Highly filled extruded thermoplastic compositions having a speckled surface appearance

A highly filled, extruded thermoplastic material which has a smooth, uniform speckled surface without any secondary finishing operations. The thermoplastic material contains a polyalkylene terephthalate resin, a polycarbonate resin, a large quantity of a filler material, a stabilizer for the resin materials and a sufficient quantity of a non-dispersing pigment to give the extruded thermoplastic material a speckled surface appearance.

BACKGROUND OF THE INVENTION 
Highly filled thermoplastic molding compositions having ceramic like 
properties may be formed into diverse articles for use in numerous 
applications. In the decorative surfacing industry custom colors and 
special-effect appearances are key properties for customer acceptance. A 
granite, fleck-like or speckled look is especially desired and is 
available in both high pressure laminates and thermoset acrylic or 
thermoset polyesters used as decorative surfaces. However, the fleck-like 
or speckled surface produced in such thermoset materials is not smooth or 
uniform and therefore requires a secondary finishing operation such as 
sanding or the like. 
The applicants have discovered that it is possible to provide a speckled or 
fleck-like appearance to a thermoplastic material by including therein a 
non-dispersing pigment prior to extruding such material. Surprisingly, 
this thermoplastic material having the non-dispersing pigment can be 
extruded with a sufficiently smooth and uniform surface that no secondary 
finishing operation is required. 
Accordingly, it is a primary object of the invention to provide a highly 
filled, extruded thermoplastic material having a speckled surface 
appearance. 
It is also an object of this invention to provide a highly filled, extruded 
thermoplastic material which can be extruded into a sheet having a smooth, 
uniform speckled surface without any secondary finishing operations. 
These and other objects of the invention will become apparent from the 
specification. 
SUMMARY OF THE INVENTION 
The present invention provides a highly filled, extruded thermoplastic 
composition having a speckled surface which comprises: 
(a) 1-70 weight percent of a polyalkylene terephthalate resin; 
(b) 0-35 weight percent of an aromatic polycarbonate resin; 
(c) an effective amount of a stabilizer; 
(d) optionally, an impact modifier; 
(e) 0-35 weight percent of a polyetherester or polyetherimide ester resin; 
(f) 30-80 weight percent of an inorganic filler; 
(g) from 0-30 percent of a fibrous glass reinforcing filler; and 
(h) an effective amount of a non-dispersing pigment. The amount of resin 
(a) must be equal to or greater than (b). The inorganic filler is selected 
from barium sulfate, strontium sulfate, zinc oxide, zinc sulfate, or 
mixtures thereof. The amount of the non-dispersing pigment is sufficient 
to provide the extruded thermoplastic composition with a speckled surface. 
It is also desirable that the speckled surface be smooth and uniform. It 
is particularly preferred that the surface of the extruded material be 
smooth, uniform and speckled without any secondary finishing operations. 
DETAILED DESCRIPTION OF THE INVENTION 
The present invention is particularly well suited for thermoplastic 
materials which can provide a ceramic-like look and feel such as highly 
filled crystalline polyesters and their blends. Polyesters suitable for 
preparing the present compositions include those comprising structural 
units of the formula (I) 
##STR1## 
wherein each R.sup.1 is independently a divalent aliphatic, alicyclic or 
aromatic hydrocarbon or polyoxyalkylene radical, or mixtures thereof and 
each A.sup.1 is independently a divalent aliphatic, alicyclic or aromatic 
radical, or mixtures thereof. Examples of suitable polyesters containing 
the structure of formula (I) are poly(alkylene dicarboxylates), 
elastomeric polyesters, liquid crystalline polyesters, and polyester 
copolymers. It is also possible to use a branched polyester in which a 
branching agent, for example, a glycol having three or more hydroxyl 
groups or a trifunctional or multifunctional carboxylic acid has been 
incorporated. Furthermore, it is sometimes desirable to have various 
concentrations of acid and hydroxyl endgroups on the polyester, depending 
on the ultimate end-use of the composition. 
In some instances, it is desirable to reduce the number of acid endgroups, 
typically to less than about 30 micro equivalents per gram, with the use 
of acid reactive species. In other instances, it is desirable that the 
polyester has a relatively high carboxylic end group concentration, e.g., 
about 5-250 micro equivalents per gram or, more preferable, about 20-70 
micro equivalents per gram 
The R.sup.1 radical may be, for example, a C.sub.2-10 alkylene radical, a 
C.sub.6-10 alicyclic radical, a C.sub.6-20 aromatic radical or a 
polyoxyalkylene radical in which the alkylene groups contain about 2-6 and 
most often 2 or 4 carbon atoms. The A.sup.1 radical in the above formula 
(I) is most often p- or m-phenylene or a mixture thereof. As previously 
noted, this class of polyester includes the poly(alkylene terephthalates) 
and the polyarylates. Such polyesters are known in the art as illustrated 
by the following patents, which are incorporated herein by reference. 
______________________________________ 
2,465,319 2,720,502 2,727,881 2,822,348 
3,047,539 3,671,487 3,953,394 4,128,526 
______________________________________ 
The poly(alkylene terephthalates) are often the preferred polyesters for 
the present invention, with poly-(ethylene terephthalate) (PET), 
poly-(cyclohexylene terephthalate) (PCT), and poly (butylene 
terephthalate) (PBT) being the most preferred members of this class. 
Various mixtures of PET, PCT and PBT are also sometimes very suitable. 
The polyester may include structural units of the formula (II) 
##STR2## 
wherein R.sup.1 is as previously defined. R.sup.2 is a polyoxyalkylene 
radical and A.sup.2 is a trivalent aromatic radical, usually derived from 
trimellitic acid and has the structure (III) 
##STR3## 
Such polymers and their mode of preparation are described, example, in 
U.S. Pat. Nos. 4,544,734; 4,556,705; and 4,556,688, which are incorporated 
herein by reference. 
Because of the tendency of polyesters to undergo hydrolytic degradation at 
the high extrusion and molding temperatures encountered by the 
compositions of this invention, it is preferred that the polyester be 
substantially free of water. 
The polyesters generally have number average molecular weights in the range 
of about 20,000-70,000, as determined by gel permeation cromatography, and 
an intrinsic viscosity/(IV) at 30.degree. C. in a mixture of 60 percent 
(by weight) phenol and 40 percent 1,1,2,2-tetrachloroethane of 0.4 to 1.5 
dl/g, and preferabley 0.6 to 0.8 dl/g. 
The amount of the polyester according to the present invention varies with 
the properties which are required by the given application but preferably 
the total amount of polyester ranges from about 0-70 percent by weight and 
more preferably from about 5 to 50 percent by weight and most preferably 
from about 10 to 30 percent by weight. 
The aramaic polycarbonate resins of the invention are, of themselves, well 
known compounds which are described along with methods for their 
preparation in U.S. Pat. Nos. 3,989,672; 3,275,601 and 3,028,365, all of 
which are incorporated herein by reference. 
They may be conveniently prepared by the reaction of at least one dihydric 
phenol and a carbonate precursor. The dihydric phenols employed in the 
practice of this invention are known dihydric phenols which may be 
represented by the general formula: 
##STR4## 
wherein: R.sup.3 is independently selected from halogen, monovalent 
hydrocarbon, and monovalent hydrocarbonoxy radicals; 
R.sup.4 is independently selected from halogen, monovalent hydrocarbon, and 
monovalent hydrocarbonoxy radicals; 
B is selected from divalent hydrocarbon radicals, 
##STR5## 
n' and n" are independently selected from integers having a value of from 
0 to 4 inclusive; and 
y is either zero or one. 
The monovalent hydrocarbon radicals represented by R.sup.3 and R.sup.4 
include the alkyl, cycloalkyl, aryl, aralkyl, and alkaryl radicals. 
The preferred alkyl radicals are those containing from 1 to about 12 carbon 
atoms. The preferred cycloalkyl radicals are those containing from 4 to 
about 12 ring carbon atoms. The preferred aryl radicals are those 
containing from 6 to 12 ring carbon atoms, i.e., phenyl, naphthyl, and 
biphenyl. The preferred aralkyl and alkaryl radicals are those containing 
from 7 to about 14 carbon atoms. 
The preferred halogen radicals represented by R.sup.3 and R.sup.4 are 
chlorine and bromine. 
The monovalent hydrocarbonoxy radicals may be represented by the general 
formula --OR.sup.5 wherein R.sup.5 has the same meaning as R.sup.3 and 
R.sup.4. The preferred hydrocarbonoxy radicals are the alkoxy and the 
aryloxy radicals. 
The divalent hydrocarbon radicals represented by B include the alkylene, 
alkylidene, cycloalkylene, and cycloalkylidene radicals. The preferred 
alkylene radicals are those containing from 2 to about 30 carbon atoms. 
The preferred alkylidene radicals are those containing from 1 to about 30 
carbon atoms. The preferred cycloalkylene and cycloalkylidene radicals are 
those containing from 6 to about 16 ring carbon atoms. 
Some illustrative non-limiting of suitable dihydric phenols include: 
2,2-bis(4-hydroxyphenyl)propane (bisphenol-A); 
2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane; 
2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane; 
1,1-bis(4-hydroxyphenyl)cyclohexane; 
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)cyclohexane; 
1,1-bis(4-hydroxyphenyl)cyclododecane; 
1,1-bis(4-hydroxyphenyl)decane; 
1,4-bis(4-hydroxyphenyl)butane; 
p,p'-dihydroxydiphenyl; 
bis(4-hydroxyphenyl)ether; 
1,1-bis(4-hyroxyphenyl)3,3,5-trimethylcyclohexane; 
and 4,4'-thiodiphenol. 
Other useful dihydric phenols are described, inter alia, in U.S. Pat. Nos. 
3,028,365; 2;999,835; 3,148,172; 3,271,368, 2,991,273; 3,271,367; 
3,280,078; 3,014,891 and 2;999,846, all of which are incorporated herein 
by reference. 
The carbonate precursors employed in the practice of the instant invention 
include the carbonyl halides, the bishaloformates, and the 
diarylcarbonates. The carbonyl halides include carbonyl bromide, carbonyl 
chloride, and mixtures thereof. Typical of the diarylcarbonates are 
diphenyl carbonate; di(halophenyl) carbonates such as 
di(chlorophenyl)carbonate, di(bromophenyl) carbonate, 
di(trichlorophenyl)carbonate, and di(tribromophenyl)carbonate; 
di(alkylphenyl)-carbonates such as di(tolyl)carbonate; dinaphthyl 
carbonate; di(halonaphthyl)carbonates; and naphthyl phenyl carbonate. The 
bishaloformates suitable for use herein include the bishaloformates of 
dihydric phenols such as the bischloroformates of hydroquinone and 
bisphenol-A; the bishaloformates of glycols such as the bischloroformates 
of ethylene glycol, neopentyl glycol, and polyethylene glycol. 
The polycarbonates of the instant invention contain at least one recurring 
structural unit represented by the formula: 
##STR6## 
wherein: B, R.sup.3, R.sup.4, n', n" and y are as defined above. 
Monofunctional phenols can be added as end capping agents to the 
polymerization to control molecular weight and provide desired properties. 
The term "polycarbonate" according to the invention also contemplates 
resins such as polyarylates, polyestercarbonates or the like. 
The instant polycarbonates are preferably high molecular weight aromatic 
carbonate polymers having an intrinsic viscosity, as determined in 
chloroform at 25.degree. C. of from about 0.3 to about 1.5 dl/gm, 
preferably from about 0.45 to about 1.0 dl/gm. These polycarbonates may be 
branched or unbranched and generally will have a weight average molecular 
weight of from about 10,000 to about 200,000, preferably from about 20,000 
to about 100,000 as measured by gel permeation chromatography. 
Preferred polycarbonates are those derived from bisphenol A and tetrabromo 
bisphenel A. 
The amount of the polycarbonate resin in the composition is preferably 
between about 0 and about 35 weight percent, and more preferably between 
about 5 and 25 weight percent, and most preferably between about 10 an 20 
weight percent of the thermoplastic composition. 
The branched polycarbonates may be prepared by adding a branching agent 
during polymerization. These branching agents are well known and may 
comprise organic polyfunctional organic compounds containing at least 
three functional groups which may be hydroxyl, carboxyl, carboxylic 
anhydride, haloformyl and mixtures thereof. Specific examples include 
trimellitic acid, trimellitic anhydride, trimellitic trichloride, 
tris-p-hydroxy phenyl ethane, isatin-bis-phenol, trisphenol TC 
(1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene), trisphenol PA 
(4(4(1,1-bis(p-hydroxyphenyl)-ethyl).alpha.,.alpha.-dimethylbenzyl)phenol) 
, 4-chloroformyl phthalic anhydride, trimesic acid and benzophenone 
tetracarboxylic acid. 
The branching agent may be added at a level of about 0.05-2.0 weight 
percent. Branching agents and procedures for making branched 
polycarbonates are described in U.S. Pat. Nos. 3,635,895; 4,001,184; and 
4,204,047 which are incorporated by reference. 
In the practice of the present invention, it may be desirable to add an 
impact modifier. Although the specific type of impact modifier is not 
critical, it is preferred to use an impact modifier which is based on a 
high molecular weight styrenediene rubber. 
A preferred class of rubber materials are copolymers, including random, 
block and graft copolymers of vinyl aromatic compounds and conjugated 
dienes. Exemplary of these materials there may be given hydrogenated, 
partially hydrogenated, or non-hydrogenated block copolymers of the A-B-A 
and A-B type wherein A is polystyrene and B is an elastomeric diene, e.g. 
polybutadiene, polyisoprene, radial teleblock copolymer of styrene and a Y 
conjugated diene, acrylic resin modified styrene-butadiene resins and the 
like; and graft copolymers obtained by graft-copolymerization of a monomer 
or monomer mix containing a styrenic compound as the main component to a 
rubber-like polymer. The rubber-like polymer used in the graft copolymer 
are as already described herein including polybutadiene, styrene-butadiene 
copolymer, acrylonitrile-butadiene copolymer, ethylene-propylene 
copolymer, ethylene butylene copolymer, polyacrylate and the like. The 
styrenic compounds includes styrene, methylstyrene, dimethylstyrene, 
isopropylstyrene, .alpha.-methylstyrene, ethylvinyltoluene and the like. 
Procedures for the preparation of these polymers are found in U.S. Pat. 
Nos. 4,196,116; 3,299,174 and 3,333,024, all of which are incorporated by 
reference. 
The thermoplastic multi-block copolymer elastomers that are used in this 
invention are copolyetheresters and copolyetherimide esters. 
The copolyetheresters consist essentially of a multiplicity of recurring 
long chain ester units and short chain ester units joined head-to-tail 
through ester linkages, said long chain ester units being represented by 
the formula: 
##STR7## 
and said short chain ester units being represented by the formula: 
##STR8## 
where G is a divalent radical remaining after the removal of terminal 
hydroxyl groups from a poly(alkylene oxide) glycol having a number average 
molecular weight of about 400-6000; R is a divalent radical remaining 
after reaction of carboxyl groups from an aromatic dicarboxylic acid 
having a molecular weight less than about 300, and D is a divalent radical 
remaining after reaction of hydroxyl groups from a diol having a molecular 
weight less than about 250; provided said short chain ester units are 
about 20-85 percent by weight of said copolyetherester. 
The term "long-chain ester units" as applied to units in a polymer chain of 
the copolyetherester refers to the reaction product of a long-chain glycol 
with a dicarboxylic acid. Such "long-chain ester units", which are a 
repeating unit in the copolyetherester, correspond to formula (I) above. 
The long-chain glycols are polymeric glycols having terminal (or as nearly 
terminal as possible) hydroxy groups and a molecular weight from about 
400-6000. The long-chain glycols used to prepare the copoly-etheresters 
are poly(alkylene oxide) glycols. Representative long-chain glycols are 
poly(ethylene oxide) glycol, poly(1,2- and 1,3-propylene oxide) glycol, 
poly(tetramethylene oxide) glycol, random or block copolymers of ethylene 
oxide and 1,2-propylene oxide, and random or block copolymers of 
tetra-hydrofuran with minor amounts of a second monomer such as ethylene 
oxide. 
The term "short-chain ester units" as applied to units in a polymer chain 
of the copolyetherester refers to low molecular weight chain units having 
molecular weights less than about 550. They are made by reacting a low 
molecular weight diol (below about 250) with an aromatic dicarboxylic acid 
having a molecular weight below about 300, to form ester units represented 
by formula (II) above. 
The term "low molecular weight diols" as used herein should be construed to 
include equivalent ester-forming derivatives, provided, however, that the 
molecular weight requirement pertains to the diol only and not to its 
derivatives. 
Preferred are diols with 2-15 carbon atoms such as ethylene, propylene, 
tetramethylene, pentamethylene, 2,2-dimethyltrimethylene, hexamethylene, 
and decamethylene glycols, dihydroxycyclohexane, cyclohexane dimethanol, 
and the unsaturated 1,4-butenediol. 
The term "dicarboxylic acids" as used herein, includes equivalents of 
dicarboxylic acids having two functional groups which perform 
substantially like dicarboxylic acids in reaction with glycols and diols 
in forming copolyetherester polymers. These equivalents include esters and 
ester-forming derivatives, such as acid anhydrides. The molecular weight 
requirement pertains to the acid and not to its equivalent ester or 
ester-forming derivative. 
Among the aromatic dicarboxylic acids for preparing the copolyetherester 
polymers, those with 8-16 carbon atoms are preferred, particularly the 
phenylene dicarboxylic acids, i.e., phthalic, terephthalic and isophthalic 
acids and their dimethyl ester. 
The short-chain ester units will constitute about 20-85 weight percent of 
the copolyetherester. The remainder of the copolyetherester will be 
long-chain ester units comprising about 15-80 weight percent of the 
copolyetherester. 
Preferred copolyetheresters are those prepared from dimethyl terephthalate, 
1,4-butanediol, and poly(tetramethylene oxide) glycol having a molecular 
weight of about 600-2000. Optionally, up to about 30 mole percent of the 
dimethyl terephthalate in these polymers can be replaced by dimethyl 
phthalate or dimethyl isophthalate. Polymers in which a portion of the 
butanediol is replaced by butenediol are also preferred. 
The dicarboxylic acids or their derivatives and the polymeric glycol are 
incorporated into the copolyetherester in the same molar proportions as 
are present in the reaction mixture. The amount of low molecular weight 
diol actually incorporated corresponds to the difference between the moles 
of diacid and polymeric glycol present in the reaction mixture. When 
mixtures of low molecular weight diols are employed, the amounts of each 
diol incorporated depends on their molar concentration, boiling points and 
relative reactivities. The total amount of diol incorporated is still the 
difference between moles of diacid and polymeric glycol. 
The copolyetheresters described herein are made by a conventional ester 
interchange reaction which, preferably, takes place in the presence of a 
phenolic antioxidant that is stable and substantially nonvolatile during 
the polymerization. 
The copolyetherimide ester elastomers differ from the copolyetheresters 
only in that repeating hard segments and soft segments are joined through 
imidoester linkages rather than simple ester linkages. The hard segments 
in these elastomers consist essentially of multiple short chain ester 
units represented by the formula: 
##STR9## 
described hereinbefore. The soft segments in these polymers are derived 
from poly(oxyalkylene diimide) diacids which can be characterized the 
following formula: 
##STR10## 
wherein each R" is independently a trivalent organic radical, preferably a 
C.sub.1 to C.sub.20 aliphatic, aromatic or cycloaliphatic trivalent 
organic radical; each R' is independently hydrogen or a monovalent organic 
radical preferably selected from the group consisting of C.sub.1 to 
C.sub.6 aliphatic and cycloaliphatic radicals and C.sub.6 to C.sub.12 
aromatic radicals, e.g., benzyl, most preferably hydrogen; and G' is the 
radical remaining after the removal of the terminal (or as nearly terminal 
as possible) amino groups of a long chain ether diamine having an average 
molecular weight of from about 600 to about 12,000, preferably from about 
900 to about 4,000. 
Representative long chain ether glycols from which the polydxyalkylene 
diamine is prepared include poly(ethylene ether)glycol; poly(propylene 
ether)-glycol; poly(tetramethylene ether)glycol; random or block 
copolymers of ethylene oxide and propylene oxide, including propylene 
oxide terminated poly(ethylene ether)glycol; and random or block 
copolymers of tetrahydrofuran with minor amounts of a second monomer such 
as methyl tetrahydrofuran (used in proportion such that the 
carbon-to-oxygen mole ratio in the glycol does not exceed about 4.3). 
Especially preferred poly(alkylene ether) glycols are poly(propylene 
ether)glycol and poly(ethylene ether)glycols end capped with 
poly(propylene ether) glycol and/or propylene oxide. 
In general, the polyoxyalkylene diamines will have an average molecular 
weight of from about 600 to 12,000, preferably from about 900 to about 
4000. 
Useful in capping the polyoxyalkylene diamines are various tricarboxylic 
compounds. The tricarboxylic component may be a carboxylic acid anhydride 
containing an additional carboxylic group or the corresponding acid 
thereof containing two imide forming vicinal carboxyl groups in lieu of 
the anhydride group. Mixtures thereof are also suitable. The additional 
carboxylic group much be esterifiable and preferably is substantially 
nonimidizable. 
The tricarboxylic acid materials can be characterized by the following 
formula: 
##STR11## 
where R is a trivalent organic radical, preferably a C.sub.2 to C.sub.20 
aliphatic, aromatic, or cycloaliphatic trivalent organic radical and R' is 
preferably hydrogen or a monovalent organic radical preferably selected 
from the group consisting of C.sub.1 to C.sub.6 aliphatic or 
cycloaliphatic radicals and C.sub.6 to C.sub.12 aromatic radicals, e.g., 
phenyl; most preferably hydrogen. A preferred tricarboxylic component is 
trimellitic anhydride. 
These copolymers are described in U.S. Pat. Nos. 4,988,740; 4,544,734; 
4,556,688 and 4,579,884 all of which are incorporated by reference. 
It is further preferred to employ an inorganic filler to the thermoplastic 
resin to impart a series of additional beneficial properties, not the 
least of which are thermal stability, increased density, and texture. 
Inorganic fillers are well known in the art and most inorganic fillers 
known in the art which provide a ceramic-like feel can be used in the 
present invention. 
Preferred inorganic fillers which are employed in the present thermoplastic 
compositions include: zinc oxide, barium sulfate, zirconium silicate, 
strontium sulfate, as well as mixtures of the above. The preferred form of 
barium sulfate will have a particle size of 0.1-20 microns. The barium 
sulfate may be derived from a natural or a synthetic source. 
The molding compositions may include from 20-85% by weight, preferably 
30-75% by weight or most preferably 30-45% by weight of total composition 
of an inorganic filler component. For certain applications where a ceramic 
like product is desired, more than 50%, or more preferably 60-85% by 
weight of the total composition of filler component should be employed. 
The thermoplastic resin composition may also include other additives which 
are well known in the art. For example, the resin composition may contain 
external lubricants, antioxidants, flame retardants or the like. If 
desired, ultraviolet stabilizers, flow aids, metal additives for 
electromagnetic radiation shielding such as nickel coated graphite fibers, 
anti static agents, coupling agents such as amino silanes and the like may 
also be added. 
The filamentous glass to be employed as a reinforcing agent in the present 
compositions is well known to those skilled in the art and is widely 
available from a number of manufacturers. For compositions ultimately to 
be employed for electrical uses, it is preferred to use fibrous glass 
filaments comprised of lime-aluminum borosilicate glass that is relatively 
sodium free. This is known as "E" glass, however other glass compositions 
are useful. All such glasses are contemplated as within the scope of the 
present invention. The filaments are made by standard processes, e.g., by 
steam or air blowing, flame blowing and mechanical pulling. The preferred 
filaments for plastics reinforcement are made by mechanical pulling. The 
filament diameters preferably range from about 3 to about 20 microns, but 
this is not critical to the present invention. It is known, however to 
those skilled in the art, that smaller filament diameters will also 
increase the strength. 
The length of the glass filaments and whether or not they are bundled into 
fibers and the fibers bundled into yarns, ropes or rovings, or woven into 
mats, and the like are also not critical to the invention. However, in 
preparing the compositions of the present invention, it is convenient to 
use filamentous glass in the form of chopped strands of from one-eighth to 
about 2 inches long. In articles molded from the compositions, on the 
other hand, even shorter lengths will be encountered because, during 
compounding, considerable fragmentation will occur. 
In the thermoplastic compositions which contain a polyester and a 
polycarbonate resin, it is preferable to use a stabilizer material. 
Typically, such stabilizers are used at a level of 0.01-10 weight percent 
and preferably at a level of from 0.05-2 weight percent. The preferred 
stabilizers include an effective amount of an acidic phosphate salt; an 
acid, alkyl, aryl or mixed phosphite having at least one hydrogen or alkyl 
group; a Group IB or Group IIB metal phosphate salt; a phosphorous oxo 
acid, a metal acid pyrophosphate or a mixture thereof. The suitability, of 
a particular compound for use as a stabilizer and the determination of how 
much is to be used as a stabilizer may be readily determined by preparing 
a mixture of the polyester component, the polycarbonate and the filler 
with and without the particular compound and determining the effect on 
melt viscosity or color stability or the formation of interpolymer. The 
acidic phosphate sales include sodium dihydrogen phosphate, mono zinc 
phosphate, potassium hydrogen phosphate, calcium hydrogen phosphate and 
the like. The phosphites may be of the formula: 
##STR12## 
where R.sup.6, R.sup.7 and R.sup.8 are independently selected from the 
group consisting of hydrogen, alkyl and aryl with the proviso that at 
least one of R.sup.6, R.sup.7 and R.sup.8 is hydrogen or alkyl. 
The phosphate sales of a Group IB or Group IIB metal include zinc 
phosphate, copper phosphate and the like. The phosphorous oxo acids 
include phosphorous acid, phosphoric acid, polyphosphoric acid or 
hypophosphorous acid. 
The polyacid pyrophosphates of the formula: 
EQU M.sup.z.sub.x H.sub.y P.sub.n O.sub.3n+1 
wherein M is a metal, x is a number ranging from 1 to 12 and y is a number 
ranging 1 to 12, n is a number from 2 to 10, z is a number from 1 to 5 and 
the sum of (xz)+y is equal to n+2. 
These compounds include Na.sub.3 HP.sub.2 O.sub.7 ; K.sub.2 H.sub.2 P.sub.2 
O.sub.7 ; Na.sub.4 P.sub.2 O.sub.7 ; KNaH.sub.2 P.sub.2 O.sub.7 and 
Na.sub.2 H.sub.2 P.sub.2 O.sub.7. The particle size of the polyacid 
pyrophosphate should be less than 75 microns, preferably less than 50 
microns and most preferably less than 20 microns. 
The purpose of the non-dispersing pigments in the present invention is to 
impart to the thermoplastic composition a granite, fleck-like or speckled 
surface appearance. This speckled surface is achieved through a 
non-dispersing pigment as opposed to a filler because the non-dispersing 
pigment does not appreciably add to the base color of the resin. Rather, 
the non-dispersing pigment provides a separate, visibly distinct and 
identifiable color at numerous sites across the surface of the material 
wherever the pigment material is visible. In other words, the speckle is 
visible in the filled polymer matrix as a distinct region of contrasting 
color. 
Although this speckled surface appearance can be achieved with a number of 
non-dispersing pigments, it is desirable from a manufacturing standpoint 
that the pigment be such that the thermoplastic material can be extruded 
into a sheet which is sufficiently smooth and uniform on the surface that 
it need not undergo any secondary or subsequent finishing operations such 
as sanding or the like. However, the present inventors surprisingly 
discovered through extensive experimentation with a variety of 
non-dispersing pigments that only certain types of non-dispersing pigments 
having a particular shape provide the speckled look and the smooth, 
uniform surface without secondary finishing operations. 
In particular, it is preferred that the surface of the thermoplastic 
composition have an RMS value of no greater than about 200, and more 
preferably no greater than about 130, and most preferably no greater than 
about 75. RMS stands for root mean square and the RMS value can be 
measured, e.g., by using a Taylor Hobson Subtronic 3P over a specific 
distance of the material (0.01" is usually sufficient). 
Thus, in order to achieve a suitable RMS value without subsequent finishing 
operations, it is preferred that the non-dispersing pigments have a large 
aspect ratio (aspect ratio being defined as the ratio of the diameter to 
thickness of the particle), with the relative thickness being the more 
important measurement. It is preferred that the non-dispersing pigment 
have an aspect ratio of greater than about 20, more preferably greater 
than about 40, and most preferably greater than about 60. It has been 
determined by the present inventors that when a non-dispersing pigment 
having a low aspect ratio (spherical or large particles) is used, the 
extruded thermoplastic composition has an uneven or rough surface and a 
secondary sanding operation is required to remove the surface 
irregularities. 
Materials which typically have high aspect ratios and are thus particularly 
well suited for the present invention include cellulose fibers, mica, 
metallic flakes, carbon fibers, or similar such fibrous materials. Other 
potential non-dispersing pigments which are useful provided the aspect 
ratio is suitable include titanium whiskers and other natural fibers as 
well as ground thermoset, thermoplastic or rubber materials. The most 
preferred non-dispersing materials include cellulose fibers, mica and 
metallic flakes. The non-dispersing pigments may be uncoated or coated 
with organic or inorganic coatings such as azo dyes or mineral coatings. 
Additionally, the non-dispersing pigments may also be added in combination 
with colorants or added into an already colored thermoplastic composition. 
It is not necessary to add large amounts of the non-dispersing pigments to 
the composition in order to achieve a speckled surface appearance. It is 
usually sufficient to add between about 0.1 and 5 weight percent pigment 
based on the weight of the composition and preferably between about 1 
weight percent and about 3 weight percent of the composition. 
______________________________________ 
Preferred compositions include the following: 
polybutylene terephthalate 
7-25 wt. % 
polyethylene terephthalate 
3-10 wt. % 
aromatic polycarbonate 
10-25 wt. % 
stabilizer 0.01-10 wt. % 
impact modifier 0-15 wt. % 
barium sulfate 40-79.99 wt. % 
non-dispersing pigment 
1-5% 
Other preferred compositions include: 
polybutylene terephthalate 
15-30 wt. % 
polyethylene terephthalate 
5-15 wt. % 
branched arom. polycarbonate 
20-30 wt. % 
stabilizer 0.05-2 wt. % 
barium sulfate 30-59.95 wt. % 
non-dispersing pigment 
1-5% 
polybutylene terephthalate 
6-10 wt. % 
polyethylene terephthalate 
5-10 wt. % 
polycarbonate 12-20 wt. % 
stabilizer 0.01-5 wt. % 
impact modifier 1-10 wt. % 
barium sulfate 59-72.99 wt. % 
non-dispersing pigment 
1-5% 
polybutylene terephthalate 
15-50 wt. % 
polyethylene terephthalate 
5-15 wt. % 
polyetherimide ester 5-15 wt. % 
barium sulfate 50-75 wt. % 
non-dispersing pigment 
1-5% 
______________________________________ 
As used herein and in the appended claims, the term "weight percent" means 
the percent by weight of each component based on the total weight of 
composition. 
The invention also includes the novel articles made from the compositions 
of the invention and methods of extrusion, blow molding, sheet forming and 
thermoforming. 
These articles may comprise, e.g., countertops, sinks, shower stalls, 
building panels, bathroom and kitchen fixtures, plumbing fixtures, tiles, 
floor coverings, profile moldings, picture flames, as well as other 
extruded articles of manufacture. 
The method of extruding or thermoforming is facilitated by the addition of 
a rubbery impact modifier and/or a polycarbonate or especially a branched 
polycarbonate to a highly filled composition, i.e. more than 50 weight 
percent of an inorganic filler such as barium sulfate, which includes a 
polybutylene terephthalate and/or a polyethylene terephthalate resin.