Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2Q1071~
O.Z. 0050/40641
Thermopla~tic molding compositions based on polyphenvlene
ethers and aromatic vinyl polymers
The present invention relates to thermoplastic
molding composition~ containing as es~ential components
S (A) 9.9 89.9% by weight of a polyphenylene ether,
~B~ 10-90% by weight of an aromatic vinyl polymer and
(C) 0.1-5% by weight of a low molecular weight compound
which contains at least one Si-O-C group ~nd at
least one epoxy, nitrogen-containing or sulfur-
containing group.
MoldLng compositions based on polyphenyleneethers and high impact polystyrene and polysiloxanes are
known from DE-A-3 118 629. Their stress crack resistance
is not wholly 3atisfactory.
&erman Application P 37 41 670. 7 describes
mixtures of polyphenylene ethers, impact modifiad poly-
styrene and a silane-containing polymer of styrene and
silane-containing methacrylate.
According to EP-B-107 835~ alkanesulfonates can
influence the stress crack resistance of blends of
polyphenylene ethers and impact modified polystyrene.
However, di~advantages are the poor heat distortion
resi~tance and the poor self-color. In addition, the
stress crack resistance and toughness are still in need
of improvement.
EP-A-182 163 discloses mixtures of polyamide,
polyphenylene ether and a silane as processing aid.
Disadvantages of these polyamide molding compositions are
their high water regain, their low dimensional stability
30 after processing and their unfavorable color quality.
DE-A-3 619 225 discloses molding compositions
based on aromatic vinyl polymers and a polyphenylene
ether which has been modified with maleimide. It turns
out that the stress crack resistance is still in need of
improvement.
It i~ an ob~ect of the present invention to
provide thermoplastic molding compositions based on a
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polyphenylene ether and an aromatic vinyl polymer which
have good mechanical propertiQs ~uch as toughne~ , good
distortion resiQtanCe, good stress cracX resi~tance and
~ood color quality.
5We have found that this ob~ect i~ achieved by the
thermoplastic molding compositions defined above.
We have also found pre~erred embodiments as set
forth in the cubclaim~, a process for producing the
molding compositions, and the use thereof for producing
10moldings and semi-finished products.
The molding compositions according to the present
invention contain a3 essential components from 9.9 to
89.9, preferably from 19.9 to 79.9, in particular from
29.7 to 69.7, % by weight of A, from 10 to 90, preferably
lSfrom 20 to 80, in particular from 30 to 70, % by weight
of B and from 0.1 to 5, preferably from 0.1 to 4, in
particular from 0.3 to 3, % by weight of C, all the
weight %ages being based on the total amount of A, B and
C.
20Suitable polyphenylene ethers A are known per ~e;
they are prepared in a conventional manner by oxidative
coupllng from phenols which are di~ubstituted Ln the
ortho po~ition by alkyl, alkoxy, chlorine or bromine
(c~. US Patents 3,661,848, 3,378,505, 3,306,874,
253,306,875 and 3,639,656). The alkyl or alkoxy groups,
which preferably contain from 1 to 4 carbon atoms but no
~-dispo~ed tertiary hydrogen atom, may in turn be sub-
stituted by chlorine or bromine. Suitable polyphenylene
ether~ are for example poly-2,6-diethyl-1,4-phenylene
30ether, poly-2-methyl-6-ethyl-1,4-phenylene ether, poly-
2-methyl-6-propyl-1,4-phenyleneether,poly-2,6-dipropyl-
1,4-phenylene ether, poly-2-ethyl-6-propyl-1,4-phenylene
ether, poly-2,6-dichloro-1,4-phenylene ether and poly-
2,6-dibromo-1,4-phenylene ether, copolymers such as those
35which contain 2,3,6-trimethylphenol, and also polyblends.
Preference is given to poly-2,6-dimethyl-1,4-phenylene
ether. The polyphenylene ethers generally have an
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3 - O.Z. 005~/40641
:Lntrinsic vi~co~ity of 0.5 to 0.9 dl/g, measured in
chloroform at 25C.
It is normally advantageous to u~e the polypheny-
lene ethers mentioned~ In some cases, however, it will
5pro~e advantageous to use modified polyphenylene ethers.
Such polyphenylene ether~ incorporate for example a
compound containing a C-C double or triple bond and a
carboxyl group or a derivative thereof, such as maleic
acid, maleic anhydride, fumaric acid, maleimide or the
10acyl chloride of trimellitic anhydride. Such modified
polyphenylene ethers are known for example from NO-A-
87/00540.
~he aromatic vinyl polymer B can be any customary
homopolymer or copolymer of styrene. Customarily, the
15molecular weights of the useable styrene polymers (weiqht
average M~) are within the ranqe from 150,000 to 300,000.
SuLtable styrene polymers are prepared in a known manner
from, predominantly, styrene but also from ring- or
sidechain-C1-C4-alkylated styrenes such as ~-methylstyrene
20or p-methylstyrene, by bulk, solution or suspension
polymerization (cf. Ullmanns Encyklopadie der Technischen
Chemie, Volume 19, pages 265-272, Verlag Chemie, Weinheim
1980).
The aromatic vinyl polymer is preferably an
25impact modified grad~.
Impact modification can be achieved by admixing
small amounts, preferably 2-20~ by weight, based on the
aromatic vinyl polymer, of a rubber. Suitable rubbers are
olefin rubbers such as EPDM rubber, acrylate rubber~ and
30polymers of a con~ugated diene such as butadiene or
i~oprene. The diene polymers may have been partially or
completely hydrogenated. The rubber should have a glass
tran3ition temperature of below 0C, measured by the
method of R.H. Illers and ~. Breuer, Kolloid Zeitschrift
35176 (1961), llO. It is possible to use customary rubbers
such as polybutadiene rubber, acrylate rubber, styrene-
butadiene rubber, hydrogenated styrene-butadiene rubber,
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acrylonitrile-butadiene rubber, polyisoprene rubber,
ionomer~, styrene-butadiene block copolymer~, including
AB, ABA, ABAB tapered block copolymers, star block
copolymers and similar isoprene block polymer~, and in
particular (partially~ hydrogenated block copolymers as
described in EP-A-62 283. Such synthetic rubbers are
known to those skilled in the art.
Impact modification can preferably also be
effected by preparing the aromatic vinyl polymer in the
presence of minor amounts, for example in the presence of
2-20% by weight, ba~ed on the aromatic vinyl polymer, of
a rubberlike polymer of the abovementioned type, for
example a rubberlike polymer based on a con~ugated diene,
with or without an acrylate rubber, to prepare a HIPS
type product. Suitable for this purpose are rubberlike
polymers based on butadiene, eg. styrene-butadiene
polymer~, polybutadiene and butadiene-styrene block
copolymers.
The~e ~pecific high impact styrene polymers are
80 familiar from the prior art and usage that no further
explanation i8 required here (cf. Ullmanns Encyklopadie
der techni~chen Chemie, 4th edition, Volume 19, pages
272-295, Verlag Chemie GmbH, 1980).
The compound C is known per se. It has a low
molecular weight, containing not more than 10, preferably
not more 3, in particular not more than one Si atom. It
is customary to use a compound of the general formula I
OR2
R~ (CH2) -X
oR3
where
R1, R2 and R3 are each independently of the other~ alkyl,
cycloalkyl or aralkyl of up to 20 carbon atoms, in
particular methyl, ethyl, or propyl,
X is a radical which contains a group containing a culfur
atom or preferably an epoxy group or a group containing
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a nitrogen atom, and
n i5 an integer from 1 to 8, preferably from 1 to 3.
Preference i~ given to compound-~ which contain no
olefinic CC double bond.
Examples are the compounds having the structures
indicated in the Table below. The Table also indicates
the names used.
Nbme Str~Nre
~ lxql~Qyltrim~thoxysila~e ~(C~)3Si(OCH3)3
~-AIl~qn~pyltriethoxysilane ~N(C~33Si(OC~)3
N-~-B~i~x~hyl-7_~1nqp~Qyl-
trimE~xysilane H2N(C~ (C~)3Si(OCH3)3
( ( (N'-,9-h~i~l)-N-~l~lli~ E~N(cH2)2NEl(cE~)2NH(cHz)3si(a~H3)3
ethyl)-~a~sop~Iyl)trimetho~y-
silane
4,5-Dihy~1-[3-(triethoxysilyl)- ~ - C~
prcQyl]imic~ole l l
N N - (C~)3Si(OE~)3
CH
~-~erc~pt~pyltrimethoxy~llane HS(C~)3Si(OCH3)3
~-Glycidylo~xpyltri ~ - /0
silane c~-cH~o~o(o~)3si(ocH3)3
Such compound~ are commercially available, for
example from H~ls Troisdorf AG under the name Dynasilan.
In addition to these essential components the
molding compo~itions according to the present invention
may contain as component D customary reinforcing
materials such as glass ball~, mineral fibers, whiskers,
aluminum oxide fibers, mica or in particular glasq fibers
in amounts of from 10 to 40 parts by weight, based on 100
parts by weight of the total amount of component~ A, B
and C.
The glass fibers can be made of E-, A- or C-
glas~. They may be ~ized with an adhe~ion promoter. Theirdiameter is in general within the range from 6 to 20 ~m.
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Xt i8 possible to use not only strandlike continuous
fibers (rovings) but also chopped glass fibers from 1 to
10 mm, preferably from 3 to 6 mm, in length or ultrashort
511ass fibers from 0.05 to 1.5 mm in length.
In ~ome cases, it has proved advantageous to use
no reinforcing materials D.
In addition to the components mentioned, the
molding compositions according to the present invention
may contain further substances such as customary heat and
light stabilizer~, lubricants, mold release agent~ and
colorants such as dyes and pigments in customary amounts.
Other possibilities are flame retardants, in particular
phosphorus-containing ones, such a-q phosphoric esters,
phosphinic esters and phosphine oxides. Good flame
lS inhibition is achieved with triphenyl phosphate and
triphenylphosphine oxide.
The thermopla3tic molding compositions according
to the present invention are advantageously prepared by
mixing the components at 200-320C, preferably 250-300C,
in customary mixing apparatug, eg. kneaders, Banbury
mixers and single-screw extruders, preferably in a twin-
screw extruder. To obtain a very homogeneous molding
composition, it is nece3sary to ensure thorough mixing,
which can be achieved in a conventional manner. The
residence times are in general within the range from 0.5
to 30 minutes, preferably from 1 to 5 minutes. The order
of addition of the components can be varied; selected
components can be premixed, or else all the components
may be mixed together at one and the ~ame time.
Component C can be incorporated in the mixture
with or without an inert solvent or diluent, eg. toluene
or a low-boiling hydrocarbon such as hsxans. If a solvent
or diluent is used, a uniform distribution of C in the
molding composition is quickly produced in some cases. In
such a case the solvent or diluent is then removed by
suitable measures, for example the employment of reduced
pressure.
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It may be mentioned that the molding compositions
according to the present invention may also contain
minor amount3 of reaction products of the components.
The molding compositions according to the present
invention are highly ~uitable for producing moldings of
any kind, for example by in~ection molding or extrusion.
They can also be used for producing sheets and semi-
finished products for thermoforming or blow molding.
The molding compositions and the molded articles
produced therefrom have a balanced ratio of thermal and
mechanical properties. Among the~e, they po~sess good
heat distortion resistance, multiaxial toughness, stress
crack re~i~tance and color quality.
EXAMPLES 1 ~O 4 AND COMPARATIYE TESTS 2* AND 4*
The Examples and Comparative Tests were carried
out using the following components:
Component A
A (1): Poly-2,6-dimethyl-1,4-phenylene ether having an
intrinsic viscosity of 0.55 dl/g, measured in
CHCl~ at 25
A (2)s same a~ A(1), except the relative viscosity is
0.65 dl/g.
Component B
B (1): High impact polystyrene 576 ~ (BASF) containing
8% by weight of butadiene and having a melt flow
index of 5.5 g/10 min., measured by German
Standard Specification DIN 53 735 at 200C under
a load of 5 kg.
B 12): High impact polystyrene 586 G from BASF AG,
containing 10% by weight of butadiene and having
a molt flow index (200C/5 kg) of 4 g/10 min.
Component C
C (1): y-Aminopropyltrimethoxy~ilane
C (2)s (((N'-~-Aminoethyl)-N-~-aminoethyl)-~-amino-
propyl)trimathoxysilane
C (3)s ~-Glycidyloxypropyltrimethoxysilane.
~he components indicated in Table 1 were each
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melted together with 0.08 kg of tris~nonylphenyl) phos-
phite and 0.15 kg of polyethylene at 280~C in a 2-shaft
extruder, homogenized, mixed and then granulated.
The parameters mentioned in Table 2 were deter-
mined on te~t specimens in~ection molded at 280C as
ollows:
the Vicat temperature Vicat B by German Standard Specifi-
cation DIN 53 460;
the penetration energy PE by German Standard Specifica-
tion DIN 53 443.
The stres~ crack resistance was determined byGerman Standard Specification DIN 53 449 Part 1 on test
specimens immersed in isopropanol for one hour. The
indication characteristics used were the tensile ~trength
and the breaking extension as defined in German Standard
Specification DIN 53 455.
TABLE 1
Examples and M~oeup of the mDlding co~x~ition
Co~x~ative Iype hnLunt [kg] ~ hK~nt [kg] Type h~nt [kg]
~8
_
1 A~ 4.0 ~ 5.9 C~ 0.1
2 ~ 3.5 B2 6.3 C3 0.2
2* A2 3.5 E~ 6.3 - - )*
3 ~ 5.0 E~ 4.a5 C~ 0.15
4 A2 6.5 E~ 3.25 C~ 0.25
4* ~ 6.5 E~ 3.5 - -
)* 2* contains 0.2 kg of aL ~ lfonate R30 fmnE~er AG
;201(~71~
- 9 - O. Z . 0050/40~41
TABLE 2
-
Exa~ple~ an~ Prop~tie~
Ca~arative Vicat B PE [Nm] Crack limit ~ [~
Test~ [C] Tensile str~gth E3realci~ ext~sion
132 40> 500 ~ 500
2 125 38> 500 > 500
2~ 122 32 400 -390
3 145 48> 500 ~ 500
4 157 65> 5CO > 500
4~ 152 12 90 80
