POLYMER ELECTROLYTES AND PROCESS FOR THEIR PREPARATION

CETONES POLYETHER SULFONEES ET LEUR PROCEDE DE PRODUCTION

English Abstract

A sulfonated aromatic polyether ketone of the formula
(II)
[[Ar-O-]p -Ar'-]x-O-Ar]m-[CO-Ar'-]y-[O-Ar-]n-CO-]
(II)
in which from 1% to 100% of the O-phenylene-CO units are
substituted with an SO3M group, with sulfonated and
unsulfonated O-phenylene-CO units and sulfonated and
unsulfonated O-phenylene-O units being able to be in any
desired sequence with respect to one another,
and where Ar, Ar' , M, x, n, m, y and p are, defined as
follows:
Ar is a phenylene ring with para and/or meta bonds,
Ar' is a phenylene, naphthylene, biphenylylene or
anthrylene unit or another divalent aromatic unit,
x, n and m independently of one another are 0 or 1,
y is 0, 1, 2 or 3,
p is 1, 2, 3 or 4, and
M, taking into account the ionic valencies, comprises one
or more elements selected from the following group : H,
NR4 +, where R = H or C1-C4-alkyl, or a metal, preferably
an alkali metal or alkaline earth metal or a metal from
subgroup 8, with the exception of the combination p=1,
m=0, Y=2, n=1.

French Abstract

La présente invention concerne une cétone polyéther aromatique sulfonée contenant des unités de la formule (II): [Ar-O-]p-Ar-[[CO-Ar'-]x-O-Ar]m-[CO-Ar'-]y-[O-Ar-]n-CO-], où entre 1 et 100 % des unités O-phénylène-CO sont substituées avec un groupe SO3M, où les unités O-phénylène-CO sulfonées et non sulfonées et les unités O-phénylène-O sulfonées et non sulfonées peuvent se présenter dans n'importe quelle séquence; et où Ar, Ar', M, x, n, m, y et p ont les notations suivantes: Ar représente un noyau phénylène avec p- et/ou m-liaisons; Ar' représente une unité aromatique phénylène, naphtylène, biphénylène, anthrylène ou une autre unité aromatique divalente; x, n et m valent tous, indépendamment les uns des autres, 0 ou 1; y vaut 0, 1, 2 ou 3; p vaut 1, 2, 3 ou 4; M représente un ou plusieurs éléments soigneusement choisis en fonction des valences ioniques dans le groupe suivant: H, NR4, où R représente H, alkyle C1-C4 ou un métal, de préférence un métal alcalin ou alcalino-terreux ou encore un métal du sous-groupe 8.

Claims

-22-
CLAIMS:
1. A sulfonated aromatic polyether ketone, comprising
units of the general formula (II):
[[Ar-O-]p-Ar-[[CO-Ar'-]x-O-Ar]m-[CO-Ar'-]y-[O-Ar-]n-CO-]
(II)
wherein:
from 1% to 100% of the O-phenylene-CO units are
substituted with an SO3M group, and wherein the sulfonated
and unsulfonated O-phenylene-CO units and sulfonated and
unsulfonated O-phenylene-O units are in any sequence with
respect to one another;
Ar is a phenylene ring with para, meta or para and
meta bonds;
Ar' is a phenylene, naphthylene, biphenylylene,
anthrylene or another divalent aromatic unit;
x, n and m independently of one another are 0
or 1;
y is 0, 1, 2 or 3;
p is 1, 2, 3 or 4; and
M, taking into account the ionic valencies, is
selected from the group consisting of H, NR4+, a metal and a
combination thereof, wherein R is H or C1-C4-alkyl.
2. A sulfonated aromatic polyether ketone as claimed
in claim 1, wherein M when a metal is an alkali metal, an
alkaline earth metal or a metal from subgroup 8.

-23-
3. A sulfonated aromatic polyether ketone as claimed
in claim 1 or 2, which comprises units of the formula (III):
<IMG>
4. A sulfonated aromatic polyether ketone as claimed
in claim 1 or 2, which comprises units of the formula (IV):
<IMG>
5. A sulfonated aromatic polyether ketone as claimed
in claim 1 or 2, which comprises units of the formula (V):
<IMG>
6. A sulfonated aromatic polyether ketone as claimed
in claim 1 or 2, which comprises at least two units of the
formula (II) as defined in claim 1 or 2, formula (III),
formula (IV), formula (V) or formula (VI):

-24-
<IMG>
7. A process for the preparation of a sulfonated
polyether ketone in which from 1% to 100% of the
O-phenylene-CO units are substituted with an SO3M group,

-25-
wherein M is as defined in claim 1, by dissolving a
polyether ketone of the general formula (I):
[[Ar-O-]q-Ar-[[CO-Ar'-]r-O-Ar]s-[CO-Ar'-]t-[O-Ar-]u-CO-]~(I)
wherein:
Ar and Ar' are as defined in claim 1;
r, u and s independently of one another are 0 or
1;
t is 0, 1, 2 or 3; and
q is 1, 2, 3 or 4
in 94 to 97% strength by weight sulfuric acid, adding a
sulfonating agent to the solution obtained at an appropriate
temperature, and working up the reaction mixture thus
obtained as soon as the desired degree of sulfonation of the
O-phenylene-CO units is reached, and, optionally, converting
the sulfonic acid groups into their salt form.
8. The process as claimed in claim 7, wherein the
dissolution temperature is in the range from 10 to 80°C.
9. The process as claimed in claim 7 or 8, wherein
the sulfonation temperature is in the range from 10
to 100°C.
10. The process as claimed in any one of claims 7
to 9, wherein after adding the sulfonating agent the
temperature of the solution is at least 30°C.
11. The process as claimed in any one of claims 7
to 10, wherein the sulfonating agent used is sulfuric acid,

-26-
fuming sulfuric acid, oleum, chlorosulfonic acid, sulfur
trioxide or a mixture thereof.
12. The process as claimed in any one of claims 7
to 11, wherein oleum is added to the polyether ketone
dissovled in sulfuric acid until the concentration of
sulfuric acid is from 98 to 100% by weight or the
concentration of oleum is from 0.01 to 15% by weight of S03.
13. The process as claimed in any one of claims 7
to 12, wherein the radical Ar' is phenylene.
14. The process as claimed in any one of claims 7
to 12, wherein an aromatic polyether ketone is employed
which is a copolymer synthesized from at least two different
units of the formulae (II), (III), (IV), (V) and (VI) as
defined in claim 6.
15. The process as claimed in any one of claims 7
to 12, wherein a mixture of different aromatic polyether
ketones is employed in which at least one such ketone is
synthesized from units of the formulae (III), (IV), (V) or
(VI) as defined in claim 6.
16. The process as claimed in any one of claims 7
to 15, wherein an aromatic polyether ketone is employed
wherein the nonsulfonatable units are CO-phenylene-CO units.
17. The process as claimed in claim 7, wherein for the
polyether ketone of the general formula (I), the polyether
ketone of the formula (III) as defined in claim 3, is
dissolved in 95 to 97% strength by weight sulfuric acid at
not more than 80°C and is sulfonated in 95 to 99% strength
by weight sulfuric acid at a temperature from 10 to 80°C.
18. The process as claimed in claim 7, wherein for the
polyether ketone of the general formula (I), the polyether

-27-
ketone of the formula (IV) as defined in claim 4, is
dissolved in 95 to 97% strength by weight sulfuric acid at
not more than 80°C and is sulfonated in 95 to 97% strength
by weight sufuric acid at a temperature from 30 to 90°C.
19. The process as claimed in claim 7, wherein for the
polyether ketone of the general formula (I), the polyether
ketone of the formula (V) as defined in claim 5, is
dissolved in 95 to 97% strength by weight sulfuric acid at
not more than 80°C and is sulfonated at a temperature from
50 to 100°C.
20. A process for the preparation of a sulfonated
polyether ketone by dissolving the polyether ketone of the
general formula (I) as defined in claim 7 in 94 to 97%
strength by weight sulfuric acid, sulfonating the polyether
ketone in sulfuric acid, fuming sulfuric acid, oleum,
chlorosulfonic acid or a mixture thereof and working up the
reaction mixture as soon as the desired degree of
sulfonation is reached, wherein from 1 to 100% of
O-phenylene-CO units are substituted with an SO3M group
wherein M is as defined in claim 1 or 2.
21. A polymer electrolyte solution comprising a
sulfonated aromatic polyether ketone as claimed in any one
of claims 1 to 6.
22. A polymer electrolyte solution as claimed in
claim 21, which comprises at least 1% by weight of polyether
ketones of the formulae (II), (III), (IV), (V), (VI) or a
combination thereof, as defined in claim 6.
23. A polymer electrolyte solution as claimed in
claim 21, which comprises as principal constituent one or
more aprotic dipolar solvents.

-28-
24. A polymer electrolyte solution as claimed in
claim 21, which comprises a further sulfonated or
unsulfonated polymer and, optionally, a small quantity of an
auxiliary.
25. Use of a polymer electrolyte solution as claimed
in any one of claims 21 to 24, for the production of an
asymmetric membrane.
26. Use of a polymer electrolyte solution as claimed
in any one of claims 21 to 24, for the production of a
cohesive film.
27. Use of a polymer electrolyte solution as claimed
in any one of claims 21 to 24, for establilshing an
intensive contact between two polymer electrolyte surfaces.
28. Use of a polymer electrolyte solution as claimed
in any one of claims 21 to 24, for obtaining a porous or
rough surface after contacting the solution with a
precipitating agent.
29. Use of a sulfonated aromatic polyether ketone as
claimed in any one of claims 1 to 6, for preparing a polymer
electrolyte solution or for producing a polymer film.
30. Use of a sulfonated aromatic polyether ketone as
claimed in any one of claims 1 to 6, or a polymer film as
claimed in claim 29, in an electrochemical cell.
31. The use as claimed in claim 30, wherein the
electrochemical cell is a fuel cell or an electrolyzer.
32. A film having a thickness of from 5 µm to 1 mm,
which comprises a sulfonated aromatic polyether ketone as
claimed in any one of claims 1 to 6.

Description

19 SEP '97 14:23 HOE PATENT-U.LIZ.ABT 06930581255
S.3
~ -- ,
~-.7 WO 96/29360 PCT/EP96/01177
SULFONATED POLYETHER K~TONES, PROCESS FOR TFlEIR
PREPARATION AND USE FOR THE PRODL7CTION OF NM+LElRANES
De~criptioa _
The- iavention relates to polymer el.ectrolytes comprising
a. sul.f.onatied aromatic polyether ketoae, to a. procees for
their., preparati.on, to the use of these polyme= electro-
lytes and to solutions of.these poLymer electrolytes and
the use thereof.
4 ,
Sulfonated polyether ketones constitute cationic ion
exchangers. They are ueefu7,' as menabrane materials, for
example for ultrafiltration, for desa].ination and for the
ramoval of microorganisms, since in many cages they are
mechanically stabla even in the pregence of water.
Sulfonated polyether ketones are proton- and cation-
ccnducting materia].s which axe useful for electrodialygis
or as a component of electrochemical ca7.ls.
Starting materials are aromatic polyethar ketones as
indicated by the formula (2)
[ [Ar-O-3 qAr- ( [CO-Ar' -] =-o-Ar1 .- iCO,Ar' -] t- [p-Ar-] u-CO-3
(I?
in which
Ar is a phenylene ring with para and/or meta bonds,
Ar' is a phenylene, naphthylene, biphenylylene or
anthrylene unit or another divalent aromatic unit,
r, u and=s independently of one another are 0 or 1,
t is 0, 1, 2 or 3, and
q ie l, 2, 3 or 4.
The pollriner where q-1, rs0, s"l., t=;0 and u=0 fca commex-
cial.ly available u.ndex the name Vl.ctrex~ff', The polymer
UZ:[.C;:r,Z~AT. ,'.70GLr~?~,NZ'.~
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19 SEP '97 14:23 HOE PATENT-U.LIZ.ABT 06930581255 S.4
- 2 -
where q=1, r-0, s=0, t-0 and u=0 is ],ikewise produced by
Victrex. Furthermore, the polymer where q=1, r=0, 0=0,
t!=2, ua 1 and Ar ig 1,4-phenylene is commercially
available under the.name D'ltrapek .
Polyether ketonee are readily accessible. They ca= be
synthesized in prizzcip7.e by an eletrophilic Friedel-
Crafts polycondensation reaction, in which an appropriate
aromatic bis-acid dihalide is raacted with. an arcmatic
ether. This possibility is described, for example, in
IIS-3 065 205, GB-971 277, US-3 441 538, GB-1 387 303. arsd
WO 84-03891 and in the paper by Iwakura, Y., Uno, X. and
Tahiguchi, T.J., Polym. Sci., Pat. A-1, 6, 3345 (1968).
In addition, the ether ketones can be obtained by nucleo--
philic aromatic, subatittition. To this end an appropriate
arornatic bisdiol ig reacted with an aromatic bis-
haloketone, as described for example irn:
R.A. Clendinning, A.G. Farnhant, -W.F. Hall, R.N. Johnson
and C.N. Merriam, J. Polym. Sci. Al, 5, 2375, (1967),
GS-1 177 183, GB-1 141 421, EP-0 001 879, US 4],08 837,
US 4 175 175, T.E. Attwood, A.B. Newton, J.B. Rose, Br:
Polym. Journ., 4, 391, (1972); T'.E. Attwood, P.C. Dawson,
J.L. Freeman, L.R.J. Roy, J.B. Rose, P.A. Staniland,
Polyamer, 22, 1096, (1981).
The preparation of sulfoxxated polyether ketones from some
of these polyether ketones is described in Ep-A-008 895,
EP-A-041 780 and EP-A-575 807.
According to EP-A-008 895, the polymer to be sulfonated
is suspanded at roozn tamperature in 98% strength by
weight sulfuric aaid. The dissolution procegs an,d the
sulf'onation take place si.multaneousl.y, to give,
gradually, a highly viscous solution. Thi.s solution ia
either left as it is or diluted at the same temperature
with sulfuric acid of the saxne coneentration.. The reac-
rian progresses very slowly. Not until after 10 we ks
war..c about 90% of the guJ.fonatable plzeny'J..tne units
su1fonal:ed. Xn the ;poyy'a-L:ze:r ketones etiployod,, the,
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19 SEP '97 14:23 HOE PATENT-U.LIZ.ABT 06930581255 S.5
- 3 -
numexical ratio of ether bridges to Co bridgee was
approximately 2:1.. According to EP-A-008 895, under these
ooaditions only O-phenylene-O units are sulfonated.
According to the process of EP-A-041 780, aromatic
polyether ketoneg which. cQrrstitute copolymers are sul-,
fonated at e7.evated temperatu're. Onll! some of the monomer
units (A) are suscQptib7.e to sulfonation, while other
monomer units (H) are not sulfonated. Thus the degree. of
sulfonation can be controlled by the ratio A/9. However,
here too the zeaction conditions remain unchanged during
the dissolution procose and thereafter. Corresponding
homopolyiners (A) would under the conditione inda.eated= be
sulfonated to an excescive degrea and would therefore
lead to water-solubie compounds. Since in this case
sulfonati.on takes place during the actual dissolution
proceao of the polymer, it is difficult to control the
degree of sulfonation and. to obtain low-sulfonated
products. In the proceso according to EP-A-041 780,
likewise, under these conditions only O-phenylene-O units
are sulfonated.
In the case of the pxoc ss disclosed in EP-A-575 807, the
polymer to be sulfonated is suspended at room temperature
in 94 to 97% strength by weight sulfuric acid. The
dissolution procegs and partial sulfonation of the
poZymer take place simultaneously to give, gradually, a
viscous solution. A su7,fonating agent is added to the
solution until the concentration of sulfuric acid is from
98 to 99 .9 % by weight. The golutioz3, is held until the
desired degree of sulf_onation is reached' and. is then
worked up. Under these conditions, only O-phenyXene-O
uzlits are su].fonated, whi].e 0-phenylene-CO units remain
unatracked. This is also confirmed by Daoust et al.
(Polymer, Vol. 35 (25), 5491-5497 (1994) ), where the
sulfonation procegs is Ximited to one sulfonic acid group
per repeating unit and to one of the four ecluivaleznt
pos5_ti.o:xa of thQ phenylene riziJ r~urx'ounded by two etkler
.",i'he r)tltier two phenyJ_erin r.-iri,gs are, accordiz::; to
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CA 02215911 2006-08-25
30885-12
_ a. -
I)aoust, so highly deactivated by the neighboring ketone
unit that no sulfonation takes place here.
_n the case of the sulfonation. of polyether ketones using
chlorosulfonic acid or using a S03/triethyl phosphate
complex, a high degree of crosslinking and of decomposi-
tion of the polymer mai.= chain i.s observed
(Marvel. et al. , Journal of. Polymer Science, Polymer Chem.
E.dition, vol. 23, 2205-2223 (1985) and Bishop et al.,
Macromolecules, vol. 18, 86-93 (1985)).
:Cn the prior art p.rocesses, only O-phenylene-O units in
the polyether_ ketones employed. are sulfonated, while
cD-phenylene-CO units and CO-phenylerne-CO units are
sulfonated either not at all or only to an extremely
iainimal extent, or, if more severe conditions are em-
ployed, crosslinking takes place or the polymer main
chain is destroyed. Polymers which do not have
O-phenylene-O units cannot be sulfonated to any signifi-
cant extent. The products obtained when relatively severe
:reaction conditions are employed are insoluble in the
customary solvents and can therefore not be processed
further from solution, or only with very great diffi-
<<u l ty .
According to the prior art it was not to be expected. that
O-phenylene-CO units in a polyether ketone could be
sulfonated. Likewise, the prior art gave no reason to
axpect that correspondingly sulfonated products would he
soluble in customary solvents. It was regarded, in the
;orior art, as impossible to achieve gentle sulfon.ati.on,
in a polyether ketone, of phen.ylene rings directly
,:.djG"cent to a keto group without at the same time ex-
periencing crosslinking= or the breakdov,m of the polyner
main chain.
'I'he present invention provides a gentle and controllable
process for the sulfonation of polyether ketones of the
f'ormula (I), which
J .i

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30885-12
- 5 -
process makes it possible to sulfonate not only
O-phenylene-O units but also 0-phenylene-CO units and, in
this way, to obtain novel sulfonated polyether ketones.
A further object-is to prepare solu.tions of these.poly-
mers.
It has surprisingly now been found that polymers accord-
ing to the invention can be sulfonated well in a control-
lable manner at not only the O-phenylene-O units but also
the- O-phenylene:-CO units, with the products- obtained evern
being soluble- above a certain degree- of sulfonation. Even
polymers which comprise only 0-phenylene-CO units are
accessible to targeted sulfonation.
The present invention therefore provides a sulfonated
aromatic polyether ketone comprising units of the formula
(II)
[[Ar-O-] P-Ar [[CO-Ar' -1 x-O-Ar] m- jC0-Ar' -] y- [O-Ar-] n-CO-1
(2z)
in which from 1% to 100% of the O-phenylene-CO units are
substituted with an S03M group, with sulfonated and
unsulfonated 0-phenylene-CO units and sulfonated and
unsulfonated O-phenylene-0 units being able to be in any
desired sequence with respect to one another,
and where Ar, Ar', M, X. n, m, y and p are defined as
follows:
Ar is a phenylene ring with para and/or meta bonds,
xr' is a phenylen.e, naphthylene, bip}.ienylylene or
anthrylexie unit or another divalent aromatic unit,
x, T-i and n1 independently of one another are 0 or 1,
y is 0, l, 2 or 3,
is 1, 2, 3 or 4, an.d.
lK, taking into account the ionic valencies, comprises one or more
elements selected from the following group: H, NR4+, where R= H
or C,,-C4-alkyl, or a metal and particularly an alkali metal or
ialkaline earth metal or a metal from subgroup 8, and is

19 SEP '97 14:25 HOE PATENT-U.LIZ.ABT 06930581255
S.8
- 6 -
preEerably H, NR4+, Na, K, Ca, Mg, Fe or pt.
The present invention likewise provides a process for the
preparation of theae sulfonated polyether ketones having-
units of the form,ula (II), and polymer electrolyte
solutions comprisirg said.polymeza, and also provides ~cr
the use of such polymer electrolyte-solutions.
With the aid of the proaess accarding to the invesztion. it.
ie. poasible to sulforlate aromatic polyether ketones
having units of the- f.ormmula (I) even at the O-pheslylener,
l0 co units.
In agreement with the published literature it ie found
that sulfonation takes place preferentially at =the
O-phenylene-O units of the polyether ketones. It. has
surprisirngly been found that by the process according to
the S.nvention a szgn.ifi.caxit proportion of the
0-phenylene-CO units as well is sulfanated, with
relatively high degrees of sulfonation.
The proaess comprises dissolving the aromatic po].yether
ketone in 94 to 98% strength by weight sulfuric acid,
adding a sulfonating agent to the solution obtained un.til,
the coxzcentration of sulfuric acid is from 98 to 100% by
r-:
~-; weight or until the concentratiorn of oleum is from 0.01
to 15% by weight of SO3, eatablishing a suitable reaction
temperature and working up the reaation mixture as soon
as the desired degree of sulfonation is reached.
The aromatic polyether ketone iB preferably dissolved in
sulfuri.c acid under gexltle conditions, i.e. under condi-
tioxzs in which sulfonation is largely suppressed vr does
not yet occur. The concentration of the sulfuri_o acid
ased for dissolution is preferably from 94 to 97% by
weight. The dissol.utiori tentperatuze chosen is as low as
possible, in order substaritially to avoid coznmencement of
the sulfonatiolz reaction at this stage. In gpn.eraJ.,, the
cl ~;r_aOJ.ut~On tiexnp ~'atLl.r? ~* 2:)r tV:'er>_n 10 axl.ti. QO C;, :i_~
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19 SEP '97 14:25 HOE PATENT-U.LIZ.ABT 06930581255 S 9
- 7 -
particular between 20 and 70 C and, preferably, between
30 and 60 C.
A13. of the divalent aromatic radicals Ar and Ar' of the
polymer to be sulfoaated are, in particular, phenyletie,
pref-erajaly 1,4-phenylene.
xt is pr.eferzed to emplQy homopolymers of tha fonaulae
(IYI), (IV) and (V), so that. the resulting polyether
ke.tone according to the inventioa comprises sulfonated
unite of. these formul.ae. 'Under controllad conditions, th .
sulfonatiors proceBm degcribed $ermits the sulfonation.o~
polyether ketones even at O-phenylene-CO units.
~' .
~~ ~ ~ ~ ~ I 1 1 }
r= '
! V 1
~. .-..
~='
0
Y (V
O
In a further preferred e:abodixnent, the polyether ketone
to be sulfonat-ed is a copolyrcie:r Gompz'ising at least two
dif_~erent vxlit.s of tl4e foz-mulae (11), (IV), (V)
and ( V I ) .
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19 SEP '97 14:26 HOE PATENT-U.LIZ.ABT 06930581255
5.10
- 8 -
~ ~ !~'; ~ ~V1 )
For the homopolymer of the formula (III), for example,
after a disaolution procedure at not. more, thaa 80 C a=d
after 5 h at roo:n temperature in 95 or 97% strength by
weig2zt. oulfuric acid, degrees of sulfonation of lees than
14 mol% are observed, based on.one repeating unit..
For the homopolymer of the formula (IV) , for example,
after a disaolution procedure at nat more than 80 c and
after 2.4 h at r.oom temperature in 95 or 97% strength by
weight sulfuric acid and at a su].fonation te,uiperature in
the range from 30 to 900C, degrees of sulfonation of
about 25 mo3.t are obeezved, based on one repeating unit.
For the homopolymer of the formula (V), for example,
after a dimeo3.ution procedure at 80 C and after 24 h at
room temperature in 95 br 97% strength by weight sulfuric
acid, a degree of sulfonation of 12 mo1% is observed,
baBed an one repeating unit. The oulfonation teanperature
ia preferably in the range from 50 to ],00 C.
Preferred dissolution Conditions are those leading to a
degree of sulfornation of not more than 35 molo baged on
one repeating unit. During the disaolution process,
sulfonation of the main chain is largely Buppressed.
lnvest.igstiona have shown that no breakdown occurs during
the dissolution process.
As the sulfonating agent used to increase the concentra-
tion of su3.furia acid and to carzy out sulfoz'lation,
preferenca is givezi tc-) empJ,oying sulfuric acid, fuming
sul.fu.ri.c aCid, oleuici, chlar,=osulfonia acid Ernd suJ_f.ui:
tr_ i.oxide.
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19 SEP '97 14:26 HOE PATENT-U.LIZ.ABT 06930581255 S.11
~ 9 -
The sulfonation behavior of the polyether ketones varies
as a function of the ratio of the O-phenylone-0 units to
the O-phenylene-CO unita to the CO-pheaylene-CO units and
as a function of the sequence of these units along the
polym.er anain. chain. Changes in the electron balance- o~
the phenylene rings- have a direct, effect on their
sulfotsation behavior. However, secondary reactions are
also influenced by changes in the electron balance of the
phenylene rings; the combination of the reaction .para-
1.0 meters--concentration. of sulfuric acid, reaction tempora-
ture and. duration of reacti.on-detezzaines- to what extent
O-phenylene-O units and 0-phenylor1e-CO unit$ are sul-
~. -:. fonated and to what cxtenc crozslinking via 8ulfone
groups or breakdown of the main chain occurs.
i5 For each polyether ketone, therefore, thexe- will be a
different combination of reaction parameters which is
ideal on, the one hand to obtain a high proportion of
sulfonated O-phenylene-CO units and on the other hand to
minimize crosalinking reactions and chain breakdown. The
20 proGeee according to the invention is disting'uished by
the choice of that combination of parameters which is
most appropriate to ei'lsure, in this sense, a highly
favorable course of the sulfonation reaction.
it is a general rule that electiron-ri.ch aromatic struc-
tures are sulfonated preferentially. Where different
reaCtion sites are available for sulfonatxon, i.e. where
the starting polymer has a variety of aromatic structures
with different electron densities, then the selectivlty
of the reaction site depends inter alia on the respective
reaction parameters (Lizne, temperature, acid concentra-
tion).
rn order to obtain a preferred degree of sulfonation in
Q-phenylene-CO units different selectivities are de.sir-
able depandi,.ng on the struature of Lha starting polymer.
Z'2ierefore, in depende .ca ori the stz~u.cture Uf the Fst=artirig
pol.y7:nez:, di.f-F_eran.t Gc~r.n4ir~~tion.a of z'cract,io1-1
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19 SEP '97 14:26 HOE PATENT-U.LIZ.ABT 06930581255 S.12
- 10 -
are particul.arly preferable.
The polyether ketones will therefore be subdivided in
accordance with the electron status of their aromntic
structures.
O-phenylone-d unito are richer in electrons and therefore
easier to sulfonate than O-phenyl.ene-CO units, whi.laO-pheaylene-CO unitg. ia
turn ara more readily sul-
gonatable tihaa CO-phenylene-CO units. A measure ot the
sulfonata.bility (S) of a. polyether ketone is:
8 4 ES + ER - RK
where
S ffiulfonatabili.ty parameter
EE - percentage proport.~on of the O-phenylene-O units
EIt = percentage proportion of the O-phenylene-CO units
XS KR = percentage proportion of the C4-pheziylcne-CO units
on the aromatic structures in the polymer.
Therefora:
EE + ER + ICK = 100%
In selecting the pxeferred combinations of reaction
parameters, account must, al.so be taken of the ratio V:
V = EK / EE
It can generally be assumed that
1. the higher the value of V, the more sevexe the
reaction conditions required to obtain a high proportion
of sulfonated O-phenylene-CO u.nits;
2. the lower the sulfona.tabiJ.i.ty S, the longer the time
an,d/or the more sevez'2 th,e reaction conditions required.
in order to obtain the desired degree of sul.tonEition; and
3. C.he nzo,re severe the reaet:ior.x coz'tdit7.onc and the
1.onger tri.e rea:tlon times, the gx-eater tha exte-r,.t to
which secondary r eaction:s occu.z.
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19 SEP '97 14:27 HOE PATENT-U.LIZ.ABT 06930581255 S.13
- 11 -
If the polymers to be sulfonated are subdivided in
accordance with the schema set out above, the fol.lowing
claesification results: polymers where 9> 150% are
regarded as read;Lly aulfonatable, polymers where
150% > 5> 80% are mQderately sulfonatable and polymers
were S.< 80% are classed as difficult to sulfonate.
Taking these points into account, it is evideut. that
certain combinations of reaction parameters are partinu-
larly suitabla for prepari.ng the_ desired sulfonatioa
products. Di~fereat combinations= do not lead to the,
required products. The examples- in the tablee clarify
this interrelationship.
Considering, for example,. a moderately sulfornatable
polyether ketone of the formula (XII) (Table 1) , it is
found that the proportion of 0-phenylene-CO units which
are sulfonated inczeases, for a given temperature, as the
reaction time inCreases. in this case it is poseib].ato
set the temperature at a].evel such that the sulfonation
of 0-phenylene-Co units takes place in adjusttable periods
of time, and, at the aame time, any unwanted secorxdary
reactions are largely exCluded. Below a certain tempera-
ture threshold (60 C), however, only minimal or no
sulfonation of the ether ketone units is obeerved even in
the case of relatively long reaction times. The same
applies to the reaction concentration ot the eulfuric
acid. Thus at a sulfuric acid concentration of -q 90% by
weight, no sulfonation of the O-phany].ene-CO units is
obaerved even at appropriately long reaction times. With
an acid caxi.centratiorx of > 90 and s 99% by weight, on the
other hand, disttnct su].tonatiorl is observed even at
ntioderate tentperatures within short reaction tiuties, and
this degree of $ulfonation can be increased etz.ll further
by increasing the reaction time while uiaintaini.ng the
tempers.ture.
By an appropriate coznba.n.a.t.iorl of the reaction paramE:ters
it io posini.b:Le, with the aid of the process accorda.rig to
th= i=r.avention, to obtairi urlde:r rc,i.ld c.oxa.ditione -
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19 SEP '97 14:27 HOE PATENT-U.LIZ.ABT 06930581255 S.14
~ 12 -
polyrners whiah have a high degree of sulfonation of the
ether ketone units (from 3. to 50%), with disruptive
secondary reactiona being largely auppressed. By appro-
priate combination of the reaction parameters it is
possible to employ the process according to the invention
under relatively severe conditions._to obtaxa polymers
having a, high degree of aulfonatioxx, df. the- ether ketone
unxts (from 1 to 100%).
In. the course of the preparation_ of tho auLfonated
polymers according to the inventioa, the coacentxatioa o~
sulfuzic acid is inareased after the dipsolutioxz process,
for example by adding oleum, until the concentration of
sulfuric acid ia from 98 to 100% by weight or until the
concentration of oleum is from 0.01 to 15% by weight of
s03 , in particular until the concentration of sulfuric.
acid i.s from 98.5 to 100% by weighti. or. until the concers,
txation of oleurn in from 0.01 to- 5 e by weight of SO3, a.nd
preferably until the concentration of sulfuric acid is
froua 98.5 to 100% by weight or until the concentration of
oleum is from 0.01 to 1% by weight of S03.
During the actual su7,foiriation, the reaction temperature-
ntay be higher or else lower than in the dissolution
proceeg. Sulfonation is in general carried out at
temperatures in the range from 10 to 100 C, in particular
from 30 to 951C and, with particular preference, from 50
to 90 C. An increase in temperatuze and an increase in
the Xeacti.on time both raise the degree of su].fonation of
the polymer. The tempexature of the stiolution aEter adding
the sulfonating agent is in parti.culax at J.eas t 300C.
Typical reaction tiutes are in the range frorn-45 minutes
to 24 hours, preferably between I. and 8 hours,
particularly preferably in the range from I to 4 hours.
As soon ast the desired degree of eulfonaGion is reached,
the reaction is terminated &zxd, the polymer in
preci,pitated, for exa.mple in an aqueous medi.um, isolated
aad dried.
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19 SEP '97 14:28 HOE PATENT-U.LIZ.ABT 06930581255 S.15
- 13 -
Investigations have shown that breakdown of the polymer
main chal.n takes place only to a small extent during the
sulfonation reaction. Any CO-phenylcne-CO units present
in the aromatic polyether ketone employed are not sul-
fonated by the process of the invention.
The advantage of. the sulfoaated G-pheaylene-CO uai.ts ovor
sulfonated O-phenylene-O units in conventional polymers
lies, inter alia., ia the, improved stabili.ty to hydrolysis
off the S03H or S03M groups . In an aclueoue enviroameat a.nd
at elevated temperatures, desu1 fonati.on oE the sulfonated
polyether ketones may take place. It is- knowa, tha.t the
extent of hydro].ytic desv.lfoaatiost depends oa the elec-
~.
tron status of the aromatic rings. When sulfonated
polymers are employed in an.aqueous medium, it ie vital
that the properties of the sulfonated polymer remain
aonstant. In the case of such applications, therafore, it
ia advantageous to use a sulfonated polyether ketone
which allowg minimal or zero desulfonation. Consequentl.y,
a polymer' whose sulfonic acid groups are located to as
high as possible an extent at 0-pheny7.ene-CO units ia
particularly suitable in such cases. Following sulfona-
tion, the sulfonic acid groups (S03H) can be converted
into their salt form (SO3M) by the known methods.
The process described results in sulfonation productg
which above a certain degree of aul,fonation can be
dissolved in customary solvents, for examtple NMP or DMSO.
The polymer electrolyte solutions prepared in this way
comprise, in a preferred embodiment, at least 1% by
weight of po].yether ketones of the t ormula (II) and, as
principal constituent, aprotic dipolar solvents, for
example N-methylpyrrolidone (NMP) or dimethyl sulfoxide
(DMSO) .
Depending on the purpose for which the polymer electro-
lyte
soluti.on is subsequ.ently to be used, it xnay if
desired comprise a further unsulton.at.ed polymer Qr else
sr.aall quazltities of a.uxifiazies.
CA 02215911 1997-09-19

19 SEP '97 14=28 HOE PATENT-U.LIZ.ABT 06930581255 S.16
- 14 -
The polymer electrolyte solutions according to the
inventi,on are particularly suitable for the production of
aaymmetria membranes, for exaampl.a for nano-, ultra- or
microfiltration, and for the production of cohesive films
having a thickness in the range from 5 m to 1 mm.
The polymer electrolyte solutions' according to the
invention have an especially important role to pl.ay in
the establisriment of particularly intensive. aontact
between two polymer electrolyte surfaces. A porous or
rough surface can ba obtained in this way, for exa=nple,
aftez, contacting the solution with a precipitating agezit.
~- .
The novel polymers and polymer electrolyte solutions or
polymer ff.lms compriaing these polymera are particularly
suitable for use in eleatroChemical aglls, for example
3'5 fuel cells or water electrolysis cells.
Examples:
96% strength concentrated sulfuric acid was placed in a
four-necked stirred apparatus fitted with. dropping funrnel
and oil bath, and va~i.ous polyether ketones of the
formula (I) were dissolved. oleum (containing 20% by
weight of SO3) was then. added to obtain a sulfonating
mi.xture having sulfuric acid concentrations of from 98.5
to 100% by weight, or oleum concentrations of trom 0.1 to
0.7% by weight of S03. The mixture was then brought to
room temperature in order to ensure optimum, controlled
sulfonation. After the desired degree of sulfonation had
been reached, the reaction was t rminated and the product
was isolated. The product was characterized by
vi.sCometry, 1'3C-NMR spectroscopy and elemental analysis.
The experiments in Table 1 were carx=ied out with a
hGmopaXymer of the foznluJ.a (rIl) . The experiments in
Table 2 were carried out with a hornopo7.ymcAr of the
formula (IV) . X'olyulers of the formula (111) havQ an S
vZZLla of 125% and ~-).re t.h.a_r,efo:-e el.aesif _ec=', ais
zttor].e=r.atc:]õy.
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19 SEP '97 14:28 HOE PATENT-U.LIZ.ABT 06930581255
5.17
~ 15 -
sulfonatable, while those of the formula (IV) have an S
value of 180% and are regarded, in accordance with the
invention, as readily su].fonatable.
Examples which show a degree of sulfonatioa of the
O-phenylene-CO units. (SEX based on one repeating urxit in
mol%) of zero are to be viewod as comparative examples.
The following abbreviations are used,ia the tabl.es:
No. Experiment Number
DT Dissolution temperature in C
Dt Dissolutioa time in minutes
PC Polymer concentration in % by weight
RX Reaction concentration. of oleum in t by weight- of
S03
RC Reaction concentration of sulfuric aaid in % by
weight of H2S04
RT Reaction temperature in C (sulfonation temperature)
Rt Reaction time in mi.nutea
D5 Degree of sulfonation in mol% based on one repeating
unit
SEE Degree of aulfonat'ion of the O-phenylene-O units in
mo].% baged on, one repeating unit
SEK Degree of sulfonation of the 0-phenylene-CO units in
mol a based on one repeating unit
IV Zntrinsic viscosity in dl/g (meagured in conc. H2SO4
at 25 C)
CA 02215911 1997-09-19

19 SEP '97 14:29 HOE PATENT-U.LIZ.ABT 06930581255
S.18
- ~6 -
Table 1:
Homopo7.ymer of the formula (11I)
No. pC DT Dt= RC RT Rt DS SEE SEX IV
1 6.7 60 60 98.5 80 0 32.3 31.0 1.3 0,86
2 6.7 60 60 98.5 80 30 53..1 47.8 5"-3 0-84
3 6.7 60 60 98.5 80 60 71 52.9 8.7. 0-84
4 6.7 60 60 98.5 80 90 82.7 73_4 9.3 0.80
5 6.7 60 60 98.5 80 120 88.5 49.3 9.2. 0.80
6 6.7 60 60 98.5 80 150 94.0 83.9 10.1 0.76
7 6.7 60 60 98.5 80 210 100.6 90.0 10.6 0.~3
8 6.7 60 60 98.5 80 240 102.1 92.1 10.0 0.72
[ ..
9 6.7 60 60 98.5' 60 0 29.0 29.0 0 0.87
10 6.7 60 60 98.5 60 30 33.7 33.7 0 0.87
11 6.7 60 60 98.5 60 60 38.8 38.8 0 0.86
12 6.7 60 60 98.5 60 90 42.3 42.3 0 0.84
1,3 6.7 60 60 98.5 60 120 44-9 44.9 0 0.81
14 6.7 60 60 98.5 60 150 48.a 48.2 0 0.79
15 6.7 60 60 98.5 60 210 53-1 53.1 0 0.77
16 6.7 60 60 98.5 6o 240 55.8 54.8 1..0 0.72
17 6.7 60 60 98.5 90 0 20.5 20.5 0 0.83
18 6.7 60 60 98., 90 30 33.1 30.8 2.3 0.82
19 6.7 60 60 98.5 90 60 48.0 43.2 4.8 0.79
20 6.7 60 60 98.5 90 90 58.4 51.6 6.8 0.74
21 6.7 50 60 98.5 90 120 66.7 58.1 8.6 0.70
22 6.7 60 60 98.5 90 150 74.6 65.0 9.6 0.65
23 6.7 60 60 98.5 90 210 85.7 73.9 11.8 0.61
24 6.7 60 60 98.5 90 240 90.0 77.0 13.0 0.59
25 6.7 60 60 98.5 100 0 19.5 19.5 0 0.&0
26 6.7 60 60 98.5 100 30 43.4 39.1 4.3 0.78
27 6-7 60 60 98.5 100 60 74.3 64.7 9.6 0.74
28 6.7 60 60 98.5 100 90 87.7 72.8 14.9 0.71.
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19 SEP '97 14:29 HOE PATENT-U.LIZ.ABT 06930581255 S.19
- 17 -
Iso. PC DT X1t RC FiT FLt 08 8&S SEX IV
29 6.7 60 60 98.5 100 120 96.5 83.0 13.5 0.68
30 6.7 60 60 98.5 1.00 150 103.2 86.7 16.5 0.63
31. 6.7 60 60 98.5 100 210 11.8 93.5 18.3 0.59
32 6.7 60 60 98.5 100 240 7,15.a 95.3 19.9 O.S5
33 6.7 68 60 90.0 80 0 37.7 . 37.7 0 0.86
34 6.7 60 60 90.0 80 30 38.2. 38.2 0 0.86
35 6.7 60 60 90.0 80 60 38.7 38.7 0 =0.83
36 6.7 60 60 90.0 80 90 39.2 39.2 0 0.82
3'7 6.7 60 60 90.0 80 120 39.7 39.7 0 0.81
38 6.7 60 60 90.0 80 150 41.6 41.6 0 0.T9-
{. 39 6.7 60 60 90.0 80 210 44.3 44.3 0 0.76
40 6.7 60 60 90.0 80 240 45.7 45.7 0 0.75
41 6.7 60 60 99.0 80. 0 30.4 29.4 1.0 0.85
1 5 42 6.7 60 60 99.0 80 30 48.2 43.3 4.9 0.84
43 6.7 60 60 99.0 80 60 68.3 59.9 8.4 0.81
44 6.7 60 60 99.0 80 90 = 82.0 73.9 8.1 0.79
45 6.7 60 60 99.0 80 120 88.9 76.1 12.8 0.77
46 6.7 60 60 99.0 80 150 93.9 83.0 10.9 0.73
47 6.7 60 60 99,0 80 210 99.5 84.6 14.9 0.70
48 6.7 60 60 99.0 80 240 101.8 86.5 15.3 0.68
49 6.7 60 60 95.~i 80 0 25.4 25.4 0 0.85
50 6.7 60 60 95.2 80 30 29.4 29.4 0 0.85
51 6.7 60 60 95.2 80 60 32.8 32.8 0 0.85
52 6,7 60 60 95.2 80 90 35.4 35.4 0 0.84
53 6.7 60 60 95.2 80 120 38.2 38.2 0 0.84
54 6.7 60 60 95.2 80 150 41.0 41 0 0.80
55 6,7 60 60 95.2 90 210 45.1 46.1 0 0.78
56 6.7 60 60 95.2 80 240 48.4 48.4 0 611
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19 SEP '97 14:29 HOE PATENT-U.LIZ.ABT 06930581255
5.20
- 18 -
Tab1e 2:
Somopalymer of the ~orinula (IV)
No. PC DT Dt RC RT Rt DB 9EE SE1C IV
6.7 60 60 95 60 0 27.a 27.2 0 0.93
a 6.7 60 60 95 60 30 32.4 32.4 0 0.93-
3 6.7 60 60 95 60 60 35-.7 35..7 0 0.92
4 6.7 60 60 95 60 90 39.1 39.1 0 0.90
6.7 60 60 95 60 110 42.5 42.5 0 0'.87'
6 6.7 60 60 95 60 180 49.3 49.3 0 0.86
7- 6.7 60 60 95 60 240 54.8 54.0 0.8 0.86
8 6.7 60 60 95 60 300 59.1 38.1 1.0 0.85
9 5.7 60 60 95 60 360 63.6 6a.5 1.1 0.85,
10 6.7 60 60 97 70 0 34.3 33.0 1.3 0.88
11 6.7 60 60 97 70 30 59.7 53.a 6.5 0.87
7.5 12 6.7 60 60 97 70 60 72.1 63.a 8.3 0.86
13 6.7 60 60 97 70 90 82.2 72.7 9.5 0.84
14 6.7 60 60 97 70 120 89.4 79.9 9.5 0.83
6.7 60 60 97 70 zs0 101.5 89.3 12.a 0.79
16 6.7 60 60 97 70 180 110.2 96.a 14.0 0.75
17 6.7 60 60 97 70 240 116.3 100 16.3 0.74
18 6.7 60 60 97 70 300 12a.7 100 23.7 0.73
19 6.7 60 60 981 90 0 31.2 a9.1 1.1 0.84
20 6.7 60 60 98 90 30 103.9 89.5 14.4 0.80
21 6.7 60 60 98 90 60 119.8 97.8 22.0 0.78
_F'% 90 ].28.5 100 28.5 0.7a
2 5 22 6.7 60 60 98 90
(, .
23 .6.7' 60 60 98 90 120 140.2 100 40.2 0.70
24 6.7 60 60 98 90 150 145.2 100 45.2 0.68
6.7 60 60 98 90 2a5 148.7 100 48.7 0.65
26 6.7 60 60 98 60 0 32.5 31.7 0.8 0.87
3 Q 27 6.7 60 60 98 60 30 55.4 49.9 5.5 0.87
CA 02215911 1997-09-19

19 SEP '97 14:30 HOE PATENT-U.LIZ.ABT 06930581255
S. 21
-i9-
NO. PC DT Dt RC RT Rt D$ 3x:E 9ER IV
28 6.7 60 60 98 60 60 68.1 60.5 7.6 0.86
29 6.7 60 60 98 60 90 79.5 72.6 6.9 0.84
30 6.7 60 60 98 60 120 89.2 80.8 8.4 0.83
31 6.7 60 60 98 60 150 96-.5 86.5 10.0 0.78
32 6.7 60 60 98 60 7.80 102,.1 93.9 8_2 0.75
33 6.7 60 60 98 60 240 110.6 96.5 14.1 0.72.
34 6.7 60 60 98 60 300 121.8 100 21.8 0.70
35 6.7 60 60 95 90 0 35.5 35.5 0 0.25
I.0 36 6.7 60 60 95 90 30 58.3 50.1 8.1 0.85'
37 6.7 60 60 95 90 60 82.3 73.4 8.9 0.84
t,..i
38 6.7 60 60 95 90 90 95.7 86.5 9.2 0.81
39 6.7 60 60 95 90 120 105.1 97.6 7.5 0.79
40 6.7 60 60 95 90 150 115.3 98.5 16.8 0.76
1S 41 6.7 60 60 95 90 180 120.7 100 20.7 0_76
42 6.7 60 60 95 90 240 132.4 100 32.4 0_73
43 5.7 60 60 95 90 300 135.8 100 35-8 0.72
CA 02215911 1997-09-19

19 SEP '97 14=30 HOE PATENT-U.LIZ.ABT 06930581255
5.22
- 20 -
Table 3:
Iiomopolymers of the forzaula (V)
Yto. PC DT Dt R]C RT Rt SSS BER DS YV
1 6.7 50 60 0.4 60 0 0 2.3 2.3 0.92
2 6.7 50 60 0.4 60 30 0 8.7 8.7 0.91
3 6.7 50 60 0.4 60 60 0'. 14.0 14.0 0.88
4 6.7 50 60 0.4 60 90 0 17.2 17.2 0.84
6_7 50 60 0.4 60 120 0 20.2 20.2 0.13S
6 6.7 50 60 0.4 60 150 0 23.5 23.5 0.81
7 6.7 50 60 0.7 50 0 0 3.7 3.7 3..00
8 6.7 50 60 0_7 50 30 0 7.0 7.0 0.97
9 6.7 50 60 0.7 50 60 0 11..1 11.1 0_92
10 6.7 so 60 0.7 50 120 0 17.8 17.8 0.90
11. 6.7 50 60 0.7 50 180 0 22.1 22.1 0.88
1 5 12 6.7 50 60 0.7 50 240 a 26.0 a6.0 0.85
13 5.7 50 60 0.7 50 360 0 31.3 31.5 0.e2
14 6.7 50 60 0.7 50 460 0 38.2 38.2 0.75
6.7 50 60 0.7 50 525 0 41.0 41.0 0.73
16 6.7 50 60 0.7 70 0 0 2.7 2.7 0.95
17 6.7 50 60 0.7 70 60 0 40.2 40.2 0.78
18 6.7 50 60 0.7 70 120 0 62.3 62.3 0.72
19 6.7 50 60 0.7., 70 180 0 75.2. 75.2 0.61
20 6.7 50 60 0.7 70 240 0 84.2 84.2 0.59
21 6.7 50 60 0.7 70 320 0 92.0 92.0 0-96
22 5.7 50 so 0.1 50 0 0 1.2 1.2 1.03
23 6.7 50 60 0.1 50 60 0 2.1 2.1 0.98
24 6.7 50 60 0.1 50 120 0 4.1 4.1 0.93
25 6.7 50 60 0.1 50 180 0 5.7 5.7 0.90
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19 SEP '97 14:30 HOE PATENT-U.LIZ.ABT 06930581255
S.23
- 21.
-
No. pC DT 1]t RR RT Rt 8EE SE7C DS IV
26 6.7 50 60 0.1 50 240 0 7.3 7.3 0.88
27 6.7 50 60 0.3. 50 300 0 B.I. 9.1 0.89
28 6.7 50 60 0.1 50 435 a 12.9 12.9 0.85
29 6.7 50 50 0.1 70 0 0 2.5 2.5 0.90
30 6.7 50 60 0.1 70 30 0 14.3 14.9 0.88
31 6.7 50 60 0.1 70 60 0 17.7 17_7 0.86
32 6.7 30 60 0.1 70 120 0 21.2. 2X.2 0=,83
33 6.7 50 60 0..1 70 1.80 0 23.4- 23.4. 0.78
34 6.7 50 60. 0.1 70 330 0 31.9 32.9 0.73
35 5_7 so 60 0.1 70 390 0 35.2 35.Z 0.71
i. ,
CA 02215911 1997-09-19