub.7--O--CHFCOO.sup.-. T.sub.1/2 is the renal half-life
and is the time required for the amount of a particular substance
in a biological system to be reduced to one half of its value by
biological processes when the rate of removal is # approximately
exponential. In these examples the value of T.sub.1/2 is calculated
by exponential least squares curve fitting (y = Ae.sup.Bx and
T.sub.1/2 = 0.693/B) where y represents the concentration of
analyte in urine and x represents time in hours.
[0205] TABLE-US-00003 TABLE 3 2 C-1 C-2 C-3 1 (140 mmol) 3 4 5 6
Polymerization 101 77 87 74 109 69 82 73 84 time (min) Average
Particle 111 118 113 110 129 115 109 122 122 Size (nm) SSG 2.166
2.165 2.149 2.169 2.157 2.165 2.163 2.169 2.175 (g/cm.sup.3) Solid
content 9.9 10.0 10.3 10.3 9.7 10.1 10.2 10.0 7.1 (w-%) 7 14 (140
mmol) 8 9 10 11 12 13 (140 mmol) 15 Polymerization 73 79 72 72 82
82 83 75 78 time (min) Average Particle 129 115 113 102 126 108 128
127 105 Size (nm) SSG 2.159 2.167 2.165 2.166 2.168 2.167 2.164
2.151 2.154 (g/cm.sup.3) Solid content 10.1 10.0 10.2 10.1 10.2
10.3 10.2 8.1 10. (w-%)
[0206] Recovery of Fluorinated Ether Carboxylic Acids from
Adsorbents
[0207] 300 ml of Amberlite IRA 402 OH a strong basic anion
exchanger from Rohm & Haas was charged with
CF.sub.3O(CF.sub.2).sub.3OCF.sub.2COONH.sub.4 until break-through.
The resin was transferred into a column and washed with 3 1 of
deionized water.
[0208] 700 ml of a mixture of 60:20:20 wt-% of methanol:water:
sulphuric acid (conc.) (herein called regeneration solution) was
circulated for 6 hours through the column with a flow rate of about
1.4 l/h. The regeneration solution was pumped from the top of a
feeding tank through the column and back into the feeding tank
(flow direction through the column from top to bottom). The elution
was done at room temperature. During the recovery step phase
separation occurred in the tank due to the formation of the
corresponding ester
(CF.sub.3O(CF.sub.2).sub.3OCF.sub.2COOCH.sub.3). The lower phase,
essentially consisting of the ester was separated.
[0209] The resin was then washed with 1.5 l of methanol/water
(90:10 wt-%) and 800 ml of deionized water (both with a flow rate
of 300 ml/h). The washing solutions and the upper phase of the tank
were allowed to stand for a period of 16 hours to achieve
additional phase separation. The lower phase was separated and
added to the ester phase.
[0210] The upper phase, mainly containing methanol, water,
sulphuric acid and residual ester, was distillated under
atmospheric pressure. The purified methanol contained residual
amount of ester and was used for the next regeneration process. The
overall recovery efficiency calculated on ester was about 88%. The
regenerated ion-exchange resin could be re-used several times.
[0211] Recycling of Fluorinated Ether Carboxylic Acids
[0212] 70 g of CF.sub.3O(CF.sub.2).sub.3OCF.sub.2COOCH.sub.3, 50 g
methanol, 30 g water and 7 g of sulphuric acid were flash
distillated at atmospheric pressure. The distillate formed two
phases and the upper phase was returned to the flask. The lower
phase, mainly consisting of the ester
(CF.sub.3O(CF.sub.2).sub.3OCF.sub.2COOCH.sub.3) was separated and
purified in a further step via fractionated distillation. 53 g of
pure ester were collected at a boiling point of about 50.degree. C.
at 50 mbar. The ester was saponified with aqueous ammonia at
60-80.degree. C. and methanol was removed by distillation. The
resulting aqueous solution of
CF.sub.3O(CF.sub.2).sub.3OCF.sub.2COONH.sub.4 was used as an
emulsifier for tetrafluoroethylene polymerization to show
"polymerization grade" of the product after the recycling process.
No deviation between virgin and recycled material was observed
during polymerization process.
* * * * *