Note: Descriptions are shown in the official language in which they were submitted.
1~0~94
FL~ORINATION OF AGETALS._KET~LS AND ORTHOESTERS
Back~round
Perfluoropolyethers are highly regarded in the
~peci~lty lmbricant field because of thelr wide
liqu~d ran~e~l low vapor pressure5 and high thermal
and oxidat~ve ~t~billt~s. Because o$ the~e
propert~os (msny of whlch are unique to
fluoroc~rbons), they are excellent high performance
lubricants, superlor base stocks for ~reases,
~xcellent lu~icat~ng olls, ~nd heat transfer
flu~ds. ln sdd~tlon, because of these uniquely
outst~nding propert~es. satur~ted
perfluoropolyethers ~re of current interese as
speci~lty sealAnts, ela~eomers and pl~stic~.
In splee of their unlimlted poten~lal, only
three perfluoropolyethers ~r~ co~mercially av~ll8~1e
to date bec~u~e o~ the lack of fl~orocarbon
inter~edlates which are suitable for prepar~n~ the
polymers, They are: -
1. DuPont'~ Krytox~ flu~d ~hich is m~de bypolymerizing hexafluoropropyleno ox~de.
.. , .. ~
~ ~3 10294
2. Demnum~ fluid, a product of Daikin
Industries, is obtained by ring opening
polymerization of 2,2,3,3-tetrafluoro-
oxetane using a catalyst with subsequent
treatment of the highly fluorinated
polyether with fluorine gas to give a
perfluorinated product.
3. Montedison's Fomblin Z~ and Fomblin Y~
fluids which are prepared by
photooxidizing tetrafluoroethylene and
hexafluoropropylene oxide, respectively,
in the presence of oxygen.
A process has been described for preparing
perfluoropolyethers by reaction of a hydrocarbon
polyether with elemental fluorine in the presence of a
hydrogen fluoride scavenger. See U.S. Patent No.
4,755,567.
Summary of the Invention
The present invention relates to perhalogenated
polyethers having essentially the following formula:
R1 R3
X-[O~I~(O~CF2~~F)p]n~[OIC~(O-CF2-1CF)t]m-oz
R2 R5 R4 R6
wherein R1, R2, R3, R4, Rs and R6 are the same or
different and are selected from the group consisting
of -F, -Cl, -CF2Cl, -CFC12, -CC13, perfluoroalkyl of
one to ten carbon atoms, perfluoroalkoxyalkyl of one
to ten carbon atoms and perfluoroalkoxyether of one
to ten carbon atoms wherein one or more of the
fluorine atoms can be substituted by a halogen atom
other than fluorine; X and Z are the same or
different and are selected from the group consisting
of -(CF2)rCOF, -(CF2)rOCF3, -(CF2)rCOOH and
1~102!~ 1
-CrF2r+1_qClq~ wherein r is an integer from 1 to 12
and q is an integer from O to 25; n is an integer
from 2 to 1,000; m is an integer from O to 1000; p
and t are the same or different and are integers from
1 to 50, provided that when p and t are one and R1,
R2, R3 and R4 together are F, then Rs or R6 is a
group other than fluorine.
The invention also relates to perhalogenated
polyethers of the formula:
IRl
X-(o-c)n~~z (II)
R2
wherein X and Z are the same or different and are
selected from the group consisting of -(CF2)rCOF,
-(CF2)rOCF3, -(CF2)rCOOH and ~CrF2r+1_qClq~ wherein r
is an integer from 1 to 12 and q is an integer from O
to 25; R1 and R2 are the same or different and are
selected from the group consisting of -F, -Cl, -
CF2Cl, -CFCl2, -CCl3, perfluoroalkyl of one to ten
carbon atoms, perfluoroalkoxyalkyl of one to ten
carbon atoms and perfluoroalkoxyether of one to ten
carbon atoms wherein one or more of the fluorine
atoms can be substituted by a halogen atom other than
fluorine, provided that R1 and R2 together are not F;
and n is an integer from 2 to 1,000.
The invention also pertains to perhalogenated
polyethers having the formula:
IRl
Y--O--C--O--Y '
R2
wherein Y and Y' are the same or different and are
selected from the group consisting of perfluoroalkyl,
' ~3-10294
perfluoroalkoxyalkyl, perfluoroalkyleneoxyalkyl and
perfluoroalkoxyether, preferably each having 1 to 50
carbon atoms and wherein one or more of the fluorine
atoms can be halogen other than fluorine; R1 and R2
are the same or different and are selected from the
group consisting of -F, -Cl, -CF2Cl, -CFCl2, -CCl3,
perfluoroalkyl having one to twenty carbon atoms,
perfluoroalkyleneoxyalkyl of one to ten carbon atoms
and perfluoroalkoxy of one to ten carbon atoms,
wherein one or more of the fluorine atoms can be
substituted by a halogen atom other than fluorinei
and wherein the polyether preferably comprises 12 or
more carbon atoms.
A preferred perfluorinated polyether consists
essentially of:
Y-O-CF2-0-Y '
wherein Y and Y' are the same or different and are
selected from the group consisting of perfluoroalkyl of
one to ten carbon atoms, perfluoroalkoxyalkyl of one to
ten carbon atoms, perfluoroalkyleneoxyalkyl of one to
ten carbon atoms and perfluoroalkoxyether of one to ten
carbon atoms; wherein one or more of the fluorine atoms
can be substituted by a halogen atom other than
fluorine and wherein the polyether comprises less than
8 or at least 12 carbon atoms provided that Y and Y'
cannot both be -CF3 or -C2Fs.
The perhalogenated polyethers of this invention
can be used as lubricants, hydraulic fluids, thermal
shock fluids, vapor phase soldering fluids and in
numerous other applications in which an inert,
nonflammable, oxidatively stable fluid is required.
The low molecular weight perfluoropolyethers of the
present invention have many useful applications in the
electronics industry.
-5- 13~029~
Detailed Description of the Invention
In general, the perfluoropolyether and
perhalogenated chlorofluoropolyether polymers have the
formula:
Rl R3
X-[O-c-O-Y]n _ [~-C-~-Y']m - OZ (I)
R2 R4
wherein Y and Y' are the same or different and are
selected from the group consisting of linear and
branched perfluoroalkylenes having at least 2 carbon
atoms, preferably having 2 to 6 carbon atoms;
perfluoroalkyleneoxyalkylene and perfluoropoly-
(alkyleneoxyalkylene) each having alkylene groups
containing at least two carbon atoms, preferably having
from 2 to 30 carbons and most preferably having 4 to 8
carbons; wherein in Y or Y' one or more of the fluorine
atoms may be substituted by a halogen atom other than
fluorine. Y and Y' can be isotactic perfluoropoly-
ethers or atactic perfluoropolyethers, such as -
CF2CF2CF2, -CF2CF2CF2CF2-,-CF2CF20CF2CF2-~
- CF2 ( CF3 ) CFOCF ( CF3 )CF2- and
~,~
-6- 1~029 l
-CF2cF2~cF2cF2~cF2cF2- X and Z are the same or
different and are selected from the group consisting
of -(CF2)rCOF, -(CF2)rOCF3, -(CF2)rCOOH and
CrF2r+1 qClq, wherein r is an integer from 1 to 12
and q is an integer from 0 to 25. R1, R2, R3 and R4
are the same or different and are selected from the
group consisting of -F, -Cl, -CF2Cl, -CFCl2, -CCl3,
perfluoroalkyl of one to ten carbon atoms, such as
-CF3, -C2F5, -C3F7 and -C4Fg and perfluoroalkoxy-
alkyl of one to ten carbon atoms, such as -OCF3 and
F5~wherein one or more of the fluorine atoms in
said perfluoroalkyl and perfluoroalkoxyalkyl may be
substituted by a halogen atom other than fluorine.
Preferably R1 to R4 are F and -CF3 groups. n is an
integer from 2 to 1,000; and m is an integer from 0
to 1,000; provided that when R1, R2, R3 and R4
together are F then Y or Y' comprises an ethylene
group having at least one fluorine atom which is
substituted with a halogen atom other than fluorine,
preferably by chlorine.
The n and m subscripts of formula I are average
indices of composition such that when m is zero the
polyether is referred to as an alternating copolymer
Rl
(-O-C-) and (OY).
R2
~ ~0294
When m ~nd n are gre~ter than zero, the polyether ~ 5
a texpoly~er contAining
( -O-C- )
~2
groups havin~ ran~om OY and OY' units ~long the
polymer chain. Th~ si~plest ~ember of this class of
compounds is a 1:1 copolymer of difluoromethylene
oxide and ~etrafluoroethylene oxide which is the
subJect of U.S. Patent No. 4,760,198.
This invention lso relates to perfluoro-
poly~ther~ and perhalogenated chlorofluoropolyether~
of Formula I where Y and Y' are polyethers and hsve
the average formula:
Rl ~3
X-tO~ o-~F2-lF)p]n-~o-~-(o-cF2-cF)t] ~oz ~V
R2 R5 R4 R6
~herein Rl~ R2~ R3~ R4~ Rs and R6 are the same o~
different ~nd are selected from the g~oup con~is~in~
of -F, -Cl, -CF2Gl, CFCl2, -CC13, perfluoroalkyl of
one to ten c~rbon atoms and perfluoraalkoxyalkyl of
one to ten ~arbon atom~ where~n one or more of the
fluorine atoms ~ay be substituted by a halogen ato~
ot~er t~an fluorine; wher~in X and 2 are the ~a~e
or differe~t and are selected from the ~roup con-
si~tlng of -~2)rC0~, -(CF~)rOCF3, -(CF2)rCOOH and
CrF2r+l qClq wherein r i5 an integer fro~ l to
-8- ~3'1029~
twelve and q is an integer from O to 25; wherein n
is an integer from 2 to 1000, m is an integer from O
to 1000; and p and t are the same or different and
are integers from 1 to 50, provided that when p and
t are one and Rl, R2, R3 and R4 together are
fluorine, then R5 or R6 is a group other than
fluorine. Preferably, p and t are integers from 1 to
10 .
Examples of perfluoropolyethers where m in
formula I is zero and p is an integer between 2 and
50 are shown below:
X-[O-CF2-(0-CF2-CF2)p]n-OZ
X-[O-CF -(O-CF -CF -CF ) ] -OZ
X-[O-CF-(O-CF2-CF2)p]n-oz
CF3
X-[o-lc-(o-cF2-cF2)p]n~~z
CF3
Examples of perfluorinated polyethers of
formula I where m is zero, p is defined above and Y
is an isotactic perfluoropolyether or atactic
perfluoropolyether are:
X-[O-CF2-(0-CF2-CF)p]n-oz
CF3
~ 3 ~029~
X ~o-cF2-(o-cF2 ~F)p3n
C2F~
X~o-cF2(o-&F2cF)p]
CF2Cl
~ amples o~ ran~o~ copolymers of formula I in
which m and n ~re greater than zero, and p is
defined above, lnclude;
x.~o-CF2-~0-CF2~~F2)p]n~[~ C~2 ( 2 ~ t
CF3
X- ~O-CF2- (0-CF2- ~CF)p~n- ~O-CF2 (0-CF2-~F~t]m-OZ
CF3 CF
Perfl~oropolyethers an~ perhalogenated chloro-
~luoropoly~thers can also be prepared which have the
average formula:
FCt (OC~2-1 F~n-OX~3
or
C~(OCF2-~F)n-OX~4 VI
whereLn X is ~elected from the group co~si~ting of
~ 2)r OOH, ~CF2)r F3~ ( 2~rC~~' and
CrF2r+l q~l~ where ~ i~ an integor ~rom 1 to 12 and
q is an In~ege~ fro~ O to 25. Preferably X ls -CF3,
-C2F5, -CF2COOH, -CF20CF3 ~nd CF2coF; w~erein n i8
~3~û294
- 10
an inte8er from 1 to 50; and wherein R ~s selecte~
from the group conC~sting of -F, -CF2Cl, -CFC12,
CC13 and perfluoroalkyl of one to ten earbons.
T~is inven~lon fur~her pertai~s to perfluoro-
polyether~ and perhalogenated chlorofl~oropolyether~
having the average formula:
Rl
X ~0-Cln-OZ II
wherein Rl, R2, X ~nd Z are deflned above, and n is
an integer f~om 2 to 1000; provided that Rl a~d ~2
cannot bo~ be fluorine atoms.
This invention ~lso pertains ~o the co~pounds
shown below an~ to compo~nds consisting essentially
of th~se~ formulae. -~he co~po~nds can b~
perfluor~nated formals wh~ch have the formula:
Y-O-CF2'~-Y'
wherein Y and Y' ~re the same or d~fferen~ and ~re
selected fro~ t~e group consis~in~ of perfl~oro-
alky}, perfluoroalkoxyalkyl, and perfluoroalkylene-
oxyalkyl; ~nd wherein t~e polyethe~ comprises fewer
than 8 or, 12 or more carbon atoms provided ~hat Y
and Y' cannot ~oth b~ -CF3 or -C2F5. Pre~erably,
the polye~her wIll comprise 12 to 20 carbon ~toms.
Perhalo~enated acetal compo~nds can also be
made which having an average fo~ula:
y.o-CF-O-Y~
~ ~3i~029 1
whereln Y and Y' ar~ the same or differe~t and are
selected fro~ the group consisting of perfluoro-
alkyl, perfluoroalkoxyalkyl, and perfluoroalkylene-
oxya}kyl; wh~rein R is ~elected from the group
conslstin~ of -Gl, CF2Cl, -CFCl2, -CCl3, perfluoro-
alkyl having 1 to 2~ carbon atoms and perfluoro-
alkyleneoxyalkyl; and ~herein the polyether co~-
pri~es 12 or more carbon atoms. Pre~ere~ly, the
polyether will comp~ise from 12 to 50 carbon atom~
and more preferably, w~ll comprise 12 to 25 carbon
atoms.
The invention also includes perhalogenated
ketals having an a~erage formula:
Y-O-C-O-Y'
~2
where~n Y ~nd Y' sre ~he same or different and are
selected fro~ the group conslsting of perfluoro-
alkyl, perfluoroal~oxyalkyl, and perfluoroalkylene-
oxyalkyl; whereln Rl and R2 ~re the sa~e or
différent and are selected from t~e grOup cons~s~in~
of -Cl, CF2Cl, -CFCl2. -CC13, perfluoroalkyl havin~
1 .o 20 carbon atom~ and perfluoroal~yleneoxyalkyl;
and wherein the polyether comprises 12 or mo~e
carbon atoms. Preferably, the polyether will
comprLse 12 to 25 ca~on atoms.
~ he invention al~o pertain~ to ether~ ha~ing an
~verage formula:
~ 1
Y-O-C-O-Y'
R2
~3~ 294
-12-
wherein Y and Y' are the same or different and are
selected from the group consisting of perfluoro-
alkyl, perfluoroalkoxyalkyl, and perfluoroalkylene-
oxyalkyl; wherein R1 and R2 are the same or
different and are selected from the group consisting
of -F, -Cl, CF2Cl, -CFC12, -CC13, perfluoroalkyl
having 1 to 20 carbon atoms and perfluoroalkylene-
oxyalkyl; and wherein the polyether contains at
least one halogen atom other than fluorine. The
perfluoroalkylpolyether may be atactic, isotactic or
a block copolymer having l to 50 carbon atoms.
Examples of two polymers of this formula are
Y-O-CF2-OY and Y-O-CF-(CF3)-OY wherein Y is the
same.
This invention further pertains to a method of
making perhalogenated formal, acetal, ketal and
orthocarbonate compounds and perfluoropolyether and
perhalogenated chlorofluoropolyether polymers
thereof. The compounds are made by fluorination of
acetal, ketal, formal or orthocarbonate hydrocarbon
precursors.
The reaction of a diol with either an aldehyde,
acetal, ketal or trialkyl orthoesters can be used to
give a polyether if the starting materials and
reaction conditions are carefully chosen. For
example, if an aldehyde such as formaldehyde,
acetaldehyde or butyraldehyde is reacted with a
diol, a linear polyether can be made. Such a
reaction is shown in Equation (1) below:
HO(CH2)nOH + RCHO ~ [(CH2)nOCHO]x + H20 (l)
R
,' ~ , . . .
.. .
.
~; ~ iO29 l
-13-
Suitable dlols incl~de e~hylene ~lycol, dlethylene
glycol, tri~thylene glycol, te~rsethylene glycol,
other higher polye~hylene glycols, propyle~e ~lycol,
dipropylene ~lycol, trlpropylene glycol, ~,2-di-
methyl 1,3-prop~nediol, 1,4-butanediol, 1,5-
pentanediol, 1,6-hex~nediol, 1,7-heptanediol, .
1,8-oc~anediol, l,9-nonanediol, and l,lO-decanediol.
Suitable aldehydes include formsldehyde, para-
formaldehyde, l~3,5-trioxane, acetaldehyde and its
~rimer~ b~tyraldehyde ~nd its tri~er, pentanal,
he~anal, 2-ethyl butanal, chloroacetal~e~yde,
dichloroacetaldehyde and trichloroacetaldehyde,
An alternative means of preparing the same
polymer involves the reactlon of an acet~l wlth a
diol. Tbe synthesi~ involve~ the inieial prepara-
tion of an ~cetal by react~on of an alcohol with the
aldehyd~ ~s shown ln Equ~tion (2~ below:
RCHO + 2R'OH ~ ~'0)2C(R)~ ~ H20 (2~
The acetal interchange is followed by a smoo~hly
reversible react~on in acid media givins rise to the
polyacetal. This resctlon i5 ~iven in Equation (3)
below:
(R'~)~C(R)H ~ HO(CH2)nO~ ~
HOt(CH2)noC(R)~o~x~ ~ 2~'oH ~3)
Suitable ~ce~sls lnclude the dietbyl, d~propyl,
dibutyl, dipentyl and diphenyl acet~lx of all o~ the
prevlously mentioned aldehyde~,
d~; 3 1 ~ 2 9 4
A well kno~n reaction whlch i~ pArticularly
well suited for preparing copoly~e~s o~ ~cetaldehyde
involve-~ t~e react~o~ of divinyl ethe~s ~it~ diols.
Fo~ example, ethylene gl~col ~ivinyl et~er will
react w~th ethylene ~lycol in the pre~ence of ~ at
-10~~ to glve a l:l copolymer of ~thylene gly~ol and
aceta}dehyde. ~imila~ly. the divinyl ether of l/S-
pentanediol wlll react with l,S-pentanediol to give
a copolymer of pentanedlol and aceta~dehyde:
CH2-cHc)cH2cH2~H2C~12cH20cH~cH2 + ~CH 2CX2CH2CH2C~20H
H
[CH2C~12C~2cH2~H20cH~~n
CH3
F2~N2
- .~ [CF2CF2~F2c~2cF2OqHo]n
CF3
Terpolymers can be prep~red by rea~tln~ a div~nyl
ether of one d~ol with ~ dlol of a d~fferen~
~tructure. For example, the divinyl ether of
ethyle~e ~lycol will react with 1,3-propanediol to
yieLd a polye~her ~fter fluorin~tion having the
followin~ structure;
~OCF2CF20(~0CF~CF2CF2 In
CF3
1029~
- 15 -
The divinyl ethers are conveniently for~ed by
reactlng a dihydroxyl ter~nated compound with
acetylene a~ 160~C ~n the presence of KOH as shown
below in Equatlon (5).
HOCH2CH2OH + H GCH ~ CH2-CHOC~CH2OCH~CH2
(~H2- CHOCH~C~120CH=~C~12 + HOCH~CH2CH20H ~
~OCH2C~2Ol~Oc~2cH2cH2ln
CH3
~2/~2
~- ~ E~CF2cF2~pFo~2cF2cF2~n (g)
CF3
A variety of aldehydes can be polymerized snd
fluor~nated to give perfluoropolyethers that ha~e
uni~ue ~nd often ~seful properrles. For example,
chloroace~sldehyde can be polymerized ~nd fluori-
nated to ~i~e perfluoropolychloroacetaldehyde.
Similarly, d~c~loroacetaldehyte and trichlo~o-
acetaldehyde can be poly~er~zed and ~luorinated to
~ive the perfl~orocarbon analog of the polyethers.
Chloro~luoroe~hers such as these are po~entially
useful no~ mab~e a~rcraft hydraulic fluids.
Their relatively ~igh oxidatl~e st~bil1ty and low
compressibility ~ake the~ attract~ve candidates.
Other ald~hydes ~uch as acetaldehyde, trifluoro-
acet~ldehyde and propanal c~n be pol~erlzed ~nd
fluorlnated to give stable poly~ers,
-
~34029 1
~ etsls undergo a fac~le rever~ible motathes~s
reaction with alcohol~ to ~i~e polyketals ~s shown
below in Equation ~4):
) 2 C ( E~ ) R ~ HO ( C H 2 ) nOH
HO[(CH2)nOC(R)(~'')O]XH +2R~oH (6)
The list of u~eful k~tal~ w~uld include 2,2-dlme-
thoxypropane, 2,2~ ethoxybutane, 2,2-dimethoxy-
pentane, 2,2-dimethoxyhexane, 3,3-dimethoxypentane,
3,3-dimethoxyhexane ag well a5 ~he diethoxy,
dipropoxy, dib~toxy ~nd diphenoxy a~alo~ues o~ the
prev~ou~ly mentioned ke~al~.
The direct reac~ion of a ketone with an
alcohol, a reaction analogous to the reaction of an
aldehy~e with an ~lcohol, gener~lly wor~ only for
several isolated ketones. For ~his rea~on, the
ketal is normally used.
The react~on of a ~ri~lkyl or triaryl ortho-
ester with ~lcoholg gives form~tes according to t~8
reaction prex~nted in Formul~ ~5):
OH
(l~2)n
(RO)3C~ t 3~0~G~)nO~ ~ H~-O(CH2)nOH ~ 3R~ (7)
o
2~n
OH
.... .. .
1~ 102~4
Use~~1 orthoe~ters include tri~ethylorthoformate~
~rieth~lorthoformste, trlpropylorthoformate, t~i-
butylorthoformate, ~riphenylor~hofoYm~te, trimethyl
orthoace~e, ~riet~ylor~hoacetate, erlpropylortho-
~cetate, tributylorthoacetste, triphenylortho-
acetate, tr~e~ylorthopropionate, triethylortho-
prop~onate, trlpropylortho~ropionate, ~rlbutylortho-
~ropionate, criphenylor~hopropionate, trimethyl-
orthobuty~ate, txiethylortho~tyrate, tr~propyl-
orthobut~rate, tributylorthobutyrate and ~riphenyl-
o~thobutyrat~.
It should be clear from ~he preceeting discus-
sions that a wlde variety of linear 8s well ~s
hi~hly branched polyethers can be madé using ~hese
interc~an~e reactions. ~y care~ully c~oosin~ the
app~opriate d~ol and aldehyde ~t is possi~}e ~o
prepare cyclic ~cetals which can often be poly-
merized to g~ve polyether~. For exa~ple/ for~alde-
hyde reacts with diethylene glycol ~o give 1, 3, 6 -
trioxoc~ne w~ich oan be poly~erized to ~ive linear
polyacetals as ~hown in ~o~mula (S) below:
(C~2~)3 + ~OcH~cH20c~2cH20H ~ CH2CH20CH2CH2GC~20
H ~ [CH2CH20GH2cH2oc~o~ ~8)
S~ilar~, the cyclic product~ for~ed by the re-
action of tri~ethylene ~lycol wit~ dibutyl formal
and the reaction of hexamethylene ~lycol with
propionaldehyde polymerize In the presence of an
acid to gi~en l~near polyme~s ~s descr~bed in U.S.
Pa~ent N~. 2,071,252. In general, if the glycol is
C
.
~ 3 1029~
-18-
1,4-butanediol or higher a linear polymer is formed
whereas glycols having fewer carbons generally form
rings. If the glycol used is a polyether glycol,
such as diethylene glycol or triethylene glycol, the
linear polymer represents a thermodynamically more
stable structure. However, it is often possible to
convert the linear polyether to the cyclic ether by
vacuum pyrolysis.
The invention also pertains to "single
compound" formals, acetals and ketals and a method
of making formals, acetals and ketals, including
polymeric compounds of the above-formulae and single
compounds of Formula III:
~Rl
Y-o-C-O-Y' III
R2
wherein Y and Y' are the same or different and are
selected from the group consisting of perfluoro-
alkane, perfluoroalkylether and perfluoroalkylpolyether
wherein fluorine may be substituted with one or more
halogen groups other than fluorine; wherein R1 and R2 are
the same of different and are selected from the group
consisting of -F, -Cl, -CF2Cl, -CFCl2, - CCl3,
perfluoroalkyl of one to ten carbons; wherein fluorine
may be substituted with one or more halogen groups other
than fluorine and wherein the perfluoroalkyl group may
contain one or more ether oxygens. The perfluoroalkyl
polyether which is Y and Y' may be atactic, isotactic or
a block copolymer having 1 to 50 carbon atoms.
As an example, a monohydridic alcohol will
react with an aldehyde, acetal or divinyl ether to
give a new acetal.
2ROH+HCR'O RO-CHR'-OR (9)
~3102~
-20-
~ipropylene glycol bu~yl et~er, tripropylene glycol
~ethyl ether, ~rlpropylene gl~col ethyl e~her and
tripropylene ~lycol butyl ether,
Low moleculAr welght, unimolécular perfluoro-
polyether fluids find numerous applicat~on in che
eleccronics lndu~try. Fluoroc~rbon fluids arc
usef~l ~s coolants and lnsulator~ in high-voltage
electronic equipment, as i~mersion ~ediu~ for leak
testing, as heat transfex agents for v~por phase
solderin~, as fluids for dlrect cooling of elec-
tron~c de~ices and as thermal s~ock fluids.
Fluorinated polyether acetal~, such as the ones
descr~bed hereln ~ay al-~o find uses ~s fluoroc~rbon
blood substitutes,
~ on~er~ion of the hydrocarbon polyether ~o ~
perfluoropolyether can be acco~plished by reactlng
the polyethe~ with elemental fluorine. Because o~
the reactive nsture of elemental ~luorlnc, it ~s
p~eferably to dilute the fluor~ne wi~h an inert gss
such as nltrogen or helium. Typically, the fluorine
is diluted with ni~rogen and as highex de~rees of
fluorlnation are achleved, the concentr~tio~ of
fluorlne is usually increased. ~ue to the extreme
exothermicity of the reactlon, t~e fluorina~ion ~u~t
be carried out slowly unless provisions have been
~a~e ~or rapidly xemoving the heat of reaction.
Submersion of che reac~or in a cooled llquid bath is
usually adequate for achievlng commerclally
acceptable rates o~ reaction.
Fluorine ~as i~ the preferred fluorinating
a~en~ and is comm~rciall~ availsble at ~ufficiently
.. . ...
. .
-
~ 3 '~ O 2 9 4
1g -
2ROHf~R' '0~2CR'H ~ RO-CHR'-OR ~10)
2ROH+CH2 CHoR~oc~l-c~2~RocH(cH3)oR~ocH(c}~3)oR (11
The reaction of an alcohol with a ketal will result
in an interchange reactlon glven rise to a ketal.
~ROH~(R''0~2CR'R'''-~ RO-CR'R'''-OR (12)
A monohydxidic alcohol will ~eact ~lth ~n ort~oester
to give another or~hoester.
3R~H+~R'0)3CH -~(RO)3CH (13)
Low molecul~r we~ght uni~olecular pol~ethers
can be made by re~ctlng any of the previously
mentioned aldehyde~, ~cetals, ketals, or or~hoesters
with ~ monhydridic alcohol ~uch ~s ~ethoxyethanol,
ethoxyethanol, butoxyethanol, diethylene glycol
methyl ether, d~ethylene ~lyco~ ethyl ether, d~-
ethylene glycol bu~yl ether, triethylene gl~col
methy~ ether t triethylene ~lycol cthyl ether, tri-
ethylene glycol butyl ether, tetr~ethylene glycol-
methyl ~the~, tet~aethylene glycol ethyl ether,
cetr~ethylene ~lycol bu~yl ether, pentaethylene
glycol methyl ether, pentaethylene glycol ethyl
e~hex, pentaet~ylene glycol ~utyl ethe~, propylene
~lycol methyl ether, propylene glycol e~hyl ether,
propylene glycoL butyl ether, d~ propylene glycol
me~hyl ether, dipropylene glycol ethyl ether,
~ J ~029~
-21-
high purity levels and at an acceptable cost. The
fluorination reaction is generally carried out at a
temperature between -40 and +150~C, preferably
between -10 and +50~C. It can be carried out in a
reactor containing an ultraviolet radiation source
or in the dark. Using the preferred temperature
range, it is not necessary to have an ultraviolet
light source since the fluorine is sufficiently
reactive. If an ultraviolet light source is used,
however, a wavelength between 250 and 350 nm is
preferred. When the reactor is irradiated with an
external light source, a transparent window is
needed which does not react with either fluorine or
hydrogen fluoride. A quartz lens coated with a thin
film of fluorinated ethylene-propylene copolymer
works well.
The fluorination reaction can be carried out in
a variety of ways. The polyether can be coated on
sodium fluoride powder to give a free-flowing powder
which can be fluorinated in either a stationary
tube, in a rotating drum-type reactor, or in a
fluidized bed. See U.S. Patent No. 4,755,567 and U.S.
Patent No. 4,859,747, issued August 22, 1989.
Alternatively, the polyether, if soluble, can be
dissolved in a solvent inert to fluorine and can be
fluorinated while in solution using a liquid phase
fluorination reactor. See Canadian Patent Application
Serial No. 613,091, entitled "Liquid Phase Fluorination",
. ... : . . ....... . . . .
13~029~
-22-
by Thomas R. Bierschenk, Timothy Juhlke, Hajimu Kawa and
Richard J. Lagow, filed September 28, 1989. A typical
laboratory-size reactor for example, has a volume of
about 10 liters and contains approximately 2 to 8 liters
of a suitable solvent. Perhalogenated chlorofluorocarbons
are typically used as the fluorine-inert fluorination
medium. However, perfluorocarbons, such as Fluorinert~
FC75 [3M Corporation; mixture of perfluoro(2-butyltetra-
hydrofuran) and perfluoro(2-n-propyltetrahydropyran)] and
perhalogenated chlorofluoropolyethers may also be used as
the liquid phase fluorination medium. One preferred
fluorination medium is 1,1,2-trichlorotrifluoroethane
since it does not react appreciably with fluorine when
the preferred temperature range is used (above the
melting point of the material and below the temperature
at which the fluorine reacts with it). Other fluorinated
solvents can be used, such as perfluoroamines,
perfluoroalkanes, low molecular weight polyethers, etc.
During a typical reaction, the polyether is fed
into the reactor at a rate of 10 to 60 grams per
hour. Fluorine gas is delivered to the vigorously
stirred reactor at a rate sufficient to react with
all of the organic feed plus an additional 5 to 10
percent. Typically the fluorine gas is diluted with
an inert gas such as nitrogen. This is of
. ~ ,
..... .. .
1~40294
particular importance if a liquid fluorination medium
such as 1~lr2-trichlorotrifluoroethane is used. It is
imperative to keep the fluorine concentration low so that
the liquid fluorination medium and fluorine in the vapor
space do not form a flammable mixture. The flammability
limits of various solvents in fluorine gas can be
determined by spark testing. In a typical reaction, a
fluorine concentration of 10 to 40% works well. If
operating properly, the fluorine concentration in the
exit gas will be between 2 and 4%.
Fluorination can be carried out either in a
batch mode where all of the polyether is dissolved
in a solvent prior to fluorination or in a
continuous mode where the polyether is continuously
being pumped into the solvent as fluorine is being
bubbled through the solution. Generally speaking,
the continuous operation gives a preferred yield,
better product quality and improved rates.
If the polyether is insoluble in the liquid
fluorination medium it can still be fluorinated in
high yield as an emulsion in the liquid phase
reactor. An emulsified solution of the polyether
and the fluorine-inert liquid fluorination medium
can either be pumped into the reactor or the
reactant can be emulsified in the reactor with the
fluorination medium prior to the reaction.
An alternative method for fluorinating poly-
ethers which are insoluble in the liquid
fluorination medium involves adding a solvent to the
polyether which allows limited solubility of
,
2 9 1
-24-
polyether in the liquid fluorination medium. For
clarity, 1,1,2-trichlorotrifluoroethane has been
selected as the liquid fluorination medium; however,
other highly fluorinated solvents can also be used.
Typically, a mixture containing one part polyether,
one part solvent and one part 1,1,2-trichlorotri-
fluoroethane will give a homogeneous solution. A solvent
is selected which readily dissolves the polyether. Often
it is possible to choose a solvent which will consume
little, if any, of the fluorine gas. Trifluoroacetic
anhydride, trifluoroacetic acid, chloroform,
~ 2-trichloroethylene and 1,1,2-trichloroethane work
especially well and have high solvating power.
The polyether/solvent/1,1,2-trichlorotri-
fluoroethane solution is metered into a vigorously
stirred fluorination reactor. As the polyether
solution contacts the 1,1,2-trichlorotrifluoroethane
in the reactor, an emulsion is formed. The
polyether droplets in the solution are in most cases
sufficiently small and react quickly with the
fluorine gas with negligible side reactions.
When carrying out the reaction in a liquid
fluorination medium, a hydrogen fluoride scavenger
such as sodium fluoride or potassium fluoride may or
may not be present in the solution to scavenge the
by-product hydrogen fluoride. However, the prefer-
red mode of carrying out the fluorination reaction
is with a sufficient quantity of sodium fluoride
being present to complex with all of the hydrogen
fluoride formed. When fluorinating ethers in the
. . .
2 g ~1
-25-
presence of sodium fluoride, improved yields are
obtained while chain cleavage and rearrangements are
minimized. See U.S. Patent No. 4,755,567.
Products produced using the methods just described
usually have a residual hydrogen content of 0.001% or
less. In order to obtain a fluid which is essentially
free of residual hydrogen and void of any reactive
terminal groups such as acyl fluoride groups resulting
from chain degradation reactions, a final fluorination
near 175~C with 30% fluorine for several hours works
well.
The following examples will further illustrate
the invention, but are not to be construed as
limiting its scope.
Example 1
A mixture of 1060 g diethylene glycol (10 mol),
210 g paraformaldehyde (7 mol), 500 ml benzene and
10 g acidic ion exchange resin was refluxed for 6
hours in a 2 liter flask equipped with a water
separator and a reflux condenser. The solution was
filtered to remove the acid catalyst and the benzene
was removed by distillation. Upon removal of all of
the benzene, several drops of sulfuric acid were
added to the polymer and the temperature was raised
to approximately 140~C. The entire contents of the
flask were distilled at 160~C with a reduced pres-
sure (25 mm). Redistillation of the high boiling
fraction gave 463 grams of 1,3,6-trioxocane (78%
conversion).
1~40294
- 26-
Polymerization of 450 g of 1,3,6-tr~oxocans was
ca~ried out ~t room temperature In 1 liter dry
meth~lene chLoridc using 0.04 ml of trifluoromet~ane
sulfonic ~cld ~s a catalyst. T~e poly~eri~ation was
complete in 24 hours at which time 1 g of sodiu~
methoxide disso~ved ~n 50 ml of dry methanol was
added to neutralize the acid catalyst. 3600 ~
sodium fluoride powder wa~ added to the poly~er
along wi~h sn additional 1 liter of methylene
ehloride, T~e mi~ture was stlrred, t~e methylene
chloride w~s allowed to evaporate and tbe re~aining
solid~ were ground to a powder. The polymer-coated
sodium fl~or~de was placed in a 20 liter rot~ting
drum reactor and dried under a stream of inert ~as
te.g., nitrogen) for a perlod of 12 hours, The
mlxture was t~en exposed to 500 cc fluorine diluted
with ~ literg of nitrogen for approximately 30 hours
at 25~C. Next, the nltro~en flow was red~ced to 1
llter/min and the re~ctiOn w~s a~lowed to continue
for an additional 12 hours after which ti~e the
reactor was slowly warmed to 70~C o~er a 6 hour
period. Trea~ment with pure fluorine for several
hours at 70~C ~ave a product which contained very
few hydrogen a~oms. Extraction of the reaceion
product wlth 5 liters of 1,1, 2 - trichlorotrlfluoro-
ethane ga~e 386 grams of fluid (34~). Washing of
the solids wit~ 100 liter~ of ~ater resulted in the
isol~tion of 430 ~rams of an elasto~eric solid (38
yield). The crude ~luid w~s treated with 30~
fluorine at Z60~C for 12 hours ~o ~emove t~e last
rem~inin~ hydxogens. The fluid was distilled to
gi~e the followin~ fractions:
~3~0294
Klnematic
b.p. Weight Vlsoosity (cst.
ran~ f~ac~on ~ of ~otal 20~C 80~C
<200~C ~t 100 mm 120 31 3.2 1.07
~200~C at lO0 mm12~ 33 11.8 2.~3
C245~C ~t 10 mm
>~45~C at l~ ~m 62 16 38.9 7.06
c288~C at 0.~5 mm
~288~C at 0.05 ~m 39 10 8~.3 13.1
~370~C a~ 0.05 mm
~370~C at 0.05 mm 39 10 290.3 3g.5
The l F data and elemental analy~is were consistent
with the structu~e:
~CF2CF20 CF2CF20 CF20]n
Example 2
In this example the fluid prepared in Example 1
w~s prepared usin~ an alternate method whlch was
better sui~ed for preparing fluid-~ while the method
described in Example 1 yLelds a con~lderable amount
of polymeric solids.
Into a l liter stlrred flask equipped with ~
wa~er ~eparator were placed 500 g d~ethylene ~lycol
(4.7 mol), ~0 g diethylene glycol ~ethyl ether
(10.75 mol), 225 g paraformaldehyde ~7,5 ~ol), 150
ml toluene and 5 g ion excha~ge resln (H fo~m).
The mixture wa~ refluxed for several hours to remove
the water formed dur~ng the reaction. The solu~ion
was ~irs~ filtered to remove the ion exchange resin,
-- ~ 3~029~
-28-
then distllled to 150~C ac 0.05 mm/Hg to remove the
tol~ene and other lights. A nearly quantltatlve
yie}d of polymer having an a~erage molecular welght
of 1500 wa~ obtained.
320 g of polymer. mixed wlth 170 g chloroform
and 300 g 1,1,2-trichlorotrifluoroethsns w~re slowly
pumped over ~ 23 hour period into a 15 llter stirred
fluorination reactor containlng 6 llters of 1,1,2-
trichlorotrifluoroethane ~nd 1300 g of sodium
fluorlde powder. 20~ fluor~ne was bubbled t~rough
the liquid fluorinstion medlum at a rate 15~ hlgher
than that required to theoretically replace all of
the ~ydrogen on ~he hydrocarbon being pumped into
the reactor. The reactor temperature was maintaine~
between 0 and +lO-C throughout the reaction.
Follo~ing the reaction, the reactOr contents were
~iltered and the liquld fluorination med~um (l, l,
2-triohlorotrifluoroethan~) was removed from the
flltrAte Vi8 an at~ospheric distil}ation to 120nC to
~ive 53~ g of crude fluid (66~), Fl~orlnation of
the ~luid at 260~C gave a clear7 colorless fluid
whloh ~as shown by element~l analysi~ and 19F NMR to
have t~e ~ollowin~ structure:
[C~2~F20CF2CF20CF20]n
Example 3
100 g triethylene glycol (0.67 mol), 28.5 g
para~ormaldehyde (0.95 ~ol), 100 ~l benzene and 1 g
lon exchange resin (H form) were placed in a 500 ml
stirred ~ k eq~ipped ~ith a water xepara~or and a
2 9 4
-29-
r~flux con~enser. The solution wa~ allowed to
reflux ~or ~ hour~ while t~e water wa~ continuou~ly
removed. Upon removal o~ the w~er, the 801ution
was filtered ~o remove the acid cat~ly~t. At-
mosph~ric distlllatlon of the flltrate followed by
~educed pressure dist~llation (100 m~ Hg) to 120-C
was u~ed to remove th~ benzene solvent ~s well ~s
any light~ presen~.
Twenty grams of the viscou~ poly~er were mixed
wlth approximately 100 ml of ~ethylene chlorlde and
120 ~ sodium ~luoride powder (200 ~esh). The
resulting paste was dried ln ~ ~acuum oven at 60~C
for sever~l hour~ prior to grlndlng eO ~ coarse
powder (~ppro~imately 30 ~esh), The powder wa~
placed in a 1 lltor rot~ting brass reac~or a~d wa~
puxged wlth 200 cc of dry nitrogen for ~everal ~ours
prior to the fluorin~tion. The ~sactor was cooled
to 0~C, the nitro~en flow wax reduced to 150 ~c/mln
and the fluorine flow was set at ~0 cc~mln. ~hese
conditions were mainta~ned for ~pproxl~tely 30
hours af~er whlch time the nitrogen flow was reduced
to 100 ce/min and the ~eactor was ~llowed to slowly
warm to 45~C ovsr a 4 hour period, Next, the
nitrogen flow was turn~d off and the reac~or wa~
slowly warme~ to 70~C over a 3 hour period. Upo~
heatin~ to 70~C, the polym~r was exposed to pure
flouri~e for an addi~lonRl hour. Extraction of the
~odium fluorlde~polymer mlxtu~e with approxima~ely 1
llter of 1,1,2-trichlo~orrlfluoroethane g~v~ 23 g of
fluid (45~ yield) h~vin~ the following struc~ure
which has been confirmed spectroscopic~lly:
l~ 1029~
-30-
~ CF2CF2~C~2~2~CF 2CF2~CF2~ }
Example 4
~ 00 ~ butoxyethoxyethanol (2.5 mol), 4~ g
paraformalde~yde ~1.6 mol), 300 ml benzens and 5 g
io~ exchan~e resin ~acid form) w~re placed in a 1
liter ~t~rred flask. A water separstor attached to
a reflux condenssr wa-~ used to collec~ the water
produced ~s the ~lcohol ~nd aldehyde reacted. After
approxim~tely 6 hours, the ~e~ction w~s compl~te and
the solutlon wa~ filtered to remove the resin.
V~cuum dis~llatlon of the so~ut~on to 120~C gAve
414 g of a product (~g% yield) ~hich w~s e~senti~lly
~ree of benzene and unreacted start~n~ materials.
The hydrocarbon product was fluarinated in a 22
liter stirred tank reactor w~ic~ co~ta~ned 6 l$ters
of 1,1,2-tric~lorotrifluoroetha~e and 13~0 g sod$um
fluoride p~wde~. A gas dispersion tube in the
botto~ of the reactor provided an inlet for the
fluorlne and nitroge~ gasses. 275 gram~ of the
hydrocarbon reactant was d~luted w$th 1,1,2-tri-
chlorotrifluoroeth~ne, in a separ~te ~es~el, to ~ive
a total volu~e of 700 ml. This solut$on was metered
~nto the ~luorinatlon ~eactor over a 20 hour period.
The reactor teDper~ture was maintained at 0~C wlth
external cooling throughout th~ react$on whlle the
fluorine flow was ~et at a levcl lO~ highsr than
th~ requlred ~o theoretically replace all of the
hydrogens on the materiAl ent~r~ng ~he reactor.
Upon completion of the reactlon, the fluor~ne ~as
-turne~ off, the re~ctor was re~oved from the low
-
~ 3-~102~4
-31-
temper~ure ~at~ and purged for 30 min w~th ni~rogen
~2 liter~/~in) ~o remove the unreacted fluorine.
Fil~ration of the reaction product followed by
distlllation to re~ove ~he 1,1,2-tric~lorotrifluoro-
ethane gave ~4~ g of a highly iluorlnated fluid ~0
yield). Treat~ent of the fluid a~ 260- C with 304
fluorine ~or several hours gave a perf~orinated
fluid having essentlally the following ~truc~ure:
3 2 2 2 F2 2 2 2 2 CF2C~20cF2c~2ocF2c~2
CF2CF3
The ele~ental analy~l~ was COnsistent with the
formula:
C17F36~6 '
b.p. 226.5~~
~ F NMR ~ ppm ~s CFC13):
-89.0, -90.7: CF2CF20; -51-8: CF20 -81-8, -83.7.
-126.7: CF3CF~F2CF20.
Example S
A mixture of 400 g triethylene g~ycol monoethyl
ether ~2.2 mol), 48 ~ par~formalde~yde (1.6 mol),
150 ml tol~ene and 10 ~ of a~ acid ion exchange
resin was reflu~ed for ~ hours in ~ 1 liter flask
equipped with a water ~epara~or and reflux con-
denser. Filtra~ion o~ the product followed by
dlstill~t~on gave a qusntitative yield of the
desired product.
Fluorination of 201 ~ of the ma~erial in a
s~irred liquid ~luorination resctor containing
. ~ . ,
0 29 4
liters of 1,1,2-trichlorotrifluoroet~ane and 1055
sodium fluoride ga~e 401 g fluid ln an 18 hour
reaotion at 0~C. Distillation of the ~rude product
~xture gave 35g g of the perfl~orinated fluid:
CF3cF2ocF2cF2ocF2cF~ocF2cF2ocF2ocF2c;F2ocF2cF2ocF2 -
CF20~F2CF3
C17~8F3~
b.p, 217~C
9F ~ISR (iS. ppm vs CFC13):
- 51. 7: CF20; - 87 . 3, - gO . 7: CF3CF2; - 88, 7 CF2CF20 .
Ex a~np 1 e 6
Into a l liter flask were placed 600 g tri-
ethylene glycol butyl eth~r (2.91 mol), 74 g para-
formaldehyde (2.46 mol), lS0 ml benzene and 10 g of
a~ acid~c ion ex~hange ~e~ln. The mixture w~s
reflu~ed for 5 hours as water was remo~ed a~ ~he
water/ benzene a~otrope. Filtratlon of the product
and re~oval of t~e benzene by distill~tion g~ve a
90~ yield of rhe polyethsr. 2S9 gram-~ of the
produc~ wa~ diluted wlth 400 ml 1,1,2-trlchlorot~i-
fluoroethane and W8S slowly ~etered in~o a 10~~
reac~or conta~ni~ 5.7 liters of 1,1,2-trichloro-
trifluoroethane and 1200 g sodiu~ fluoride powder.
A fluorocarbon fluld (660 g, 88.7% yield) wa~
obt~ined follo~lng filt~atlon and removal of ~he
1,1,2-trichlorot~ifluoroethane. Fluorlnatlon of the
fluid at 220~~ wlth 30~ fluorine ~or 12 hours
followed by d~stilla~ion gave the ~ollowln~ fluid in
60~ yield:
~ ~!10294
CF3cF2~F~C~2OCF2cF20cF2cF2 2 2~~2~CF2 F2 2~ 2
OCF2C~2QCF2CF2 CF~CF3
b.p. 262~C
F NMR (6 ppm ~s CFC13):
-8~.7, -90.5:CF2CF20; -51.7;CF20; -81.6, -8~.4,
-126.5:CF3CFz~F2CF20.
Example 7
Inco a ~tirr~d 1 liter flask equipped with a
water separato~ were charged 350 g tetrae~hylene
glyco} butyl ether ~1.40 mol), 35 g paraformalde~yde
(1.18 mol), 200 ml benzene and 10 g ion exchan~e
resin. ~he mixture ~ax refluxed untll the water
produc~ion ceased. ~iltration of the product
followed by removal of tha li~hts via a vacuum
dis~ tion to 140VC ~ave 343 g of a llght yellow
fluid,
~ 306 g sample of ~he fluid was diluted w~th
450 ml of 1,1,2-trlchlorotrifluoroethan~ and slo~ly
p~ped ~nto a -6~C resctor over ~ 23 hour period.
The reactor contslned 1450 g o~ sodium fluoride
powder to react with ~he hydrogen fluorlde for~ed
during t~e reaction along wit~ 6 l~ters of
1,1,2-trichlorotr~fl~oroethane. Filtration of the
pro~uot followed by dlsrillation gav~ 736 g of
fluid.
Treat~ent of the fluid at 250-C wit~ 30~
fluorlne gave a clelr, odorlas~ fluid which upon
distillation gave a 52% yield of a material having
the following structure:
-
? 3 1~29~
3 2 F2CF2~CF2 F2 2 2 2 20cF2cF2ocF2ocE~2cF2
O C F 2 ~ F 2ocF2cF2oçF2~2ocF2cF2 2 3
b.p. 29~.7~C
F NMR (~ ppm v~ CFC13):
-51.B:CF20; -88,8, -90.6:CF~CF2~; -8~,7, -83.6,
-12~.7:CF3CF2CF2GF2O,
Example 8
400 8 tet$ae~hylene glycol (2.0~ mol), 109 g
paraformaldehyde ~3.62 mol), 17 ~ triethylene glycol
methyl ether {0.103 ~ol), 150 ~1 benzene and 5 g ion
exchange resin were ~llowed to react in a 1 liter
flask containing a water separator, After 6 hours,
~he contents o~ the flask were filtered and t~e
lights were removed via ~ vacuum filtratlon. A 265
g ~ample of the polymer was mixed with 160 g
chloroform and 2~5 g 1,1,2-trichlorot~ifluoroethane,
The polymerlc sol~tion was metered, over a 22 hour
period, ~nto a stirred 10 liter fluorinatlon reactcr
which contdined 1150 B sodium fluoride powder and
4.5 lite~s of 1,1,2-trichlorotrif}uoroethane. The
reactor was malnta~ned fft 7~C while 20S fluorine
(diluted with nitrogen) was metered into the reactor
at a r~te su~flci~nt to ~eact with all of the
organlc enterin~ the reactor. Upon completion of
the reaction, the solut~on was filtered and the
li~uid fl~orination ~edium was removed via a d~s-
tillation yielding 422 g (62~ yield) of a clearl
~tab}e fluld ~he product was fractionated into
~ ~ ~0294
~ree ~amples, one which boiled b~low 200~ C at 0 . OS
m~ Hg (40%), ~ second which boiled between 200 and
300~C at 0.05 mm ~3596) and a third ha~in~ a ~oil~ng
point above 300~C at O.OS rum Hg (259~). The inter-
mediate fracti on had a visco~ity of 33 .1 cst. at
20~, 6 . 3 c:st . at 80~ and 2 .13 cst, ~t lSû~C . The
pour point was -7~C. The analy~l~ wax con~i~tenc
with the formula:
1 CF~F20CF2CF20CF2CF20CF2cF2OcF20 3 n
19
F NMR ~ ~ ppm v~ CFCl 3 )
- 51 . ~: CF20 - 5 6 . 0: CF30; - 88 . 8, - 90, 6: CF2GF20 .
Anal. Calcd. for GgF1~05: 2~ . 4, C; 6~ . 5 ~ F .
~ound. 21.0, ~; 65.1, F.
Example 9
Dlpropylene glycol methyl ~ther ~300 g, 2.04
mol~, 60.8 g paraformaldehyde (2.03 ~ol), lO0 ml
toluene and S g o~ an acid catalyst were mixed in a
st~ r~d 1 liter fla~k. After refluxing for 12
hours, the solution was filtered and dist~lled to
give 203 g of a fluid whlch bolled at 140~C at 0.05
n~m Hg. The fluld (200 g) was r~ixed wich 300 ml
1,1,2-~ichlorotr~fluoroeth~ne and g~0 g sodium
~luorlde powder, The reaet~on ~7as compl~te ~L 18
hours after whlch tl~e the solu~ion was flltered and
dls'c~ lled to ~ive 405 g of a clear 1 iquid having the
followlng ~tructure (71~ yi~ld)
~3 102~4
' CF30C3F60C3F60CF20G3F60C3F60C~3
The fluid contains CF(CF3)CF20CF(CF3)CF20,
~F(~F3)CF20CF2CF~CF3)0 and CF2CF(CF3)0CF(CF~)CF20
l~nk~ge~. The structure was conflrmed by F ~MR
and el emeRtal analysi~:
1~
F NMR (~ ppm vs CFCl3) :-47.~:CF3O;-54,0:CF20;
-~O.O:CFtCF3)CF20;-~2 to-87:CF(CF3)CF20;-140 to-150:
CF(C~3) CF20 .
Example 10
A mixture of 300 g tripropylene ~lycol methyl
e~her (6.46 mol), 33.7 g parafor~aldehyde ~1.12
mol), 150 ml benzene and 3 g ion exchange re~in was
refluxed for 6 hours in a 1 liter flask equipped
with a water sepa~ator and reflux conde~sc~.
Filtration of the product followed by vacuu~ dis-
tillation of the 11ghts ~ave 16~ g of a product with
a boiling point abo~e l50~C at 0.05 mm Hg.
Fluorinat~on of 145 g of the ~aterial, dis-
solved in 4S0 m1 1,1,2-trichlorotr~fl~oroetha~e , in
a stirred fluorlnation r~actor containing 6 lit~rs
of 1,1,2-trichlorotrlfluoro~thAne ~nd 700 g o~
sodium f~uoride gave 244 g of a fluorocarbon product
in a 20 hour reactlon at -3~C. Dist~llation of the
prod~ct gave 180 g of the perfluorinated fluid:
CF30~FCF20)3C~2(0lFcF2)ocF3
CF3 CF3
2 9 4
-37-
where the ~exafluoropropylene oxide units are
attached randomly ln a head to head, head to tail
and tall to tall fashion.
F ~M~ (~ ppm ~-~ CFC13):-47.3,-56.0:CF30;-
-54.0:CF20; -80,0 CF~CF3)C~20;~83,0,-
-8$.3:CF(CF3~CF20;-145.3, -l46~o:cF(cF3)cF
b.p. 2~0.0~C,
Example ll
A mixture of 400 g dipropylene glycol ~3.0
mol), 358 g paraformaldehyde (12 mol), 150 ml
tolue~e ~nd lO g ion exchange ~e~in was refluxed for
5 hour~ in ~ ~tirred 1 liter fla~k equipped wi~h a
water separator. The ion exch~nge resin was removed
p~io~ to distillation of the mi~ture to 150~C under
a full v~cuum to ~emove a~y low molecular ~el~t
polyme~. Approximately 200 g of polymer remalned in
the fl~sk which was sho~n by ~el permeation
chro~atography to h~e an average molecular wei~ht
of appro~imately 30~.
The polymer (~80 g~ was mixed wi~h 340 ml
1,1,2-~ic~lorotrlfluoroeth~ne and was slowly pumped
into a 15 liter stirred reactor over a 24 hour
perio~. The reacto~, which contained 5.5 llte~s of
1,1,2-trichlorotri~luoroethane and 1220 8 sodium
fluorlde powderl was ~aintained at lO~C throughout
the react~on while 20~ fl~orine was bub~led throu~h
the llq~id fl~orination medium ~t a rate just
exceedin~ that req~lr~d to react with all of the
~, 1029 1
- 38 -
starting material being pumped into the reactor.
The reactor contents were filtered and distilled to
give 587 g of fluld which was further tre~ted with
50~ fluorine ~t 270UC to give a fluld whlch was
essent$ally free of hydrogen. The purl~ied pro~uct
w~s fractionated into three samples. The first
f~action boiled below 200~C at 0.05 m~ H~, the
second distilled ove~ ~etween 200 and 300~C ~t 0.05
mm an~ the d~still~tion bottomg had a boiling po~nc
~bo~e 300~C at 0.05 mm ~g. The second fraction
comprised approximately 20~ of the total fluid with
the ~a~ority of the sa~ple h~ving ~ boil~ng point
below 200~C at 0.05 m~.
The visco~ity of the secon~ fraction at 20~C
w~s 72.2 cst. (ASTM slope of 0.644). ~he pour point
was -62-C.
F ~ilME~ (S ppm vq CFC13):-47.3,-49.3,~Sl.4:CF20;
-54 O, -5s~8;cF3o;-79~7:ocF(~;F3)cF2o;
- 84 . 7: OCF ( CF3 ) GF20; - 8 7 . 3: GF3CF20; -130 . 0 ~ F3CF20;
-140.3, -144.8, -146.0:0GF2CF~CF3)0,
Anal. Calcd. fo~ CF30[CF2CF(~F3)0CF2CF~CF3)QGF20]n-
CF2CF3; C, 2}.02; F, 67.02.
Found. C, 21.08; F, 67.08.
~xample 12
Using techni~ues similar to tho~e described in
the previous examples~ 350 g 1,4 butanediol, 43 g
n-propanol ~nd 200 g paraform~ldehyde were reacted
in benzene to give a fluid which ~as treated with
-
2 9 4
-39-
85g acetlc anhyd~ide to give 325 g of a polymeric
material ~aving a viscos~ty of 162 cst. at 30~C.
Fluorin~tion of 3~5 g o~ ~he fluid in ~ typical 40~C
fl~orination reactlo~ gavs 577 g of fluid of whi~h
approximately 30~ boiled b~tween 200~ and 300~C at
O.OS mm/Hg,
F ~MR (~ pp~ vs CFC13):-51.7(f), -82.1(a),
-85.4(d), -8~.5~c), -125.9(e) and -130.3(b)
CF3cF2cF2~cF2c~2cF2cF2ocF2o]n CF2CF2CP3
a b c d ~ e d f c b a
Exam~le_13
In~o ~ 1 liter stirred fla k were plac~d 350g
1,5 pentan~diol (3.4 ~ol), 23g n-b~tano} (0.3 mol),
175g paraform~ldehyde (5.8 mol) snd 200 ml benzene.
Upon refluxin~ the mixture for app~oxi~ately 3 hour~
wi~h an acld catalyst present, 390g of a poly~eric
fl~id was obtained which h~d a vlscosi~y of 4S0 ost.
at lOO~F. Fluorination of 310g of the f~uid ~n a
~ypical fluor~nation reaction at 14~C ~ave 708g of
fluid t80~ y~eld) of w~ich appro~mately 30% boiled
between 200 and 300~C at 0.05 m~ Hg.
~F NMR (~ ppm v~ CFC13) -51.3(g), -55.7~c),
-81.7(a), -8S,O(d), -122.3(f), -125,5(e) and
-126.7(b)
CF3C~2CF2CF20{CF2CF2CF~CF2CF20CF20~nCF2CF2CF2CF3
a b ~ c d e f e d ~ c b b
02~4
-40-
Example 14
Usin~ techniques s~mila~ to those ~escribed in
the previous examples, 350~ 1,6-hexanediol (3.0 mol)
49.3~ n-pen~anol (0.S6 ~ol), 134g paraformaldehyde
(4.46 mol) were re~cted in benzene ~o ~ive 425g of a
polymeric material having a viscosity o f ~00 c~t. at
100~F. Fluorin~tion of ~2~g of the fluid ln a
typical react~on at 10~C ~ave 6~8g o~ flu~d (71~
yiel~), of whic~ approximstely 30& boiled be~ween
~00 and 3~ at 0.05 mm H~,
~F NMR (~ ppm vs C~C13):-51.3(i), -5~.0~b),
-81.7(a), -85,~ 85.3(e), -122.7(h), -123.0(c),
-125.5(g) and -126.3(d)
CF3CF2CF2CF2CF2o[cF2cF2cF2cF2cF2cF2ocF2o~ CF2CF C~
a b c d e f ~ h h g f i e d c
GF2CF3
b a
Exa~ple 15
Into a 500 ml ila~k were placed 100 g
diethylene ~lycol (O.g4 mol), S5.7 g acetaldehyde
diethyl acetal (0.47 mol), 200 ~1 benzene and ~.5 g
acidic ion exchan~e resin Attached ~o the flask
was ~n apparatus designed to continuously ext~act
t~e by-product ethanol from the refluxing benzene.
Af~er appro~i~ately ~ hours, the ~e~lux~n~ benzene
~ag essen~ially free of ethanol and the reaction was
assumed to be complete. Filtration of the c~ude
~~ ~029~
-41-
re~ction product ga~e a solu~ion free of the ion
exch~nge resin. Removal of the benzene was accom-
plished using a ro~a~y evaporator ~7~~C bath with a
n~trogen purge through the solution),
20 ~ra~s of the poly~erio product were mixed
with lOO ml of methylene chloride and 12~ g sodium
fluorlde powder. On drying the paste, 140 g of a
~ree-flowing powder was obtaln~d. U~ing the ~luor-
ination procedures of E~ample 3, ~ 50~ yield of the
following fluorinated fluid w~ obtained~
~CF2CF20CF2CF20CE~(CF3)0]n
19
F NMR (~ ppm vs CFC13~:
-5~.0:C 30;-8~.3:0CF(~F3)0;-87.3:C~3CF2o;
-87~7:CF3~F20;-ss~7:0cF2cF20;-g6.3:0CF(CF3)0.
Example 16
Using the procedures detailed in the prevlou6
examplex, 400g tetraethylene glycol (2.06 mol) wa~
reacted with 243.5g acetaldehyde diethyl acetal
(2.06 ~ol) in 250ml benzene to give 250g oi a
polymeric fl~id upon refluxl~g for 6 hours. T~e
polymeric liquid (350g) was coated on ~S55 ~ of
sodium fluorlde and placed in a 22 liter rotating
drum reactor. After p~rging fo~ sever~l hours, t~e
reactor was cooled to -1~~C and the fluorine and
nlt~o~en flow rates were set at 350 cc/~in and 2
liters/~in, respectiv~ly. After 2$ hours, the
nitrogen flow w~s decreased to 1. 5 liter/min. After
an ~ddltional 14 hours, the nitrogen flow ~as
~ ~10~9~
-42-
f~rther re~uc~d to 1 liter~min and the re~ctor was
allowed to ~lowly warm to 35~C o~er a 4 hour period.
Upon reaching 35~C, the nitrogsn was turned off and
t~e re~ctor was further warmed to 65~C pr~or to
terminating the fluorine flow. An oll ~371g) w~s
qxtractsd from the sodium fluo~ide with
l,l,~-trichloro~rifluoroeth~ne which was determined
to h~e t~e following structure:
)o]
9F N~ ppm vs CFC13)
-S~.O:CF30;-86.7:0CF~CF3)0;-87.4:CF3CF20;
-BO.O:CF3CF2o;-88.7:0CF2CF20;-~6.7:oCF(C~3)0.
Exsmple 17
A mlxture of 600g d~ethylene glycol and 30g
pot~ss~um hydroxide was heated to 160~C in a l liter
flask. Acetylene gas w~ bu~bled throu~h the
solu~ion ~s it was rapidly stirred, The reaction
was stopped afte~ 48 hours and t~e product wa~
extr~cted with water s~veral times to remov~ any
unreact~d diethylene ~lycol. The product, a d~vinyl
ether of dlet~ylene glycol, was reco~ered by
distill~tion (b.p. 196~C) in about an 80~ yield.
A 1 litsr flask cooled to -10~C was charged
with 250g ~riethylene glycol ethyl ether ~nd a
catalytic amount of methane sulfonic ~c~d. To th~s
~o~ut~on w~s a~ded slowly lOOg dlethylsne divinyl
ether. Following t~e addition, the flask w~s slowly
warmed to ~oom temperature ovsr a 3 hour period.
~029~
-43-
The product was dist~lled to 150~C at O.OS mm Hg to
re~ove any unreacted starting materials.
The product from t~e above reaction can be
f}uorlnated ~t ~O~C ~slng the procedures outl~ed in
the prevlous l~quid phase fluorination exsmples to
glve a perfluorlnated fl~id o~ the follo~ng
struc~ure:
C~3CF20(CF2CF20~CF~CF3)0(CF2CF20)2CF~C~3)0-
( CF2CF20) 3CF2CF3
C24F50 11
b.p. 300~C
Example 18
A mixture of 600g 1,5-pentanedio} and 30g
potassi~m hydroxlde w~s heated to 160~C in a 1 lite~
flask. Acet~lene gas w~ bubbled throu~h the
sol~tion as it was rapidly stirred. ~he re~ction
was stopp~d af~e~ 40 hours ~nd the product was
washed ~ith water and di~t~lled to giVR an 85~ yield
of pen~anediol di~inyl ether ~b.p 192~C).
A 1 liter ~lask cooled ~o -12~C was char~ed
w~th 104g pen~anediol and a traoe of me~hane
sulfonic acid. To this solutlon was added 15~g
pen~anediol divlnyl ether. The ~olution was stirred
rapidly for 2 ~ours. Then slowly w~rmed to room
temperature over a 6 hour period to ~ive a v~scou~
polymer having viscosity of 650 cst. ~ lOO~F.
1 0 2 9 ~
-44-
The product from the abo~e reaction can be
fluorinated in a li~uid phase reactor contalning
1,1,2-~xichloro~rifluoroethane and a sufficient
amount of fluorlne to co~plex with all of the
h~drogen fluoride for~ed durin~ the reaction. A
perfl~oropoly~ther having t~e follo~ing structure ~s
obtalned:
CF3cF2cF2c~2o~c~2cF2cF~cF2cF2oc~(cF3)o]ncF2cF2cF2cF3
Exa~ple lg
A mixture of 400 g triethyle~ glyool ethyl
ether (2.24 mol), 2~8 g acetalde~yde diethylscetal
(1,39 mol), ~0 ml benzene and lO g acidic ion
exchange resin were refluxed in a 1 llter stlrred
flask equipped wi~h a continuous extractor to remove
the by-p~oduct ethanol from the refluxing benzene.
The solutlon was refluxed for 6 hours, then filtered
and placed in a rotary evaporator to re~ove the
benzen~ sol~ent,
The product was fluorinated in a 22 liter
stirred tank which contained 5.7 llters of
2-erichlorotr1~luoroethane and llOO g sodiu~
fluori~e po~der. The hydrocarbon, 219 g, wa~
dilu~ed to a ~olu~e of 700 ml with
tric~lorotrifluoroethane. The solution W8S
slowly pumped into the fluorinat~on reactor, which
was held at -5~C~ over a period of 28 hou~s. Ths
fluorine flow was se~ at a level approximately 1~
hi~er than th~t req~lred ~o resct with all of ths
organic entering the re~ctor. Filtration of the
1~3 ~-10 29~
-45-
crude reactor product followed by dl~tillation
yielded 224 g of a clear fluid which analyzed to be:
~F3c~2ocF2cF2ocF2cF2ocF;2cF2ocF(cF3
CF2cF2ocF2cF2ocF2c~3
~F NMR (~ ppm vs ~FC13):-86.5:0CF(CF3);
-87.4 CF3C~20; -~8.0:CF3CF20;-8~.7 OCF~CF20;
-~6.3: o C~(CF3)0.
Example 20
In an experi~e~ ~ery sim~ to the previou~
one, 400 g dipropylene glycol mono~e~hylether (2.70
mol) w~s ~eacted ~ith 159.~ 8 acetaldehyde
diethylacetal (1.35 mol) $~ ~enzene with an acid
ca~alyst. Fluorlnation of 250 g of ~he material
afforded 480g o~ a perfluorinated fluid havlng the
~ollowing -~tructure:
CF3ocF2c~(cF3)oc~2cF(cF3)oc~cF3)ocF2cF(cF3)
(CF3)0C~3
Ex~mple 21
Chloroacetaldehyde ~50 to 55 wt ~ in water) was
dlstilled to give a fraction boiling between B7 and
92~C. A 3 li~er st~red fl~sk contaln~ng 128l g of
the chloroacet~ldehyde distillate was placed i~ a
roo~ tempera~ure water bath. Whlle m~intainin~ a
~emperature below 55~C, 500 ~1 o~ concentrated
sulfuric acid was slowly added over ~ one hour
period. The ~ixture was stirred for an additionsl 3
~3-~0294
-46~
days at 53~C, ~hen allowed to sep~rate into two
phase~. The lower phase, co~t~ini~g sulfuric acid,
was removed with a separ~tory funnel whlle the upper
ph~se wa~ placed into a 3 liter flssk equipped with
a mech~nical stirrer. Concentrated sulfuric acid
~200 ml) was carefully added to ~he ~ol~tion while
the te~perature was held below 60~C wi~h ~ water
bath ~hroughout the ad~ltion. The flask wa~ hsld at
50~C for an add~ional 20 hour~ ~esult~ng in a
visco~s oil being for~ed. The polymeric product was
dissolved ln l liter methylene chloride and the
solu~ion w~ washe~ with water several times fol-
lowed by a rinse with dllute sodi~m bicsrbonate
solution. The organ~c phase was i~olated, dried
over magnesi~m sulfate and concen~r~ted to give a
dark, viscous product (719 g polychloroace-
ta}dehyde). The product was dls~olved in 450 g
chloroform and 305 g 1,1,2-trichlorotrifluoroethane
to give 8 solution which was metered over a 22 hou~
period into a 20DC fluorination reactor containing
5 5 llters of 1,1,2-trichl~~otrifluoroe~ane.
Following the resction, the solvent was re~oved
leaving behlnd ~ ~luid with the followlng structure
E p~~ ] n
CF2G~
Te~perature ~F Visco~ity (cst.)
-65 1240
100 2,S3
~76 1.14
134029~
-47-
Example 22
Butoxyethoxy~thanol (400 g, 2,47 mol~ was
r~acted with 130 8 polymeric chloroAcetaldehyde in
150 ml benzene to ~ flui~ which ~ixtilled at
190~C at approximately 1 torr. The prod~ct (2~6 g)
~as mixed w~ th 500 ml 1,1,2-trichlorotrifluoro~thane
and pu~p~d into a 15 liter fluorination reac~or
contai~ing 5.7 lL~ers 1,1,2-~richlorotrifluoroethane
and 1150 g sodlum fluoride powder. Flu~rine,
diluted with approximately four volu~es of nitro~en,
~as metered into the O~C reaetor at a r~te
approxi~ately 10~ grea~er tha~ th~t requlred to
react ~to~chiometrically w~th ~he polyet~er. The
org~nic ~eed r~te ~as sec to allow co~plete sddit~on
in approximat~ly ~3 hours. Filtrat~on of the
prod~ct and remov~l of the 1,1,2-trichloro~ri-
fluoroethane via a distlllation gave ~ fluoroc~bon
product which ~ further p~rif~ed by ~ 12 hour
fl~orlna~lon at 200~C with 40~ fluor~ne,
Approximately 520 g of fluid was reco~er~d ~i~h
~pproxim~ely 50~ b~in~ t~e ~arget mAterial,
CF3cF2cF2cF2o~::F2cp2ocF2cF ;~ocF(c~2Gl)
CF2CF2CF2CF3
b.p. 245.5~C
9F NMR (~ pp~ vs CFC13)
-73.3:0CF(C_2C1)0;-81.7:CF3CF2CF2CF20;
-83.3:CF3CF2¢F2C~2o;-88.0 and -8~,7:o~2GF2o;
-96.7:oc-(cF2cl)o;-126 5 cF3cF2¢-2c~2o
~ ~'1029~
-48-
Ex~mple 23
Chloroacetaldehyde dimethyl acet~l (12~ g, 1
mol), 1,3-dlchloro-2-propanol (258g, 2 mol) and S~
ion exchange resin were mixed in a 1 llter stirred
flask, The mixt~re w~s heated to allow t~e methanol
fo~med in the reaceion to slowly distill fro~ the
flask. Approximately 70 ml o~ methanol wa~7
recovered over a 6 hour period. ~he rem~ining
solution w~s vacuum-distilled and the ~raction ~120
g, 38~ yield) boiling 7Detween 100~C and 145~C at 2
mm Hg was collected, The fluid was ~hown by 19F NMR
and element~l analysis to have the following struc-
ture:
(ClCH2)2C:HO~HOCH(CH2C1)2
GH2Cl
Th~ above acetAl ~210 g) diluted wi~h a small
amount of ~hlorofor~ and 1~l~2-trichlorotrifluoro-
ethane was ~etere~ over A 14 hour period into a 22~7 C
~luorination reactor cont~in~ng 5.7 liters of
1,1,2-tri~hlorotr~luoroethane. The crude p~oduct
was further ~ea~d with 30~ fluor~ne ~t 200~7 C for
several ho7ur~ to give lg7 7 (57% yleld) of clear
fluid:
(CF 2 Cl)2cFO~FOcF(cF2cl)2
CF2
b.p.: 202DC
1 F N~R (~ ppm vs CFC13):-64.5 and -~5.~(a),
-71.0(~) 7 -8~.7(c) and -133.7(b)
I 310294
-49
(ClCF2)2CFO]2 CF(~F2Gl)
a b c d
Example 24
lnto ~ l liter stirred fl~sk contaln~n~ 300 ml
benzene were placed 516 g 1,3-dichloro-2-prop~nol (4
~ol), l~0 g parafor~aldehyde (4 mol) and lOg ion
exchAnge re~in. The ~ixture was refl~xed as ~he
w~ter formed ~ur~ng the re~ction w~s continuously
re~oved. After refluxing for 6 hours, the reaction
mixture was filtered and vacuum-distilled to give
354 g of a product with the following structure:
(ClCH2)2C~oC~2oG~(CH2Cl)2
b.p.: 141~C/0.05 mn Hg.
~ he abo~e acetal (354 g) was mixed with 7~ ~
chlorofor~ and 360 g ~,1,2-trichlorotrifluoroeth~ne
and fluorinated over a 24 hour period at 20~C using
~he procedure described in the pre~iou~ exa~ple.
The reaction product was concen~rated and the crude
product was further treated with fluorine ~t 2~0~C
to gi~e 430 g of a clear fluid (69~ yield) hav~ng a
boiling polnt of 178~C.
F NM~ (~ pp~ vs CFC13~:-45.5(c~, -65.3(a) and
137.1(b)
[( 2)2C~~]2 2
a b c
:~ 1029~
-50-
Example 25
A mlxture of 300g l-propanol (5.0 mol), 231 g
epichlorohydrin and 10 g ion exchan~e re~ln waB
refluxed for 22 hours. The reaction mlxture was
then ~ooled, filtered and distilled to &lve 281 g of
l-chloro-3-propoxy-2-propanol ~74~ yield). ~eaction
of this pro~uct with para~ormaldehydc (2.8 ~ol~ ~ave
202 g of product (~ yield) having the follow$n~
s~ructure:
CH3CH2CH20lHOcH2 ~ 2 2 2 3
CH2Cl CH2Cl
.p.: 132~C a~ 2 mm H~.
Fluorination o~ the above acstal i~ a 23 hour
reac~on at 20~C gave 404 g or produot (81~ yield)
~avln~ th~ fol~owing structure:
CF3cF2c~2ocF2~FocF2oc~cF2oçF2cF2CF3
CF2Cl CF2Cl
b,p.: 207~C
F N~R ~ pp~ vs CFC13):-46.3~g), -67.3(f),
-80.4(d), -8~.9~a), -84.5(c~, -130.0(b) and
-141 . 6(e)
[cF3cF2cF2ocF2cF(cF2cl)ol 2CF2
a b c d e f g
02~4
Exa~ple 26
A m~xture of 600 ml ethoxyethanol, 200 g
eplchloro~y~rin and 10 g lon exc~an~e ros~n waR
heated to 130~C ~or 20 hour~. The reaction mix~ure
was then cooled, filtered and distilled to ~ive 250
g of product whl~ wa~ then reacted with 116 g
p~raiormaldehyde to gi~e 266 g of a product boiling
above 150~C at 0.01 mm ~g.
~ luorLnation of 261 g of the produc~ in a
reactor con~ining 5 liters of 1,1,2-trichlorotri-
fluoroethane and 1000 g sodium fluoride ~ave 446 g
of perfl~orlnated fluid of whl~h Rpp~oxi~ately 708
h~d the following Rtructure:
CF3CF20CF2CF20CF2qFOC~20C~FCF20CF2CF20CF2CF3
CF2Cl F2Cl
b.p, 224VC
9~ ~MR ~ ppm V8 GFC13): -46.4(h), -67.6(g),
-80.9~e), -87.6(a), -8~.0(b,c,d), and -141.8~)
CF3CF20CF2CF20CF2CF(C~2~1)0CF2~)CF~CF2Gl)CF2 -
a b o d e f g h f g e
OCF2CF20CF2CF3
d c b
Exa~ple 27
A mixt~re consi~t~ng of lOOg 2-chloro~thanol
(12.4 m~ 73g epich~orohydrin (6.2 ~ol) and 20g
of an ~cidic ion exchan~e resin ~ere reflu~ed for 24
-~4029~
-52-
hours. The mixtur~ was then filt~red to remove the
ion exchange res~n and th~ exces~ ~lcohol and
unre~oted ep~chlorohydrln we~e re~oved by distil-
latlon. The resid~e was ~isti~led under ~ac~u~ and
~he produc~ l-chloro-3-(2-chloroethoxy)-~-propanol
(804g, 7S~ y~eld) distilled betwecn 89 and 91~C at
0.05~m ~g,
Into a l-lit~r stirred flask was place~ 346g
l-c~loro-3-~2-chloro~thoxy)-2-propanol (2 mol), 90g
paraformaldehyde (3 mol), lOg ion exchange resin and
300~1 benzene. The mlxture was refluxed for four
hours as the w~er for~ed duri~g the react~on was
re~oved. Th~ reactlon mixtur~ was filte~ed and
d~s~illed to give 2~7g of a product (75~ yleld) wieh
the followin~ ~tructure:
ClcH2c~2ocH2c~ocH2o7H 2 2CH2
1H ~C1 CH2C1
Fluorlnatlon of the product (660g) in a typical
reactlon ~ 20~C ~ave 1086~ of a product (82~ yield)
havin~ the follow~ng ~t~uct~r~:
ClCF2CF20GF2CFOCF20~FCF~OCF2CF2Cl
CF2Cl CF2Cl
b,p.: 223~C
19~ NMR; (~ ppm v~ CFC13): -46.3~f), -67.3(e),
-74.3ta). -81.0(c~, -87.3(b) and -141.9(d)
~ClcF2CF~OCF2CF(cF2c1)0]2 CF2
a b c d e f
.. .. . . .
~ 0 2 9 1
-53-
Example 28
Into a 1 liter flas~ was c~arged 300
trichloropentaery~hri~ol, (1.5~ mol), 150 ~1 o~
benzene, 10 g ion exchange resi~ ~nd 60 g
paraformsldehyde (2 mol). The ~ixture was refluxed
as w~ter wa~ beln~ removed continuously.
A portlon of the a~ove product, lg2 ~, wa~
dlluted wi~h 1,17 2-trichlorotrifluoroeth~e to gi~e
210 ml of ~olut~on whlch was pumped ~nto a 22~C
reactor containing 4.3 liters of 1,1,2-tr~chlo~otri-
fluoroeth~ne . The reactlon w~s co~plete in
approximately 8 hours. The unreacted fluorine wa~
~lushed from the reac~or with nit~ogen ga~ ~nd the
produet (30~ ~7 87.8% yield) was recovered by
~istillation:
9F NMR (~ pp~ vs CFC13): -48.9~a), -Sl.l(~),
-66.4(b~
E ( cl~2 ) 3 c CF2 o ] 2CF2
a b c
Example 29
A m~xture o~ 3~2 g 1~4-cylcohexanedl~ethanol
t2.72 mol~, 140 g parafor~aldehyde (4,7 mol~, 200 ml
benzene and 10 g of a H ion exchange resin wa~
refluxed for sev~ral hours in a flask containing ~
water separator. A nearly quantitati~e yleld of a
sticky solid was obtained after re~o~al of the
solvent: by d~stillation.
~ ~02~
-54-
Fluorin~lon of 2~3 ~ of the poly~er, d~luted
with 220 ~ chlorofo~ and 340 g 1,1,2-trichlorotri-
~luoroethane in a reactor ~lO~C) coneaining 4.8
liters 1 t l,~-~richlorotrifluoroethsne and 1300 g
sodlu~ fluorid~ power, gave 440g of a perfluoro-
polyether ~aving ~he fol~owing structure:
CF2 ~F2
ICF2~FCF2CF2 F CF2~CF2~]n
Example 30
Into a 1 li~er fl~k were placed 350 g
~eeraethylene glycol ~1.8 ~ol), 300 ml ben~ene, and
10 ~ ion exchange resin. The ~ixture was refluxed
~or 1 hour to remove ~ny moist~re presen~. To the
~ixture was added 200 ml di~ethoxypropane. The
distillate was continuou~ly ~emoved over ~ 2-hour
period in 50 31 increments, which were extracted
with water to removR the ethanol formed in t~e
react~on. After drying, the distlllate wa~ returned
to t~e flask. An additional 200 ml dimethoxypropane
~as added and the dlstillate was collecee~,
extracted, dried, and return~d ~o the flask for an
additional 3 hours. ~emoval of the resin and
solven~ yielded 410 g of a polymeric fluid having a
viscosity of 5~0 cst. at 30~C.
Fluorina~ion of 336 gr~ms of the polyether ~n
lO~C reactor ~ontaini~g S liters of l,l,~-trichloro-
trifluoroethane and 1420 g sodium fluoride powder
gave 642 g of a perfluoropolyether ~69.8~ yield).
.
1~4~2~
-55-
F ~M~ ppm v~ CFC13): -S5.8(a), -76.3(e),
-87.3~d), -~8.6(c) and -90.5~b)
CF30 [CF2(CF20G~2)3 ~20C~CF3)2 ~]n
a b c c d e
Example 31
A mixture of 300 g pentanedlol t2.88 mol), 450
~ chloroacetaldehyde/water mixture having a bo~ling
poin~ b~tween 87 and 92~C and lS0 ml benzene W8~
refluxed in a flalk conta$ning a water sepa~ator.
Approxi~ately S gra~s of an ~cidlc lon exchan~e
resin w~s adde~ to ~atalyze the ~eaction. Aft~r
refluxi~g for approximate}y f~ve hours the solution
wa~ filterad and the benzene ~a~ removed by
distillation to leave ~ residue (approximately ~00
~) having a visco.city of 9,700 cst. at 100~F.
Fluorin~tion of 318 g of the polymer, diluted
wlth 235 g chloroform snd 375 g 1,1,2-trichlorot~i-
fluoroetha~e, in a 12~C ~esctor co~aining 5 liters
of 1,1,2-trichlorotrifluoroethane and 1200 g ~odium
fluoride powder gave 623 g (84~ yield) of the
fluorlnat~d polye~her in ~ 22-hour reaction.
19
F ~M~ (~ ppm vs ~FC13~
-73,4(h), -74.3(c), -81.6(~ 82.3(d), -87.1(g),
-122.1(f), -125,3(e) and -126.3(b)
~4029~
C~3cF2cF2cF2o[c~2cF2cF2cF2cF2ocF(cF2cl)o~ CF2CF2-
a b b c d e f e d g h ~ b
CF2CF3
b a
Eq~ivalents
Those skllled in the ~rt w~ll recognize or be
able to ascertain using no more than routine
experimentatlon many equivalents to the ~pecific
embodi~ent~ of the lnvention described hereln. Such
~qu~valents are int~nded ~o be encompassed by the
following cla~m~;
. . ,
-
- 57 -
SUPPLEMENTARY DISCLOSURE ~~ 4~ 2 g 4
sriefly, in one aspect, this invention provides a
perfluocinated gem-alkylenedioxy composition which can be
normally liquid and which consist or consist essentially
of one or a mixture of perfluorinated gem-alkylenedioxy
compounds, viz., perfluoroacetal or perfluoroketal
compounds, having 6 to 100, and preferablyl at least 12,
e.g. 12 to 50, carbon atoms, which are useful, for
example, as lubricants, hydraulic fluids, liquid heat
transfer media such as thermal shock fluid and vapor phase
soldering fluids
In another aspect, this invention provides a normally
liquid, perfluoroacetal composition which is useful, for
example, as a thermal shock testing fluid. The
composition can consist or consist essentially of a
saturated perfluoro-1,1-bis(alkyloxy)alkane compound as
the single molecular species in the composition (and such
composition is hereafter on occasion referred to for
brevity as a "single molecular perfluoroacetal
composition" or "unimolecular~ composition or fluid).
Said compound (hereafter referred to on occasion as a
perfluoroacetal compound) thus has a
perfluoro-l,1-alkylenedioxy moiety, -O-CF-O-, but can have
another perfluoro-l,l-alkylenedloxy moiety, provided it is
separated from the other by at least two catenary carbon
atoms of a perfluoroalkylene moiety. In another aspect,
this invention provides a normally liquid, perfluoroacetal
composition which consists or consists essentially of a
mixture of two or more such compounds (and such
composition is hereafter referred to on occasion for
brevity as a "mixed perfluoroacetal composition"~ of --
discrete, non-random molecular weights, said compounds
pceferably being those having complementary properties,
.A~''
1 3~029~ 1
for example, boiling points and pour points each within
respective narrow ranges, desired for a particular use of
the composition, e.g. for use as a heat exchange medium.
Unless otherwise stated or apparent, the term
~perfluoroacetal composition" as used herein means that
consisting or consisting essentially of one or a mixture
of said compounds, that is, the term is used in a generic
sense to cover the single molecular and the mixed
perfluoroacetal compositions of this invention.
he perfluoroacetal compound can have one or a few,
e.g. 2 or 3, chlorine atoms, each of which is bonded to
carbon atoms other than those carbon atoms to which an
ether oxygen atom is bonded; stated otherwise, the
compound can have 1, 2, or 3 carbon-bonded chlorine atoms
in place of 1, 2 or 3 carbon-bonded fluorine atoms of the
alkyloxy moieties if the carbon atoms to which the
chlorine atoms are bonded are other than those to which
the ether oxygen atoms are bonded.
The perfluoroacetal composition, which is liquid at
ambient conditions, e.g. 20 C at 740 Torr, generally has a
boiling point greater than 20~C, preferably a boiling
point of at least qO~C, and more preferably a boiling
point greater than 125~C, e.g. 180~C, and can have a
boiling point as high as 300~C. Generally the
perfluoroacetal compound has at least 6 carbon atoms, and
can have as many as 24 carbon atoms or even up to 30
carbon atoms, but preferably the compound has at least 12
carbon atoms, e.g. 12 to 17 carbon atoms. Where a
perfluoroacetal compound is a chlorine-containing
perfluoroacetal compound, its effect on the boiling point
of the perfluocoacetal composition will be approximately
the same as that of a perfluoroacetal compound which does
not contain chlorine atoms and has a higher carbon
content. Generally, one chlorine atom will have about the
same effect on boiling point as 1.5 to 2 carbon atoms.
A particularly useful property of the perfluoroacetal
composition of this invention is its wide liquid range,
meaning it is normally liquid over a wide temperature
~':
2 9 1
- 59 -
range; in fact, some of them can be considered as having
exceptionally wlde liquld ranges. A feature of the
perfluocoacetal compositions of this lnvention i5 that the
perfluoroacetal compound or compounds thereof are each of
well-defined, definite, certain, and known structure of a
non-random nature and with fixed carbon, fluorine, and
oxygen ratios and of a definite (or pacticular or
distinct) molecular identity. In the mixed
perfluoroacetal compositions, specific molecular
structures and amounts of each compound in the mixture are
features which can be completely predetermined and the
mixture made by mixing or blending selected single
molecular perfluoroacetal compositions or the mixture made
as such as a reaction product of the corresponding
precursor mixture of acetals. These features are in
contrast to those perfluoropolyether chemicals which are --
polymeric or oligomeric in nature and have a distribution
of molecular weiqhts, those which have a random structure,
or those which are a random mixture of compounds. The
control over the nature of the single molecular
perfluoroacetal compositions of this invention is a
feature which means that their physical properties,
particularly thelr low temperature viscosity and their
discrete boiling point, are invariable under conditions of
use, for example where in use as a thermal shock fluid
some of such single molecular weight perfluoroacetal
composition is lost through volatilization. Some of the
mixed perfluoroacetal compositions can have these
advantages if the perfluoroacetal compounds ln the mlxture
are judiciously selected, for example by empirically
selecting those with the desired boiling points and low
temperature viscosities.
The above-described features of the compositions of
this invention advantageously contribute to their
usefulness as heat exchange liquids, such as thermal shock
testing fluids. The perfluoroacetal compositions also
have utility as hydraulic fluids, as pump fluids for
corrosive environments, and as fluids for vapor-phase
'.1 3
. . . . . . .
1 0 2
- 60 -
condensation heating for soldering and polymer-curing
applications. Their low temperature viscosities are
especially low compared with the viscosities of prior art
perfluorinated polyether fluids which have a distribution
of molecular weights and compositions. These low
viscosities render the perfluoroacetal compositions of
this invention especially effective, particularly in
comparison with the prior art fluids, as heat transfer
media at low temperatures.
In another aspect of this invention, the
perfluoroacetal and perfluoroketal compositions are
prepared by direct fluorination of their
perfluorinateable, saturated or unsaturated acetal or
ketal precursors which can be fluorine-free or
partially-fluorinated and chlorine-free or partially
chlorinated. ("Perfluorinateable" means the acetal or
ketal precursor contains carbon-bonded hydrogen atoms
which are replaceable with fluorine and any carbon-carbon
unsaturation in the precursor can be saturated with
fluorine.) The resulting perfluoroacetal or
perfluoroketal compounds can be made with the same number
and spatial arrangement of carbon atoms as the precursors
thereof. The fluorination can be carried out at a
temperature between -80 C and +150 C or at moderate or
near ambient temperatures, e.g. -20 C to +50 C, preferably
between -10~C and +40 C, with a stoichiometric excess of
fluorine gas, which is preferably diluted with an inert
gas, such as nitrogen, helium, argon, perfluoromethane, or
sulfur hexafluoride, to minimize or avoid hazards and to
control the amount of heat generated upon initial contact
of the precursor with the fluorine.
A class of perfluoroacetal compositions of this
invention is that whose members consist or consist
essentially of one or of a mixture of perfluorinated
'
~ .
- 61 - ~3~029~
acetal compounds whlch fall within the follo~l~g
representational general formula:
Rl(OR~)~[OfF(ORt)yJ~OfFO~~R~O)~R5
R6 R6
wherein: R~ and R~ are each independently selected from
the group consisting of Cl to C" preferably Cl to C6,
linear or branched perfluoroalkyl, C~ to C~, preferably C
to C6, linear or branched chloroperfluoroalkyl, and
unsubstituted or lower alkyl-substituted
perfluorocycloalkyl or chloroperfluorocycloalkyl wherein
the lower alkyl substituent has 1 to 4 carbon atoms and
the number of ring carbon atoms in the cycloalkyl is 4 to
6, preferably 5 or 6; R~, Rt, and R~ are each
independently selected from the group consisting of C2 to
C~ linear or branched perfluoroalkylene and C~ to C~
linear or branched chloroperfluoroalkylene; each R~ is
independently a fluorine atom or perfluoroalkyl with 1 to
4 carbon atoms, and is preferably perfluoromethyl or, more
preferably a fluorine atom; x and w are each independently
an integer of 0 to 4; y is an integer of l to 6,
preferably 1 to 3; z is an integer of 0 or 1; and the
total number of carbon atoms in said compound can be 6 to
30, preferably at least 12, e.g. 12 to 17, and more
preferably 13 to 14 because of the extremely low viscosity
at low temperatures, e.g. less than about 300 centistokes
at -70~C, coupled with high boiling point, e.g. above
about 175~C, that the compositions have when the total
carbon atoms are 13 or 14. (The term "chloroperfluoro-n
is used herein to describe a perfluoro moiety in which 1
or 2 fluorine atoms are replaced in a sense by chlorine
atoms, e.q. as in the case of ClC2F~- or -CF2CF(CF2Cl)-.)
The perfluoroacetal compositions preferably have a boiling
point in the range of 160~C to 250~C, and more preferably
in the range of 175~C to 200~C.
The perfluoroacetal compounds of this invention
contain at least one perfluoro-1,1-alkylenedioxy unit,
A
.... . . .
- 62 - ~t, f~0 29~
e.q. -OCF(R~)O- in formula I, wh~ch can be located
approximately at the center of the perfluoroacetal
molecule, but a perfluoroacetal compound can contain two
perfluoro-~ alkylenedioxy units separated by at least
two catenary carbon atoms of a perfluoroalkylene moiety
and each of the units located at approximately the center
of a different molecular half of the compound. Here,
"approximately at the center~ means having about the same
number, plus or minus about one, of perfluoroalkyleneoxy
units on each side of the molecule (in the case of a
single alkylenedioxy unit) or molecular half (in the case
of two such units). The acetals having one
perfluoro-1,1-alkylenedioxy unit which is centrally
located are generally more easily prepared because their
precursors are readily available materials.
A particularly useful subclass of the perfluoroacetal
compositions of this invention is that whose members
consist or consist essentially of one oc a mixture of two
or more perfluoroacetal compounds falling within the
following representational general formula:
C F~ l(Oc~F~.-OcF[(cF2)~F]O-(c.~F2.~o)bcn~F2n~
wherein: each n and n' is independently an integer of 1 to
6, each m and m' is independently an integer of 2 to 4, a
and b are each independently an integer of 0 to 4, and p
is 0 or 1 (if p is 0 then the central moiety is -OCF~O-
and if it is 1 then the central moiety is -OCF(CFl)O-),
each said compound preferably having 13 to 14 total carbon
atoms, said composition having a viscosity at -70~C of
less than about 300 centistokes, preferably less than
about 200 centistokes.
In another aspect, this invention also provides a
method of transferring heat from an article, such as an
electronic component or device, to a cooling liquid, the
method comprising directly contacting_the article with an
above-described perfluoroacetal composition of this
invention.
.
~- - 63 - ~ 1029~
This invention further provides a method of inducing
a thermal shock to an article, such as an electronic
component or device, for example for purposes of testing
the integrity or soundness of the article as described
earlier herein, the method comprising the following steps:
a) heating a first bath of a heating liquid to a
temperature above ambient temperature;
b) cooling a second bath of a cooling liquid to a
temperature below ambient temperature; and
c) sequentially:
i) immersing the article in an initial bath which is
one of said first and second baths and allowing said
article to come to the temperature of said initial
bath before removing said article from said initial
bath, and
ii) then immersing said article in the other of said
first and second baths and allowing said article to
come to the temperature of said other bath before
its removal therefrom;
wherein said liquids are inert, thermally stable,
perfluorinated liquids, at least one of which is, but
preferably both are, a perfluoroacetal composition of this
invention, more preferably the version which is a single
molecular perfluoroacetal composition.
When a prior art fluorochemical made up of a mixture of
molecular weights is used as a single thermal shock fluid,
the lower molecular weight components of such fluid can boil
off from the heating bath and the remaining higher molecular
weight components can lead to increased viscosity through
pollution or contamination of the cooling bath. The single
molecular perfluoroacetal composition of this invention,
which is essentially a single perfluoroacetal compound, does
not have these disadvantages of prior art fluids (which have
a distribution of molecular weights). The version of the
perfluoroacetal composition of this invention which is a
mixture of perfluoroacetal compounds also can overcome these
disadvantages if each of the compounds in the mixture have
the same or about the same boiling point, e.g. boiling points
..
- 64 - ~?~'102~
within a 10 to 15~C range, and viscosity, e.g. viscosities at
-70~C of up to ~00 cs, necessary to maintain the desired bath
temperatures.
The perfluoroacetal compositions and perfluoroketal
compositions of this invention may be prepared from their
hydrogen-containing, saturated or unsaturated,
non-fluorinated or partially-fluorinated, non-chlorinated or
partially-chlorinated hydrocarbon analog acetals and ketals
which are perfluorinateable by direct fluorination. Although
the perfluorinated products may contain small amounts of
fluorinated materials having one or a few residual hydrogen
atoms, the perfluoroacetal and perfluoroketal compositions of
this invention are, except for any chlorine content,
essentially fully-fluorinated, i.e. perfluorinated, with a
residual carbon-bonded hydrogen content of generally less
than about 0.4 mg/g, usually less than 0.01 mg/g, and
preferably less than about 0.1 mg/g, e.g. 0.01 to 0.05 mg/g.
This residual hydrogen content can be lowered or essentially
completely removed (as well as traces of undesired carboxylic
acid derivatives such as terminal acyl fluoride groups
resulting presumably from chain degradation reactions) upon
treating at elevated temperature, e.g. at 150~C or higher,
e.g. 175~C or even 260 C, the fluorinated product with
fluorine, for example fluorine diluted with an inert gas such
as nitrogen, such treatment being referred to hereinafter on
occasion as the "polishing" finishing technique.
''~''
. .
- 65 - ~ ~4029
Suitable liquids u~ful as liquid phas~ reaction
media are chlorofluorocarbons such as Freon~ 113,
1,1,2-trichlorotrifluoroethane, and Freon~
fluorotrichloromethane, and chlorofluoroethers such as
2,5,5-trichloroperfluoro-2-butyl tetrahydrofuran,
perfluoro-bis(chloroethyl)ether, and perfluorinated
polyepichlorohydrin liquids, which media generally will
function as good solvents for non-fluorinated precursors, and
Fluorinert electronic liquids FC-75, FC-72, and FC-40,
perfluoroalkanes such as perfluoropentane and
perfluorodecalin, perfluoropolyethers such as ~rytoxT~ and
FomblinSM, perfluoroalkanesulfonyl fluorides such as
perfluoro-1,4-butanedisulfonyl fluoride and
perfluorobutanesulfonyl fluoride, and the perfluoroacetal
compositions of this invention, and this latter group of
media, i.e., perfluoroalkanes, etc., generally will function
well as solvents for some precursors or as reaction media for
forming dispersions of other precursors. Mixtures of such
liquids can be used, e.g. to get good dispersion of precursor
and intermediate reaction products. The reaction media are
conveniently used at atmospheric pressure. Lower molecular
weight members of the above classes of reaction media can
also be used, but elevated pressures are then required to
provide a liquid phase. The fluorination reaction is
generally carried out at a temperature between about -10~C to
+50~C, preferably between about -10 C to 0~C if a hydrogen
fluoride scavenger is used,~-and~if-such scavenger~ls not~ ~
used, between about 0 C to 150~C, preferably about 0~C to
50~C, most preferably about 10~C to 30~C, the temperature
..,~ f
- 66 -
~ 3~029~
-
being sufficient to volatilize the hydrogen fluoride
by-product and with the aid of the inert gas, flowing at a
sufficient rate, cause the purging of the by-product from the
- fluorination reactor as it is generated. At these
temperatures, the liquids utilized as reaction media do not
react appreciably with the diluted fluorine and are
essentially inert. The reaction medium and other organic
substances may to some extent be present in the gaseous
reactor effluent, and a condenser may be used to condense the
gaseous reaction medium and such substances in the effluent
and permit the condensate to return to the reactor. The
condenser should be operated so as to minimize or prevent the
return to the reactor of hydrogen fluoride by-product (which
would have an adverse effect on yield of perfluorinated
product if allowed to remain in the reactor during
fluorination). The return of the hydrogen fluoride can be
minimized or prevented by selective condensation of the
organic materials while allowing the hydrogen fluoride to
pass through the condenser, or by total condensation into a
separate vessel of both hydrogen fluoride and the organic
materials followed, if desired, by separation of the hydrogen
fluoride as the upper liquid phase and the return of the
lower liquid phase. The reaction may be carried out in a
batch mode, in which all of the precursor is added to the
liquid prior to fluorination to provide a precursor
concentration of up to about 10% by weight, and the
fluorine-containing gas then bubbled through the
precursor-containing liquid. The reaction can also be
carried out in a semi-continuous mode, in which the precursor
is continuously pumped or otherwise fed neat, or as a diluted
solution or dispersion or emulsion in a suitable liquid of
the type used as a reaction medium, into the reactor, e.g. at
a rate of about 1 to 3 g/hr into 400 mL of liquid reaction
mixture, as fluorine is bubbled through, e.g. at a fluorine
flow rate of about 40 to 120 mL/min and an inert gas flow
rate of about 150 to 600 mL/min. The fluorination can also
be carried out in a continuous manner: the precursor (either
neat or dissolved or dispersed in a suitable liquid of the
s
.. . . ...
~ 67 - ~ 34a2~
type used as a reaction medium to form a solution or
emulsion) being continuously pumped or otherwise fed into the
reactor containing the reaction medium as the
fluorine-containing gas is introduced, as described above,
and the stream of unreacted fluorine, hydrogen fluoride gas,
and inert carrier gas being continuously removed from the
reactor as is a stream of liquid comprising perfluorinated
product, incompletely fluorinated precursor, and inert liquid
reaction medium, and the necessary separations being made to
recover the perfluoroacetal composition, and, if desired,
with recycling of the unreacted fluorine and the incompletely
fluorinated precursor. The perfluorinated produ~t frn~ tn~
batch mod~ generally wi
, ~ ~ .
f~
.. .. .,~ ~
- 68 - ~31023~
have significant residual hydrogen, e.g. about 7 mg/g,
whereas the perfluorinated product made by the contlnuous or
semi-continuous mode will generally have less residual
hydrogen, e.g. less than 0.1 mg/g. In general, the
continuous addition of precursor is preferred and provides a
higher yield, better product quality, and more efficient use
of fluorine, though the batch mode has similar advantages if
the "polishing" finishing step is used.
Due to the extremely high exothermicity of the
fluorination reaction, a cooled liquid or ice bath is
generally employed in order that acceptable rates of reaction
may be achieved. When the reaction is complete, the reactor
is purged of fluorine and the reactor contents are removed.
In the solids fluorination technique, the reactor contents
can be mixed with Freon 113 or Fluorinert FC-72 solvent, the
resulting slurry filtered, and the solvent stripped, e.g. by
vacuum distillation, to provide crude perfluorinated product.
Where the fluorination is carried out by the liquids
fluorination technique in the presence of a hydrogen fluoride
scavenger, the spent scavenger can be separated by filtration
or decantation from the liquid reactor contents and the
latter then distilled to separate the reaction medium from
the crude perfluorinated product. Where the fluorination is
carried out by the liquids fluorination technique without
using the scavenger, the reaction product mixture can be
distilled to recover the perfluorinated product.
The crude perfluorinated product can be treated with a
base, e.g. sodium hydroxide, to remove acid and hydride
impurities or treated, e.g. at a temperature above 150~C, by
the polishing finishing technique to remove hydrogen and acid
impurities and the so-treated product distilled. The order
of these purification steps can be varied to obtain best
results.
The precursor acetals used for preparation of the
perfluoroacetal compositions of this invention can be
prepared in a variety of ways by reaction of alcohol(s) with
appropriate co-reactants. Symmetrical acetals result upon
heating two moles of a single alcohol with an aldehyde, e.g.
,'~;
- 69 -
- ~' 3~0294
formaldehyde, under acld catalysis, with removal of water
during the reaction, as illustrated in Equation 1.
2ROH + R'CHO --> ROCHOR + H20 Eq. 1
Lower acetals can be converted to higher ones by heating
with the higher alcohol under acid catalysis, as
illustrated in Equation 2.
C ~R n
2ROH + R'O HOR' --> ROCHOR + 2R'OH Eq. 2
A third route, to symmetrical acetals, as illustrated in
Equation 3, involves basic conditions and is useful for
hindered or acidic alcohols in which the above acid-catalyzed
equilibria are unfavored. Under phase transfer catalysis, a
mixture of NaOH, or preferably ROH, and the alcohol displaces
chloride from methylene chloride.
2ROH + 2ROH + CH2C12 --> ROCH2OR + 2KCl +2H20 Eq. 3
The preferred route to asymmetric acetals requires prior
formation of the alpha-chloroalkyl derivative of one
alcohol and subsequent reaction with the second alcohol
under basic conditions, as illustrated in Equations 4 and
5.
ROH + R'CHO + HCl --> ROCHCl + H20 Eq. 4
IR' IR'
ROCHCl + RnOH + KOH --> ROCHOR" + KCl +H20 Eq. 5
This latter reaction is also the preferred method to
prepare precursors containing two alkylenedioxy units.
0294
- 70 -
The other methods illustrated in Equations 1-3 can be used
for preparing those precursors with two of such units,
although yields are lower due to competinq
oligomerization.
In the schemes illustrated in above Equations 1 to 5,
mixtures of alcohols, aldehydes, and/or acetals can be
used as reactants to prepare mixtures of precursors that
are fluorinated to make perfluoroacetal compositions of
this invention which are mixtures of perfluoroacetal
compounds. Thus, the process of Equation 1 can be modified
by use of two different alcohols, as lllustrated in
Equation 6.
R.n ~rl
4ROH + 4R'OH + 4R~CHO --> 2ROCHOR' + ROCHOR +
~ n
R'OCHOR' + 4H20 Eq- 6
~'
~ ~1029~
Useful precursor acetals for conversion by direct
fluorination to the perfluoroacetals of this invention
include each of those in the following list of materials
and mixtures of 2, 3, or more thereof:
CH3(CH2)50CH20(CH2)sCH3
CH3(CH2)30cH20(cH2cH2o)2(cH2)3cH~
2 ~ {
OCH2 0
Cl ~ OCH20 ~ Cl
~CH2 OCH2 OCH2~
CH3(CHz)60CH20(CH~)6CH3
CH (CH2)2(ocH2cH2)3ocH2o(cH2cH2o)3(c 2)2 3
CH =cHcH2(ocH2cH2)3ocH2o(cH2cH2o)3c 2 2
CHz CHCH20(CH2)30cH2o(cH2)3ocH2cH~cH2
- 72 ~ 0 2 9
CF~CHFCF20(CH~)30CH20(CH2)~0CF2CHFCF~
CH,(CH2)2(0CH2CH2)~0CH20(CH2CH20)~(CH2)2CH3
CF3CHFCF20C~H60CH~OC3H60CF2CHFCF3 and
CH3[0C3H6]~0CH20[C3H6 0 1 2 CH3 (where C3H6 can be
either -CH2~H- or -ICHCH2- or a mixture of both)
CH3 CH3
ClCH2CH2OCH2CH2OCH2OCH2CH2OCH2CH2Cl
CH3(CH2) 3 ocH2cH2ocH2ocH2cH2o(cH2) 3 CH
CH3(cH2)3(ocH2cH2) 2 ~CH2 ~( CH2 CH2 ~) 2(CH2)3CH3
CH3(cH2)3ocH2ocH2c-ccH2ocH2o(cH2)3cH3
CH3cH2(ocH2cH2) 2 ~CH2 ~ ( CH2 CH2 ~ ) 2 CH2CH3
CH3(CH2) 2 ( OCH2 CH2 ) 2 ~CH2 ~( CH2 CH2 ~ ) 2 (CH2)2CH3
3OcH2cH2ocH2(ocH2cH2)3ocH2ocH2cH2OcH3
3 C 2ocH2cH2ocH2(ocH2cH2)3ocH2ocH2cH2ocH2cH
CH3.CH20CH2CH~OCH2(0CH2CH2)20CH20CH2CH~OCH2CH3
CH30CH2CH20CH20(CH2CH20) 2 (CHl)3CH3
CH3cH2(ocH2cH2) 2 OCH20(CH2)sCH3
CH3cH2ocH2o(cH2cH2o)3(cH2)3cH3
CH3(CH2)30CH2CH20CH(CH3)0CH2CH20(CH2)3CH3
CH3(cH2)3ocH2cH2OcH(cH2cH2cH3)OcHzcH2o(cH2)3cH3
~ C
,, , , . . . ~ , .. ... . .. . ..
, 1 02g i
( CH3 ) 3 COCH, CH2 OCHl OCH2 CH2 OC ( CH3 ) 3
C3 H7 OCH2 CH2 OCH ( CH2 Cl ) OCH2 CH2 OC3 H,
CH3 OCH2 CH2 OCH2 CH ( CH3 ) OCH2 OCH ( CH3 ) CH2 OCH3
CH3 CH2 OCH2 CH ( CH2 Cl ) OCH~ OCH ( CH2 Cl ) CH2 OCH2 CH3
CH3 CH2 OCH2 CH2 OCH2 CH2 OCHZ OCH2 CH2 O ( CH2 ) 3 CH3
C, Fl 5 CH2 OCH2 OCH2 C, Fl 5
C3 F, CH2 OCH2 CH2 OCH2 OCH2 CH2 OCH2 C3 F7
Representative examples of the perfluoroacetal
compounds of this invention include the perfluorinated
counterparts of the precursor acetals listed above. Where
the precursors have unsaturation, the corresponding
perfluoroacetals thereof are saturated.
The perfluoroacetal compositions of this invention
generally have surprisingly low viscosities at low
temperatures compared with the viscosities of commercial
GALDENR perfluoropolyether immersion fluids of comparable
molecular weiqht, which commercial fluids contain a
distribution of molecular compositions. These low
viscosities render the perfluoroacetal compositions of
this invention especially effective, particularly in
comparison with the prior art fluids, as heat transfer
media at low temperatures. A preferred utility for the
perfluoroacetal compositions of this invention is in
cooling an article to a temperature below ambient, e.g., a
temperature far below ambient temperature, such as -65~C.
Such cooling may take place as part of a thermal shock
method which can be used to temper or test a material. An
especially preferred utility is use in the thermal shock
method of this invention, which is preferably car-ried ~ut
in accordance with Condition B or C of U.S. Military
Standard MIL-STD-883C, Notice 4, method 1011.6,
~Al ~
- 74 -
- 3.. 3llO2~
incorporated herein by reference, with a perfluoroacetal
composition of this invention substituted for both of the
fluids specified in that procedure. The thermal shock
method may also be carried out using two thermal shock
liquids, one being a conventional electronic testing
fluorochemical liquid which may be used in either of the
two baths, and the other being a perfluoroacetal
composition of this invention which is used in the
remaining bath. Examples of suitable conventional liquids
include the inert, perfluorinated organic compounds
available from 3M as FLUORINERT Electronic Liquids
described in product bulletin No. 98-0211-2267-0(161)NPI
issued February 1986.
The thermal shock method of this invention using a
single thermal shock liquid can be carried out, for
example, as follows in accordance with MIL-STD-883-1011.6,
Condition C. The article, such as an electronic component
or device to be tested, can be preconditioned by being
immersed in a heated bath of a perfluocoacetal composition
of this invention at an elevated temperature between 150~C
and 160~C for a minimum of 5 minutes. Immediately upon
conclusion of the preconditioning period, the article is
transferred to a cooled bath of the perfluoroacetal
composition at a temperature between about -65~C and
-75~C. The article is held at the low temperature for 5
minutes, at the end of which time it must itself reach
-65~C, and it is then transferred back to the heated bath
of the perfluoroacetal composition. The article remains
at the high temperature for 5 minutes. Transfer time from
the high temperature bath to the low temperature bath and
from the low temperature bath to the high temperature bath
is less than 10 seconds. The duration of the test is
generally about 15 complete cycles, where one cycle
consists of immersion in and removal from the heated bath
of the perfluoroacetal composition and immersion in and
removal of the article from the cooled bath of the
perfluoroacetal composition. After completion of the final
cycle of a thermal shock test, an external visual
.. .
2 9 ~
examination of the article is generally pecformed without
magnification or with a magnifying viewer. Typical
effects of thermal shock on defective articles include
cracking and delamination of substcates or wafers, opening
of terminal seals and case seams, and changes in
electrical conductivity due to moisture or to mechanical
displacement of conductors or insulating materials. The
electronic performance of the electronic components can be
determined and compared with the electronic performance of
the article prior to thermal shock testing.
In an alternative thermal shock method of this
invention using two thermal shock liquids, a
perfluoroacetal composition of this invention can be
placed in the heating bath of a thermal shock apparatus
and a different perfluorinated, inert liquid, such as a
conventional, perfluorinated, inert thermal shock testing
liquid, e.g., FLUORINERT FC-77, is placed in the cooling
bath. In this alternative method, the manipulative steps
and conditions used can be the same as those described
above for the single thermal shock method. As the
alternative thermal shock method is practiced, the
perfluoroacetal composition, when carried over into the
cooling bath, will generally not raise the viscosity of
the cooling bath to the extent that a conventional thermal
shcck heating liquid, e.g., FLUORINERT FC-40, does over
extended use.
In another alternative thermal shock method of this
invention using two thermal shock liquids, a
perfluoroacetal composition of this invention can be
placed in the cooling bath of a thermal shock apparatus
and a different perfluorinated, inert liquid, such as a
conventional, perfluorinated, inert, thermal shock testing
liquid, e.g., FLUORINERT FC-40, is placed in the heating
bath. In this alternative method, the manipulative steps
and conditions used can be the same as those described
above for the single thermal shock method. As the thermal
shock method is practiced, the perfluocoacetal composition
of this invention, when carried ovec into the heating
- 76 - ~ 3 '10 2~ i
bath, will generally not volatilize from the heating bath
to the extent that a conventional thermal shock cooling
liquid, e.g. FLUORINERT FC - 77, does over extended use.
While the methods of this invention of inducing a
thermal shock can be applied to almost any article which
is immersible in the baths used in the method, the methods
are preferably used to induce a thermal shock in an
electronic device or component to evaluate the electronic
component's response to the thermal shock. Examples of
electronic components and devices include inteqrated
circuits, integrated circuit assemblies, micro-electronic
components and devices, ceramic and plastic carriers for
electronic chips, and assemblies of micro-electronic
components, e.g., integrated circuits, transistors,
diodes, resistors, capacitors, and the like.
Apparatus suitable for performing a thermal shock
test are available from many manufacturers, e.g., Blue M
Engineering, Blue Island, IL; Cincinnati Sub-Zero
Products, Inc., Cincinnati, OH; Maruberi, Santa Clara, CA;
Ransco Industries, Oxnard, CA; Standard Environmental
Systems, Inc., Totowa, NJ; and Thermodynamic Engineering,
Inc., Camarillo, CA. Each of these apparatus possesses
particular features and makes different demands on the
fluid, especially in the cold bath. While some baths in
such apparatus can tolerate a higher cold bath viscosity
than others (e.g., at a cold bath temperature of -65~C),
others tolerate a maximum in viscosity of about 600 cs at
-70~C. Preferred perfluoroacetal compositions used in
this invention have cold bath viscosities below the above
value and thus have general utility in such apparatus.
This variability in apparatus apparently relates to the
observation that fluid in the vicinity of the cooling
coils or panels of the apparatus tends to be somewhat
cooler (e.g., -80 C or -85 C) than the set temperature of
the cold bath and, as a result, problems in maintaining
the set point can occur due to thickening of this fluid
and/or due to the formation of an insulating coating on
the coil. For prior art fluids and, by inference, many of
1 3 1 0
the fluids of this invention which have low viscosity at
-70~C, but not at -85~C, this can be overcome by increased
mechanical agitation. However, in order for a fluid to be
most useful in heat transfer applications, good fluidity,
i.e., low viscosity, at temperatures as low as -85~C is
especially desirable. Single molecular weight
perfluoroacetal compositions of this invention offer an
advantage over fluids which contain higher molecular
weight components which can selectively congeal on cooling
coils and also have the advantage that thermal or
mechanical losses in use do not change the composition
(and, therefore, properties) of that volume or residual
amount remaining. The desiqn characteristics and
specifications for a number of commercially available
apparatus are described in a product bulletin of Ransco
Industries, Oxnard, CA, entitled "Thermal Shock
Temperature Cycling, Product Bulletin 7000 Seriesn.
Minor amounts of optional components may be added to
the perfluoroacetal compositions, e.g., thermal
stabilizers, dyes, etc., to impart particular desired
properties.
The perfluoroacetal compositions of this invention
can also be as additives for other inert fluorochemical
liquids, used, for example, as thermal shock fluids,
hydraulic fluids, heat exchange media, and other working
fluids, to modify or adjust their viscosities or pour
points. The pour points given in the
examples below were estimated by first immersing a
thermometer in a sample of distilled liquid product
contained in a glass vial and then placing the vial in a
liquid nitrogen or dry ice bath to cool the sample to a
solid, glassy state. The vial was then allowed to warm
slowly and the temperature at which complete fluidity was
~h'~
.. .. . .
.. .. .
- 78 - ~ ~40291
attained wa~ noted and recorded as the pour point. The
viscosity in these examples was measured by conventional
means using a wescan viscometer timer and Cannon-Fenske
viscometer tubes, as described in ASTM D446-74 (reapproved
in 1979~. Stable low temperatures for the viscosity
measurements were achieved using Fluorinert FC-75 as the
bath medium; the temperature of the perfluoroacetal
composition was measured with a resident thermocouple.
EXAMPLES
~xample 32
A cylindrical brass reactor (about 7.5 cm in diameter
and about 30 cm long, with a sealed bottom and a removable
head) was fitted with a copper tube through the head
reaching to within about 5 cm of the bottom as the gas
inlet and a hole in the head was fitted as the exit. An
intimate mixture of 30.0 g (0.139 mol)
bis(n-hexyloxy)methane (prepared by the procedure
described in Example 7 usinq methylene chloride as a
source of the formal moiety) and 210 g t5.0 mol) NaF
powder was placed in the reactor, which was then installed
horizontally in a water-ethylene glycol bath and rotated
at about 20-30 rpm. Fluorine and nitrogen were mixed
prior to entry. The bath was cooled to -17~C and the gas
mixture of 60 mL/min fluorine and 240 mL/min nitrogen was
begun. An exotherm of abouat 2 to 5~C was registered by
an internal thermocouple. After 22 hr, the exotherm was
<1~C and the temperature was increased by 10-15~C
increments over the next 8 hrs to 55 C. At hour 25, the
nitrogen was reduced to 120 mL/min and, at hour 29, to 60
mL/min. The fluorine was stopped at the 30th hr. The
resulting white powder (364.2 g) was combined with 7.0 g
of condensate from a cooled trap tcontaining dry ice) in
line after the condenser and was washed three times with
500 mL Freon 113. The--~ombined Freon 113 washings was
stripped on a rotary evaporator at less than 25~C. The
residue, 72.4 g, was distilled on a short path to 19.4 g
.~ ,j .
"~
134029~
(19%) of 88% pure perfluoro-bis(n-hexyloxy)methane
~structure confirmed by fluorine nuclear magnetic
resonance and gas chromatography-mass spectrometry),
having a boiling range of 120-130 C/60 Torr, a pour point
of -70~C, and a viscosity greater than 2000 cs at -85~C.
47.4 g of higher-boiling materials was also isolated.
Examples 33, 34 and 35
Using the fluorination technique of Example 32 and
formals prepared by the methylene chloride route of
Example 38 three perfluoroacetal compositions were made:
Ex. 33,perfluoro-bis (cyclohexyloxy)methane, having a
boiling range of 105-130~C/60 Torr and a pour point of
-45~C, was prepared from bis(1,1-cyclohexyloxy)methane:
Ex. 34,perfluoro-bis(2,4-dichlorocyclohexyloxy)methane,
having a boiling point of 150~C/40 Torr and a pour point
of -25~C, was prepared from bis(2,4-dichlorophenoxy)-
methane: and Ex. 35,[n-C4Fg(OC2F~)2O]2CF2, having a
boiling point of 130-155~C/25 Torr, a pour point of -75~C,
and a viscosity greater than 2000 cs at -85~C, was
prepared from the corresponding hydrocarbon acetal.
Example 36
A mixture of 130.2 g (1.0 mol) isooctyl alcohol, g2
ml (1.05 mol) CH3OCH2OCH3, and 1 g p-toluenesulfonic acid
was stirred at reflux for 18 hr. The internal temperature
was now 60~C. Gas-liquid chromatography showed 30%
unreacted isooctyl alcohol, 41% presumed
1-isooctyloxy-1-methoxy methane, and 13%
bis(isooctyloxy)methane, the latter as three distinct
peaks on the SE-52 chromatographic column. The reflux
condenser was removed and the mixture was heated for 3 hr.
The temperature rose rapidly to 220 C. Gas-liquid
chromatography now showed 13% isooctyl alcohol, 2%
1-isooctyloxy-1-methoxy methane, and 84~ bis(isooctyloxy)-
methane. The p-toluene sulfonic acid was neutralized with
Na2 C~3 and the filtered product was distilled to 102.3 g
(75%) of pure bis(isooctyloxy)methane, bp 110-120~c/0.8
Torr.
Perfluoro-bis(isooctyloxy)methane, having a boiling
~"~ .
. ... ...
- 80 -
~3 lO29~
range o~ 120-140~C/60 Torr and a pour point of -40~C, was
prepared from the above-prepared bis(isooctyloxy)methane
using the fluorination technique of Example 32.
Example 37
In a 250 ml glass flask, a solution of 20.3 g (0.025
mol) bis(1,1-dihydropecfluorooctyloxy)methane (prepared
from the alcohol by the method of Example using
methylene chloride) in 80 mL Fluorinert FC-75 was treated
with 8.0 g (0.154 mol) NaF. The mixture was flushed with
nitrogen and chilled in an ice bath to 10~C. A slow feed
(approximately 50-100 mL/min) of 9% fluorine in nitrogen
was maintained over about 40 hr, using approximately 18 g
fluorine. Gas-liquid chromatography and mass spectrometry
showed two products in a 5:1 ratio, the larger being
perfluoro-bis(perfluoro-octyloxy)methane (920 mol wt) and
the smaller being monohydrido derivative(s) thereof.
Filtration and distillation gave a main cut of 10.2 g, bp
140-145 C/40 Torr, melting point -10 C. Gas-liquid
chromatography showed two main isomers and a minor amount
of the monohydrides. The total yield including other
fractions was approximately 13g (56%).
Example 38
A mixture of 1645 g (13.9 mol) 2-butoxyethanol, 225 g
(7.5 mol) paraformaldehyde, 2.0 g p-toluenesulfonic acid,
and 1.5 liters toluene was stirred at reflux under a
Dean-Stark trap, with steady evolution of water. After 16
hr, 10 g more paraformaldehyde was added and, at 18 hr, 20
g of 37~ formaldehyde was added, in attempts to force the
reaction to completion. Conversion, as determined by
gas-liquid chromatography was greater than 95~ and the
mixture was cooled, washed with water containing a few
grams NaOH, and the toluene allowed to evaporate. The
residue was distilled, yielding 1430 g (83%) of
bis(2-butoxyethoxy)methane, bp 100-110~C at 0.5 Torr.
Bis(2-butoxyethoxy)methane was also prepared from
methylene chloride and 2-butoxyethanol as follows. A
mixture of 590.9 g (5.0 mol) 2-butoxyethanol, 1120 g (20
mol) KOH, 3 g AdogenT~ 464 quaternary ammonium salt, and 1
A ~
- 81 -
0294
liter tetrahydrofuran was stirred for 30 min. The
temperature rose to 45 C. -Careful addition of 750 ml
(11.5 mol) methylene chloride and continued stirring at
55~C for 18 hr gave complete conversion of the alcohol to
bis~2-butoxyethoxy)methane. The mixture was filtered with
additional methylene chloride and distilled, yielding 552
g (96%) bis(2-butoxyethoxy)methane, bp 106~C/0.25 Torr,
which is a product equivalent to that prepared above using
formaldehyde as the source of the formal moiety, -OCH2O-.
A 600 mL Parr reactor of Monel~ metal was equipped
with a 0.6 cm diameter Monel metal gas feed line (for
premixed fluorine and nitrogen) with its outlet being
about 2.5 cm from the bottom of the reactor, a 0.15 cm
diameter nickel organic feed line with its outlet being
about 7.5 cm below the top of the reactor, and a condenser
cooled by the same bath as the jacket. The condenser was
a 50 cm long straight double-tube construction, the inner
tube having a diameter of about 1.2 cm and the outer tube
having a diameter of about 2.5 cm. Gases from the reactor
are cooled as they flow through the inner tube by
ethylene-glycol-water flowing in the annulus between the
tubes. This reactor was charged with 450 mL Freon 113 and
105 g (2.5 mol) NaF. The reactor was purged with nitrogen
(175 mL/min) for 1 hr while stirring at 3~C. Fluorine was
introduced into the nitrogen stream at 35 mL/min. After
15 min, a solution of 15.7 g (0.063 mol) of the above
prepared bis(2-butoxyethoxy)methane diluted to 200 mL with
Freon 113 was placed in a syringe pump and addition of the
resulting solution was started at 9.2 mL/hr. The
additions were maintained over the next 22 hr and after
the organic addition was complete the fluorine addition
was continued for 15 min more. The NaF and NaHF2 were
filtered from the reaction product mixture, washed well
with Freon 113, which was stripped at less than 25~C on a
rotary evaporator, and the combined filtrate and washings
were distilled, yielding 26.0 g (55%) of perfluoro-bis-(2-
butoxyethoxy)methane, which was 95% pure as determined by
gas-liquid chromatography. This perfluoroacetal product
~A~
..... . ....
- 82 - 13~0294
had a boillng range of 100-110 C/40 Torr, boiling po~nt of
183~C, pour point of -95~C, and viscosities of 147 cs, 504
cs, and 858 cs at -70 C, -80~C, and -85~C, respectively.
(In another run, the product had viscoSitieS of 117 cs and
690 cs at -70~C and -85~C, respectively). Traces of acid
fluoride and hydrides (0.02 mg/g) were present (as found
by infra-red and proton nuclear magnetic resonance
analyses). The perfluoroacetal product was purified by
stirring it with hot, aqueous KOH (25%) for 18 hrs, then
washing the separated product with water and drying the
washed product over silica gel. In another run, the
distilled residue was purified by bubbling into it for 5
hrs at 175~C a mixture of fluorine diluted with nitrogen.
Both purification procedures gave colorless, odorless,
thermally stable perfluoro-bis(2-butoxyethoxy)methane.
The thermal stability was determined by heating the
purified product with aqueous sodium acetate for 22 hrs.
at 180~C in a closed, stainless steel tube and
subsequently analyzing the aqueous layer for released
fluoride ion, low fluoride ion content being indicative of
thermal stability.
In a similar fluorination at -5~C (using a condenser
temperature of about -5 C), bis(2-butoxyethoxy)methane
precursor was fed into the reactor as an undiluted liquid
to the mixture of NaF and Freon 113.
In another variation of the fluorination, the
precursor diluted in Freon 113 was fed to a mixture of
15.7g NaF in Freon 113 and the fluorination carried out at
-3~C with the condenser at -3 C (resulting in 51% yield).
In another variation of the fluorination, the
precursor diluted in Freon 113 was fed to a mixture of NaF
and Freon 113 at -10 C (resulting in 42% yield compared to
essentially no yield in a run when no NaF was used). In
these runs, the condenser temperature was set at -25~C.
In another variation of the fluor-ination, the
precursor was fed (diluted in Freon 113) to a mixture of
Freon 113 and NaF at 18 C with the condenser set at -25~C
(resulting in 50% yield compared to a yield of 77% from a
,~-,
- 83 - ~ 4~29~
run where no NaF was used). Another run without NaF at
0~C qave a 65% yield.
In another variation, the precursor was fed undiluted
into Fluorinert FC-72 at 18 C (58% yield), and in another,
fed diluted in Freon 113 into a slurry of NaF and
Fluorinert FC-75 at 18 C and in another, fed diluted in
Freon 113 into perfluoro-bis(2-butoxyethoxy)methane at
18~C. In these runs, the condenser was set at -25~C.
In another variation, the precursor was fed undiluted
into Fluorinert FC-75 at 70 C tS5% yield) and in another
run, fed undiluted into Fluorinert FC-87 at 20~C (42%
yield). In these runs, the condenser was set at about
-25~C.
In another variation, the reactor was charged
initially with 15.7 g bis(2-butoxyethoxy)methane, 105 g
NaF, and 400 mL Freon 113 and cooled to -8~C with the
condenser set at -8 C. A flow of 30 mL/min F2 and 120
mL/min N2 was continued for 20.5 hours. The c.ude product
was isolated as above. H-nmr analysis showed the product
contained 7.1 mg H/g liquid, corresponding to an average
composition of C13H5F23O~. Gas-liquid chromatography
showed little perfluoroacetal; instead the analysis
revealed a series of many small peaks at retention times
intermediate between those of the perfluoroacetal and the
hydrocarbon acetal precursor. In a 200 mL vessel of Monel
metal equipped with a water-cooled condenser, 25.0 g of
the crude product was exposed to a gas flow of 20 mL/min
F2 and 80 mL/min N2 for 0.5 hr at 50 C, then 2.6 hr at
100~C, 1.6 hr at 150 C, and 2.0 hr at 175 C. Distillation
of the residue (16.4 g) yielded 12.7 g (41%) of
perfluoro-bis-(2-butoxyethoxy)methane. H-nmr indicated it
contained 0.3 mg H/g liquid.
Perfluoro-bis(2-butoXyethoxy)methane was also
prepared by the solid fluorination technique of Example 32,
the yield of the product being about 20%.
Example 39
A mixture of 150 g (1.5 mol) n-hexanol and 122 g (1.5
mol, 37%) formalin was treated with 140 g HCl gas over 3
.
- 84 -
.,
~ ~029~
hr. The result~ng chloromethyl hexyl ether (172 g, 73%)
was used directly. A mixture of 147.4 g (1.1 mol)
2-(2-ethoxyethoxy)ethanol, 130 g (1.3 mol), and 275 mL
acetonitrile was heated to 65 C and the above chloromethyl
hexyl ether was added slowly, followed by refluxing
overnight. Gas-liquid chromatography indicated 12%
unreacted RocH2cl and another 14 g of the alcohol was
added. After an additional hour, the mixture was cooled,
washed with water, and the product was dried in methylene
chloride over Mg2SO~ and distilled to 205.6 g (75%)
3,6,9,11-tetraoxaheptadecane, bp 126~C/0.5 Torr.
The tetraoxaheptadecane, prepared as described above,
was fluorinated by the liquids fluorination technique of
Example 7 at about -5~C in the pcesence of NaF to produce
C6Fl3OCF2O(C2F~O)2C2Fs, which had a boiling range of
75-88~C/11 Torr, boiling point of 170~C, viscosities at -70~C
and -85~C of 237 cs and >2500 cs, respectively, and pour
point of -80~C.
Examples 40-58
Using the liquids fluorination technique of Example 38
at about -5~C in the presence of NaF, different
perfluoroacetal compositions, each containing a single
perfluoroacetal compound listed below (except as
indicated) together with properties of the composition,
were prepared from corresponding precursor acetals (made
by the routes illustrated by Equations 1, 2, or 3 or by
Equations 4 and 5, supra) which were saturated except as
noted.
3 (CF2)3OCF2O(C2F~O) 2 ( C~2 ) 3CF3, boiling range of
100-120 C/46 Torr, boiling point of 173 C, pour point
of -90~C, and viscosities at -70~C and -85~C of 148
cs and >2000 cs, respectively.
41- (cyclo-C6Fl1O)2CF2,- boiling range of 100-120 C/20
Torr, pour point of -60~C, made from
diphenoxymethane.
,
- 85 -
1 ~ 4 !~ 2 9 4
42. (cyclo-C6FllCF~O)2CF2, boiling range of 95-115 C/10
Torr, pour point of -60~C, and viscosity at -70~C of
>2000 cs, ~ade from dibenzyloxymethane
[CF3 (CF2 )2 ~OC2F~)3O]2CF2, boiling range of
110-125~C/8 Torr.
44. [CF3 (O-isoC3 F6)2O]2CF2, boiling at 120 C/35 Torr,
pour point of -75~C, and viscosity of 1111 cs at
_70~C.
45. (ClC2F4OC2F~O)2CF2, boiling range of 155-170~C/740
Torr, and viscosities of 55 cs and 398 cs at -70~C
and -85~C, respectively.
46.... [C2F5(OC2F~)2O]2CF2, boiling range of 100-110~C/60
Torr, boiling point of 176 C, pour point of -8S C,
and viscosities of 106 cs, 469 cs, and 1531 cs at
-70~C, -80~C, and -85~C, respectively.
lCF3 (CF2 )2 (OC2F~)2Ol2CF2, boiling at 120~C/35 Torr
pour point of -85 C, and viscosities of 429 cs and
>2000 cs at -70~C and -85~C, respectively.
48. 3 ~C2 F~ ~CF2 ( ~C2 F~ ) 3 OCF2 ~C2 F4 OCF3, boiling at
115~C/30 Torr, pour point of -95 C, and viscosities
of 162 cs and 1500 cs at -70~C and -85~C,
respectively.
3 C2 F~ ~CF2 ~ ( C2 F~ ~ ) 2 ( CF2 ) 3 CF3, boiling at 90~C/40
Torr, pour point of -85~C.
C F Oc2F~ocF2(oc2F4)3ocF2oc2F~oc2F5l boil g
120-140~C/40 Torr.
51. 2 5 OC2 F~ OCF2 ( OC2 F4 ) 2 OCF2 OC2 F4 OC2 F5 ~ boiling range of
90-110~C/15 Torr, boiling at 190~C/740 Torr, and
viscosities of 274 cs and 2375 cs at -70~C and -85~C,
.
- 86 - ~ q~ ~02
respectively.
52. CF3(CF2)3(OC2F~)~OCF~OC2F5, boiling range of
70-90~C/lS Torr, boiling point of 165~C, and
viscosities of 120 cs and 750 cs at -70~C and -85~C,
respectively.
53. (n-C~Fl~O)2CF2, boiling range of 125-140~C/24 Torr,
boiling point of 211 C, and melting point of -50~C.
54. [(CF3 )2CFCF2OC2F4O]2CF2, boiling range of 70-110~C/25
Torr, and viscosities of 240 cs and 1015 cs at -70~C
and -80~C, respectively.
55. [(CF3 )3COC2F4Ol2CF2, boiling range of 80-88 C/17
Torr, boiling point of 183~C, and pour point of
-80~C, and viscosity of 2600 cs at -70~C.
56. [CF3 (CF2)3OC2F4O]2CFCF3, boiling range of 85-95~C/40
Torr, and viscosities of 180 cs and 2504 cs at -70~C
and -80~C, respectively.
57. An approximately equimolar mixture of
( C2 F5 ~C2 F~ ~C2 F, ~ )2 CF2 and (C~ Fg ~C2 F4 ~ )2 CF2, made by
fluorinat-on of a mixture of 11.2g and 10.0g of the
respective hydrocarbon precursors, boiling at 178~C
and having a viscosity of 104 cs and 395 cs at -70~C
and -80~C, respectively.
58. A ternary mixture of approximately one part
(C2F5OC2F4OC2F4O)2CF2, one part (C4FgOC2F4O)2CF2l and
two parts C4 Fg ~C2 F4 OCF2 ~C2 F4 ~C2 F4 ~C2 F5 ~ made by
fluorination of the reaction product of an equimolar
mixture of C2 Hs ~C2 H4 ~C2 H4 OH and C4 Hg ~C2 H4 OH wi th
formaldehyde, said fluorinated mixture boiling at
179~C and having viscosities of 87 cs and 340 cs at
-70~C and -80~C, respectively.
;, j
