Note: Descriptions are shown in the official language in which they were submitted.
Z~3C~
METHOD FOR CROSSLINKING ~EACTIVE POLYOLEFINS
VIA A RHODIUM CATALYZED HYDROSILATION REACTIO~
USING POLYORGANOSILOXANE CROSSLINKERS
Field of the Invention
The present ~nvention relate6 to a method
of crosslinking reactive polyolefins with
polyorganosiloxanes via a rhodium catalyzed
hydrosilation reaction. The present invention also
relates to novel alkoxy-terminated
polyorganosiloxanes which can be employed in the
cros61inking of reactive polyolefins as claimed
herein.
ackqround of the Invention
The crosslinking of vinyl containing
polymers with sulfur in the presence of various
catalysts, accelerators and additive~ is well
known. The sul~ur-induced cros~linking of the
vinyl-containing polymers generally involves the
formation of mono-, di-, and tri-sulfido bridges
between vinyl groups on the polymer backbone,
resulting in the vulcanization of the polymer. The
sulfide crosslinking imparts greater strength and
resiliency to the polymer, allowing for it6
6ubsequent use in a variety of demanding
applications. The method reguires the continuous
heating of the polymer and i8 therefore energy
inten6 ive.
The cro~slinking of vinyl containing
polymer6 w~th organic peroxides is also well known.
The mechanism of organic peroxide-induced
cros61inking involves the generation of radical6
that ab6tract hydrogen atoms from the polymer,
thereby further generating polymer-bound radicals
D-15,654
3~
- 2 ~ 3~80
which link together to form covalent carbon-carbon
bonds. The formation of the carbon-carbon bond6
produces the crosslinking of the polymer necessary
to impart sreater strength and resiliency to the .
vulcanized substrate. Organic peroxide cro~slinking
typically is used when heat age resistance or
continuous vulcanization i5 desired. This process
also requires the continuous input of heat energy.
A third method ~f crosslinking vinyl-
containing polymers involves the use of moisture
crosslinkable 6ilanes, such as vinylalkoxysilanes,
which have been grafted onto the polymer backbone
via a peroxide coupling reaction. The process
involves a peroxide-induced grafting reaction of a
vinylalkoxysilane onto the polymer backbone and the
blending of the alkoxysilane hydrolysis catalyst,
such as a tin compound. The graft polymer is then
submitted for the fabrication step. ~he
crosslinking of the vinyl containing polymer ~
initia~ed when the fabricated article is exposed to
a source of moisture. The rate of crosslinking is,
however, dependent upon mass transfer of moisture
into an inherently hydrophobic polymer matrix. This
method of crosslinking is subseguently limited to
fabricated articles having high 6urface area~volume
ratios, such as is found in thin walled pipe or
certain cable insulations.
An alternative to the aforementioned
crosslinking methods i6 taught in GB 1,118,327 which
involves the u6e of multi-SiH containing ~iloxanes
and a platinum hydrosilation cataly6t to promote the
hydrosilation crosslinking of vinyl containing
D-15,654
1~3(! 80
-- 3 --
polymers. The vinyl containing polymers described
in GB 1,118,327 are primarily ethylene/propylene/
diene monomer terpolymers (EPDM). The source of
pendant unsaturation in EPDM rubbers are
di-unsaturated, unconjugated olefins such as
ethylidene norbornene, dicyclopentadiene,
1,5-cyclooctadiene, 1,4-hexadiene and 1,7-octadiene.
The hydrosilation crosslinking of the vinyl-
containing polymer is achieved via the addition of
multiple SiH groups of an individual siloxane
molecule to the pendant vinyl groups of the EPDM
terpolymer. The network of Si-C bonds formed from
the hydrosilation reaction ultimately results in the
crosslinking of the terpolymer. GB 1,118,327
describes the use of a specific class of
organohydridopolysiloxanes of the general formula:
[Rmsi(4-m)/2]
where at least five units of the molecule are
HRnSiO3_n/2 where n = 1 or 2, m = O, 1, 2 or 3 and R
is a monovalent hydrocarbon radical free from
aliphatic unsaturation. The most useful structure
is said to be the siloxane having the general
formula:
(CH3)3Sio-(CH3Hsio)x-si(cH3)3
where x has an average value of 10 to 90. Catalysts
disclosed as useful in the process are various forms
of platinum hydrosilation catalysts, such as olefin
complexed platinum, platinum complexed with
D-15,654
- 4 ~ 3~8~
sym-1,2-divinyl-1,1,2,2-tetramethyldisiloxane or
chloroplatinic acid. This method is found to result
in bubble formation within the fabricated articles,
thereby making its use unattractive.
The use of Group VIII transition metal
complexes as hydrosilation catalysts has been well
documented in the literature as described in Organo-
metallic Chemistry Reviews No. 5, by Lukevics et al.
pp 1-179 (1977). For the most part, H2PtC16"6H20
dissolved in an alcohol such as ethanol or
isopropanol, is the most widely used hydrosilation
catalyst. The use of other platinum complexes with
a wide variety of attached ligands, such as organo-
phosphines, organosulfides, unsaturated organics
such as alkenes, have also been extensively used.
Other Group vIII transition metal complexes contain-
ing similar ligands have also been described as
catalysts for the hydrosilation reaction. These
catalysts and their use in the hydrosilation reaction
are well known by those skilled in the art. However,
some of these hydrosilation catalysts will also
catalyze various side reactions, many of which lead
to the production of volatile by-products. These
by-products can then cause undesirable bubble
formation within the polymeric substrate.
In addition to Group VIII transition metal
catalysts, a number of inhibitors for the
hydrosilation reaction are also known. The use of
the inhibitors for the hydrosilation reaction stems
from the high activity of the Group VIII transition
metal catalysts; so active that some compositions
containing the vinyl containing substrate, the SiH-
containing substrate and the hydrosilation catalyst
D-15,654
._
A
_ 5 ~ 3S~
undergo the hydrosilation reaction even at ambient
temperatures. The incorporation of a hydrosilation
catalyst inhibitor thereby improves the shelf life
stability of the composition at ambient temperatures.
The hydrosilation crosslinking of vinyl
containing polymers is not limited to the multi-SiH
containing siloxanes or the EPDM terpolymers as
described in GB 1,118,327. Hydrosilation
crosslinking has also been reported for polymers
such as polyisobutylene functionalized with terminal
unsaturation utilizing various multi-SiH containing
siloxanes and platinum hydrosilation catalysts. In
particular, HMe2SiOMe2SiOSiMe2H and Si(OSiMe~H)4
(described in Polymer Bulletin 1 575 (1979)),
[MeHSiO]5 (described in Macromolecules 13 681-685
(1980)); and HMe2Si(Me2SiO)nOSiMe2H where n = 3-7
(described in the Abstracts of the 20th
Organosilicon Symposium, Tarrytown, NY (1986)) are
all examples of other multi-SiH containing siloxanes
useful in the crosslinking of olefins.
Most recently, a hydrosilation crosslinked
vinyl-containing polymer composition was described
in JP 61.60,727. Specifically, it discloses the
crosslinking of a polyolefin containing terminal or
pendant unsaturation via a hydrosilation reaction
using siloxanes containing preferably greater than
10 organohydrogensiloxane units per siloxane
molecule and a platinum catalyst. It further
discloses a method to avoid the generation of
hydrogen gas and therefore bubble formation due to a
deleterious side reaction between the multi-SiH
containing siloxane and the platinum hydrosilation
catalyst.
D-15,654
- 6 - ~ ~ ~3~
Objects of the Invention
It is an object of the invention to provide
a method for crosslinking reactive polyolefins using
a rhodium catalyzed hydrosilation reaction using
known and/or novel polyorganosiloxanes as
crosslinkers.
It is another object of the present
invention to provide a method for crosslinking
reactive polyolefins which is suitable for
crosslinking fabricated articles and which minimizes
~ubble formation therein.
It is further an object of the invention to
provide novel siloxane compounds which are useful in
the claimed method of crosslinking polyolefins.
It is still another object of the invention
to provide polyolefin compositions which have been
crosslinked through the method of the present
invention.
SUMMARY OF THE IN~TION
The present invention provides a novel
method of crosslinking reactive polyolefins
comprising
1) mixing with said polyolefin
a) a polyorganosiloxane of the
formula:
R R
R' - Si - D - D' - T - Si - R'
R" R"
R R
R' - Si - D - D' - Q - Si - R' or
R" R"
mixtures thereof
D-15,654
,'~
- 7 ~ 3~ ~
R represent~ an alkyl group having
from l to about 4 carbon atoms,
R' represents a hydrogen atom, an alkyl or
alkoxy group having from 1 to about 24 carbon atoms,
R" represents R or a hydrogen atom;
D representg the group [ -SiO-l ;
R
D' represents the group ~ -SiO-]
H
... ..
T repres~nts the group ~ -SiO-]
O --
O
Q represents the group t -SiO-~ :
O --
x is an integer having a value ranging from
about 2 to about 12;
y i8 an integer having a value ranging from
about 2 to about 12: and
z is an integer having a value ranging from
O to about 6;
b) a hydrosilation cataly6t of the
formula
LlL2~hX
where~n Ll and L2 are neutral
coordinating ligands and X is a halide atom or
pseudo-halide ligand, and
D-15,654
- 8 - 1~3C~
2) initiating a hydrosilation reaction
between the polyorganosiloxane and the polyolefin.
The present invention also is directed to
polyolefin compositions containing the :
above-identified polyorganosiloxane(s) and
hydrosilation catalyst.
The present invention is further d~rected
to cross-linked polyolefin compositions produced
through the above process.
The present invention is also directed to
novel alkoxy-terminated polyorganosiloxanes which
may be employed in the claimed method of
crosslinkinq reactive polyolefins.
Detailed Descrivtion of the Invention
Olefin polymers 6uitable for purposes of
this invention are normally solid materials and
include homopolymers of olefins as well as
interpolymers of one or more olefins with each other
and/or up to about 30 percent by weight of one or
more monomers which are copolymerizable with such
olefins. Homopolymers and interpolymers of such
olefins as ethylene, propylene, butene-l,
isobutylene, hexene-l, 4-methyl-pentene-1,
pentene-l, octene-l, nonene-l, decene-l as well as
interpolymers of one-or more of ~uch olefins and one
or more of other monomers which sre
interpolymerizable with 6uch olefins, 6uch as vinyl
and diene compounds, are suitable for purposes of
this invention.
D-15,654
9 1~3~
Exemplary interpolymers containing some
degree of unsaturation are ethylene copolymers such
as ethylene-propylene copolymers, ethylene-butene-1,
copolymers, ethylene-hexene-l copolym~rs,
ethylene-octene-l copolymers, polymers of ethylene
and two or more of the following compounds:
propylene, butene-l, hexene-l, 4-methyl-pentene-1,
octene-l and the like.
Particularly preferred reactive polyolefins
for purposes of this invention are
ethylene/propylene/diene monomer polymers (EPDM).
The diene component of the EPDM polymers typically
is 1,4 hexadiene, dicyclopentadiene, ethylidene
norbornene, 4(5~-methyl-1,4-hexadiene or
1,5-cyclooctadiene. These polymers furthermore
typically contain from about 60 to about 80 wt.% of
ethylene. EPDM polymers are commercially available
as Vistalon~ (EXXON), Nordel~ (Shell) and Royalene~
(Uniroyal).
The polyorganosiloxanes useful in the
practice of the present invention are of the formula:
R R
X y Z
R" R"
R R
R' - C - Dx ~ D'y - Qz - C - R', or mixtures
R" R"
thereof wherein
R represents an alkyl group having from 1
to about 4 carbon atoms, preferably 1 carbon atom;
D-15,654
r ~ ~
~'
( i
- 10~
R' represent~ a hydrogen atom, an alkyl or
alkoxy group having from 1 to about 24 carbon atoms,
preferably an alkyl or alkoxy group having from
about 8 to abcut 14 carbon atoms;
~" represen~s R or a hydrogen atom, I
preferably R,
R
D represents the group ~ -Si0-] :
R
R
D' represents the group ~ -S.O-]
R
T represents the yroup ~ -Si0-]
O --
O _
Q represents the group ~ -SiO-]
x is an integer having a value ranging from
about 2 to about 12, preferably about 4 to about 8;
y is an integer having a value ranging from
about 2 to about 12, preferably about 4 to about 8;
and
Z i6 an integer havin~ a value ranging from
O to about.6, preferably about O to about 4.
It is further preferred that the sum of x,
y and z not exceed about 18, and preferably about 12.
Certain polyorganosiloxanes can be prepared
by means well known to those skilled in the art.
For example, one class of the silicone additives,
useful in the compositions of this invention, havs
the nominal formula:
D-15,654
93~0
Formula $
R - 61 - t8i - ~7i 0 ~ 6i - R
~ R H R
wherein the variables are as previously defined, can
be conveniently prepared by reacting a mixture
containing hexamethyldisiloxane,
octamethylcyclotetrasiloxane, trimethyl end blocked
methyl hydrogen polysiloxane and an acid catalyst.
The number of repeating units can be varied, as
desired, by ~arying the mole ratio of the
reactants. A specific procedure for preparing a
precursor falling with~n the scope of the above
formula is set forth in Example 2 of U.S. Pat. No.
4,046,930.
Another class of polyorganosiloxanes may be
prepared by reacting the compounds of Formula I with
a stoichiometric deficiency of an unsaturated
organic compound containing one terminal olefinic
group, in the presence of an platinum catalyst, ~uch
as chloroplatinic acid. Addition of this group
derived from the olefin group is useful for
rendering 6iloxanes more compatible with certain
polyolefins. This type of reaction is also
described in Example 2 of U.~. Pat. No. 4,046,930.
A third clas6 of polyorganosiloxanes, these
compounds being both novel and useful in the process
claimed herein, can be prepared by reacting
organohalosilane monomers with a ~toichiometric
deficiency of a Cl_24 alcohol. ~his ~s followed
D-15,654
- 12 - 12~3~80
by hydrolysis with water of She resulting reaction
product to generate a siloxane equilibrat~on
reaction. Upon equilibration, the hydrogen halide
generated during the hydrolysis of the organosilane
monomers may be removed by heating the reaction
mixture. Final residues of ~ydrogen halides can be
neutralized with conventional reagents, Guch a~
sodiu~ bicarbonate or potassium carbonate. Thi6
procedure is demonstrated in the Examples in the
preparation of Siloxanes I and XIV.
The polyorganosiloxanes are mixed with the
polyolefins in amounts ~uch that the molar ratio of
polyorganosiloxane to pendant u~sa~urated groups
present on the poly~lefins ~nqes from about 0.90:1
to about 1:0.90. ~referably, this ratio ranges from
about 0.95:1 to ab~ut 1:0.9~, while most preferably
the ratio is about 1:1. Anything less than a 1:1
ratio will result in an incompletely crosslin~ed
composi~ion. On the other hand, a composition
containing an excess of the multi-SiH containing
polyorganosiloxane will result in a completely
crosslinked composition: however, the exceæs
polyorganosiloxane will ser~e no obvious purpose
except to dilute the crosslinked composition.
The hydrosilation catalyst useful in the
practice of the current invention is of the formula
LlL2R~X
~herein Ll and L2, which may be the same or
different, are neutral coordinating ligands and X is
a halide atom or pseud~-halide atom.
D-15,654
- 13- 1293(~80
Neutral coordinating ligands include linear
olefinic groups containing from 2 to about 8 carbon
atoms and cycloaliphatic hydrocarbons containing at
least one double bond and hav~ng from 5 to about 12
carbon atoms. Also included within the definition
of neutral coordinating ligands are carbon monoxide,
and phosphine P(R"'~3 and phosphite P~OR'")3
compounds wherein R'" represents a phenyl group or
an alkyl-substituted phenyl group wherein the alkyl
group contains from 1 to about 6 carbon atom~.
Preferably, Ll and 1~ represent linear olefinic
- groups containing from 2 to about 8 carbon atoms,
cycloaliphatic hydrocarbons containing at least two
double bonds and having from 6 to about 12 carbon
atoms.
As stated above, X represents a halide atom
or a pseudo-halide atom. Therefore, X may represent
a chlorine atom, bromine atom, iodine atom or cyano
group. Preferably, X represents a chlorine atom.
The desired level of catalyst used will
depend on variables such as the temperature at which
the polymer is fabricated, or processed, the length
of time that the polymer is exposed to the
processing temperature, and the desired rate and
extent of cro661inking. Typically, catalyst
loadings fall in the range of 25 to 1000 ppm of
rhodium compound based on the total polyolefin
compo6ition, 50 to 200 ppm of rhodium compound being
the preferred range.
Al60 useful in the practice of the present
invention are mixtures of the above-described
rhodium catalyst~ with platinum-containing
hydrosilation catalysts, such as
(C2H5~)2PtC12. These mixtures can contain
rhod~um to platinum ratios which vary from about
D-15,654
. ~
.
- 14 ~ 3~ ~0
10:1 to about 1:10. Preferred are mixture~ wherein
the ratio of rhodium to platinum compounds i8 about
1:1. These mixtures may be employed in the same
amounts as the pure rhodium catalyst, namsly at .
levels from about 25 to about 1000 ppm based upon
the total polymer composition. Preferably, t~e
mix~ure is employed at levels of about 50 to about
200 ppm, on the same basis. Use of the
above-described mixtures offers a substantial cost
reduction and decreased cure times over use of the
rhodium catalyst alone. Its use further offers
improved production of a more highly cross-linked
polymer compared to that produced through the use o~
a platinum-containing catalyst alone.
The method of addition of the
polyorganosilixanes to the reactive polyolefins can
vary in that the polyorganosiloxanes may be
pre-mixed with the reactive polyolefins. On the
other hand, it may be added during processing of the
reactive polyolefin by various methods, such as
direct in;ection or by employing the use of a cavity
transfer mixer. Regardless of the method of
addition of the polyorganosiloxane, the important
conditions to be satisfied are (1) that sufficient
mixing and dispersion of ~he polyorganosiloxane
throughout the reactive polyolefin occurs and (2)
that if the catalyst iB then present, a sufficiently
low temperature must be maintained 60 that the
entire crosslinking reaction does no~ occur during
the mixing or processinq steps. However, the
claimed process and it~ use of the rhodium
hydrosilation catalyst reguires less critical
contro: of the reaction temperature as compared with
most platinum hydrosilation catalysts in regard to
D-15,654
. _
- 15 ~ 3~
premature crosslinking of the polymer. In many
cases, the use of platinum catalysts requires the
addition of inhibitors ko prevent premature
crosslinking.
The rate of addition is maintained at the
most expedient rate in order to minimize the length
of time required to prepare the compounded reactive
polyolefin; nevertheless, it is important to avoid
too rapid addition since this may ultimately prevent
inadequate dispersion of the polyorganosiloxane into
the reactive polyolefin.
The mixing of the polyorganosiloxanes and
the hydrosilation catalyst can be performed by a
variety of procedures. For example, the polyorgano-
siloxane can be compounded into the reactive poly-
olefin at the recommended level of a 1:1 molar ratio
of SiH to C=C, and the hydrosilation catalyst added
just before its processing. It may also be performed
by pre-compounding the hydrosilation catalyst into
the reactive polyolefin and the polyorganosiloxane
added just before the processing step. Using a
different approach, the polyo~ganosiloxane can be
compounded at twice the recommended level into a
given weight of the reactive polyolefin. The
hydrosilation catalyst compounded at twice the
desired level into a similar weight portion of the
reactive polyolefin, and then equal weight portions
of the polyorganosiloxane-containing reactive olefin
and the catalyst- containing reactive olefin can be
integrally mixed before the processing step. Yet
another method is to compound the polyorganosiloxane
into the reactive polyolefin at the recommended
concentration while the hydrosilation catalyst is
D-15,654
.
(~ - 16 - 1 Z~ 3 C ~0
added a6 a concentrated mixture of catalyst in
react ve polyolefi~ (catalyst masterbatch). The
order of addition may of course be reversed, this
being the preferred method.
In the compounding step, it is of prime
importance that adeguate dispersion of the catalyst
and polyor~anosiloxane into the vinyl reactive
polyolefin must take place in order to obtain an
evenly crosslinked polymer. Inadequate dispersion
may impart an uneven distribution of crosslinking.
If the use of a catalyst masterbatch is employed,
the concentration of the catalyst within the
masterba~ch does not by necessity fall within a
narrow range, but is adjusted to the desired level
after consideration of two important factors, (1)
the rate of dispersion of the catalyst masterbatch
in the reactive polyolefin and (2) the desired level
of catalyst concentration in the final compounded
reactive polyolefin. If the time of the compounding
step o~ the catalyst masterbatch is short, then it
would be important to use a lower concentration
catalyst masterbatch. It would be easier to
disperse the desired amount of catalyst using a more
dilute catalyst masterbatch. If the time of the
compounding of the catalyst masterbatch can be
extended, then the use of a more concentrated
catalyst masterbatch may be preferred, ~o that the
overall volume o~ matertal added, in the form of a
catalyst masterbatch, is kept to a minimum, A more
concentrated masterbatch will require a more lengthy
compounding step in order to adeguately disperse the
catalyst throughout the reactive polyolefin.
D-15,654
(~ !
- 17 ~ 1 ~ 3~ 80
The hydrosilation crosslinking of reactive
polyolefins described herein i6 accomplished by
compounding the reactive polyolefin, the
polyorganosiloxane and the hydro6ilation catalyst at r
a temperature below the point at which the
hydrosilation reaction is initiated. Thi6
composition is then shaped, formed, extruded, molded
or pres6ed into the desired 6hape and the
hydrosilation reaction is initiated by heating the
composition. The temperature to initiate the
hydrosilation reaction is primarily dependent on the
- nature and/or composition of the hydrosilation
cataly6t, in that certain catalysts initiate the
hydrosilation reaction at lower temperature~ and
~ome at more elevated temperatures. A u6eful
temperature for initiating the hydrosilation
crosslinking reaction is one at which the polymer i6
molten, thereby increasing catalyst mobility during
the hydrosilation reaction. Although the polymer i8
fluid or molten, the crosslinking reaction does
impart mechanical integrity to the polymer melt.
This induced mechanical integrity may be useful when
polymer flow, or 6agging, is undesirable. After a
period of time, which is dependent on the rate o~
the hydrosilation reaction, the 6haped, molded, or
extruded part can be removed from the 60urce of heat
and allowed to cool so that another part may undergo
the fabrication process. The hydro~ilation reaction
will continue at lower temperatures, although at a
much slower rate. Alternatively, the hydro6ilation
reactio~ may be driven to completion while the part
~s undergo~ng the initial ~eat treatment ~tep. Then
again, it may be driven to completion by a post
processing heat treatment step after the shaped
article has been removed from the fabrication step.
In any case, it is important to complete the
D-15,65~
- lB - lZ~3~
hydrosilation reaction in order to render a fully
crosslinked polymer composition.
To the compositions of this invention can
be also added various materials commonly added to .
extrudable compositions. These materials include
additives ~uch as pigments, plasticizers,
antioxidants, as well as inorganic materials, such
as clay, talc, glass, silica, zinc oxide, titanium
dioxide and the like in amounts well known in the
art.
Whereas the exact scope of the instant
invention is set forth in the appended claims, the
following specific examples are provided to further
illustrate certain aspect~ of the present
invention. These examples are 6et forth for
illustration only and are not to be construed as
limitations on the present invention. All parts and
percentage are by weight unless otherwise specified.
Definitions
g græms
mg. milligrams
mm. millimeter
psi. pounds per 6quare inch
C degree centigrade
OD~ Oscillating Disc Rheometer, manufactured by
Monstanto
(COD) cyclooctadiene
P ( Ph ) 3 triphenylpho~phate
M (CH3)3Si(O)1/2-
D-15,65~
- 19 ~ 31r;~0
D (CH3)2si(0)1~2
D' (CH3)HSi(O)1/2
Me (CH3)- --
Siloxane I C -H O-D D -C H
Siloxane II . MD D M
5 5
Siloxane III MD D M
10 5
Siloxane IV MD D M
13 5
Siloxan~ V MD M
Siloxane VI D
.
Siloxane VII 4 4
D-15,654
- 20 - lZ~3~80
Siloxane VIII C ~ Me SiO-D -~iMe-C H
18 37 2 4 2 18 37
Siloxane IX HMe2SiOD~2-Si~e2H
Siloxane X ~Me2SiO-D13-SiMe2H
Siloxane Xl (HMe2SlO)4Si
Siloxane XII C H O-D -C H
12 25 ll 12 25
Siloxane XIII C H O-D -C H
12 25 23 12 25
Siloxane XIV C H O-D -C H
12 25 4 12 25
EXAMPLES
The reactive polyolefin used in the
following examples was a commercially a~ailable
ethylene/propylene/ethylidene norbornene terpolymer
rubber (EPDM) marketed by Exxon Chemical Company
under the designation Vistalon 2504. The
composition of the terpolymer is said to ~e 64.1%
ethylene containing 5.82 C-C bonds, as ethylidene
norbornene, per l000 carbon atoms with the remainder
being comprised of polypropylene. The terpolymer
therefore contains 4.58 x 10 4 moles of C~C per
gram.
D-15,654
_ 21 ~ 3~ 8 0
Preparatian ~f Silcx~ne I
A 3 liter three neck rou~d bottom flask was
fitted with a mechanical etirrer, addition funnel
fitted with a nitrogen adapter~ a ~lai6en adapter _
fitted with a Friedrich c~ndenser (also fitted with
a nitrogen adapter), and a thermometer. Ths flask
was charged with Me2SiC12 (~69.7 ~, 5.96 mol)
and MeSi~C12 (6a6.6 g, S.96 mol). Ihe addition
funnel was charged with l-dodecanol (554.9 g, 2.983
mol). The flask was immersed in a~ ice bath. When
the contents of the flask reached ~C to 10C, the
dodecanol was slowly added over a 2 hour period
while maintaining the ~emperatur~ ~f the reaction
mixture below 10C. Upon complete addition, the
reaction mixture was allowed to stir for an
additional 1 hour below 1~C. The addition funnel
wa~ then charqed with di6till~d water (187.9 g,
10.44 mol). The water was added ~lowly to the flask
over 1.5 hours while maintaining the reaction
temperature below 10C and allo~ing for ~ontrollable
evolution of HCl gas. Upon complete addition of the
water the reaction mixture was stirred and allowed
to warm to 20C over a 16 hour period. The addition
funnel was replaced with a nitr~g~n sparging tube
and the reaction mixture was slowly heated to 80C
with gentle sparging. After 3 hours of heating with
6parging, the reaction mixture was allowed to cool
to 500C and 1 g of an aqueou~ NaH~03 paste was
added while maintaining stirring. After ~ hour an
aliquot of the reaction mixture was titrated for HCl
content with a 0.1 N NaOH ~olution to a pink
phenolphthalein endpoint. This step was repeated
until the HCl content was below 0.2%. Celite
D-15,654
- 22 ~ 1 ~ ~3~ ~
filter aid was added to the reaction mixture with
stirring and the temperature was allowed to cool to
around 25'C. The reaction mixture was pressure
filtered through a 0.1 micron pad to yield the clear
colorless wa~er white product, (1196 g, 90.0%
yield). The low boiling components of the product
had been removed by vacuum stripping at 135C a~ 1
mm Hg.
Preparation of Siloxane XIV
A 5 liter three neck round bottom flask was
fitted with a mechanical stirrer, addition funnel
fitted with a nitrogen adapter, Claisen adap~er
fitted with a Friedrich condenser (also fitted with
a nitrogen adapter), and a thermometer. The flas~
was charged with the 1645.7 grams of MeSiHC12,
under a dry nit;-ogen atmosphere. The addition
funnel was charged with l-dodecanol ~1329.7 g). The
flask was then immersed in an ice bath to cool the
chloro~ilane to a temperature of between 5C and
10C. When the desired temperature range was
achieved, the l-dodecanol was 810wly added to the
mechanically stirred chlorosilane over a 2.5 hour
period. The reaction mixture was allowed to stir
for an additional 2 hour~. The addition funnel was
then charged with distilled water (193.02 g, 10.72
mol). The water was then slowly added to the
reaction mixture the temperature of which was 6till
maintained at 5C to 10C. The addition o~ water
generated an evolution of HCl gas which was allowed
to vent through the Fr~edrich conden6er nitrogen
outlet, but not through the sid2 arm of the addition
funnel. The rate of water addltion was maintained
~o that the temperature of the reaction d~d not
D-15,654
- 23 ~
exceed 10C and so that the rate of HCl ga6
evolution was controlla~le. Upon complete addition
of the water over a two hour period, the reaction
mixture was allowed to ~tir for 16 hours while
slowly warming to 20~C. The addition funnel was
then replaced with a nitrogen cparging tube. The
flask was 610wly heated to 80C over a three hour
period while the reaction mixture was gently sparged
with nitrogen. The reaction mixture was allowed to
cool to 50OC and 1 g of an aqueous ~aHC03 paste
was added while maintaining stirring. After 1 hour
an aliquot of the reaction mixture was titrated for
~Cl content with a 0.1 N NaOH ~olution to a pink
phenolphthalein endpoint. ,This step was repeated
until the HCl content was below 0.2~. Celite~
filter aid was added to the reaction mixture with
stirring and the temperature was allowed to cool to
about 25C. The reaction mixture was then pressure
filtered through a 0.1 micron pad to yield the clear
colorless water white product, (2048.47 g, 95.8%
yield). Low boiling components were then removed by
vacuum stripping the product at 150C/l mm Hg.
Example 1
A Brabender~ Plasticorder fitted with a
mixing head was charged with 40 g. of the EPDM
terpolymer followed by the addition of 4.0 g. of
Siloxane I over a two minute period via syringe.
Upon complete incorporation of Siloxane I into the
terpolymer matrix, 250 mg of [(COD)RhCl]2
hydrosilation catalyst was added to the
compo~ition. Mixing was continued for another 5
minutss. The final composition was removed from the
mixing head and placed into a 3 in. x 3 in. x 1~4
D-15,654
- 24 ~ 3C~
in. cavity mold. The cavity mold was placed into a
press pre-heated to 180C. The press was closed and
the mold was subjected to 20,000 psi of pressure for
5 minutes. The mold was then removed from the press
and allowed to cool. The rubber sample was removed
from the mold and e~amined for crosslinking and the
undesirable presence of bubbles due to gas
formation. The heat treated sample contained no
bubbles.
The composition was then evaluated for
crosslinking by cutting off a 1~8 in. strip and
pulling repeatedly on the sample. A comparative
qualitative strength test was subsequently run by
pulling or stretching an untreated 1/8 in. strip of
terpolymer. The heat treated sample exhibited
greatly increased strength in comparison to the
untreated terpolymer.
Comparative Example A
Using the same procedure described in
Example 1, 3.0 ml of a 10 mg/ml isopropanol solution
of H2PtC16 hexahydrate was used as the hydrosilation
catalyst. The heat treated composition was removed
from the mold and evaluated for crosslinking and the
presence of bubbles. The sample was crosslinked,
but it contained many bubbles due to gas formation.
Comparative E~ample B
Using the same procedure described in
Example 1, 250 mg of K2PtC14 was used as the
hydrosilation catalyst. The heat treated
composition was removed from the mold and evaluated
for crosslinking and the presence of bubbles. The -
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A~.
~ ~ .
- 25 ~ 3 ~ ~
~ample contained many bubbles and exhibited very
little or no increase in strength, evidently from
low hydrosilation crosslinking.
Comparative ExamPle C
Using the same procedure described in
Example 1, 250 mg of (PPh3)3RhCl was used as the
hydrosilation catalyst. The heat treated rubber
composition was removed from the mold and evaluated
for crosslin~ing and the presence of bubbles. The
sample contained ma~y bubbles and exhibited very
little or no increase in strength derived from
hydro6ilation crosslinking.
Com~arative ExamPle D
Using the same procedure described in
Example 1, 250 mg of (PPh3)2RhCOCl was used as
the hydrosilation catalyst. The heat treated
composition was removed from the mold and evaluated
for crosslinking and the presence of bubble6. The
sample contained many bubbles and exhibited very
little or no increase in strength derived from
hydrosilation crosslinking.
Comparative ExamPle E
Using the same procedure described in
Example 1, 250 mg of (C6H5CN)2PtC12 was used
as the hydrosilat~on catalyst. The heat treated
composition was removed from the mold snd evaluated
for crosslinking and the presence of bubbles. The
sample contained many bubbles; however, it did
contain a recognizable amount of strength derived
from hydrosilation crosslinking. The strength was
les6 than the strength of 6amples wherein
[(COD)RhCl]2 was employed as the hydrosilation
catalyst.
D-15,654
~3~30
- 26 -
Comparative Example F
Using the same procedure described in
Example 1, 250 mg of (COD)PtC12 was used as the
hydrosilation catalyst. The heat treated sample was
removed from the mold and evaluated for crosslinking
and the presence of bubbles. The sample contained
many bubbles. However, it did contain a
recognizable amount of strength derived from
hydrosilation crosslinking. The strength was less
than the strength of the sample in wherein
[(COD3RhCl]2 was employed as the hydrosilation
catalyst.
Comparative Example G
Using the same procedure described in
Example 1, 250 mg of (PPh3)2IrCOCl was used as the
hydrosilation catalyst. The heat treated
composition was removed from the mold and evaluated
for crosslinking and the presence of bubbles. The
sample contained many bubbles and did not contain a
recognizable increase in strength in comparison to
the treated terpolymer.
Comparative,,~xample H
A masterbatch of H2PtC16 hexahydrate, in
the terpolymer of Example I, was prepared with a
catalyst concentration of 2.0 mg of H2PtC16
hexahydrate per g. of terpolymer. Using the same
procedure as described in Example 1, 3.0 g of the
freshly prepared catalyst masterbatch was used as
the hydrosilation catalyst. The heat treated
composition was removed from the mold and evaluated
for crosslinking and the presence of bubbles. The
sample contained many bubbles; however, it did
D-15,654
,
A
- 27 - ~ ~3~0
contain a recognizable amount of strength. The
strength was less than the sample in Example I which
used [(COD)RhC1]2 as the hydrosilation catalyst.
Example 2
Using the same procedure described in
Example l, 250 mg of [(CO)2RhC1]2 was used as the
hydrosilation catalyst. The heat treated sample was
removed from the mold and evaluated for crosslinking
and the presence of bubbles. The sample did not
contain many bubbles and it did contain a
recognizable amount of strength derived from
hydrosilation crosslinking.
Example 3
Using the same procedure described in
Example l, 250 mg. of (PPh3)2CORhCl was used as the
hydrosilation catalyst. The heat treated sample was
removed from the mold and evaluated for crosslinking
and the presence of bubbles. The sample contained a
moderate amount of bubbles and it did exhibit a
recognizable amount of strength derived from
hydrosilation crosslinking. The strength was less
than the sample of Example 1 employing t(COD)RhC1]2
as the hydrosilation catalyst.
Example 4
A Brabender~ Plasticorder fitted with a
mixing head was charged with 39 g. of the terpolymer
of Example I. To the terpolymer was added 3.75 g of
Siloxane I over a three minute period via syringe.
Upon complete incorporation of Siloxane I into the
rubber matrix, 2 g of a 2.5 mg [(COD)RhCl]2~g
terpolymer masterbatch was added, as the
D-15,654
A
, .. ,~
~ - 28 ~ 3~80
hydrosilation catalyst, to the composition and
allowed to mix for another 5 minutes. The ~inal
composition was removed from the mixing head and a
small sample was placed into a Monsanto Oscillating _
Disc Rheometer, pre-heated to 180C. The unit was
c}osed and the mold was subjected to 80 psi of~
pressure. After 24 minutes, the sample was removed
and allowed to cool. The sample was removed from I
the disc and examined for the undesirable presence
of bubbles due to gas formation during the
crosslinking step. The heat treated composition was
evaluated for crosslinking by examining the maximum
torgue reading, in rheometer unit6.
The sample contained no bubbles and had
excellent strength derived from the hydrosilation
crosslinking step. The maximum tor~ue achieved was
20 rheometer unit~.
The heat treated sample was evaluated for
gel content following the procedure outline in ~STM
test D1225. This procedure generally involves
contacting the sample with boiling decalin for 6
hours followed by oven drying for more than 10 hour6
at 150C at 1 mm Hg. The weight of the remaining
material i6 then determined. The % extract of this
6ample was determined to be 4.1%, corresponding to a
95.9% gel content.
ExamPle 5
Using the same procedure outlined ~n
Example 2, 5.17 g of Siloxane I was used as the
6iloxane crossllnking agent. The heat treated
sample contained hO bubbles and had excellent
6trength. The max~mum torgue achieved on the ODR
was 22 rheometer unit6.
D-15,654
- 29 - 1 ~ 9 3~ ~o
The heat treated sample was evaluated for
gel content following the procedure outline in ASTM
test D1225, as outlined above. The % extract was
determined to be 4.6%, corresponding to a 95.4% gel '~
content.
ExamPle 6
Using the same procedure outlined in
Example 2, 3.29 g of Siloxane II was used as the
siloxane crosslinking agent. The heat treated
sample contained no bubbles and had excellent
strength derived from the hydrosilation crosslinking
step. The maximum torque achieved on the ODR was
19.5 rheometer units.
ExamPle 7
Using the same procedure outlined in
Example 4, 4.69 g of Siloxane III was used as the
siloxane crosslinking agent. The heat treated
sample contained no bubbles and had substantial
6trength derived from the hydrosilation cro slinking
step. The maximum torgue achieved on the ODR was
15.5 rheometer units.
Com~arative Exam~le I
Using the same procedure outlined in
Example 4, 5.10 g of Siloxane IV was used as the
siloxane crosslinking agent. The heat treated
sample contained no bubbles but had only moderate
strength derived from the hydrosilation crosslinking
step. The maximum torque achieved on the ODR was 9
rheometer units.
D-15,654
- 30 - l~t~3~0
ComParative Exam~le J
Using the same procedure outlined ~n
Example ~, 1.21 g of Siloxane V was used as the
siloxane crosslinking agent. The heat treated .
sample contained many bubbles and had no ~ubstantial
strength derived from the hydrosilation crosslinking
step. The maximum torque achieved on the ODR was
only 4 rheometer units. I
ComParative ExamPle K
Using the same procedure outlined in
Example 4, 2.91 g of Siloxane VI was used as the
siloxane crosslinking agent. The heat treated
sample contained many bubbles and had no substantial
strength. The maximum torgue achieved on the ODR
was 2 rheometer units.
Using the same procedure outlined in
Example 4, 3.36g of Siloxane VIII was used as the
siloxane crosslinking agent. The heat treated
sample contained no bubbles and had excellent
strength derived from the hydrosilation crosslinking
step. The maximum torque achieved on the ODR was 24
rheometer units.
Exam~le 9
Using the same procedure outlined in
Example 4, ~.;'3 g of Siloxane VIII was used as the
siloxane crosslinking agent. The heat treated
sample contained ~o bubbles and exhibited excellent
strength. The maximum torque achieved on the ODR
was 20 rheometer units.
D-15,654
- 31 - i 2~ 3~ ~ 0
Example 10
Using the same procedure ~utlined ln
Examp~e 4, 2.56 g of Siloxane IX was used a6 the
siloxane cro6slinXing agent. The heat treated
sample contained no bubbles and had subs~antial
strength derived ~rom the hydrosilation crosslinking
6tep. The maximum tor~ue achieved on the ODR was
~7.~ rheometer units.
ExamPle 1~
Using the same procedure outlined in
Example 4, 3.31 g of Siloxane X was used as the
6iloxane crosslinking agent. ~he heat treated
eample contained no bubbles and exhibited
6ubstantial strength. The maximum torque achieved
on the ODR was 16 rheometer units.
~xamPle 12
Using the same proceture outlined in
Example 4, 1.88 g of Siloxane XI was u6ed as the
6iloxane crosslinking agent. The heat treated
6ample contained no bubbles and exhibited excellent
strength. The maximum torque achieved on ~he ODR
was 19 rheometer unit6.
ComParative ExamPle M
Using the ~ame procedure outlined in
Example 4, 2.23 g of Siloxane XII was used a6 the
6iloxane crosslinking agent. The heat treated
6ample contained many bubbles and exhibited no
6ubstantial 6trength. The maximum torque achie~ed
on the ODR was 6 rheometer units.
D-lS,654
-
- 32 ~ 3~0
Comparative ExamPle ~ -
Using the ~ame procedure outlined in
Example 4, 1.68 g of Siloxane XIII was used as the
siloxane crosslinking agent. The heat treated
sample contained many bubbles and exhibited ~o
subs~antial ~tsength. The maximum t~rque achieved
on the ODR was 4 rheome~er uni~6.
ExamPle 13
A Brabender~ ~lasticorder fitted with a
mixing head was charged with 40 g of the terpolymer
of Example I. To the mixer was added 4.00 g of
Siloxane XII over a three minute period via
6yringe. Upon complete incorporation of
Siloxane XII into the matrix, 3 g of a 2.5 mg
~(COD)~hC1~2/g terpolymer masterbatch was added,
as the hydrosilation catalyst, to the composition
and allowed to mix for another 5 minutes. The final
composition was removed ~rom the mixing head and a
small sample was ~laced into a Monsanto Oscillating
Disc Rheometer pre-heated to 180C. The ODR was
clo~ed and the mold was subjected ~o 80 p6i of
pressure. After 24 minutes the sample was removed
from the ODR and allowed to cool. The rub~er sample
was remo~ed from the disc and examined for the
undesirable presence of bubbles due to gas formation
during the crosslinking step. The heat treated
compo6ition was evaluated for crosslinking by
examining the maximum torgue reading, in rheometer
unit6, on the ODR graph.
The 6ample contained no bubbles and
exhibited excellent strength derived from the
hydrosilation crossllnking step. The maximum torque
achieved was 22.5 rheometer units.
D-15,654
- 33 - lZ~3~
ExamPle 14
Using the same procedure outlined in
Example 13, the sample was cured in the Oscillating
Disc Rheometer at 160C. The heat treated ~ample .
contained no bubbles and exhibited substantial-
strength derived from the hydro~ilation crosslinking
step~ The maximum torgue achieved on the ODR was 16
rheometer units.
ExamPle 15
Using ~he same procedure outlined in
Example 13, the sample was ~ured in the Os~illating
Disc Rheometer at 200C. The heat treated ~ample
contained no bubbles and exhibited excellent
strength derived from the hydrosilation crosslinking
step. The maximum torque achieved on the ODR was 20
rheometer units.
Example 16
A Brabender Plasticorder fitted with a
mixing head was charged with 30 g of the terpolymer
of Example I. To the mixer was added 4.00 g of
Siloxane I over a three minute period via syringe.
Upon complete incorporation of Siloxane I into the
rubber matrix, 3 g of a 2.5 mg ~(COD)RhC132/g
terpolymer masterbatch was added, as the
hydrosilatio~ catalyst, to the composition and
allowed to mix for another s minutes. At this
point, 30 g of calcined clay was slowly added to the
mixing composition over a five minute period. Upon
complete mixing, the final composition was removed
from the mixing head.
A 6mall sample was placed into a Monsanto
D-15,654
_ 34 _ i2~3~0
Oscilla~ing Disc Rheometer (OD~) pre-heated to
180C. The ODR was closed and the mold wa6
subjected to 80 psi bf pressure. After 24 minute~
the sample was removed from the ODR and ~llowed ~o
cool. The sample was removed from the disc and
examined for the undesirable presence of bubbles due
to gas formation during the crosslinking step. The
heat treated composition was evaluated for
crosslinking by examining the maximum torque
reading, in rheometer units, on the ODR graph.
The heat treated sample contained no
bubbles and exhibited superior strength derived from
the hydrosilation crosslinking step. The maximum
torgue achieved was 32.5 rheometer unit~.
The remaining system of the original sample
was placed into a 6 in. x 6 in. x 0.075 in. cavity
mold and placed into a press pre-heated to 180C.
The mold was subjected to 20,000 psi with heating
for 15 minutes and then removed from the press and
allowed to cool. Tensile bars where punched out of
the smooth grey crosslinked sample and evaluated for
tensile 6trength and elongation. A sample exhibited
a tensil~ strength of 1170 psi with a corresponding
elongation value of 340%.
Exam~le 17
A Brabender Plasticorder fitted with a
mixing head was charged with 40 g of the terpolymer
of Example I. To the mixer was added 4.00 g of
~iloxane I over a three minute period via ~yringe.
Upon complete ~ncorporation of Siloxane I ~nto the
composltion, 2 g of a 2,5 mg t(COD)RhCl]2/g
terpolymer masterbatch was added, as the
hydrosilation catalyst, to the composition and
D-15,654
- 35 ~ 3C~0
allowed to mix for another 5 minutes. Upon complete
mixing, the final composition was removed from the
mixing head.
A small sample was placed into a Monsanto
Oscillating Disc Rheometer preheated to 180C. The
ODR was closed and the mold was subjected to 80 psi
of pressure. After 24 minutes the sample was
r~moved from the ODR and allowed to cool. The
rubber sample was removed from the disc and examined
for the undesirable presence of bubbles due to gas
formation during the crosslinking step. The heat
treated rubber composition was evaluated for
crosslinking by examining the maximum torque
reading, in rheometer units, on the ODR graph.
The sample contained no bubbles and
exhibited excellent strength derived from the
hydrosilation crosslinking step. The maximum torque
achieved was 22.5 rheometer units over a 24 minute
period.
The remaining portion of the original
sample was placed into a 6 in. x 6 in. x 0.075 in.
cavity mold and placed into a press pre-heated to
180C. The mold was subjected to 20,000 psi with
heating for 15 minutes and then removed from the
press and allowed to cool. Tensile bars were
punched out of the smooth clear crosslinked sample
and evaluated for tensile strength and elongation.
The samples exhibited a tensile strength of 320 psi
with a corresponding elongation value of 380%.
I
E~ample 18
The same procedure was used as described in
Example 15, except that 4.0 ml of Siloxane XIV was
D-15,654
~."
- 36 - 1~3C 8~
used as the crosslinking agent. A small sample was
placed into the ODR and evaluated for hydrosilation
crosslinking at 180C for 24 minutes.
The heat treated sample contained no
bubbles and had excellent strength derived from the
hydrosilation crosslinking step. The maximum torque
achieved was 22 rheometer units.
The remainder of the original sample was
placed into a 6 in. x 6 in. x 0.075 in. cavity mold
and placed into a press preheated to 180C. The
mold was subjected to 20,000 psi with heating for 15
minutes and then removed from the press and allowed
to cool. Tensile bars were punched out of the
smooth clear crosslinked sample and evaluated for
tensile strength and elongation.
The samples exhibited a tensile strength of
380 psi with a corresponding elongation value of
370%.
Comparative Example O
A masterbatch of the platinum hydrosilation
catalyst (C2H5S)2PtC12 in the terpolymer of Example
1 was prepared such that the catalyst concentration
was 2.5 mg. per gram of terpolymer. 2.0 grams of
the catalyst masterbatch were then employed in the
procedure of Example 4.
A portion of the compounded sample was
cured by heating in the ODR. The sample contained a
few bubbles and exhibited reasonable degree of
strength. However, the maximum torque achieved was
only 16.9 rheometer units.
D-15,654
~ . ,.
A
_ 37 _ 1~ 3~ 8
Ex~m~le 19
The procedure o~ ~xample 4 was repeated .
except that the ~atalyst Y~S composed of ~) 1.0
grams of the platinum-catalyst materbatch of
Comparative Exa~ple 0, ~nd b) 1.0 grams of the
rhodium-catalyst master~rh of Example ~.
The cured sample contained no bubbles and
exhibited excell~nt 6trength. The maximum torque
achieved was 26 sheometer unit~; a value higher than
attained with the same c~talyst loading of either
the platinum catalyst of ~mparative Ex~mple O or
the rhodium cat~lyst of ~ample 4. In addition, the
rate of crossliDking was ~nhanced as about 90% of
the crosslinking which o~sured within the sample d~d
so within the first 6 min~tes.
D-15,654
