Note: Descriptions are shown in the official language in which they were submitted.
ZQ56573
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RD-20240
The present invention relates to polyimides
containing impact modifiers.
Polyimide materials in the form of moldings are
useful in bearings, electrical conductor insulation and
printed circuits. Polyimides can also be reinforced with
glass and carbon fibers and used in aerospace applications as
aircraft skins or honeycomb structural members. Polyimides
are well known for their superior mechanical and dielectric
properties and chemical stability at high temperatures. In
addition to a broad range of polyimides, there are also many
imide copolymers, such as polyamideimides, polyesterimides,
polyetherimides, polycarbonate imides, polythioesterimides,
polyketoneimides and the like.
The polyimides, the imide copolymers and the
methods of making such polymers are known in the art and will
not be discussed in detail. Examples of polyimides, imide
copolymers and methods of manufacture are disclosed in
Polyimides: Progress in Materials Science, Volume 7, 1977 by
Androva and U.S. Patents 3,666,709, 3,817,927, 3,847,B67,
4,111,906, 4,588,804, 4,586,997, 4,620,497, 4,634,760,
4,701,511 and 4,820,781 which are hereby incorporated by
reference. Polyimidesr imide copolymers and methods of
manufacture are also disclosed in many other patent and
literature references. The list of patents relating to
polyimides is neither representative nor inclusive of the
polyimide and imide copolymer art.
~ While polyimides have a broad range of desirable
properties, polyimides and to a lesser degree imide
.
- 2 - Z~56573
RD-20240
copolymers are lacking in impact resistance. Improvement in
impact properties is difficult due to the instability of
impact modifiers at the temperatures required for the
processing and extrusion of polyimides.
The present invention is based upon the discovery
that a polydiorganosiloxane-based impact modifier ~SIM)
having a grafted structure can effectively improve the impact
strength of the polyimide. More particularly, there is
employed a graft polymer preferably prepared by emulsion
polymerization, said polymer having an elastomeric
polydiorganosiloxane first stage and at least one subsequent
grafted stage comprising specific vinyl monomer-derived
structural units.
In one of its aspects, the invention includes
compositions comprising a polyimide in combination with a
sufficient amount to improve the impact resistance of the
polyimide of an impact modifier comprising a graft polymer
having: (a~ an elastomeric polydiorganosiloxane as the first
stage and (b) at least one subsequent stage graft polymerized
in .he presence of any previous stages, said subsequent graft
polymerized stage comprising polymers selected from the group
consisting of copolymers of acrylonitrile with vinyl aromatic
monomers, copolymers of methacrylonitrile with vinyl aromatic
monomers, homopolymers of vinyl aromatic monomers,
homopolymers and copolymers of lower alkyl acrylates or
methacrylates, homopolymers and copolymers of acrylamide or
methacrylamide and homopolymers and copolymers of acrylic
acid or methacrylic acid.
Most of the known preimidized polyimides can be
described by a general formula of a repeating unit which
contains two cyclic imide rings. For example, see the
definition of polyimides in U.S. Patent 4,485,140. These
~56S73
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RD-20240
polyimides are defined as condensation type polymers having
structural units of the formula
11 1l
-N \ / Z \ N Q
U \C/
O O
O
where Z is a suitable tetravalent organic radical, which may
be a simple structure such as that derived from the benzene
rlng or a more complex structure such as that derived from
benzophenone, or any other approprlate, usually aromatic,
.tetravalent organic radical; and Q is a divalent organic
radical. Further detail is disclosed in the aforementioned
U.S. Patent 4,985,140 which is hereby incorporated by
reference.
There are some polymers which can be represented by
lS a repeating unit which contains only one cyclic imide ring.
An example of such a repeating unit is
-C - ~ N - ~ - X - ~ - N-
where X is 0, S, or ~CH2)m and m has a value of from 0 to 6.
The unassigned bonds to the aromatic rings can be in any
. . , . ,. ;, . ; . . .. :
2~56S73
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RD-20240
available position. The benzene rings can be substituted
with alkyl or halogen.
U.S. Patent 3,847,867, which patent is hereby
incorporated by reference, discloses polyetherimides made by
S reacting an aromatic bis(ether anhydride) and an organic
diamine in the presence of an organic solvent at temperatures
of at least 130 C. Such polyetherimides consist essentially
of chemically combined units of the formula
( T ) ~ o_l~ _o ~<
where Al is a divalent aryl radical including bis-aryl
radicals and can be substituted with methyl and bromine
radicals. The two aryl radicals of the bis-aryl radical can
be joined by a covalent bond or by one or more divalent
radicals of the formulas
1l f
-A -, -C- ~ -~- and -S-
The divalent bonds of the -O-A-O- radical are usually equally
situated on the phthalimide end groups, e.g., in the 3,3'
positions or the 4,4' positions. A2 is an alkylene radical
having frcm 1 to 5 carbon atoms. Rl is a divalent organic
radical selected from the class consisting of ta) aromatic
2(!56S73
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RD-20240
hydrocarbon radicals having from 6-20 carbon atoms and
halogenated derivatives thereof, (b) alkylene radicals and
cycloalkylene radicals having from 2-20 carbon atoms, and (c)
divalent radicals included by the formula
s
~ A ~
where A3 is selected from the class consisting of
11 a
-o-, -c- ~ R -s- and -A2-
10 '
where A2 is as previously defined.
U.S. Patent 3,905,942 also discloses a
corresponding high temperature method for making polyimides
from the corresponding tetracarboxylic acids.
U.S. Patent 3,818,927 discloses polyimides prepared
by condensing a tetracarboxylic acid of the formula
HO0 ~ S0~ cCoOoOHH
or a derivative thereof which forms amido groups with 4,4'-
diaminobenzophenone in a polar organic solvent at a
temperature above 160-C.
U.S. Patent 4,111,906 discloses polyimides prepared
from perfluoroisopropylidene diamine. The polyimides can be
illustrated by the idealized formula
- 6 - 2~565~3
RD-20240
Cr'
o
\ / n
wherein n is an integer sufficient to provide a structure
having an average molecular weight of at least 5000 and R3 is
an organic radical of 5 to 22 atoms which may be an aliphatic
or alicyclic radical or an organic radical having one or more
benzene rings or fused aromatic rings.
The present invention also has applicability to the
stronger, less impact resistant, highly solvent resistant
polyimides and copolyimides such as those disclosed in U.S.
Patents 4,247,443 and 4,290,936. Examples of such polyimides
and copolyimides are also shown in U.S. Patent 4,634,760,
incorporated herein by reference. Such polyimides and
~5 copolyimides contain structural units having the formula
1l 11
Il , I
O O
wherein Rl is as previously defined, optionally in
combination with structural units having formula I.
2~56573
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RD-20240
In general, the polyamic acids are useful as
intermediates for the polyimides when the latter are prepared
by the reaction of a dianhydride with a diamine as is
described in U.S. Patent 4,634,760 which is hereby
incorporated by reference. Polyimides in general can be
prepared from polyamic acids or by the reaction of diamines
with bisimides having electron-deficient N-substituents, as
more fully described hereinafter. Because the polyimide
precursors are most often dianhydrides, frequent reference to
dianhydrides will be made hereinafter.
The p~eferred polyimides are derived from 2,2-
bis~4-~3,4-dicarboxyphenoxyjphenyl~propane dianhydride (also
known as bisphenol A dianhydride) the corresponding
tetracarboxylic acid, its 2,3-dicarboxy and mixed 2,3- and
3,4-dicarboxyphenoxy isomers and mixtures thereof, with
bisphenol A dianhydride being preferred.
Examples of suitable Rl values are those in such
diamines as ethylenediamine, propylenediamine,
trimethylenediamine, diethylenetriamine,
triethylenetetramine, heptamethylenediamine,
octamethylenediamine, 2,11-dodecanediamine, 1,12-
octadecanediamine, 3-methylheptanethlyenediamine, 4,4-
dimethylheptamethylenediamine, 4-methylnonamethylenediamine,
2,5-dimethylhexamethylenediamine, 2,2-
dimethylpropylenediamine, N-methyl-bis(3-aminopropyl)amine,
3-methoxyhexamethylenediamine, 1,2-bis(3-aminopropoxy)ethane,
bis~3-aminopropyl)sulfide, 1,4-cyclohexanediamine, bis-(4-
aminocyclohexyl)methane, m-phenylenediamine, p-
phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, m-
xylylenediamine, p-xylylenediamine, benzidine, 3,3'-
dimethoxybenzidene, 1,5-diaminonaphthalene, bis(4-
aminophenyl)methane, bis(4-aminophenyl)propane, 2,4-bis(~-
amino-t-butyl)toluene, bis(p-~-methyl-o-aminopentyl)benzene,
8 2~S6S73
RD-20240
1,3-diamino-4-isopropylbenzene, bis(4-aminophenyl)sulfone and
bis(4-aminophenyl) ether. Mixtures of these R1 values may
also be present. Preferably, Rl is an aromatic hydrocarbon
radical; the m-phenylene and bis(4-phenylene)methane radicals
are particularly preferred.
Methods for the preparation of polyimides by the
reaction of tetracarboxylic acids or their esters or
dianhydrides with diamines or diisocyanates are known in the
art. A somewhat different method, comprising the reaction of
a diamine with a tetracarboxylic acid bisimide of an amine
containing an electron-deficient radical, is disclosed in
U.S. Patent 4,578,470, the disclosure of which is
incorporated by reference herein.
When a dianhydride is used as the reactant, an
initial reaction to form a polymer containing predominantly
amic acid groups may occur at temperatures as low as about
25 C. In general, temperatures no higher than about lOO C
are required for polyamic acid formation. Substantially
complete conversion to polyimide generally takes place at
temperatures up to about 250 C, most often about 235-200 C.
It may, under certain circumstances, be desirable to obtain
and isolate the polyamic acid as an intermediate in polyimide
formation. If so, the reaction temperature should be
regulated accordingly. If polyamic acid formation is not
desired, the reaction mixture may simply be heated at a
temperature within the range of about 150-400 C, preferably
about 250-350 ~, until the reaction is complete.
Polymerization may be effected in solution in a
suitable solvent, typically a polar aprotic solvent such as
dimethylformamide, dimethylacetamide, dimethyl sulfoxide or
N-methylpyrrolidone. Aromatic hydrocarbons such as toluene
or xylene and hydroxylated or chlorinated aromatic
hydrocarbons such as phenol, m-cresol, chlorobenzene or o-
2~56S73
g
RD-20240
dichlorobenzene may also be employed as solvents, usually ln
the presence of a phase transfer catalyst. Mixtures of these
solvents may also be used. For polyimide formation, the use
of a mixture containing at least one solvent which forms an
S azeotrope with water (e.~., toluene), usually in an amount up
to about 20% by weight, may be advantageous. The reaction
may also be effected in bulk, typically by the use of
extrusion and/or wiped film techniques or the like.
Copolyimides containing more than about 40 mole percent of
units of formula I are generally most conveniently prepared
in bulk.
The mole ratio of diamine to dianhydride or
bisimide is generally between about 0.9:1 and about 1.2:1.
In general, polymers of higher molecular weight are obtained
by employing ratios equal to or very close to 1:1. As used
in th~s specification, the equivalent weight of a diamine,
dianhydride or bisimide is half its molecular weight.
It is advisable in some instances to include in the
reaction mixture chainstopping agents, typically
monofunctional aromatic amines such as aniline or
monoanhydrides such as phthalic anhydride. They are usually
present in the amount of about 1-5 mole percent of total
anhydride or amine constituents, as appropriate. Metal
carboxylates or oxygenated phosphorus compounds may also be
present as catalysts in accordance with U.S. Patents
4,293,683 and 4,324,882, the disclosures of which are
incorporated by reference herein.
The weight average molecular weights of the
polyimides containing structural units of formula I are
generally within the range of about 5,000-100,000 and most
often about 10,000-50,000.
As impact modifiers, there are employed according
to this invention graft polymers containing a
2~56S73
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RD-20240
polydiorganosiloxane first stage and at least one subsequent
~tage comprising structural units selected from the group
consisting of vinyl aromatic, meth(acrylonitrile), alkyl
~meth)acrylate, (meth)acrylamide and (meth)acrylic acid
units. By (meth)acrylonitrile is meant acrylonitrile and
methacrylonitrile. By alkyl (meth)acrylate is meant alkyl
esters of both acrylic acid and methacrylic acid. By
(meth)acrylamide is meant acrylamide and methacrylamide. By
(meth)acrylic acid is meant acrylic acid and methacrylic
acid.
In the description hereinafter, the product of
first-stage grafting will frequently be identified as the
"substrate" to clarify the fact that two discrete
polymerization stages are required for the preparation of the
impact modifier. The first stage includes the preparation of
a polydiorganosiloxane and optionally also of a vinyl
monomer-derived polymer, the latter being simultaneously
produced but being a separate polymer from the
polydiorganosiloxane. The second stage includes preparation
of another vinyl monomer-derived polymer grafted on the
substrate produced in the first stage.
The preferred subsequent stages for use when the
molten resin sustains a long residence time at high
temperatures (e.g., at least 5 minutes at 370 C average
molding barrel set) during molding are copolymers of either
acrylonitrile or methacrylonitrile. Examples are set forth
below. The ~meth)acrylamide and lower alkyl (meth)acrylate-
containing subsequen~ stages are generally preferably used at
temperatures of less than 300 C if the temperature is to be
maintained for long residence times. Some decomposition does
take place in some instances.
The grafted impact modifiers useful in the present
invention include both materials formed from bonding, i.e.,
Z(~5~S73
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RD-20240
grafting between functional sites in the first and subsequent
stages, and materials in which polymeric chains of the first
stage are entangled with those of the subsequent stage(s),
without chemical reaction.
The impact modifiers have a low Tg first stage
comprised of polydiorganosiloxane and at least one subsequent
stage, preferably having a higher Tg than the first stage.
Vinyl monomer-derived polymers having Tg~s below 25 C can
also be employed as subsequent stage materials provided there
are multiple subsequent stages. The subsequent stage is
preferably a copolymer of a ~meth)acrylonitrile with a vinyl
aromatic monomer. A vinyl aromatic monomer can also be used
as a homopolymer to form a subsequent stage. Other monomers
which can be used to form the subsequent stage include
~meth)acrylamide and alkyl (meth)acrylates such as methyl
~meth)acrylate.
The first stage material is typically an
- elastomeric crosslinked polydiorganosiloxane.
Polydiorganosiloxane elastomers and related impact modifiers
are disclosed in~U.S. Patents 2,891,920, 4,690,986,
4,748,215, 4,812,515 and 4,894,415; British Patent 1,590,549;
and European Patent Applications 105,226, 106,845 and
108,701, all of which are hereby incorporated by reference.
The polydiorganosiloxane elastomer in the first
stage preferably has a glass transition temperature below
-40 C. The polydiorganosiloxane elastomer may contain units
of the formulas
R2SiO3/2~ ~R2)2SiO~ ~R2)3SiO1/2 and SiO2
~O
wherein R2 represents a monovalent radical. It is not
essential that all of the above units be present in the
polydiorganosiloxane. The amounts of the individual
~C5~i573
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RD-20240
diorganosiloxane units may range from 0 to 10 units of
R2SiO3~2, 0 to 1.5 units of (R2)3SiO1/2 and 0 to 3 units of
SiO2 per 100 units of (R2)2SiO.
The R2 radical may be a monovalent hydrocarbon
radical having 1 to 18 carbon atoms or a corresponding
substituted hydrocarbon radical and is usually methyl or
phenyl. The hydrocarbon and substituted hydrocarbon radicals
are well known in the art and will not be described in
detail. In addition, it is preferred that a limited number
of R2 groups contain vinyl, mercaptoalkyl and/or allyl
radicals to facilitate the grafting of the subsequent stage
onto the elastomeric polydiorganosiloxane stage.
Particularly preferred for facilitating grafting are R2
groups containing acrylic and/or methacrylic radicals. The
ratio of radicals which facilitate grafting may range from
0.0001 to 0.6, preferably 0.001 to 0.02 per diorganosiloxane
unit in the elastomeric polydiorganosiloxane.
Vinyl monomers free from silicon can be polymerized
simultaneously with the polydiorganosiloxane in the first
stage, to form the subctrate. Preferred vinyl monomers
include styrene and mixtures of styrene and acrylonitrile
comprising about 50-99% styrene units. Other vinyl aromatic
monomers may also be used including methylstyrene,
vinyltoluene, vlnylnaphthalene, vinylanthracene and
halogenated styrenes or their derivatives. Other suitable
vinyl monomers include (meth)acrylic acids and
(meth)acrylates, such as methyl, ethyl, allyl and butyl
acrylate, methyl methacrylate and 2-ethylhexyl acrylate. The
monomers can be uqed alone or mixed.
Crosslinkers and graftlinkers may also be presen~,
preferably at a level of 0.5 to 3% of the vinyl monomer/
cross- or graftlinker mixture. Crosslinkers and graftlinkers
2C56S73
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RD-20240
include divinylbenzene, diallyl maleate and any of the other
divinyl or polyvinyl compounds known in the art.
The vinyl monomers, if any, preferably constitute
from 0% to 45% of the active polymerizable ingredients
forming the first stage, more preferably from 5 to 25%.
The ingredients for preparation of the first stage
are polymerized in aqueous emulsion. The initiator for the
vinyl monomers can be any organic soluble radical initiator,
such as azobisisobutyronitrile and an organic peroxide, e.g.,
benzoyl peroxide, dichlorobenzoyl peroxide or t-butyl
perbenzoate. Also suitable are water soluble radical
initiators such as the persulfates. Particle size, pH and
total solids measurements can be readily monitored at this
stage of the process. The particle size is controlled by
homogenization pressure, the number of passes through a
homogenizer, surfactant concentration and/or the composition
of the reaction ingredients.
The polydiorganosiloxane component of the first
stage substrate may be crosslinked by using any of the
conventional methods for crosslinking polydiorganosiloxane
chains. These methods include using silanes having 3 or 4
hydrolyzable alkoxy groups in the formation of the
polydiorganosiloxane chain or crosslinking the
polydiorganosiloxane chains through reactive groups on the
chains. These methods are well known ln the art. The
hydrolysis and condensation of the alkoxy silanes to form
crosslinked polydiorganosiloxanes and, optionally, the vinyl
polymerization to form the firs~ stage are preferably done in
an aqueous medium. Formation of the polydiorganosiloxane by
ring opening of a cyclic polydiorganosiloxane followed by
equilibration is an acid- or base-catalyzed reaction.
Surfactants such as dodecylbenzenesulfonic acid function to
catalyze the polydiorganosiloxane polymerization and to
- 14 - Z~s73
RD-20240
stabilize the latex formed, frequently eliminating the need
for separate catalysts and surfactants.
Preferably the polydiorganosiloxane polymerization
; is quenched by neutralization. This is accomplished by
adding a caustic solution such as sodium hydroxide, potassium
hvdroxide, potassium or sodium carbonate, sodium hydrogen
carbonate, triethanolamine or triethylamine. The pH of the
reaction solution may be raised from a level of 1 to 3 to at
least about 6.5 and preferably 6.5 to 9. The neutralization
step is preferred but not required.
After polymerization, which forms the first stage
substrate particles suspended in the aqueous medium as a
latex, the latex is preferably neutralized to a pH of at
least 7.5.
The foregoing process produces an elastomeric
polydiorganosiloxane substrate, optionally also containing
silicon-free polyvinyl chains. This substrate is the first
stage of the impact modifier employed in the present
invention. The next stage involves the graft polymerization
of at least one vinyl monomer, preferably a thermally stable
vinyl monomer, onto the elastomeric polydiorganosiloxane
substrate latex formed in the initial polymerization.
Suitable monomers for grafting to form one or more
subsequent stages on the elastomeric polydiorganosiloxane
first-stage substrate are vinyl aromatlc monomers such as
styrene; the side-chain-substituted styrenes, e.g., a-
methylstyrene; the nuclear-alkylated styrenes, e.g.,
vinyltoluene; the halogenated styrenes such as a-
bromostyrene; acrylonitrile and/or methacrylonitrile; and
mixtures of these monomers. Other monomers include the loweralkyl ~meth)acrylates such as methyl methacrylate, ethyl
acrylate, butyl acrylate, n-butyl methacrylate and
(meth)acrylamide; (meth)acrylic acid and (meth)acrylonitrile.
- 15 - Z~S~573
RD-20240
Mixtures of said monomers may be employed. The subsequent
stage also preferably contains on a weight basis from 0.5 to
3%, based on active ingredient, of a crosslinking agent such
as divinylbenzene. Other crosslinking agents include tne
same divinyl, silicon-free monomers used as crosslinkers and
graftlinkers in the first stage.
Preferably, monomer mixtures of styrene and
acrylonitrile are employed for the subsequent stage(s) with
the acrylonitrile content of these mixtures preferably being
0% to 50% based upon the two components and the styrene
content being from 50% to 100%. The styrene may be replaced
entirely or in part by one or more other vinyl aromatic
monomers and the acrylonitrile may be replaced entirely or in
part by methacrylonitrile.
The impact modifiers are made by polymerizing a
subsequent stage of from 1% to 70% by weight of vinyl monomer
or monomer mixture in the presence of from 30% to 99% of the
elastomeric polydiorganosiloxane first-stage substrate.
Preferably from 20% to 50% by weight of vinyl monomer or
monomer mixture is polymerized in the presence of 50% to 80%
of the substrate. One or more intermediate subsequent s~ages
can be positioned between the substrate and the subsequent
grafted stage. Such intermediate stages and the methods of
making them are known in the art. See, for example, the
parent Wang application and the clted background art which
have been incorporated by reference. The procedure for
making the intermediate stage(s) generally follows the
procedure set forth for making the final stage.
The graft polymerization to form the final stage
may be carried out in a conventional manner, preferably by
emulsion polymerization. The conventional polymerization
additives, e.g., free radical initiators, chain texmination
agents, dispersants and the like, may be used for the graft
2~5~573
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RD-20240
polymerization. In such a process, the monomers are
uniformly added to the substrate particles, which should be
present in latex form, and are then polymerized at from 30 C
t.o lOO C, preferably from 40 C to 80 C. Conventional
S initiators, e.g., organic water-soluble peroxides,
percarbonates, persulfates, perborates, redox catalysts,
benzoyl peroxide, dicumyl peroxide or di-t-butyl peroxide or
azobisisobutyronitrile, are typically employed. The
initiators are used in concentrations of from 0.1% to 5% by
weight. Anionic, cationic, amphoteric and non-ionic
emulsifiers, such as alkyl sulfates, may also be employed to
further stabilize the latex.
In the drawings, Figure 1 is a graph comparing the
impact resistance of a commercially available polyetherimide
lS with the impact resistance of compositions of this invention
at 343 C for 2.66 minutes.
Figure 2 is a similar graph for a lO minute period.
Figure 3 is a graph similar to Figure l for a
temperature of 400 C.
Figure 4 is a graph similar to Figure 3 for a
period of lO minutes.
In the examples that follow, all parts and
percentages are by weight unless otherwise indicated. The
physical test results obtained from the materials prepared in
the examples are set forth in the tables following the
examples and in the figures. The polyetherimide employed was
a commercially available product prepared ~rom bisphenol A
dianhydride and m-phenylenediamine; it had an intrinsic
viscosity of .45 dl./gm. in CHC13 at 25 C. The
divinylbenzene had an activity of 55%, the remainder being a
mixture of isomers. The term "monomer", when used to define
a diorganosiloxane unit, includes polymerizable cyclic
2~5~i573
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~D-20240
trimers and cyclic tetramers. The specimen test procedures
used in establishing data were as follows:
The notched Izod impact test utilized a 1/8" x
1/2" x 2.5" specimen and was run according to
the procedure set forth in ASTM D-256. The
Dynatup test utilized drop dart energy to
fracture a 1/8" x 4" disk specimen with
results in (in.-lb.). The heat deflection
temperature ( F) was run using a 1/8" x 1/2" x
5" specimen according to the procedure set
forth in ASTM D-648. The results were
converted to C.
Elca~ 1
This example illustrates one embodiment of the
silicone-based impact modifiers employed according to this
invention and how to prepare the same.
A reaction vessel, equipped with a stirrer, reflux
condenser, thermometer, one feed port and a heating mantle
was charged with 69.35 parts deionized water, 0.36 parts
dodecylbenzenesulfonic acid and 29.38 parts of a monomer
mixture which contains 25.88 parts of a polydiorganosiloxane-
forming mixture containing, by weight, 84.7 parts
octamethylcyclotetrasiloxane, 9.8 parts tetraethoxysilane,
1.4 parts methacryloxypropyltriethoxysilane, 4 parts 2,4,6,~-
tetramethyltetravinylcyclotetrasiloxane and 3.5 parts of a
vinyl monomer mixture containing, by weight, 98 parts styrene
and 2 parts divinylbenzene. The above mixture was stirred
and homogenized by passing the filtered solution through a
Microfluidics Corp. MlOOT homogenizer under a pressure of
7600-8400 psi. and returning the mixture to the reactor.
'
;2~5~73
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RD-20240
The temperature was raised to 75 C via the heating
mantle while the mixture was stirred under a nitrogen purge.
Stirring was continuous throughout the reaction from this
point on. At the temperature of reaction, 75 C, purging was
ceased, though a blanket of inert atmosphere was maintained.
Subsequently, 0.18 part of a 2% aqueous solution of potassium
persulfate (KPS) was charged to the vessel. Aqueous
potassium persulfate was charged incrementally in aliquots of
equal parts at the end of hours 1, 2, 3 and 4 for a total
addition of 0.90 parts of the 2% aqueous KPS solution. The
reaction temperature was maintained at 75 C for two
additional hours after the final charge of the aqueous KPS
solution. The reaction was allowed to slowly cool under
ambient conditions and was maintained at room temperature for
a total of 18 hours in the stirred reactor. After 18 hours
equilibration time at 20-30 C, 0.21 parts of an aqueous
mixture containing, by weight, 10 parts of a surfactant,
GAFAC RE610 ~GAF Corporation, Wayne, NJ) and 90 parts
deionized water was charged to the reactor. The resulting
latex was then titrated to a pH of 7.5 with a 15% aqueous
solution of potassium carbonate.
The stirred, titrated latex was heated to 75 C via
a heating mantle under a nitrogen purge to carry out the
graft polymerization of a vinyl-bas~ed stage. At 75 C, a 2%
aqueous solution of potassium persulfate was charged
batchwise to the vessel. The amount of potassium persulfate
was 0.5 part based on the graft monomer mixture.
The addition of 30 parts of a monomer mixture
containing 73 parts styrene, 24 parts acrylonitrile and 3
parts divinylbenzene was started and continued uniformly over
3 hours. The reaction temperature was maintained at 75 C for
3 hours after the addition of the monomer feed. The reaction
was allowed to cool under ambient conditions.
- 19 - Z~5~S73
RD-20240
To a separate reactor equipped as described above
was charged an aqueous solution containing one part magnesium
sulfate and 99 parts deionized water. The volume of the
aqueous magnesium sulfate solution was two times the volume
of latex to be isolated. The temperature of the reactor was
raised to 85 C via a heating mantle. The latex from the
first reactor was filtered and added to the reactor
containing the stirred magnesium sulfate solution in order to
flocculate the latex. The mixture was filtered via a
Tolhurst centrifuge, rinsing the polymer with copious amounts
of deionized water. The polymer powder was dried for 3 days
in a vacuum oven at 60 C at -25 in. Hg.
~am~lQ 2
The procedure and formulation of Example 1 were
used except that the 30 part feed monomer mixture of the
subsequent grafting stage was 73 parts styrene, 24 parts
methacrylamide and 3 parts divinylbenzene.
Exampl~ 3
The procedure and formulation of Example 1 were
used except that the feed monomer mixture of the subsequent
grafting stage was 99 parts styrene and 1 part
divinylbenzene.
F xam~
The polydiorganosiloxane/polystyrene latex
substrate was prepared in accordance with Example 1 but
differed in that two subsequent grafting stages were
produced. For each grafting stage, 15 parts of vinyl monomer
2C5~;S73
-- o --
RD-20240
mixture was graft polymerized in emulsion onto the substrate
latex which corresponded to 70 parts of the
polydiorganosiloxane/polystyrene substrate. During the first
stage, lS parts of a monomer mixture comprised of 99 parts
S ethyl acrylate and 1 part divinylbenzene was fed uniformly
over 1-1/2 hours. At the end of this stage, a second feed
containing 99 parts styrene and 1 part divinylbenzene was
uniformly fed over a period of 1-1/2 hours.
Ex~mpl~ S
The procedure and formulation of Example 4 were
used except that the feed monomer mixture of the first
grafting stage was 99 parts butyl acrylate and 1 part
lS divinylbenzene.
The procedure and formulation of Example 4 were
used except that the substrate vinyl monomers (1.26 parts)
comprised a mixture containing 98 parts styrene and 2 parts
divinylbenzene. Two grafting stages were employed as in
Example 4, except that the first was prepared from lS parts
of a monomer mixture containing 99 parts styrene and 1 parts
divinylbenzene, and the second from lS parts of a mixture
containing 49 parts styrene, S0 parts methacrylonitrile and 1
part divinylbenzene.
ExanU~ 7
The procedure and formulation of Example 4 were
used except that the 15 part monomer mixture of the second
2C!5~573
- 21 -
RD-20240
grafting stage was 49 parts styrene, 50 parts acrylonitrile
and 1 part divinylbenzene.
~_am~1e 8
The procedure and formulation of Example 1 was used
except that the 30-part monomer mixture of the first grafting
stage was 98 parts methyl methacrylate and 2 parts
divinylbenzene.
E~ampl~ ~
The procedure and formulation of Example 1 were
used except that the grafting stage was prepared from 23.1
parts of a monomer mixture containing 59.6 parts methyl
methacrylate, 37.4 parts methacrylonitrile and 3 parts
divinylbenzene, the latter being charged to the monomer feed
at the beginning of the last hour thereof.
E~lmDle_~n
The procedure and formulation of Example 9 were
used except the feed monomer mixture of the grafting stage
comprised 60.9 parts methacrylic acid, 36.1 parts
acrylonitrile and 3 parts divinylbenzene. The divinylbenzene
was present at the beginning of the monomer feed. In
addition the surfactant, GAFAC RE610, was omitted and the pH
of the substrate latex remained at about 1.5 during the
subsequent stage.
2(~5S573
- 22 -
RD-20240
E Yam~ 1 1
The procedure and formulation of Example 10 were
used except that the feed monomer mixture of the grafting
stage contained 96.7 parts methacrylamide and 3.3 parts
divinylbenzene. The monomer mixture was dissolved in
deionized water as an 18% solution to facilitate a uniform
addition to the substrate latex.
E~amples 12-22
The polydiorganosiloxane-based impact modifiers
prepared according to the procedures and formulations of
Examples 1-11 were each melt blended at concentrations of 10
weight percent with polyetherimide molding resin in the
following manner: A dry blend of 90 weight percent of
polyetherimide and 10 weight percent impact modifier (SIM)
was tumble mixed on a jar shaker to give a homogeneous
dispersion. The well-mixed dry blend was then extruded on a
Welding Engineers 28 mm. twin-screw extruder under typical
conditions for the polyetherimide molding resin. The
extrudate was pelletized, dried and injection molded into
test specimens on a 77 ton Battenfeld molding machine.
Tables 1-3 summarize the mechanical properties of
Examples 12-22 as a function of the vinyl polymer stage(s).
Examples of both single and multi-stage impact modifiers are
included. In all cases the presence of the
polydiorganosiloxane-based impact modifier yielded an
improvement in the impact strength of the base polyetherimide
molding resin (see the control in Table 3).
- 23 - 2~5~5~3
RD-20240
Tahle ~
E~ le 12 13 14 15 16
SIM example 1 2 3 4 5
First grafting stage
composition:
Styrene 73 73 99 -- --
Ethyl acrylate -- -- -- 49.5 --
Butyl acrylate -- -- -- -- 49.5
Acrylonitrile 24 -- -- -- --
Methacrylamide 24 -- -- --
Divinylbenzene 3 3 1 0.5 0.5
Second grafting stage
-composition:
Styrene -- -- - 49.5 49.5
Divinylbenzene -- -- -- 0.5 0.5
Notched Izod (25 C), 4.3 1.8 1.3 3.0 1.9
ft.-lb./in., 10 mil
Dynatup (30 C), ft.-lb.:
Total energy 37.8 8.8 -- 6.1 7.5
Energy at maximum load 29.6 6.3 -- 4.2 4.2
Molding conditions:
Average barrel set ( C) 371 343 371 371 371
Mold surface temp. ~ C~ 114 107 114 114 114
Z(~5S5~3
-- 2q --
RD-20240
~able 2
Exam~le _ 17 1819 20 21 22
SIM example 6 7 B 9 10 11
Fir~t grafting ~tage
compoqition:
Styrene 49.5 -- -- -- -- --
Methyl methacrylate -- -- 98 59.6 -- --
Ethyl acrylate -- 49.5 -- -- -- --
Acrylonitrile -- -- -- -- 36.1 --
Methacrylonitrile -- -- -- 37.4 -- --
Methacrylamide -- -- -- -- -- 96.7
methacrylic acid -- -- -- -- 60.9 --
Divinylbenzene 0.5 0.5 2 3 3 3.3
Second grafting stage
compo~ition:
Styrene 24.5 24.5 -- -- -- --
Methacrylonitrile 25 -- -- -- -- --
Acrylonitrile -- 25 -- -- -- --
Divinylbenzene 0.50.5 -- -- -- --
Notched Izod ~25-C), 2.3 2.7 4.3 ~.5 1.3 1.5
ft.-lb./in., 10 mil
Dynatup ~30-C), ft.-lb.:
Total energy 39.4 7.8 49.9 42.2 8.9 7.2
Energy at maximum load 38.1 4.5 33.4 37.2 7.2 3.6
Molding condition~:
Average barrel ~et ~ C) 371371 366 343 343 343
Mold qurface temp. (-C) 114114 94 107 107 107
- 25 - X~S~S73
RD-20240
Tah 1 ~? 3
ExamDle _ 23 24 25 26 27Control
SIM example 1 1 1 8 8 --
Weight % 5 7 10 5 10 0
Notched Izod
(25 C), (ft.-
lb./in.):
10 mil 1.5 2.8 4.3 1.9 4.6 0.6
40 mil 6.3 9.2 10.7 -- -- --
Dynatup
(30 C), (ft.-
lb.):
Total energy 46.2 93.7 41.7 47.0 49.9 4.7
Energy at
maximum load 39.8 39.9 37.6 42.0 33.4 4.4
Dynatup
(O C), ft.-lb.:
Total energy 28.0 46.4 40.5 -- -- 2.75
Energy at
maximum load 24.0 42.0 33.2 -- -- 2.6
Heat deflection
temp. (264 psi)
( C) 185.6 182.5 185.1 -- -- 189.5
Molding
conditions
average barrel
set ( C) 343 343 343 366366 343
Mold surface
temp ( C~ 121 121 121 93.3 93.3 121
E~LUi~L 23-27
The multi-stage graft polymers of Examples 1 and 8
were each melt blended at concentrations of 4-10 wei~ht
- 26 - Z~5~573
RD-20240
percent with polyetherimide molding resin as described in
Examples 12-22.
~m~le 28
s
The ~ulti-stage graft polymers of Examples 1 and R
were each melt blended at 10 weight percent with
polyetherimide molding resin as described in Examples 11-22
except that, after extrusion, the dried pelletized blends
were molded on a 28 ton Engle molding machine under various
barrel set temperatures and cycle times. The samples were
molded into 1/8 inch Izod bars with an ASTM standard part
mold set on the 28 ton Engle molder. The mold surface
temperature was 138-C. Determination of barrel capacity
indicated that approximately six Izod bars must be molded to
exhaust the barrel of material. Molding bars in a sequence
at specified temperature and cycle time resulted in Izod bars
subjected to molding barrel melt temperatures for increasing
time periods up to bar 7. Equilibrium residence time was
reached at bar 7, hence the resin for bars 7-16 was in the
melt at a specified temperature for a maximum cycle time.
Two mold barrel temperatures were examined (343 C and 399 C)
in combination with two different equilibrium mold cycle
times (2.66 minutes and lO minutes). The ductilities of the
polyetherimide modified with two different
polydiorganosiloxane-based impact modifiers under various
molding set conditions are illustrated in Figures 1-4.
~ nele 24
The procedure and formulation of Example 1 were
used except that the 23.1 parts of a subsequent grafting
stage monomer mixture were emulsion graft polymerized onto
- 27 2~5~S73
.
RD-20240
76.9 parts of the polydiorganosiloxane/polystyrene substrate.
~he 23.1 parts feed monomer mixture contained 73 parts
styrene, 24 parts acrylonitrile and 3 parts divinylbenzene.
E~amrl~ 30
The procedure and formulation of Example 29 were
used except that the addition of surfactant was omitted and
the pH of the polydiorganosiloxane/polystyrene substrate
latex remained at 1.5.
The procedure and formulation of Example 1 were
used except that the addition of surfactant was omitted and
the pH of the polydiorganosiloxane/polystyrene substrate
latex remained at 1.5.
E~m~L& 32
The procedure and formulation of Example 1 were
used except that 45 parts of the monomer mixture were
emulsion graft polymerized onto 55 parts of the
polydiorganosiloxane/polystyrene substrate. The 45 parts
monomer mixture contained 73 parts styrene, 24 parts
acrylonitrile and 3 parts divinylbenzene.
E~ample 3~-37
The impact modifiers of Examples 1 and 29-32,
having various substrate to grafting stage weight ratios,
were each melt blended at 10 weight percent with the
polyetherimide molding resin as described in Examples 12-22.
- 28 - Z~SS573
RD-20240
The results are summarized in Table 4. The enhancement in
impact stren~th was maintained over a broad range of such
ratios. As the substrate to grafting stage weight ratio
decreased the weight percent polydiorganosiloxane in the
S blend decreased.
Tahl e 4
E mple _ _ 33 34 35 36 37
SIM example 29 30 1 31 32
Sub~trate/grafting qtage76.9/23.1 76.9/23.170/30 70/30 55/45
ratio ~3.33) (3-33) ~2.33)~2.33)(1.22)
Notched Izod
~25 C) ft.-lb./in.,
10 mil 3.8 3.5 3.5 4.0 2.8
Dynatup
~30-C), ft.-lb:
Total energy 41.5 39.2 44.7 42.4 30.5
Energy at maximum load 33.3 33.4 41.3 37.9 18.5
Molding conditions:
Average barrel set ~ C) 343 343 371 371 3~3
Mold surface temp. (-C) 107 107 110 110 107
Exampl~ 38
The procedure and formulation of Example 1 were
used except that the 30 parts feed monomer mixture of the
grafting stage was 87 parts styrene, 10 parts acrylonitrile
and 3 parts divinylbenzene.
1 5 Exan~Q~
The procedure and formulation of Example 1 was used
except that the 30 parts feed monomer mixture of the grafting
- 29 - 2~5S573
RD-20240
stage was 48.5 parts styrene, 48.5 parts acrylonitrile and 3
parts divinylbenzene.
Exampl e.c 40-43
s
The impact modifiers of Examples 1, 3, 38 and 39
were each melt blended at 10 weight percent with the
polyetherimide molding resin as described in Examples 12-22.
The mechanical property results are summarized in Table 5.
Impact strength increased with the addition of acrylonitrile
up to a maximum near the azeotropic mixture for the
polymerization of these two monomers.
ZCSS573
RD-20240
Tabl~ ~
Examele 40 41 42 43
SIM example 3 38 1 39
Subsequent stage
composition (parts by
wt.):
Styrene 99 87 73 48.5
Acrylonitrile 0 lO 24 48.5
Divinylbenzene l 3 3 3
Notched Izod (25'C), 1.27 2.1 3.8 2.5
ft.-lb./in, 10 mil
Dynatup (30 C), ft.-
lb.:
Total energy -- 29.9 40.5 36.7
Energy at maximum load -- 20.2 34.6 31.5
Dynatup (-30 C), ft.-
lb.:
Total energy -- 37.2 44.3 34.6
Energy at maximum load -- 34.2 38.2 31.3
Molding conditions:
Average barrel set
( C) 371 371 371 371
Mold surface temp.
( C) 113 117 117 117
Example 44
The procedure and formulation of Example 1 were
used except that the diorganosiloxane monomer mixture for the
substrate latex contained 89.6 parts
octamethylcyclotetrasiloxane and 10.37 parts
tetraethoxysilane.
- - : . ... . i -
- 31 - 2~5S573
RD-20240
E~am~L~ 45
The procedure and formulation of Example 1 were
used except that 25.88 parts of diorganosiloxane monomer
mixture contained 88.3 parts of octamethylcyclotetrasiloxane,
10.26 parts of tetraethoxysilane and 1.4 parts of
methacryloxypropyltriethoxysilane.
E~ample 46
The procedure and formulation of Example 1 were
used except that 25.88 parts of diorganosiloxane monomer
mixture contained 85.9 parts of octamethylcyclotetrasiloxane,
9.97 parts of tetraethoxysilane and 4.1 parts of 2,4,6,8-
tetramethyltetravinylcyclotetrasiloxane.
E~a~l~S 47-4~
The impact modifiers of Examples 1 and 44-46 were
each melt blended at a 10% by weight level with
polyetherimide molding resin according to the procedure
described in Examples 12-22. The resultant data are set
forth in Table 6.
- 32 - 2~5S573
~D-20240
Table 6
ExamDle 47 _48 49 50
SIM example
1 44 45 46
Siloxane monomer
mixture (parts by
weight)
Octamethylcyclotetra-
siloxane 84.7 89.6 88.3 85.9
Tetraethoxysilane 9.8 10.37 10.26 9.97
2,4,6,8-Tetramethyl-
tetravinylcyclotetra-
siloxane 4.0 0.0 0.0 4.1
Methacryloxytriethoxy-
silane 1.4 0.0 1.4 0.0
Notched Izod ~25 C),
ft.-lb./in., 10 mil 4.3 -- 2.7 3.2
Dynatup (30 C), ft.-lb:
Total energy 46.7 -- 38.4 41.3
Energy at maximum load 44.8 -- 35.8 35.1
Dynatup (-30 C), ft.-
lb.:
Total energy 42.4 -- 39.9 45.0
Energy at maximum load 34.6 -- 37.8 39.6
Molding conditions:
Average barrel set ( C) 371 -- 371 371
Mold surface temp ~ C) 117 -- 117 117
~3m~Q
The procedure and formulation of Example 31 were
used except that after homogenization the reaction mixture
was heated to 85 C and 0.23 parts of a 2% aqueous solution of
potassium persulfate was charged to the vessel. The
remaining~0.88 parts of the potassium persulfate solution was
.. , , . ~ . .
- 33 - Z~5~573
RD-20240
fed uniformly over 3 hours. The reaction temperature was
quenched to 4 C with an ice/water bath at the end of 3 hours.
The temperature was maintained at 4 C for 5.5 hours. At the
end of the 5.5 hours equilibration time the temperature was
raised to 75 C for the subsequent stage reaction according to
the procedure and formulation described in Example 1.
Ex~mDl~ 51
The procedure and formulation of Example 50 were
used except that the equilibration temperature was maintained
at 40 C for 17 hours.
~m~
The procedure and formulation of Example 31 were
used except that after the 6 hour simultaneous vinyl
polymerization at 75 C, the polydiorganosiloxane/polystyrene
substrate latex was quench cooled with an ice/water bath to
22-C. The equilibration temperature was maintained at 22 C
for 17 hours prior to the grafting stage.
~m~
The procedure and formulation of Example 1 were
used except that the polydiorganosiloxane/polystyrene
substrate was prepared by a slow addition technique. To a
reaction vessel, as described in Example 1, was char~ed 69.35
parts of distilled water and 0.36 parts of
dodecylbenzenesulfonic acid. No homogenization step was used
in this procedure. The solution was purged for 30 minutes
with nitrogen and heated to 75 C via a heating mantle. The
purge was stopped and 0.18 parts of a 2% aqueous solution of
- 34 - Z~S~5~3
RD-20240
potassium persulfate was charged. The addition of 29.38
parts of monomer mixture containing 25.88 parts of a
polydiorganosiloxane mixture and 3.5 parts of a vinyl monomer
as in Example 1 was started and continued uniformly over 4
hours. Aqueous potassium persulfate was charged
incrementally at the end of hours 1, 2, 3 and 4 in aliquots
of 0.18 part. At the end of the monomer feed, the substrate
latex was heated an addition 4 hours at 75 C. The subsequent
stage reaction was in accordance with the procedure and
formulation of Example 1.
~xAm~l~ 5~-58
Blends of 90% polyetherimide molding resin and 10%
polydiorganosiloxane-based impact modifier of Example 1 and
Examples 50-53 were each prepared as described in Examples
12-22. Table 7 illustrated the performance of the modifier
in the matrix resin as a function of the synthetic procedure.
Tabl~ 7
Example 54 55 56 57 58
SIM example 1 50 51 52 53
Notched Izod (25 C),
ft.-lb./in., 10 mil 4.0 3.5 3.3 1.7 3.8
Dynatup (30 C), ft.-
lb.:
Total energy 42.4 43.6 42.7 32.9 39.3
Energy at maximum load 37.9 40.3 39.9 29.1 34.7
Molding conditions:
Average barrel set ( C)371 371 371 371 371
Mold surface 111 111 111 111 112
temperature ( C)
~0
- 35 -
2~573
RD-20240
F~YamP1 e S9
The procedure and formulation of Example l were
used except that 0.2 part potassium persulfate based upon lO0
parts of vinyl monomer mixture was charged to the reactor for
the subsequent stage. The potassium persulfate was charged
as a 2% aqueous solution.
~xa~pl~ 60
The procedure and formulation of Example S9 were
used except that an additional 0.2 part potassium persulfate
based on lO0 parts of vinyl monomer mixture was charged at
the end of the vinyl monomer feed. Again the potassium
lS persulfate was added as a 2% aqueous solution.
EY~,1 e 61
The procedure and formulation of Example 60 were
used except that O.l part potassium persulfate based on lO0
parts vinyl monomer mixture was charged prior to the feed of
the monomer mixture for the subsequent stage and an
additional O.l part potassium persulfate based on lO0 parts
vinyl monomer mixture was charged at the end of the feed.
Examp 1 e,62
The procedure and formulation of Example l was used
except that an alternate free radical initiating system was
used for the subsequent stage. The initiating system
contained 0.2 part t-butyl hydroperoxide and O.l part sodium
formaldehyde sulfoxylate based on lO0 parts monomer feed in
the subsequent stage and l ppm. ferrous II sulfate based on
- 36 - Z~5S5~3
RD-20240
the total amount of impact modifier latex prior to isolation.
The polymerization temperature for the subsequent stage
reaction was 40 C. Ferrous sulfate was charged to the
reaction mixture as a 1 x 10-2 aqueous solution. Using
S separate feed pumps, a 0.1% aqueous solution of sodium
formaldehyde sulfoxylate was uniformly charged over 3.5
hours, a 0.2% aqueous solution of t-butyl hydroperoxide was
charged uniformly over 3.5 hours and a monomer mixture of 74
parts styrene, 24 parts acrylonitrile and 3 parts
divinylbenzene was charged over 3 hours. The reaction was
heated at 40 C for a total of 7 hours.
~xamplf~ 6~
The procedure and formulation of Example 60 were
used except that an alternate redox free radical initiating
system was used for the subsequent stage. The redox system
contained 0.4 part sodium persulfate and 0.4 part sodium
metabisulfite based on 110 parts of subsequent stage monomer
feed stock and 0.2 ppm. ferrous sulfate based on the total
amount of impact modifier latex prior to isolation. At 40 C,
a 1 x 10-2% aqueous solution of ferrous sulfate was charged to
the substrate latex. Immediately following the charge of
ferrous sulfate, 2% aqueous solutions of sodium persulfate
and sodium metabisulfite were each charged batchwise. The
monomer feed of 73 parts styrene, 24 parts acrylonitrile and
3 parts divinylbenzene was then begun and continued uniformly
for over 3 hours.
Exam~l~ 64-6q
Blends of 90% polyetherimide molding resin and 10%
polydiorganosiloxane-based impact modifier which had the
: 37 Z~5S573
RD-20240
subsequent stage initiated with different free radical
sources (Examples l, 59-63) were each prepared as described
in Example 12-22. The results of the impact performance are
summarized in Tables 8-9.
X~S~i573
- 38 -
RD-20240
:ca~
ExamDle 64 65 66
SIM example 1 59 60
Initiating system* KPS KPS KPS
Notched Izod, (25 C),
ft.-lb./in., 10 mil 9.3 4.6 3.9
Dynatup (30 C),
ft.-lb.:
Total energy 46.7 42.4 40.2
Energy at maximum load 44.2 36.1 31.5
Dynatup (-30 C),
ft.-lb.:
Total energy 42.4 44.4
Energy at maximum load 34.6 39
Molding conditions:
Average barrel set
( C) 371 371 371
Mold surface
temperature ( C) 117 117 117
*KPS = Potassium persulfate, TBHP-90 = t-butyl hydroperoxide,
SFS = sodium formaldehyde sulfoxylate, FS = ferrous sulfate,
NAPS = sodium persulfate, NAMBS = sodium metabisulfite.
- 39 - Z~5S573
RD-20240
Tahle 9
.
Example 67 68 69
SIM example 61 62 63
Initiating system* KPS TBHP-90 NaPS
SFS NaMBS
FS FS
Notched Izod, (25 C),
ft.-lb./in., 10 mil 4.2 2.5 3.0
Dynatup (30 C), ft.-
lb.
Total energy 41.5 40.3 3.0
Energy at maximum load 33.5 31.8 29.4
Dynatup (-30 C), ft.-
lb.
Total energy 42.1 34.5 32.6
Energy at maximum load 33.3 26.2 22.4
Molding conditions
Average barrel set
( C) 371 3~1 371
Mold surface
temperature ( C) 117 117 117
*KPS ~ Potassium persulfate, TBHP-90 ~ t-butyl hydroperoxide,
SFS = sodium formaldehyde sulfoxylate, FS = ferrous sulfate,
NAPS ~ sodium persulfate, NAMPS - sodium metabisulfite.
Fya~l~ ~O
The procedure and formulation of Example 1 were
used except that the styrene and divinylbenzene were omitted
from the initial 29.38 parts first stage monomer mixture.
This mixture contained only siloxane monomers. The
incremental addition of potassium persulfate was also omitted
during the first stage.
Exa~pl~ 71
The procedure and formulation of Example 1 were
used except that the initial 29.33 parts first stage monomer
2C`~i~57~
- 40 -
RD-20240
mixture contained 3.5 parts of a vinyl monomer mix~ure
containing by weight 73.5 parts styrene, 24.5 parts
acrylonitrile and 2 parts divinybenzene.
Exam~ 72-74
The polydiorganosiloxane-based impact modifiers
prepared according to the procedures and formulation of
Examples 2, 72 and 73 were each melt blended at
concentrations of 10 weight percent with polyetherimide
molding resin according to the method described in Examples
12-22. The results are summarized in Table 10.
Z~5~;573
- 41 -
RD-20240
Table 1 0
Example _ 72 73 74
SIM example 1 70 71
First stage monomer
mixture:
A. Siloxane monomer25.88 29.38 25.88
Mixture
B. Vinyl monomer 3.5 -- 3.5
mixture
Styrene 98.0 -- 73.5
Acrylonitrile -- -- 24.5
Dinvinylbenzene 2.0 -- 2.0
Notched Izod (25 C),5.4 4.3 3.8
ft.-lb./in. 10 mil
Dynatup (30 C), ft.-
lb.:
Total energy 43.0 38.4 16.0
Energy at maximum load 37.2 30.2 7.5
Molding conditions:
Average barrel set ( C) 371 371 371
Mold surface 126 126 126
temperature ( C)
