Note: Descriptions are shown in the official language in which they were submitted.
~WO95/14056 2 1 76937 r~l/rl,."-3~51
-- 1 --
POLYKETONE POLY~ER COMPOSITION
The present invention relates to polyketone polymer compositions.
Polyketone polymers eYhlbit many desirable physical properties
which make them suit~ble for ~n51n~r;n~ ~hf~rm^Fl~ctic applications.
In particular, high molecular weight linear alternating polyketone
polymers possess such properties as high strength, rigidity,
toughness, chemical resistance, and wear properties. While these
properties are adequate for many applications it would be o~ advantage
to further improve certain properties such as envi ~:~1 stress
crack resistance, chemical resistance, creep resistance, increased use
temperature and increased tensile strength. One method known in the
~rt for providing these 1 ~ ts has involved the cross-linking of
linear polymer chains of a thl.r~7rl ~ctiC polymer. An example of this
is polyethylene which can be made to exhibit increased durability, use
temperature and Jtrength through post-reactor cross-linking.
In order to maintain good melt proc~ h1 1 1 ty and flow during part
fabrication it is generally desirable to utilize polymers of
substantially linear molecular structure before cross-linking.
Therefore, it is particularly desirable to have a simple procedure
which can cross-link the substantially linear polymer after melt
Fro~ s1 n~. Cros5-linking a polymer after melt processing is useful
in m~1n~:~1n~n~ a high degree of cry5tallinity in the final part and
allows common methods of melt fabrication such as injection moulding,
extrusion, and blow moulding to be used.
The present invention relates to a composition, r1.~1ng a
major amount of polyketone polymer and a minor amount of a iodide
salt with the proviso that the composition is not a composition
containing 5 . 0 parts per million by weight of sodium iodide, metal
content on polymer. It ha5 been found that such composition can be
cross-linked to give a composition having and exhibiting improved
WO 95/14056 2 1 7 6 9 3 7 PcTlEp94lo3~sl ~
-- 2 --
mechanical and chemical resistant properties. Further, the present
invention relat~s to blends ~nntA;n;nq such composltion.
The polyketone polymers which are useful in the practice of the
invention are of a linear alternating structure and contain
substantially one molecule of c~rbon monoxide for each molecule of
ethylenically unsaturated hydrocarbon. The preferred polyketone
polymers are copolymers of carbon monoYide and ethylene or
terpolym~rs of carbon monoxide, ethylene and a second ethylenically
unsaturated hydrocarbon of at least 3 carbon atom5, particularly an
~c-olefin such as propylene.
When the preferred polyketone terpolymers are employed a~ the
m~or polymeric component of the blends of the invention, there will
be within the terpolymer at least 2 units incorporAtinq a moiety of
ethylene for each unit incorporating a moiety of the second
hydrocarbon. Preferably, there will be from 10 units to 100 units
incorporating a moiety of the second hydrocarbon. The polymer chain
of the preferred polyketone polymers i5 therefore represented by the
repeating formula
-[--CO--(--CH2--CH2--)-]X--[CO--(-G)--]-y
where G is the moiety of ethylenically unsaturated hydrocarbon of at
least 3 carbon atoms polymerized through the ethylenic unsaturation
and the ratio of y:x is no more than 0.5. When copolymers of carbcn
monoxide and ethylene are employed in the compositions of the
invention, there will be no econd hydrocarbon present and the
~5 copolymers are represented by the above formula wherein y is zero.
When y is other than zero, i.e. terpolymers are employed, the
--C0-(-CH2-H2-)- units and the --CO-(G-)- units are found randomly
throughout the polymer chain, and preferred ratios of y:x are from
0. 01 to 0 .1. The precise nature of the end groups does not appear
to influence the properties of the polymer to any ~nne;~-rAhle
extent so that the polymers are fairly represented by the formula
for the polymer chains as depicted above.
of p~rticular interest are the polyketone polymers of number
average molecular weight from 1000 to 200, 000, particularly those of
3~ number average molecular weight from 20, 000 to 90, 000 a~ determined
~ WO 95ll40S6 ~ 2 ~ 7 6 9 3 7 r~
by gel permeation chromatography. The physical properties of the
polymer will depend in part upon the molecular weight, whether the
polymer is a copolymer or a terpolymer, and in the case of
terpolymers the n2ture of th~ proportion of the second hydrocarbon
pr~sent. Tvpical melting point5 for the polymers are from 175C to
300C, more typically from 210C to 270C. Preferably, the polymer~
have a limiting viscosity number ~LVN), measured in m-cresol at 60C
in a st~ndard capillary viscosity measuring device, from O.S dl/g to
lO dl/g, more preferably from 0 . 8 dl/g to 4 dl/g.
A preferred method for the production of the polyketone
polymers has been described in EP-A-18101~, EP-A-24E483,
EP-A-600554, EP-A-314309 and EP-A-391579.
The useful iodide salts are tho5e which are capable of cross-
linking polyketone polymers under appropriate conditions. Examples
of these salts include those listed in Table 1.
Linear polyketone polymers aontaining a sufficlent (minor)
~mount of iodid~ salt can be cross-linked by sub~ecting the
composition to the presence of oxygen at el~vated temperature.
While not wanting to be held to any p2rticular theory, it is
believed that some oYiddtion of the polyketone polymer occurs which
in the presence of a iodide salt catalyzes the cross-linking
reaction. The eYtent of cross-linking is rrntrollAhl~ by the amount
of eyposure to hcat and oxygen. The time required to obtain a
desired level of cross-linking is inversely related to the
temperature used or the oxygen content available. An effective
oxygen source is air. The amount of heat r~quired is that which is
~ufficient to lead to the cro5s-linking of the polymer. The
required amount of heat can be obtained at a preferred operating
temper~ture of about 70C. While the inventive process can cross-
link a polyketone polymer melt in the presence of sufficient oxygen,
it is generally preferred to cross-link at temperatures below the
crystalline melting point of the polymer.
Methods known in the art for cro5s-linking polyethylene include
~1) the use of high energy radiation, ~2) ~hPrmrrh~mical reactions,
35 and ~3) moisture induced reactions. Methods ~1) and ~2) rely on the
W0 95/14056 2 1 7 6 q 3 7 ~ 8S1
-- 4 --
initiation of free-radical intermediates either through radiation or
radical initiators such ~a organic peroxide5. In polyethylene these
radical intermediates re5ult in chemical cross-links between polymer
chains; however, these methods are not applicable to all
polyolefins. Polypropylene and polybutylene are examples where
radical initiation does not result in cros5-linking, but rather
chain scission. These methods also possesS certain disadvantages
which are known to the skilled artisan.
The method of cross-linking polyethylene which utilizes
moisture first requires free-radical grafting of vinyl silane unlts
onto the polyolefin which are then cspable of reacting with water to
produce chemiczl cross-links. Since cros5-linking occurs after melt
processing, this method like radiation curihg, allows conventional
fabric~tion methods to be used and maintains a high degree of
crystallinity after cross-linking.
The above m~thods are not entirely suitable for polyketone
polymers. Radiation curing is not possible because chain scission
reactions can occur in polyketone5 . Th~rm~ h~; cal cross-linking
processes which involve adding enough heat to c~use the
subst~ntially llnear polymer to melt and flow into a desired form
just as cross-linking occurs are also not suitable. First, the
processing temperatures of polyketone5 are ~ n~ rAh1 y higher than
in polyethylene which would re5ult in the premature decomposition of
~ny free-r~dic~l initiators ~organic peroxides). Second, unlike
2~ simple polyolefins, th~ reactivity of polyketone5 is more diverse
~nd can lead to unwanted free radical ~ rA~ n reactions of the
polymer ~
Moisture cross-linking of polyketon~ polymer m_y be possible if
silane grafting could be carricd out by 50me mean5 other than a
free-radic~l proces5. It i5 envi5ioned that a 5ilane grafting
method ~or polyketones is fea5ible if the vinyl groups commonly used
in polyethylene were replaced with groUps capable of reacting with
ketone5 such as amine5. Examples would include (trialkylsilyl)-
alkylamines and ~tri~lkylsilyl) aryl-amines.
The current invention takes a line~r polymer which is
~ WO 95/14(~56 2 1 7 6 9 3 7 p~rl L~o~lTI
s
completely soluble in HFIPA (hexafluoroisopropanol) and cross-links
it such that it becomes only swollen by the solvent.~ One method
known for d~t rr;nin7 the extent of cross-Linking is by measuring
its solubility or 9T ~ 11 rl~; 1; ty in a suitable solvent . Suitable
solvents are usually polar solvents with low molar volume,
especially those having a strong hydrogen bonding r-hArA~-t~ri qtic.
Examples of such solvents include h~-v7fl1~rQ-isopropanol, m-cresol,
and phenol. heYaflUoroiSOprOpanOl is preferred because of its
ability to dissolve the polyketone polymer at room t~r~r~rAt~re.
Furthermore, it has s~rrr1~;n~1y been found that compo~itions
ntA;n;n~ certain iodide salts, show improved oxidative stability.
A disadvantage of linear alternating polymers of carbon
monoxide and at least one ethylenic~lly unsaturated hydrocarbon is
that they can exhibit a ~i~t~.rlorAtl~n of physical properties upon
thermal oxidative ~ rA~ t~n. ~his degradation i5 due to a
chemicAl attack of atmospheric oxygen on the polymer chains and is
~hArA~-t~-r1 ctic of most, if not all organic polymer6 . Oxidation is
typically autocatalytic and occurs as a function of heat and oxygen,
hence the term thermal oxidative degradation. It is desirable to
inhibit the deterior~tion of polymer properties by st7h; 1; 7~ng the
polymer toward the adver~e effect5 of heat and oxyg~n. There are a
large number of thermal oxidative 9tAh; 117 rc which are employed
commercially to 5tabilize th~rm~riA~tic polymer5 against such
degradation. however, m_ny of the thermal 5t:~h; 1; 71.rc which are
known to be effective with polyol~fins, polyamide5, polyacetals,
polyacrylates, etc. are only marginally or not at all effective when
employed with polyketone polymers.
An oxidatively 5tabilized polyketone polymer compo5ition has
now been found. ~he composition compri5es an onium iodide salt of
nitrogen, phosphorus, arsenic, or combination thereof in which the
cation coordination sphere is 6hielded by aromatic substituents or
an alkali metal iodid~, with the proviso that th~ composition is
not a composition containing 5. 0 ppmw of sodium iodide, m~tal
content on polymer. In 13P-A-600554 it has b~en described that the
melt stability of polymers can be adversely affected by the
W O 95114 0~ 6 2 1 / 6 q 3 7 r ~ ~ " ~ ~ ~ A C ¦
preaence of alkali (ne earth) metal 5alts. In experiment l has been
described a composition r~ntA;ninAj S.0 parts per mi~`lion by weight
of sodium iodide, metal content on polymer~
The composition of the present invention can be prepared by
rnntArtinrJ the polyketone polymer with the iodide salt. More
~rer;f;rA11y, the methods can comprise a) melt . ;n1 after
rrntArt; nrJ thc iodide salt with polyketone polymer by powder
mixing or solvent deposition, b) diffusion of the iodide salt into
polymer articles by treating the polymer with a solution
containing the iodide ~zlt, preferably using a solvent which has
some mi~cibility with both polymer and the iodide salt, or c) in-
situ generation of the iodide salt utilizing a polymer blend
comprising of precursors which upon application of a sufficient
~mount of heat generates the iodide salt. Preferably, the iodide
salt is introduced by diffusion.
Thermzl oxidative ~ rA~lAtirn of organic polymers relates to
the deterioration of polymer properties due to the chemical
reaction(s) between the polymer and atmospheric oxygen. While
oxidation processes are complicated and mechanistic pathways of
A~O oxidation between different polymers may vary, oxidation is
generally promoted by heat, often initiated by trace ilDpurities
such a~ metal ions or organic }~ , and rhArArt~r;
overall as autocatalytic in which ci~rbon radicals and peroxyl
radic~ls constitute key; nt~. ' ' At~ in the catalytic cycles .
~5 Consumption of oxygen by the polymer propagates the catalytic
cycle and gener~tes oxygenated ~pecies which either comprise part
of the polymer or are evolved as gaseous products. These
oxygenzted species may further be prodegradztive to the polymer.
For example, hydroperoxides are not inherently stable and are
capable of ~' -;nAJ into new radicals, either thermally or
catalyzed by tr~ce impurities, which can then initiate additional
oxidative cycles.
For polyketones it is believed that the thermal oxidative
proc~ss involves the formation of oxygenates which under aging
conditions cleave polymer chains and result in a reduction of
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~ WO 95/14a56 ~ 1 7 6 9 3 7 F~
molecular weight and a loss of polymer ~nr~n71 ~_~nt . Ultimately
this results ln a deterioration of polymer mec_dnic~l propcrtieS
such as reduced impact strength, 109s of elongation at break, and
embrittlement. It would therefore be advantageous to stabilize
the poly}:etone polymers towards the5e property losses either by
reducing their overall rate of oxidation or reducing thelr rate of
polymer chain scission.
The iodide salt- which are especially useful in thermal
oYidative stabilization, have been described in Table l.
TPBLE 1
Iodide Salts
S~:~hi1i71n~ Iodide S~lts Non-srAhi1;7in7 Iodide
salts
Tetrapheny1rh~crh^n1um PPh4+ ZnI~ - Zinc iodide
Bis~triphenylrhn~rh^r.~nylidene) CaI2 - Calcium iodide
ammonium Ph~P=N+=PPh ~
Insitu Et4NI - tetraethyl-
4-iodophenyltriphenylrh^crh^ni ammonium iodide
PPh3 + 1<~ _ ~31 PPh
or
l,4-bis(triphenylrh^~rh^nium)benzene
p* pl ~3 1' PPh2
Me4NI - tetramethyl-
~onll~ io~d~
WO95/14056 2 1 7 6937 r~ 3~
TABLE 1 (Cont'd~
S-methyl-3- (methylthio) -1, 4-diphenyl lH-1, 2, 4- PPh3MeI - Methyltri-
~r; ~7nl i phenylrhn~rhnni
iodide
~J~,CH2
CH4 S \~
9-phenanthryl triphenyl rhn~rhnn; PMe (OPh) 3I - Methyltri-
phenoxyrhnsphnn i
idodide
PPh4Cl - Tetraphenyl-
phosphonium chloride
RI (diffusion only) 1 PPh4Br - Tetraphenyl-
rhnsFhnn j bromide
1 Other alkali metal iodide salts such as lithium, potassium and sodium
iodide are also within the scope of the invention.
The iodide salts will generally be present in an amount
within the rany~ of from 0.0001 to 10, more 5pecifically 0.001 to
10 percent based on the weight of the polyketone polymer,
preferably in the range of from 0.1 to 1.0 percent based on the
weight of polyketone polymer.
Further, it wa5 found that an improved oven aginq
performance of the polymer is obtained if not orly the iodide
sDlt is present, but also a hindered phenol, more specifically a
composition, wherein the hindered phenol is benzene propanoic
acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy octadecyl e5ter and/or
benzenepropanoic acid 3,5-bis(1,1-dimethylethyl)-4-hydroxy-1,2-
ethanedyl bis (oxy-2, l-ethanediyl) ester.
~WO9S/14056 21 76937 P_-/C~51,'A'~Q~;1
_, 9 _
After preparatlon, the now stabili~ed polykctone polymers
show improved retention of desired mechanic~l properties, such as
resistance to embrittlement when tested under conditions of
elevated trr~ r~t~lre 2nd air exposure. The test as disclosed in
U.S. Pztent Uo. 4,994,511 subjects polymer samples to aerobic oven
aging at various temperatures and monitors the time until brittle
failure (cracking) occurs when sharply bent at an angle of 180.
The following eYamples and tables further lllustrate the
various aspects of the invention.
EXA~PLF S ON STASI~IZATION
Polymera used in the following example5 are deacribed in
Table 2. An oven aging test was used throughout the examples to
distinguish the performanc~ of polymer additives. In this test,
pol~mer sheet of 5.1 x 10-4 or 7.6 x 10-4 m (20 or 30 mil)
thicknesses was prepared either by melt extrusion or compression
moulding. Test specimens were then eut into 1 cm wide strips and
placed into forced air circulating ovens at 100 C or 125 C.
Periodically, the strips were withdrawn from the oven and when
cooled bent to ~ 150-degree angle. When the samples becam~
~ufficiently brittle to break under this te5t procedure it was
considered to be a failure and the time to embrittlement was
recorded .
21 76q37
WO 95/14056 F.~ I/n3~
--. 10 --
Table 2. Polyketone polymers used in illustrative eYamples.
LVN Tm Base
Polymer dl/g C Form Additivesb
A 1.95 220 Ext. Sheeta 0.5~ Irganox 1330d
0.5~ Nucrel 535e
B 1.86 220 Ext. Sheeta 0.29~ Irganox 1330d
0.29O CaHApC
0 . 3~ Nucrel S3se
C l. 77 220 Powder 0 . 2~ Irganox 1330d
O . 29~ CahAp
0 . 3S Nucrel 535e
D 1.73 220 Powder 0.2~ Irganox 1330d
0 . 2 ~ CaHAp
0 . 3S Nucrel S3se
E l. 87 220 Powder None
~Extruded sheet of 5.1 x 10-4 m ~20 mil) thickness.
bPercent b~sed on weight oS polyketone polymer.
CC~lcium HydL~ y~ te.
d 4, 4 ', 4"- [ (2, 4, 6-trimethyl-l, 3, 5-~n7~.r~rl yl) tris-
(methylene) ] tris [2, 6-bio (l, l-dimethylethyl) -phenol3
epolymer of ethene with 2-methyl-2-propenoic acid.
Examples l-5
Examples 1-5 d~ OLL~Le the utility of iodide additives to
heat aging when diff~ n~ y incorporated into polyketone
polymer. Test specimens were prep2red by immersing polymer A in
the form of 5.1 x 10-4 m (20 mil) sheet lnto a water compositlon
for 20-25 min at a temperature of 90-9SC. The water used was HPLC
grade, OmniSolv supplled by EM Science. Water compositions used
in examples 2-5 included: water alone, 0.30 wt~ ZnI2, 2.0~ ~I, and
saturated Ph4PI which is only 5paringly soluble in water at
90-95 C. After exposure, the polymer specimens were cooled,
W0 95/14056 ~ L'~ _ l
wiped clean of any surfac~ resldue, and dried in a vacuum oven at
50 C with a nitroqen purge over night. One centimetre wide oven
test strips were then cut fro~ the exposed sheets. For the sample
which wa~ exposed to Ph4PI, neutron ~ctivation tests were
conducted to determine the iodide pr~sent in the polymer after
this expo3ure. Residual iodine measured ca. 900 ppm, calculating
to 0.33~ Ph4PI present in this sample. Results of oven aging
tests are shown in Table 3.
TA3I.E 3. Iodide additives rl~ff~ct~nAlly incorporated into
polyketone polymer.
Days to Failure
Example EYposure 125 DC 100 C
- 20 78
2 N70 22 81
3 H70/ZnI7 21 3
4 H70/KI 27 121
S H70/Ph4PI 45 234
EYamples 2 and 3 show that simply exposing the polymer sheet
to water alone or to a Jolution of ZnI2 does not result ln
improved heat stability. Exposure to ~I and Ph4PI results in an
improvement in heat stability with Ph4PI being far superior in its
~bility to stabilize thi5 polyketone polymer - greater than 2
times the control, Ex3mple 1.
Examples 6-10.
Test Jpecimens used in Examples 6-10 were ~llff~ nAlly
prepared and then tested as described in Examples 2-5 using
polymer A and water compositions which contained 2. 0~ of the
rr~rr~.cp~nril n~ test additive. The results are _ rl 7~ in
Table 4.
WO 9S/14056 2 1 7 6 q 3 7 r~ 3~CI
TABLE: 4. Onium iodide salt addltives ~'iff~ nAlly'`incorporated
into polyketone polymer.
Day~ to Failure
Example Expoaure 125 C 100 C
6 - 24 108
7h70/Ph4PBr 21 113
8h70/Ph4PC1 25 llO
9~170/Et4NI 26 117
h70/Ph4PI 44 245
Examples 7, 8, & 10 show that of the Ph4P halide salts only
the iodide is 5 ~:~h; 1 i 7; nq to polyketone polymers . ExAmple 9
demonstrates that alkyl ammonium iodides such as tetr2ethyl-
alomonium iodide (Et4NI~ are not effective in s1~~hil;7in~
polyketone polymers. This demonstrates that not all onium iodide
salts are effective as s~Ahi 1 i 7~.r~ for polyketone polymer
Examples 11-13.
Examples 11-13 were prepared as described in Example 1-5 with
the exception th~t extruded ~heet of polymer E~ wzs used instead o~
polymer A. Test specimens for examples 12 & 13 were prepared
imilar to Exampl~s 7-10. Oven ~glng results are shown in
Tz~ble 5.
TABLE 5 . ~- ~ ri ~ln of iodide salts ~I; ff~ n:ll l y added to
polyketone polymer.
Days to Failure
Example Expo~ure 125 C lOO C
11 - 18 97
12 ~170/CaI7 l9 96
13 h70/Ph4PI 28 128
The~e examples show once again that not all iodide salts are
~ WO 95/14056 2 1 7 6 9 3 7 r~ R~I
s1-:~hi 1 i 7i ng to polyketone polymer. Calcium iodide shows no
improvement in time to embrittlement over the control.
Examples 14 - 16.
Exampl~s 14-16 demonstrdte that powder mixing of Ph4PI and
polyketone polymer followed by melt processing results in a
polymer composition with improved thermal oxidative stability.
~xamples lS and 16 were prepared by combining 100 grams polymer C
powder with Ph4PI powder and then ~ , ; 7; n~ by tumbling
overnight. Each mixture was then extruded on a lS mm E~aker-
Perkins twin screw extruder oper~ting at a melt ~ ror:~t~lre of
~bout 250 C. The extruded compositions were then used to make
plaques of 30 mil thicknesses by compression moulding. As shown
in Table 6, compositions with Ph4PI showed significantly improved
time to embrittlement at 125 C over the control.
TA3LE 6. Aging performance o~ Ph4PI melt blended into polykotone
polymer .
Days to
Failure
Example Additive 125 C
14 - 8
lS 0.25~ Ph4PI 18
16 0.50~ Ph4PI 17
Ex~mpl~s 17 - 26.
Examples 17-26 compositions were pr~pared by melt processing
~s described in F,xamples 14-16 with the exception that polymer D
was used instead of polymer C. Oven aging test results shown in
Table 7, illustrate that onium iodide salts with alkyl
~ubstituents (ex. 18-22) exhibit no srAh;117;n~ influence on
polyketone polymers. Examples 25 and 26 demonstr~te the
stAh; 1; 7; nq influence of iodide salts other than Ph4PI which also
contain onium cations shielded by aromatic substituents, i.e.
bis~triphenylrhn5~hnrAnylidene)ammoniUm and a ~r;A7nl; salt,
resp~ctively. In these exampl~s, the increased stability was
WO95/14056 ~ ~ 7 6937 ~ t'- I ~
~omewhat ~mall, but simil~r in magnitude to the benefit from Ph4PI
in this polymer, Example 24.
Table 7. Aging r~.rfnrr-n~-o of onium iodide 5alts melt blended
into polyketone polymer.
Days to Failure
Example Additive 125 C 100 C
17 - 17 73
18 0 . 43~ Ph~MePI 16 48
19 0.49~ (PhO)~MePI Not processable
20 0.28% Et4NI 12 30
21 0. 50~ Et4NI 12 32
22 0.223 Me4NI 11 30
23 - 22
24 0.3~ Ph4PI 26
25 0. 43~ PPNIa 25
26 0.25ê TIb 27
a bis(triphenylrhnsphnrAnylidene)ammonium iodide
b S-Methyl-3-(methylthio)-1,4-diphenyl-1H-1,2,4-tr~A.nli iodide
Examples 27-39.
Examples 27-39 compositions were prepared by melt processing
as described in Example5 14-16 using the polymers and additives
~ .nt~fi~l in Table 8. Example 30 demonstrates the improved
resistance to embrittlement using only PPh4I. Example 31 shows a
signific~nt improvement when a commercial hindered phenolic
Ant;nY;olrnt such as Irganox 1076 is combined with Ph4PI in
poLyketone polymers. This combination re5ults in improved oven
aging performance compared to using either individually. Examples
33-39 demonstrate that in-situ formation of rhn~irhnn; iodides
from a phosphine and an organic iodide ~ improves the
stability of polyketone polymer ~ust as effectively as osing
~ WO9S/14056 21 76937 r~ e3~
-- .15 --
Ph4PI. Examples 3~-37 shOW that the use o~ either triphenyl
phosphine or 1,4-~ alone do not contribute to the
atability of polyketone polymers. However, the combination of
these additlves in Example 33 yields a polymer with significantly
improved heat aging performance. Examples 38 and 39, further show
the b--n~f; ~ 1 effect when an organic iodide and triphenyl-
phosphine are combined in the additive package.
TABLE E. Aging performance of rhn~phnni iodides melt blended
into polyketone polymers and generat~sd in-situ.
Example Polymer Additive Days to
Failure
125 C
27 E None 15
28 E O.Sd Irganox 1076a 19
29 - E 0 . 5~ Irganox 245b 26
E 0.3~ Ph4PI 38
31 E 0.5~ Irganox 1076D, 0.3~ Ph4PI 43
32 E 0.5~ Irganox 24sb, 0.3~ Ph4PI 36
33 E 0.29~ PPh3, 0.39~ PhI2, 0.5~
Irganox 245b 42
34 E 0.3~ PPI7, 0.5~ Irganox 245b 11
35 D - 18
36 D 0.2~ PPh~ 13
37 D 0.33 PP~ 15
38 E 0.5~ Irganox 24sb, 0.3~ 9-
; O~lnph~n~nShrene 26
39 E 0. 5~ Irganox 24sb, 0 . 39a 9-
iodophenanthrene, 0.2~ PPh~ 38
a n-o ctadecyl 3- ( 3, S-di -te rt-butyl - 4 - hydroxyphenyl ) propi ona te
b 3,5-bis~l,l-dimethylethyl)-4-hydroxy-1,2-ethanediylbis(oxy-2,1-
ethancdiyl)benzene propanoic acid ester.
-
WO95/14056 ~ I / 6937 r~ o3x~
EXAMPLES ON CROSS--LIN~ING
Example
Polyketone polymer A with a melting point of about 220 C and
limitlng viscosity number of 1.87 dl/g was ' ' with 0.3 wt~
tetraphenylrh~-rh~nium iodide (PPh4I) and 0.5~ Irganox 1076 on a
15 mm 3aker Perkins extruder operAted at a melt t~mperatur~ of
approximately 250 C. A control wa8 prepared by extruding polymer A
as described above without the use of any additives. After this, the
pellets were dried in a vacuum oven at 50 C under nitrogen and then
compression moulded into 5.1 x 10-4 m ~20 mil) thick plaques.
Test specimens were cut from the plaques in 1 cm wide strips
and exposed to oxygen and heat using a Blue M forced air oven set at
125 C. The samples were withdrawn from the oven after ll days
exposure and submitted for GPC analysis using hexafluoroisopropanol
(HFIPA) as solvent. GPC analysis utilized ZORBAX 1000 and 60 PSM
columns in series and a Waters 410 differertial r~fr:~rt ~r as
detector .
Table l shows that as expected of linear polyketone polymers,
both unexposed samples were completely soluble in hFIPA. After
exposur~ to heat and oxygen, polyketone polymers without iodide
additives are soluble and exhibited a molecular weight loss. The
polymer sample ''I'nt:-;n;n-J iodide became a swollen gel (50~ sol)
indicAtive of a cross-linked polymer. This sample, however, did
not ~rr~r; ~ embrittlement in the same oven until 43 days
compared to the specimen without PPh4I which embrittled in only
~5 days.
~ WO 9S/14056 2 1 7 6 9 3 7 r~ Ql8C~
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Table 2. PPh4I Promoted Cross-linking of Polyketone Polymer
Molecular
PPh4I Days e Weight
Content 125C (Mn)
None 0 55900
None 11 34510
0.3~ 0 55280
0. 34 11 Insoluble
Example 2
Polyketone polymer B, with a melting point of about 220C,
an LVN o~ 1.95 dl/g, and ~ nr~inin~J 0.5~ IrganoY 1330 and 0.5~
Nucrel 535, was melt extruded into S.l x 10 4 m (20 mil) sheet. One
centimetr~ wide strips of this sheet were exposed to heat and oxygen
a~ descrlbed in Example 1. In addition to these strips, a separate
~et of strips was submitted to a saturated aqueous PPh4I solution at
85 C for 20 min. The strips were removed, wiped clean, and then
dried in a vacuum oven at 50 C under nitrogen purge. These strips
r~nl~s~in;ng PPh4I by diffusion were then exposed to heat and oxygen
as described above. Table 2 shows that after heat exposure the
polyketone polymer with iodide was again an insoluble swollen gel
(209~ sol) in BFIPA, while the s2mple without iodide treatment was
completely soluble and displayed a loss in molecular weight. This
1~ example shows that iodide can be added after part fabrication but
before heat and oxygen is applied to yield a cross-linked
polyketone .
WO 95/140~6 ~; 7 6 9 3 7 r~
Table 3. n; ff~ n71 Treatment of Polyketone Parts with PPh4I
Molecular Weight
PPh4I Treatment Days 1~ 125C (Mn)
No 0 50562
No 5 34660
Yes S Insoluble
Example 3
Polymer strips containing either potassium iodide or
tetr2ethylammonium iodide were prepared and tested as described in
Example 2 with the exception that 2 wt~ of the respect iodide
solutLons were replaced for the PPh4I solution. It was observed
that after 10 days at 125 C both samples were insoluble in HFIPA.
This demonstrates that iodides other than PPh4I also promote
oxidative curing of polyketones.
Example 4
Polyketone polymer C, melting point of about 220C and ~VN of
1. 84 dl/g, was injection moulded into 1/8 inch ASTM D-638 tensile
b~rs. Part of the bars were exposed to h~at and oxygen for 20 days
as describe in Example 1, while a separate set was first treated
with a saturated aqueous solution of PPh4I at 80 C for 90 minutes
before heat exposure. Table 3 shows the tensile property, GPC, and
DSC results before and after heat exposure. GPC was measured both
on the skin and core of the tensile bars, while DSC was measured on
the skin. This example shows that PPh4I promotes oxidative cross-
linking which provides greater tensile strength and soLvent
resistance while maintaining a high degree of crystallinity.
Thi~ example demonstrates that PPh4I promotes oxidative cross-
linking which provides greater tensile strength and solvent
resistance while m7;ntA;nin~ a high degree of crystallinity. Cross-
linking, as indicated by ;n~ hll;ty in HEIPA, is demonstrated only
in the sample 1-~nt7~n;nq PPh4I combined with sufficient exposure to
heat and oxygen, i.e. the outer portions of the sample. As a res~lt
~ WO 95/14056 2 1 7 6 9 3 7 PCTIEP941038~1
-- .19 --
of cross-linking, the PPh4I-~ nt ~ n7 sample shows ~ 24~ incre~se
in yi~ld strength, while the specimen without PPh4I exhibits
oxidatiYe degradation re3ulting in a loss of yield and molecular
weight (40~ drop in number ~ver~lge molecular weight (Mn) of s)cin).
Cross-linking in the manner described did not diminish the extent of
crystallinity relative to the uncross-linked polymer as apparent in
the large heat of fusion values which are a proportional measure to
the extent of crystallinity.
WO 95/140~6 2 1 7 6 9 3 7 P~ , 1,'Q3~
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