Filled polyetherimide resin compositions

A thermoplastic resin composition that contains a polyetherimide resin, a mineral filler and a gloss-enhancing additive selected from linear polysiloxane polymers, polyethylene resins and crystalline thermoplastic resins imparts improved surface gloss to shaped articles molded therefrom.

FIELD OF THE INVENTION 
The invention relates to filled thermoplastic polyetherimide resin 
compositions that impart improved surface gloss to articles molded 
therefrom. 
BRIEF DESCRIPTION OF THE PRIOR ART 
Polyetherimide resins impart physical properties, for example, resistance 
to elevated temperature, that make them appropriate for use in high heat 
applications. Shaped articles molded from polyetherimide resin 
compositions typically exhibit high surface gloss. Polyetherimide resin 
compositions that contain a mineral filler are known, see, for example EP 
627457 and EP 423510. Such filled polyetherimide resin compositions are 
said to provide high performance at reduced cost, but the addition of the 
filler has been found to result in a dramatic decrease in the surface 
gloss of articles molded from the filled resin compositions. Such filled 
polyetherimide resin compositions may therefore be inappropriate for use 
certain applications, that is, wherein molded articles that exhibit both 
high temperature performance and a high gloss surface appearance are 
required. 
Filled polyetherimide resins compositions would enjoy a wider range of 
applicability if the surface gloss of articles molded from such 
compositions could be improved. 
SUMMARY OF THE INVENTION 
The present invention is directed to a thermoplastic resin composition 
comprising: 
(a) a polyetherimide resin, 
(b) an inert particulate filler, and 
(c) a gloss-enhancing additive selected from the group consisting of linear 
polysiloxane polymers, polyethylene resins crystalline thermoplastic 
resins and mixtures thereof, in an amount that is effective to improve the 
surface gloss of articles molded from the thermoplastic resin composition. 
The composition of the present invention imparts improved surface gloss to 
articles molded therefrom. 
In a second aspect, the present invention is directed to a method of make a 
thermoplastic resin article having improved surface gloss, comprising 
molding the resin composition of the present invention under conditions 
effective to subject the resin composition to a shear rate of greater than 
8,500 reciprocal seconds ("s.sup.-1 "). 
The method of the present invention imparts improved surface gloss to 
articles molded thereby.

DETAILED DESCRIPTION OF THE INVENTION 
In a preferred embodiment, the polyetherimide resin composition of the 
present invention comprises, based on 100 parts by weight ("pbw") of the 
combined amount of the polyetherimide resin and the particulate inert 
filler, from 35 to 99.9 pbw, more preferably from 60 to 90 pbw, and, even 
more preferably, from 70 to 80 pbw of the polyetherimide resin, from 0.1 
to 65 pbw, more preferably from 10 to 40 pbw, and, even more preferably, 
from 20 to 30 pbw of the inert particulate filler and from 0.01 to 10 pbw, 
more preferably from 0.1 to 6 pbw, of the gloss-enhancing additive. 
In a preferred embodiment, the thermoplastic resin composition consists 
essentially of the polyetherimide resin, the inert particulate filler and 
the gloss-enhancing additive. 
Polyetherimide resins suitable for use as the polyetherimide resin 
component of the thermoplastic resin of the composition of the present 
invention are known compounds whose preparation and properties have been 
described, see generally, U.S. Pat. Nos. 3,803,085 and 3,905,942, the 
respective disclosures of which are incorporated herein by reference. 
In a preferred embodiment, the polyetherimide resin component of the 
present invention contains from greater than 1 to 1000 or more, preferably 
from 10 to 1000, structural units of the formula (I): 
##STR1## 
wherein the divalent T moiety bridges the 3,3', 3,4', 4,3', or 4,4' 
positions of the aryl rings of the respective aryl imide moieties of 
formula (I); T is --O-- or a group of the formula --O--Z--O--; Z is a 
divalent radical selected from the group consisting of formulae (II): 
##STR2## 
wherein X is a member selected from the group consisting of divalent 
radicals of the formulae (III): 
##STR3## 
wherein y is an integer from 1 to about 5, and q is 0 or 1; R is a 
divalent organic radical selected from the group consisting of: (a) 
aromatic hydrocarbon radicals having from 6 to about 20 carbon atoms and 
halogenated derivatives thereof, (b) alkylene radicals having from 2 to 
about 20 carbon atoms, (c) cycloalkylene radicals having from 3 to about 
20 carbon atoms, and (d) divalent radicals of the general formula (IV): 
##STR4## 
where Q is a member selected from the group consisting of formulae (V): 
##STR5## 
where y' is an integer from about 1 to about 5. 
In one embodiment, the polyethermide resin may be a copolymer which, in 
addition to the etherimide units described above, further contains 
polyimide repeating units of the formula (VI): 
##STR6## 
wherein R is as previously defined for formula (I) and M is selected from 
the group consisting of formula (VII): 
##STR7## 
formula (VIII): 
##STR8## 
and formula (IX): 
##STR9## 
Polyetherimide resins are made by known methods, such as, for example, 
those disclosed in U.S. Pat. Nos. 3,847,867, 3,814,869, 3,850,885, 
3,852,242 3,855,178 and 3,983,093, the disclosures of which are hereby 
incorporated herein by reference. 
In a preferred embodiment, the polyetherimide resin is made by the reaction 
of an aromatic bis(ether anhydride) of the formula (X): 
##STR10## 
with an organic diamine of the formula (XI): 
EQU H.sub.2 N--R--NH.sub.2 (XI) 
wherein T and R are defined as described above in formula (I). In general 
the reactions can be carried out employing well-known solvents, e.g., 
o-dichlorobenzene, m-cresol/toluene and the like to effect interaction 
between the anhydride of formula (X) and the diamine of formula (XI), at 
temperatures from about 100.degree. C. to about 250.degree. C. 
Alternatively, the polyethermide resin can be prepared by melt 
polymerization of aromatic bis(ether anhydride)s and diamines accomplished 
by heating a mixture of the ingredients at elevated temperatures with 
concurrent stirring. Generally melt polymerizations employ temperatures 
between about 200.degree. C. and 400.degree. C. Chain stoppers and 
branching agents may also be employed in the reaction. 
Examples of specific aromatic bis(ether anhydrides) and organic diamines 
are disclosed, for example, in U.S. Pat. Nos. 3,972,902 and 4,455,410, 
which are incorporated by reference herein. 
Illustrative examples of aromatic bis(ether anhydride)s of formula (X) 
include: 2,2-bis(4-(3,4-dicarboxyphenoxy)phenyl)propane dianhydride; 
4,4'-bis(3,4-dicarboxyphenoxy)diphenyl ether dianhydride; 
4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride; 
4,4'-bis(3,4-dicarboxyphenoxy)benzophenone dianhydride; 
4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride; 
2,2-bis([4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride; 
4,4'-bis(2,3-dicarboxyphenoxy)diphenyl ether dianhydride; 
4,4'-bis(2,3-dicarboxyphenoxy)diphenyl sulfide dianhydride; 
4,4'-bis(2,3-dicarboxyphenoxy)benzophenone dianhydride; 
4,4'-bis(2,3-dicarboxyphenoxy)diphenyl sulfone dianhydride; 
4-(2,3-dicarboxyphenoxy)-4'-3,4-dicarboxyphenoxy)diphenyl-2,2-propane 
dianhydride; 4-(2,3-dicarboxyphenoxy)-4'-(3,4-dicarboxyphenoxy)diphenyl 
ether dianhydride; 
4-(2,3-dicarboxyphenoxy)-4'-(3,4-dicarboxyphenoxy)diphenyl sulfide 
dianhydride; 
-4-(2,3-dicarboxyphenoxy)-4'-(3,4-dicarboxyphenoxy)benzophenone 
dianhydride and 4-(2,3-dicarboxyphenoxy)-4'-(3,4-dicarboxyphenoxy)diphenyl 
sulfone dianhydride, as well as various mixtures thereof. 
A preferred class of aromatic bis(ether anhydride)s included by formula (X) 
above includes compounds wherein T is of the formula (XII): 
##STR11## 
wherein each Y is independently selected from the group consisting of: 
formulae (XIII): 
##STR12## 
When polyetherimide/polyimide copolymers are employed, a dianhydride, such 
as pyromellitic anhydride, is used in combination with the bis(ether 
anhydride). 
The bis(ether anhydride)s can be prepared by the hydrolysis, followed by 
dehydration, of the reaction product of a nitro substituted phenyl 
dinitrile with a metal salt of dihydric phenol compound in the presence of 
a dipolar, aprotic solvent. 
Suitable organic diamines of formula (XI) include, for example: 
m-phenylenediamine; p-phenylenediamine; 4,4'-diaminodiphenylpropane, 
4,4'-diaminodiphenylmethane (commonly named 4,4'-methylenedianiline); 
4,4'-diaminodiphenyl sulfide; 4,4'-diaminodiphenyl sulfone; 
4,4'-diaminodiphenyl ether (commonly named 4,4'-oxydianiline); 
1,5-diaminonaphthalene; 3,3-dimethylbenzidine; 3,3-dimethoxybenzidine; 
2,4-bis(beta-amino-t-butyl)toluene; bis(p-beta-amino-t-butylphenyl)ether; 
bis(p-beta-methyl-o-aminophenyl)benzene; 1,3-diamino-4-isopropylbenzene; 
1,2-bis(3-aminopropoxy)ethane; benzidine; m-xylylenediamine; 
2,4-diaminotoluene; 2,6-diaminotoluene; bis(4-aminocyclohexyl)methane; 
3-methylheptamethylenediamine; 4,4-dimethylheptamethylenediamine; 
2,11-dodecanediamine; 2,2-dimethylpropylenediamine; 
1,18-octamethylenediamine; 3-methoxyhexamethylenediamine; 
2,5-dimethylhexamethylenediamine; 2,5-dimethylheptamethylenediamine; 
3-methylheptamethylenediamine; 5-methylnonamethylenediamine; 
1-4-cyclohexanediamine; 1,18-octadecanediamine; bis(3-aminopropyl)sulfide; 
N-methyl-bis(3-aminopropyl)amine; hexamethylenediamine; 
heptamethylenediamine; nonamethylenediamine; decamethylenediamine and 
mixtures of such diamines. 
Illustrative of a particularly preferred polyethermide resin falling within 
the scope of formula (I) is one comprising repeating units wherein R is 
paraphenylene, metaphenylene, or mixtures of paraphenylene and 
metaphenylene and T is a group of the formula --O--Z--O-- wherein Z has 
the formula (XIV): 
##STR13## 
and wherein the divalent group (XIV) bridges the 3,3' positions of the 
aryl rings of the respective aryl imide moieties of formula (I). 
Generally, useful polyetherimide resins have an intrinsic viscosity [.eta.] 
greater than about 0.2 deciliters per gram, preferably of from about 0.35 
to about 0.7 deciliters per gram measured in m-cresol at 25.degree. C. 
In a preferred embodiment, the polyetherimide resin of the present 
invention resin has a weight average molecular weight of from about 10,000 
to about 75,000 grams per mole ("g/mol"), more preferably from about 
10,000 to about 65,000 g/mol, even more preferably from about 10,000 to 
about 55,000 g/mol, as measured by gel permeation chromatography, using a 
polystyrene standard. 
The inert particulate filler component of the thermoplastic resin 
composition of the present invention may be any particulate material that 
is substantially inert under the anticipated conditions under which the 
resin composition of the present invention is to be processed and under 
the anticipated conditions under which articles molded from the resin 
composition of the present invention are to be used. 
In a preferred embodiment, the inert particulate filler is a mineral 
filler. Mineral fillers are known in the art and are available from a 
number of commercial sources. Mineral fillers suitable for use as the 
inert particulate filler component of the composition of the present 
invention include, for example, alumina, barium carbonate, barium sulfate, 
barium titanate, barium trioxide, bismuth trioxide, calcium carbonate, 
magnesium silicate, strontium ferrite, titanium dioxide, wollastonite, 
zinc oxide and mixtures thereof. 
In a preferred embodiment, the inert particulate filler of the composition 
of the present invention comprises barium sulfate. 
In a preferred embodiment, the inert particulate filler of the composition 
of the present invention has an average particle size of from about 0.2 
micrometer (".mu.m") to about 40 .mu.m, more preferably from about 0.2 
.mu.m to about 7.5 .mu.m. 
In a first preferred embodiment, the gloss enhancing additive component of 
the composition of the present invention comprises one or more linear 
polysiloxane, fluids. Suitable polysiloxane fluids are known compounds 
that are made by known methods and are commercially available from a 
number of sources. Preferred polysiloxane fluids include 
poly(dimethylsiloxane) fluids and a poly(methyl hydrogen siloxane) fluids. 
In a highly preferred embodiment, the polysiloxane fluid comprises a 
methyl-terminated poly(dimethyl siloxane) fluid or a poly(methyl hydrogen 
siloxane) fluid. Preferred polysiloxane fluids are those having a number 
average molecular weight of from about 1,000 to about 20,000 g/mol. 
In a highly preferred embodiment, the composition of the present invention 
comprises a gloss enhancing amount of from 0.01 to 2.0 pbw, more 
preferably 0.1 to 1.0 pbw, of the polysiloxane fluid, based on 100 pbw of 
combined amount of the polyetherimide resin and the inert particulate 
filler. 
In a second preferred embodiment, the gloss enhancing additive component of 
the composition of the present invention comprises one or more 
polyethylene, resins, more preferably one or more high density 
polyethylene resins. Suitable poly(ethylene) resins are known compounds 
made by known methods and are commercially available from a number of 
sources. 
In a highly preferred embodiment, the composition of the present invention 
comprises a gloss enhancing amount of from 0.5 to 8 pbw, more preferably 2 
to 6 pbw, of the poly(ethylene) resin, based on 100 pbw of combined amount 
of the polyetherimide resin and the inert particulate filler. 
In a third preferred embodiment, the gloss enhancing additive component of 
the composition of the present invention comprises a crystalline 
thermoplastic polymer. Suitable crystalline polyamide resins are known 
compounds that are made by known methods and are commercially available 
from a number of sources. 
In one preferred embodiment, the crystalline thermoplastic resin comprises 
one or more crystalline thermoplastic polyamide resins, preferably one or 
more linear aliphatic polyamide homopolymers or copolymers. In a preferred 
embodiment, the crystalline thermoplastic polyamide is one or more 
aliphatic linear polyamide homopolymer resin selected from nylon resins. 
Suitable nylon resins include, for example, nylon 6, nylon 4,6, nylon 6,6, 
nylon 6,9, nylon 6,10, nylon 6,12 and nylon 12,12 resins. 
In a highly preferred embodiment, the crystalline polyamide resin is nylon 
6 or nylon 6,6. 
In a preferred embodiment, the crystalline polyamide resin has a weight 
average molecular weight of from about 50,000 to about 150,000 g/mol. 
In an alternative preferred embodiment, the crystalline thermoplastic resin 
comprises a crystalline thermoplastic polyester resin. Suitable polyester 
resins are known compounds that are made by known methods and are 
commercially available from a number of sources. Polyester resins are 
typically obtained through the condensation or ester interchange 
polymerization of a diol or diol equivalent with a diacid or diacid 
equivalent and each comprise recurring structural units according to 
formula (XV): 
##STR14## 
wherein: R.sub.1 represents the residue of the diol or diol equivalent 
("diol residue"), 
R.sub.2 represents the residue of the diacid or diacid equivalent ("diacid 
residue"), and each R.sub.1 and R.sub.2 is independently a divalent 
acyclic hydrocarbon radical, a divalent alicyclic hydrocarbon radical or a 
divalent aromatic hydrocarbon radical. 
As used herein, the terminology "acyclic hydrocarbon radical" means a 
straight chain or branched saturated hydrocarbon radical, preferably 
containing from 2 to 12 carbon atoms per radical, such as, for example, 
dimethylene, trimethylene, tetramethylene, hexamethylene and 
octamethylene. 
As used herein, the terminology "alicyclic hydrocarbon radical" means a 
hydrocarbon radical containing one or more saturated hydrocarbon rings, 
preferably containing from 4 to 10 carbon atoms per ring, per radical 
which may optionally be substituted on one or more of the rings with one 
or more alkyl or alkylene groups, each preferably containing from 2 to 6 
carbon atoms per group and which, in the case of two or more rings, may be 
fused rings, such as, for example, 2,2,4,4-tetramethyl-1,3-cyclobutylene, 
1,4-cyclohexylene, cyclohexylene-1,4-dimethylene, 1,4-cyclooctylene. 
As used herein, the term "aromatic hydrocarbon radical" means a hydrocarbon 
radical containing one or more aromatic rings per radical, which may 
optionally be substituted on the one or more aromatic rings with one or 
more alkyl or alkylene groups, each preferably containing from 2 to 6 
carbon atoms per group and which, in the case of two or more rings, may be 
fused rings, such as, for example, 1,2-phenylene, 1,3-phenylene, 
1,4-phenylene, 2,6-naphthalene, 2,7-phenathrylene. 
Suitable diols include acyclic diols such as, for example, ethylene glycol, 
1,3-propylene glycol, 1,4-butane glycol, 1,5-pentane diol, 1,6-hexane 
diol, 1,7-heptane diol, 1,8-octane diol, 1,9-nonane diol, 1,10-decane 
diol, 1,12-dodecane diol; alicyclic diols such as, for example, 
2,2,4,4-tetramethyl-1,3-cyclobutane diol, 3,4-cyclopentanediol, 
1,4-cyclohexanedimethanol, including cis-1,4-cyclohexanedimethanol and 
trans-1,4-cyclohexanedimethanol; and aromatic diols such as, for example, 
bisphenol A and hydroquinone. Suitable diol equivalents include 
corresponding esters and ethers, such as for example, dialkyl esters and 
diaryl esters. 
Suitable diacids include, for example, dicarboxylic acids, such as, for 
example, phthalic acid, isophthalic acid, terephthalic acid, dimethyl 
terephthalic acid, oxalic acid, malonic acid, succinic acid, glutaric 
acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 
dimethyl malonic acid, 1,12-dodecanoic acid cis-1,4-cyclohexane 
dicarboxylic acid, trans-1,4-cyclohexane dicarboxylic acid, 
4,4'-bisbenzoic acid, naphthalene-2,6-dicarboxylic acid. Suitable diacid 
equivalents include, for example, corresponding anhydride, ester or halide 
derivatives, such as, for example, phthalic anhydride, dimethyl 
terephthalate, succinyl chloride. 
In a preferred embodiment, the crystalline thermoplastic polyester resin is 
a poly(alkylene phthalate) resin, more preferably a poly(ethylene 
terephthalate) resin or a poly(butylene terephthalate) resin, most 
preferably a poly(ethylene terephthalate) resin. 
In a preferred embodiment, the polyester resin has a number average 
molecular weight of from 10,000 to 100,000, more preferably 15,000 to 
50,000, as measured by gel permeation chromatography using a polystyrene 
standard. 
In a highly preferred embodiment, the composition of the present invention 
comprises a gloss enhancing amount of from 0.05 to 10 pbw, more preferably 
0.1 to 5 pbw, of the crystalline thermoplastic polymer, based on 100 pbw 
of combined amount of the polyetherimide resin and the inert particulate 
filler. 
The thermoplastic resin composition of the present invention may, 
optionally, also contain various additives which are well known in the 
art, such as antioxidants, UV absorbers, light stabilizers, flame 
retardant additives, lubricants, plasticizers, pigments, dyes, colorants 
and anti-static agents. 
The preparation of the compositions of the present invention is normally 
achieved by combining the ingredients under conditions suitable for 
formation of a blend of the components. Such conditions typically include 
solution blending or melt mixing in single or twin screw type extruders, 
mixing bowl, or similar mixing devices which can apply a shear to the 
components. Twin screw extruders are often preferred due to their more 
intensive mixing capability over single screw extruders. It is often 
advantageous to apply a vacuum to the melt through at least one vent port 
in the extruder to remove volatile impurities in the composition. 
The composition of the present invention can be molded into useful shaped 
articles, such as, for example, heat resistant containers, by a variety of 
means such as, for example, injection molding and extrusion. 
The thermoplastic resin composition of the present invention may be molded 
under typical injection molding conditions, wherein the resin composition 
is subjected to a shear rate of from 3,000 to 8500 s.sup.-1 during 
injection of the resin composition into a mold. In a preferred embodiment 
of the present invention, the thermoplastic resin composition of the 
present invention is injection molded under "high shear rate" conditions 
that are effective to subject the thermoplastic resin composition to a 
shear rate of greater than 8,500 s.sup.-1, more preferably greater than or 
equal to 10,000 s.sup.-1, even more preferably greater than or equal to 
12,000 s.sup.-1, and still more preferably greater or equal to 15,000 
s.sup.-1 during injection of the resin composition into a mold. 
The shear rate to which a resin composition is subjected under injection 
molding conditions may be calculated according to methods known in the 
art, such as for example, according to equation 1: 
EQU Shear rate=4 V/.pi.R.sup.3 (1) 
which has been found to be applicable to flow of the resin composition 
through an injection nozzle, wherein V is the volumetric flow rate of 
resin composition though the injection nozzle and R is the internal radius 
of the injection nozzle. 
Injection molding the resin composition of the present invention under high 
shear rate conditions provides enhanced surface gloss to articles made 
thereby. 
EXAMPLES 1-9 
Comparative Examples C1 
The respective thermoplastic resin compositions of Examples 1-9 of the 
present invention and Comparative Example C1 were each made by combining 
the components described below in the relative amounts (each expressed in 
pbw, based on the 100 pbw of the respective thermoplastic resin 
composition) set forth in TABLES I-IV. The components used in the 
thermoplastic resin compositions were as follows: 
PEI: Polyetherimide resin made by condensation of 
2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride with 
metaphenylene diamine and having a weight average molecular weight of 
about 52,000 g/mol, 
BaSO.sub.4 : Barium sulfate (Blanc Fixe) from Polar Minerals), 
PMHS: A methyl-terminated poly(methyl hydrogen siloxane) polymer having a 
weight average molecular weight of about 7,000 g/mol (DF1040, GE 
Silicones), 
PMDS: A methyl-terminated poly(dimethyl siloxane) polymer having a weight 
average molecular weight of about 40,000 g/mol (SF1198, GE Silicones), 
PE: A high density polyethylene homopolymer. 
Nylon 6: Nylon 6 resin having a having an average molecular weight of about 
90,000 g/mol (Allied Signal, Inc.) 
Nylon 6,6: Nylon 6,6 resin a having an average molecular weight of about 
80,000 g/mol (Allied Signal, Inc.) and 
PET: Poly(ethylene terephthalate ) resin having a having a weight average 
molecular weight of about 60,000 g/mol (grade 3948, E.I. du Pont de 
Nemours & Co.). 
The components of the compositions of Examples 1-9 and Comparative Example 
C1 were combined and blended in an Egan 2.5 inch single screw extruder at 
a temperature of about 340-360.degree. C. The compositions so formed were 
pelletized and, in a series of runs, each of the compositions was then 
injection molded using a Newbury 150T injection molding machine to form 
specimens for gloss testing. 
Gloss was measured at 60.degree. according to ASTM D523. Results of the 
gloss testing are set forth below in TABLES I-II for each of the 
compositions of Examples 1-9 and Comparative Example 1. 
TABLE I 
______________________________________ 
CEx# C1 Ex# 1 Ex# 2 Ex# 3 Ex 4 
______________________________________ 
PEI 80 77 75 79.8 79.8 
BaSO.sub.4 20 20 20 20 20 
PE -- 3 5 -- -- 
PMHS -- -- -- 0.2 -- 
PDMS -- -- -- -- 0.2 
Gloss at 60 .degree. 26 29 32 33 27 
______________________________________ 
TABLE II 
______________________________________ 
EX# 5 Ex# 6 Ex# 7 Ex# 8 Ex# 9 
______________________________________ 
PEI 79.5 79 79 79 77 
BaSO.sub.4 20 20 20 20 20 
Nylon 6 0.5 1 -- -- -- 
Nylon 6,6 -- -- 1 -- -- 
PET -- -- -- 1 3 
Gloss at 60 .degree. 29 43 43 43 43 
______________________________________ 
The compositions of examples 1-9 each exhibit improved gloss compared to 
comparative example C1. The compositions of examples 5-9, each of which 
contains a crystalline thermoplastic resin as the gloss-enhancing 
additive, provide particularly dramatic improvements in surface gloss 
compared to Comparative Example C1. 
EXAMPLES 10-13 
The compositions of examples 10-12 were made in the same manner as 
described above in regard to Examples 1-9 and Comparative Example C1. 
The components of the compositions of Examples 10-12 were combined and 
blended in an Egan 2.5 inch single screw extruder at a temperature of 
about 340-360.degree. C. The compositions so formed were pelletized and, 
in a series of runs, each of the compositions was then injection molded 
using a Newbury 150T injection molding machine, under conditions effective 
to subject the resin compositions to shear rates of 8,500 s.sup.-1, 10,000 
s.sup.-1, 12,000 s.sup.-1 and 15,000 s.sup.-1, to form specimens for gloss 
testing. Shear rates were calculated according to equation (1) above for 
flow of the resin through the injection nozzle of the injection molding 
machine. The volumetric flow rate of the resin composition was calculated 
by multiplying the weight of resin composition injected into the mold by 
the specific gravity of the resin composition and dividing the product by 
the injection time. 
The relative amounts of the components of Examples 10-12, expressed in pbw, 
based on 100 pbw of the respective thermoplastic resin composition and the 
results of the gloss testing for the test specimens formed from the 
compositions under various shear rate conditions are set forth below in 
TABLE III. 
TABLE III 
______________________________________ 
Ex# 10 Ex# 11 Ex# 12 
______________________________________ 
PEI 89 79 69 
BaSO.sub.4 10 20 30 
PET 1 1 1 
Gloss at 60 .degree. 
shear rate = 8,500 s.sup.-1 50 26 20 
shear rate = 10,000 s.sup.-1 62 32 24 
shear rate = 12,000 s.sup.-1 71 46 30 
shear rate = 15,000 s.sup.-1 82 46 37 
______________________________________ 
In each case, the surface gloss of the injection molded article increased 
with increasing shear rate during injection molding. 
The composition of the present invention imparts improved surface gloss to 
articles molded therefrom and the method of the present invention imparts 
improved surface gloss to articles molded thereby.