Polymer compositions comprise a polyphenylene ether resin and a plasticizer of the formula ##STR1## wherein X is selected from the group consisting CH.sub.2, O and S; Y is different from X and is selected from the group consisting of CH.sub.2, O, CO, S, SO and SO.sub.2 ; Ar is an aromatic ring; Z.sup.1 and Z.sup.2 are individually selected from the group consisting of alkyl, alkoxide, aryl, aryl oxide, nitrile and nitro groups; R is hydrogen or an alkyl group; m is from 0 to 3; n is from 1 to about 10; and a and b are individually from 0 to 4; provided that both X and Y are not simultaneously oxygen. The compositions may further include a polystyrene resin, for example, a rubber-modified polystryene resin.

FIELD OF THE INVENTION 
The present invention relates to polymer compositions comprising a 
polyphenylene ether resin and a plasticizing compound, which compositions 
exhibit an advantageous combination of properties including good flow or 
processability and good mechanical properties. 
BACKGROUND OF THE INVENTION 
Polyphenylene ether resins are well known in the art and exhibit a 
desirable combination of chemical, physical and electrical properties over 
a wide temperature range. This combination of properties renders 
polyphenylene ether resins suitable for use in a broad range of 
applications. Often times, polyphenylene ether resins are blended with 
other resins including various types of polystyrene resins in order to 
improve the processability or other properties of the polyphenylene ether 
resins and to increase their fields of application. 
For example, the Cizek U.S. Pat. No. 3,383,435 discloses blends of 
polyphenylene ether and one or more styrene resins having improved 
properties. Additionally, the Lee U.S. Pat. No. 3,819,761 discloses 
compositions comprising a polyphenylene ether resin and a rubber modified 
polystyrene resin, which compositions provide molded articles having 
improvements in impact resistance, surface appearance and solvent 
resistance. 
It is also known to blend polyphenylene ether resins with one or more 
additional additives for improving the processability, moldability and/or 
other properties of the resins. For example, Japanese Reference No. 
60-258252 discloses polyphenylene ether resin compositions having improved 
moldability and which are prepared by mixing a polyphenylene ether resin 
with an aromatic compound. The compositions may further include one or 
more styrene resins. 
Owing to the increasing use of polyphenylene ether resin compositions in 
various applications, there is a continuing demand for polyphenylene ether 
resin compositions having improved chemical and/or mechanical properties. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide 
polyphenylene ether resin compositions having improved properties. It is a 
more specific object of the invention to provide polyphenylene ether resin 
compositions having improved flow or processability. It is an additional 
object of the invention to provide polyphenylene ether resin compositions 
having improved flow or processability together with good mechanical 
properties. It is a further object of the invention to provide such 
polyphenylene ether resin compositions which may be used in various forms 
and applications. 
These and additional objects and advantages are provided by the 
compositions according to the present invention which comprise a 
polyphenylene ether resin and a plasticating compound which improves the 
flowability of the polyphenylene ether resin. The plasticizing compound is 
of the formula 
##STR2## 
wherein X is selected from the group consisting CH.sub.2, O and S; Y is 
selected from the group consisting of CH.sub.2, O, CO, S, SO and SO.sub.2 
; Ar is an aromatic ring; Z.sup.1 and Z.sup.2, are individually selected 
from the group consisting of alkyl, alkoxide, aryl, aryl oxide, halogen, 
nitrile and nitro groups; R is hydrogen or an alkyl group; m is from 0 to 
3; n is from 1 to about 10; and a and b are individually from 0 to 4; 
provided both X and Y are not simultaneously oxygen. The compositions may 
optionally include a styrene resin. It has been discovered that the 
compositions according to the present invention exhibit improved 
flowability together with good mechanical properties. The compositions 
according to the present invention may be easily formed into sheet 
materials, foamed materials, shaped articles or the like, and therefore 
are suitable for use in a variety of applications. 
These and additional objects and advantages provided by the compositions 
and products according to the present invention will be more fully 
apparent in view of the following detailed description.

DETAILED DESCRIPTION 
The polymer compositions according to the present invention comprise a 
polyphenylene ether resin and a plasticizing compound which improves the 
flowability of the compositions. Polyphenylene ether resins are well known 
in the art and are generally of the formula 
##STR3## 
wherein each R.sup.1 is individually selected from the group consisting of 
halogen, alkyl, aryl and alkoxy groups, each q is individually from 0 to 4 
and p is at least 20. Preferably, p is at least 50. When R.sup.1 comprises 
an alkyl group, an aryl group or an alkoxy group, the group suitably 
contains from 1 to about 12 carbon atoms. 
The polyphenylene ether polymers suitable for use in the present invention 
are well known in the art and may be prepared by any of a number of 
processes known in the art from corresponding phenols or reactive 
derivatives thereof. Examples of polyphenylene ether resins and methods 
for their production are set forth in the Hay U.S. Pat. Nos. 3,306,874 and 
3,306,875, in the Stamatoff U.S. Pat. Nos. 3,257,357 and 3,257,358, and in 
U.S. Pat. No. 4,935,472 of S. B. Brown et al, all of which are 
incorporated herein by reference. Throughout the specification and claims 
the term "polyphenylene ether resin" includes unsubstituted polyphenylene 
ether polymers, substituted polyphenylene ether polymers, polyphenylene 
ether copolymers and blends thereof. 
Preferred polyphenylene ether polymers adapted for use in the present 
invention include, but are not limited to, 
poly(2,6-dimethyl-1,4-phenylene)ether; poly(2,3,6-trimethyl-1,4-phenylene) 
ether; poly(2,6-diethyl-1,4-phenylene)ether; 
poly(2-methyl-6-propyl-1,4-phenylene)ether; 
poly(2,6-dipropyl-1,4-phenylene)ether; 
poly(2-ethyl-6-propyl-1,4-phenylene)ether; 
poly(2,6-dilauryl-1,4-ph-enylene)ether; 
poly(2,6-diphenyl-1,4-phenylene)ether; 
poly(2,6-dimethoxy-1,4-phenylene)ether; 
poly(2,6-diethoxy-1,4-phenylene)ether; 
poly(2-methoxy-6-ethoxy-1,4-phenylene)ether; 
poly(2-ethyl-6-stearyloxy-1,4-phenylene)ether; poly(2,6- dichloro 
-1,4-phenylene)ether; poly(2-methyl-6-phenyl-1,4-phenylene)ether; 
poly(2,6-dibenzyl-1,4-phenylene)ether; poly(2-ethoxy-1,4-phenylene)ether; 
poly(2-chloro-1,4-phenylene)ether; poly(2,6-dibromo-1,4-phenylene)ether; 
poly(3-bromo-2,6-dimethyl-1,4-phenylene)ether, copolymers thereof and 
mixtures thereof, and the like. Particularly preferred polyphenylene oxide 
polymers for use in the compositions of the present invention include 
poly(2,6-dimethyl-1,4-phenylene) ether, 
poly(2,3,6-trimethyl-1,4-phenylene)ether, blends of these polymers and 
copolymers including units of 2,3,6-trimethyl-1,4-phenylene ether and 
units of 2,6-dimethyl-1,4-phenylene ether. Examples of such polymers and 
copolymers are also set forth in U.S. Pat. No. 4,806,297. 
The polymer compositions according to the present invention further contain 
a plasticizing compound which improves the flowability of the 
compositions. The plasticizing compound is of the formula 
##STR4## 
wherein X is selected from the group consisting CH.sub.2, O and S; Y is 
selected from the group consisting of CH.sub.2, O, CO, S, SO and SO.sub.2 
; Ar is an aromatic ring; Z.sup.1 and Z.sup.2 are individually selected 
from the group consisting of alkyl, alkoxide, aryl, aryl oxide, halogen, 
nitrile and nitro groups; R is hydrogen or an alkyl group; m is from 0 to 
3; n is from 1 to about 10; and a and b are individually from 0 to 4; 
provided both X and Y are not simultaneously oxygen. Preferably, when any 
of Z.sup.1, Z.sup.2 and R are carbon-containing groups, they individually 
contain from 1 to 12 carbon atoms. In a preferred embodiment, m is zero or 
1 and n is from 1 to 5. In an additionally preferred embodiment, m is 1 
and n is 1. In a further preferred embodiment, X is oxygen or CH.sub.2. As 
is demonstrated in the examples set forth herein, suitable plasticizing 
compounds of the above-noted formula include, but are not limited to, 
1,3-diphenoxybenzene, 4,4,-bis(2,6-dimethylphenoxy)diphenyl sulfone, 
4,4,-diphenoxybenzophenone, low molecular weight copolymers of xylene and 
formaldehyde (commercially available as Methylon 75200 from General 
Electric Company), and low molecular weight, unsubstituted polyphenylene 
ether polymers, for example, polyphenylene ether polymers having from 
about 5 to less than about 20 phenylene ether repeat units and having an 
intrinsic viscosity of not greater than about 0.3. 
The polymer compositions of the present invention include the plasticizing 
compound in an amount sufficient to improve the flowability of the 
compositions. Preferably, the plasticizing compound is included in an 
amount from about 0.1 to about 30 parts by weight, and more preferably 
from about 1 to about 15 parts by weight, per 100 parts by weight of the 
polyphenylene ether resin. In many instances, the plasticizing compound 
improves the flowability of the compositions while maintaining an 
advantageous combination of good mechanical properties in the 
compositions. 
In one embodiment of the present invention, the polymer composition may 
further include a polystyrene resin. Various polystyrene resins are 
suitable for use in the compositions of the present invention. The 
polystyrene resins contain units derived from a styrene compound of the 
following formula: 
##STR5## 
wherein R.sup.2 and R.sup.3 are selected from the group wherein R 
consisting of lower alkyl or alkenyl groups of from, for example, 1 to 6 
carbon atoms and hydrogen, each R.sup.4 is selected from the group 
consisting of halogen, hydrogen and lower alkyl or alkenyl groups of from, 
for example, 1 to 6 carbon atoms and q is an integer of from 0 to 5. 
Throughout the specification and claims the term "polystyrene resin" 
includes unsubstituted polystyrene, substituted polystyrene and 
polystyrene copolymer resins. Suitable polystyrene resins include, but are 
not limited to, polystyrene homopolymers including atactic polystyrenes, 
halogenated polystyrenes, poly-alpha-methylstyrenes, 
poly-paramethylstyrenes, styrene-acrylonitrile copolymers, styrene-maleic 
anhydride copolymers, styrene-butadiene copolymers, rubber-modified 
polystyrenes and the like, and mixtures thereof. These polystyrene resins 
and their methods of preparation are well known in the art. In a preferred 
embodiment, the polystyrene resin which is included in the polymer 
compositions of the present invention comprises a rubber-modified 
polystyrene resin. Rubber-modified polystyrene resins are well known in 
the art and may contain one or more rubber modifiers selected from diene 
rubbers, acrylate rubbers, natural rubbers or the like. 
When the polymer compositions according to the present invention contain 
the polystyrene resin, the compositions may contain from about 5 to about 
95 parts by weight of the polystyrene resin and from about 95 to about 5 
parts by weight of the polyphenylene ether resin, based on 100 parts by 
weight of the combined polystyrene resin and polyphenylene ether resin. 
Preferably, the compositions contain from about 20 to about 80 parts by 
weight of the polystyrene resin and from about 80 to about 20 parts by 
weight of the polyphenylene ether resin, per 100 parts by weight of the 
polystyrene and polyphenylene ether resins combined. 
The compositions according to the present invention may be produced 
according to any of the methods known in the art. For example, the 
plasticizing compound may be added to the polyphenylene ether resin prior 
to or during melt compounding. Additionally, the styrene resin, if 
included, may be combined with the polyphenylene ether resin either prior 
to, during or subsequent to addition of the plasticizing compound thereto. 
Additionally, the compositions according to the present invention may 
include one or more conventional additives including, but not limited to, 
stabilizers, antioxidants, fillers, flame retardant agents and the like. 
Owing to the improved flowability of the polymer compositions of the 
present invention, the compositions may be formed into various products. 
For example, the polymer compositions of the invention may be formed into 
sheet materials or foamed materials, or be injection molded into shaped 
articles. 
The following examples demonstrate various polymer compositions according 
to the present invention. Unless otherwise indicated, all parts and 
percentages set forth in the examples are by weight. 
EXAMPLE 1 
In this example, a series of compositions were prepared by dissolving one 
gram of poly(2,6-dimethyl-1,4-phenylene) ether with a measured amount of a 
plasticizing compound in 10 ml of chloroform. The chloroform was 
evaporated and the glass transition temperatures of the resulting mixtures 
were measured using a Perkin-Elmer DSC-4 differential scanning 
calorimeter. The specific plasticizing compounds employed, the parts by 
weight of the plasticizing compound employed per 100 parts by weight 
polyphenylene ether resin and the measured glass transition temperatures, 
Tg in .degree. C., are set forth in Table I. 
TABLE I 
______________________________________ 
Plasticizing 
Compound 
Placticizer Concentration (phr)/Tg (.degree.C.) 
______________________________________ 
DPB.sup.1 
5.3/171 10.4/155 15.1/140 
20.4/123 
25.7/120 
LMWPPE.sup.2 
5.2/184 11.0/158 15.4/153 
20.4/139 
26.8/116 
DMPDPS.sup.3 
5.1/192 11.3/176 15.4/167 
20.3/161 
25.1/151 
DPBP.sup.4 
5.0/176 10.0/169 15.0/165 
20.0/131 
25.0/123 
Methylon.sup.5 
4.9/190 9.9/179 16.2/164 
20.8/158 
25.6/150 
______________________________________ 
.sup.1 DPB is 1,3Diphenoxybenzene 
.sup.2 LMWPPE is a low molecular weight unsubstituted polyphenylene ether 
polymer commercially available from Monsanto 
.sup.3 DMPDPS is 4,4Bis(2,6 dimethylphenoxy)diphenyl sulfone 
.sup.4 DPBP is 4,4Diphenoxyobenzophenone 
.sup.5 Methylon is a low molecular weight copolymer of xylene and 
formaldehyde commercially available from General Electric Company. 
The results set forth in Table I demonstrate that there is a substantially 
linear relationship between the concentration of plasticizing compound and 
the measured glass transition temperature, thereby indicating that the 
polyphenylene ether resin and the plasticizing compound are miscible at 
the tested concentrations. 
EXAMPLE 2 
In this example, polymer compositions A-D comprising a polyphenylene ether 
resin (PPE) and a plasticizing compound according to the present invention 
were prepared. A comparative composition E containing only polyphenylene 
ether resin was also prepared. The respective amounts of polyphenylene 
ether resin and plasticizing compound, and the type of plasticizing 
compound included in each composition are set forth in Table II. The 
compositions were prepared by extruding the polyphenylene ether resin and 
the plasticizing compound, or in the case of composition E only the 
polyphenylene ether resin, through a Werner-Pfleiderer ZSK-30 twin screw 
extruder at 300.degree. C. The resulting pellets were injected molded into 
ASTM test specimens using a 75 ton Newbury injection molding machine at 
315.degree. C. The tensile strength and elongation of the samples were 
measured according to ASTM D638, while the notched Izod impact of the test 
samples was measured according to ASTM D256. The glass transition 
temperatures of the samples were measured according to the method 
described in Example 1. Finally, the spiral flow of the samples was 
measured using the 75 ton Newbury injection molding machine at 350.degree. 
C. The results of these measurements are also set forth in Table II. 
TABLE II 
__________________________________________________________________________ 
Composition 
A B C D E 
__________________________________________________________________________ 
Plasticizing Compound 
Type DMPDPS DPB DPBP Methylon 
-- 
Parts by weight 
50 30 75 75 -- 
PPE, Parts by weight 
950 970 1500 1500 100% 
Tg, .degree.C. 
195 193 186 192 210 
Tensile strength (psi) 
Yield 12,700 12,400 12,200 12,400 11,600 
Break 8,700 8,500 9,000 9,000 9,900 
Elongation, % 
Yield 7.4 7.2 6.5 6.4 6.9 
Break 33.8 31.4 9.0 9.7 44.7 
Notched Izod 
.74 .74 .50 .59 .78 
Impact (ft-lb/in) 
Spiral Flow, 
19.1 18.5 20.5 19.8 15.8 
315.degree. C. (in) 
__________________________________________________________________________ 
The results set forth in Table II demonstrate that compositions A-D 
according to the present invention exhibit improved flowability, as 
indicated by spiral flow, as compared with comparative composition E which 
did not contain the plasticizing compound according to the present 
invention. Additionally, although compositions A-D exhibited lower glass 
addition temperatures as compared with comparative composition E, 
compositions A-D generally exhibited a good combination of tensile 
strength and elongation and notched izod impact properties. 
EXAMPLE 3 
In this example, compositions F-I comprising a polyphenylene ether resin, a 
high impact polystyrene resin (HIPS) and a plasticizing compound according 
to the present invention were prepared. Comparative composition J 
containing only the polyphenylene ether resin and the high impact 
polystyrene resin was also prepared. The respective amounts of resins and 
plasticizing compound, and the type of plasticizing compound included in 
each composition are set forth in Table III. The resins and the 
plasticizing compound, or in the case of comparative composition J only 
the resins, were extruded through the Werner-Pfleiderer ZSK-30 twin screw 
extruder at 270.degree. C. The resulting pellets were injection molded 
into ASTM test specimens using the Newbury injection molding machine at 
275.degree. C. The glass transition temperature, tensile strength and 
elongation and notched Izod impact of the samples were measured according 
to the procedures described in Examples 1 and 2. Additionally, the spiral 
flow of the samples were measured using the Newbury injection molding 
machine at 275.degree. C. The results of these measurements are also set 
forth in Table III. 
TABLE III 
__________________________________________________________________________ 
Composition 
F G H I J 
__________________________________________________________________________ 
Plasticizing Compound 
Type DMPDPS DPB Methylon 
Methylon 
-- 
Parts by weight 
50 30 75 75 -- 
PPE, Parts by weight 
600 600 900 750 60% 
HIPS, Parts by weight 
350 370 525 475 40% 
Tg, .degree.C. 
148 143 135 146 155 
Tensile strength (psi) 
Yield 10,000 10,100 9,900 10,100 10,500 
Break 8,900 8,500 8,100 8,000 8,100 
Elongation, % 
Yield 6.4 6.3 6.0 6.0 6.6 
Break 54.7 46.2 14.5 12.0 23.7 
Notched Izod 
2.59 2.47 1.92 1.78 2.91 
Impact (ft-lb/in) 
Spiral Flow, 
21.5 21.9 25.0 24.3 18.7 
275.degree. C. (in) 
__________________________________________________________________________ 
The results set forth in Table III demonstrate that compositions F-I 
according to the present invention exhibited improved flowability, as 
indicated by spiral flow, as compared with comparative composition J. 
Additionally, the compositions according to the present invention 
exhibited a good combination of mechanical properties. 
The preceding examples are set forth to illustrate specific embodiments of 
the invention and are not intended to limit the scope of the compositions 
and products of the present invention. Additional embodiments and 
advantages within the scope of the claimed invention will be apparent to 
one of ordinary skill in the art.