Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
-1- 8CN-3227
POLYPHENYLENE ETHER RESIN COMPOSITIONS CONTAINING
POLYOLgFI~ IN HIGH ~IOU~
ACKGROUND OF THE INVENTION
The polyphenylene ethers are known as high
perfonmance engineering thermoplastic possessing high melt
viscosities and so~tPning points which makes them useful
fox many applications where resistance to high temperatures
i5 desired. These materials are described in many publica-
lion including ~ay~ ~.5. Patent Nos. 3,306,874 and
3,306,875 and 5tamatoff, U.S. Patent Nos. 3,~57;357 and
3,257,358.
Certain properties of the polyphenylene ethers
are undesirable for some uses however. For example,
parts molded or otherwise shaped from polyphenylene ether
resins are somewhat brittle due to poor impact strength
and are thus prone to fracturing or shattering. Also,
the relatively high melt viscosities and softening points
of the polymer sometimes cause difficulties in processing.
Because of the high temperatures required to melt the
resin and achieve good flow, special equipment is often.
necessalyO Moreover, the resin is more susceptible to
degradation and discoloration at sueh elevated temperatures
It is now well known that properties of the
pol~phenylene ether resins can be altered materially by
blending with other resin materials. For instance, Cize~
discloses compositions o polyphenylene ether resin and
~2~3~
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o
polystyrene which are characterized by proved properties
both during and aster molding. Sue U.S. PatEnt No. 3,383,435.
It is also known that whey polyethylene, a polyol~fin
resin, is incorporated in polyphenylene ether resins and
compositions, melt flow and other properties are substantially
Lmproved. The amount ox polyethylene which can by incorporated
has usually been very limited however, due to delEminatlo~
and brittleness in the resultant molded article~O - -
.
It has recently been found that larger amounts of
polyolefin resin can be successfully incorpoxated in apolyphenylene ether resin if certain elastomeric triblock
copolymers are also preset in the compositions.
Such compositions, which possess good melt flow
and impact resistance properties, are described in U.S.
Patent No. 4,1~6,055 to Lee, Jr.
INTROD~CTlON TO TOE INVENTION
It has now been discovered that poly~lefin can
be compatibly admixed in large amount with polyphenylene
ether resin if a diblock or radial teleblock copolymer of
20 an alkenyl aromatic compound and a conjugated diene is
also present. The diblock copolymer and radial teleblock
copolymer each act as a "compatibilizer" for the polyolefin,
enabling it to be homogeneously hlended in substantial
proportion with polyphenylene ether.
Because of the larger amount of polyolefin in
the compositions, properties are upgraded. Moreover,
parts molded from the composition do not exhibit the
delamination and/or brittleness which normally accompanies
use of large amounts ox polyolefin.
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The polyphenylene oxide resins useful in
accordance with the present compositions are, as previously
indicated, individually well known and readily available.
where are, howevex, various preferrer composition components.
The preferred polyphenylene ethers are homo- and
copolymers of the formula:
10 .,
,o-~L
n
wherein Q, Q', Q" and Qn', are independently select d from
the group consisting of hydrogen, hydrocarbon radicals,
halohydrocarbon radicals having at least two carbon atoms
between-the halogen atom and the phenol nucleus, hydrocar-
bonoxy radicals and halohydrocarbonoxy radicals having at
least two carbon atoms between the halogen atoms and the
phenol nucleus, and Q', Q" and Q-'l in addition may be
halogen with the proYiso that Q and Q' are preferably free
of a tertiary carbon atom; and n represents the total number
25 ox monomer residues and is an integer of at least 50.
specially preferred is poly(2,6-dimethyl-1,4-
phenylene) ether.
The diblock A-B copolymers of an alkenyl aromatic
compound, A, and a conjugated diene, B, are derived from
alkenyl aromatic compounds having the formula:
~21~ 7
8CN-3227
o Cal, CHR2
R~ R3
wherein Rl and R2 are selected from the group consisting of
hydrogen and lower alk~l or alkenyl groups of from 1 to 6
carbon atoms; R3 and R4 are elected from the group consistlng
of chloro, bromo, hydrogen, and lower alkyl groups of from
1 to 6 carbon atoms; and R5 and R6 are selected from the
group consisting of hydrogen and lower alkyl an alkenyl
group of prom 1 to 6 carbon atoms or R5 and R6 may be
concatenated together with a hydrocarbyl group to form a
~aphthyl group.
Specific example of alkenyl aromatic monomers
include styrene, bromostyrene, chlorostyrene, a-methyl-
styrene, vinylxylene, divinylbenzene, vinyl naphthalene,
and ~inyl-toluene.
these are copolymerized with the polydiene, B,
which is derived from, for example, 1,3-butadiene, 2-methyl-
1,3 butadiene and 1,3-pentadieneO
the A-B block copolymers can be, made by following
procedures which are well known in the art or described
in the patent literature, for example, in U.K. Ratent No.
1,145/923. These polymers are also commercially available,
eOg~, from Shell Chemicals under the trade designation I-
Shellvis 50. Preferably, these are diblock oopolymers
in which the aliphatic unsaturation, as in block
B, has been reduced by hydrogenation. Such copolymers
will preferably have the a~erage-unsaturation of rubber
37
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block B decreased to less than 20%, and more pre$erably
less than 10~ of its original value.
ydrogenation can be curried out using a varieky
S of hydrogenating catalysts, such as ~ick~l ox Kieselguhr,
Raney nickel 9 CDpper chromite, molybdenum sulfide, and
finely divided platinum or other noble metals on a carrier.
- Hydrogenation can be conducted at vixtually any
desired temperature or pressure, eOg., ranging from
atmospheric to 3,000 p.s.i.g. and from 75 to 600F.,
for up to 24 hours. Such procedures are well known.
The term "radial teleblock copolymer" deines
a well known class of materials. These are commercially
available or can be made by following procedures
described in the patent literature, such as U.S. Patent
Nos. 3,595,942 and 4,090,996.
By way of illustration, a conjugated diene such
as butadiene and a vinyl aromatic compound suoh as styrene
are co-polymerized in the presence of an organometallic
compound such as n-butyl lithium to produce a copolymexic
product containing chains terminating in an active metal
atom, e.g., lithium. These copolymers are reacted with a
coupling agent having more than one active site capable of
reacting with and replacing the terminal metal atom on the
polymer chains. The resulting copolymer is characterized
by a structure comprised of a centrally located coupling
agent from which extend in various directions several
chains of the copolymer. If hydrogenation is desired,
the polymer can then be hydrogenated in the known
manner, for example, by procedures descried in DeVault,
U.SO Pakent NoO 3,696,088.
I k
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The polyolefin is usually polyethylene, poly~ropylene~
polyisobutylene, copolymers of ethylene and propylene as well
as co~olymers of ethylene and organic esters such as ethylene
vinyl ace~a~e, ethylene ethyl acrylate~ ethylene methyl
5 acrylate~ and so forth. These are commercially vailable
or are otherwise prepared from the known teachings.
The polyphenylene ether resin and compatibilizer
can be present in wiaely ranging proportions, but normally
are present in weight amounts of from 4:1 to 1:2 of poly-
- phenylene ether: compatibilizer (diblock copolymer or
radial teleblock copolymer).
For best effectiveness, the polyolefin should be
included in amounts ox at least about 20 and more usually
from 30 to 60 parts by weight based on the combined total
of polyphenylene ether, compatibilizer and polyolefin.
Other ingredients can al50 be included in the
compositions. These can be selected from among additives
commonly employed with plastics, such as fillers and/or
reinforcements, strengthening fibers, plasticizers, colorants,
dyes, flame retardants, antioxidants,pigments, mold release
agents, and so forth. Minor but effective amounts are
25 selected normally ranging from 1 to 50 parts by weight
of the total composition weight.
The compositions can be prepared using any of the
known procedures In one such procedure, a preblend on
3~ the ingredients is formed, extruded on a single or twin
screw extruder at a temperature of between 400 and 550'F.,
chopped, cut or ground to smaller size and injection mclded
at temperatures sf from 400 to 500~F. tQ desired shape
and size.
,~,~'3~D O
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The composition, due to the larger amount of polyolef in
which can be homogeneously incorporated, i5 characterized by
better melt f low and is more easily processed
The invention is illustrated in the examples which
follow. These are intended as best embodiments ox the
invention and are not to be construed as limiting the
invention in any way. All parts are by weight
EXAMPLES 1-3
he ingredients noted below were blended on a mixer
and the resultant blend is extruded on a twin screw 28 mm
Werner-Pfleiderer extruder or single screw Brabender extruder
at 4500F., and molded at an injection temperature of 400F.,
into test bars. The test bars were evaluated for tensile
strength and elongation, with the results shown in the Table.
For purposes of comparison f other compositions
not in accordance with the invention were also prepared,
molded and tested under the same conditions. These are
also noted in the Table below.
8 - 8CN-3227
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8CN-3227
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It can he seen that tensile elongation~is markedly
improved in the case of compositions 1, 2 and 3 versus control
blends A and B, while the tensile strength is substantially
maintained
he above mention d patenks and/or publications
are incorporated herein by reference. Obviously other
modifications and variations of the present invention are
possible in light of the above teachings. For example,
instead of poly (2,6-dimethyl-1,4-phenylene) ether there
can be substituted poly(2,6-dimethyl-co-2,3,6-trimethyl-
1,4-phenylene) ether copolymer. In addition, conventional
reinox~ements and/or fillers, flame retardants, stabilizers,
colorants, impact modifiers can be used in conventional
amounts. Xt is~therefore,to be understood that changes
may be made in the particular embodiments of the invention
described which are within the full intended scope of the
invention as defined by the appended claims.
