A colored polyester copolymer comprising the reaction product of at least one linear thermoplastic polyester precursor and at least ten parts per million by weight of a residue of at least one 1,4-bis (2,6-dialkylanilino)-9,10-anthraquinone colorant. A composition may be formed comprising the copolymer in admixture with at least one thermoplastic polymer. The copolymer may be formed by reacting at least one thermoplastic polyester precursor with a 1,4-bis (2,6-dialkylanilino)-9,10-anthraquinone colorant which has a polyester reactive group.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to colored polyester copolymer compounds and 
compositions. The greenish-blue to bluish-green (cyan) colored polyesters 
of the invention have thermally stable colorants copolymerized therein, 
thus providing colored compounds and compositions wherein the colorants do 
not sublime, extract, migrate, or exude. The copolymerized colorants have 
adequate color characteristics (hue) and are stable to heat, light, 
humidity and a variety of other environmental factors. These compositions 
are particularly useful as films and fibers. 
2. Description of the Prior Art 
It is known in the art to incorporate dyes into polyester films as 
contrasting agents. Dyes in the blue to blue-green color range have 
primarily been chosen from the anthraquinone family of dyes due to their 
thermal stability. Dyes acre typically added to the polyester during 
processing and must be stable to the temperature and chemical environment 
encountered during polyester processing. Anthraquinone dyes are described 
in U.S. Pat. Nos. 3,488,195 and 3,849,139, which are incorporated herein 
by reference. However, in these cases, the dyes are admixed with the 
polyester and are not copolymerized with the polyester. 
It is also known in the art to copolymerize certain colorants into 
polyesters as described in U.S. Pat. Nos. 4,403,092 and 5,372,864. 
Copolymerized colorants are non-migratory, thereby eliminating the 
problems of sublimation and interference of the dye with the film. The 
method disclosed for preparing copolymerizable colorants described in 
these patents involves the addition of hydroxyl containing sulfamido 
groups to the anilino substituents on the A ring of the anthraquinone of 
the Formula I: 
##STR1## 
Addition of sulfamido groups causes hypsochrornic shifts resulting in 
colorants with a reddish hue which are unsuitable for this invention. When 
incorporated in fibers or film, the known copolymerizable blue colorants 
flare redder when exposed to tungsten filament light as compared to 
daylight, which is objectionable. 
It has now been found that, in contrast to the copolymerized blue 
anthraquinone colorants disclosed in U.S. Pat. Nos. 4,403,092 and 
5,372,864, the colorants used in this invention produce cyan colored 
polyesters directly without having to blend them with more bathochromic 
colorants such as phthalocyanines. The colored polyester copolymer 
compositions of the present invention are economical, environmentally and 
toxicologically safe, and the color is fast to heat, light, high humidity 
and a variety of environmental factors. Thus, many of the known problems 
with polyesters which contain copolymerized blue dyes are overcome by this 
invention. 
SUMMARY OF THE INVENTION 
This invention provides a colored polyester copolymer which comprises the 
reaction product of at least one linear thermoplastic polyester precursor 
and at least ten parts per million by weight of a residue of at least one 
1,4-bis (2,6-dialkylanifino)-9, 10-anthraquinone colorant having the 
formula: 
##STR2## 
wherein: R and R.sub.1 are independently C.sub.1 -C.sub.6 alkyl; 
R.sub.2 groups are independently hydrogen, halogen, C.sub.1 -C.sub.6 alky, 
hydroxy, C.sub.1 -C.sub.6 alkoxy, thiocyano or C.sub.1 -C.sub.6 alkylthio; 
R.sub.3 groups are independently substituted or unsubstituted C.sub.1 
-C.sub.6 alkylthio, substituted or unsubstituted C.sub.1 -C.sub.6 
alkylsulfonyl, substituted or unsubstituted C.sub.1 -C.sub.6 
alkylsulfinyl, substituted or unsubstituted phenylthio, substituted or 
unsubstituted phenylsulfinyl, substituted or unsubstituted phenylsulfonyl, 
1,2,4-triazol-5-yl, or substituted or unsubstituted heteroarylthio, 
wherein at least one R.sub.3 comprises at least one polyester reactive 
group capable of reacting with the polyester precursor to form a colored 
polyester copolymer. 
This invention also provides a composition which comprises at least one 
thermoplastic polymer in admixture with the above colored polyester 
copolymer. 
This invention further provides a method of preparing a colored polyester 
copolymer which comprises reacting at least one linear thermoplastic 
polyester precursor and at least ten parts per million by weight of a 
residue of at least one 1,4-bis (2,6-dialkylanilino)-9,10-anthraquinone 
colorant having the above Formula I under polyester forming conditions to 
form a colored polyester copolymer. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the practice of the present invention, a colored polyester copolymer is 
prepared which comprises the reaction product of a linear polyester 
precursor and a colorant of at least one 1,4-bis 
(2,6-dialkylanilino)-9,10-anthraquinones having the Formula I: 
##STR3## 
wherein: R and R.sub.1 are independently C.sub.1 -C.sub.6 alkyl; 
R.sub.2 groups are independently hydrogen, halogen, C.sub.1 -C.sub.6 alkyl, 
hydroxy, C.sub.1 -C.sub.6 alkoxy, thiocyano or C.sub.1 -C.sub.6 alkylthio; 
R.sub.3 groups are independently substituted or unsubstituted C.sub.1 
-C.sub.6 alkylthio, substituted or unsubstituted C.sub.1 -C.sub.6 
alkylsulfonyl, substituted or unsubstituted C.sub.1 -C.sub.6 
alkylsulfinyl, substituted or unsubstituted phenylthio, substituted or 
unsubstituted phenylsulfinyl, substituted or unsubstituted phenylsulfonyl, 
1,2,4-triazol-5-yl, or substituted or unsubstituted heteroarylthio, 
wherein at least one R.sub.3 comprises at least one polyester reactive 
group capable of reacting with the polyester precursor to form a colored 
polyester copolymer. 
In the preferred embodiment, the alkyl portion of C.sub.1 -C.sub.6 -alkyl, 
C.sub.1 -C.sub.6 -alkoxy, and C.sub.1 -C.sub.6 -alkylthio comprises a 
straight or branched chain alkyl radical containing one to six carbon 
atoms, more preferably one to four carbons. 
Preferred halogens nonexclusively include fluorine, chlorine, bromine, and 
iodine, most preferably bromine and chlorine. 
The polyester reactive groups referred to herein describe groups which are 
reactive with at least one of the functional groups from which the 
polyester is prepared under polyester forming conditions. The preferred 
polyester reactive groups nonexclusively include hydroxy, carboxy, 
carbomethoxy, carbethoxy and acetoxy. When R.sub.3 is 
1,2,4-triazol-5-ylthio, the --NH--portion of the triazol ring is reactive 
under polyester forming conditions. 
The two R.sub.3 groups in Formula I are preferably located at either 
positions 6 and 7 or positions 5 and 8 in Ring C of the anthraquinone 
structure, most preferably at positions 6 and 7. Compounds in which 
R.sub.3 is an alkylthio group substituted with hydroxy are useful as 
textile dyes and are broadly disclosed in U.S. Pat. No. 3,666,778, which 
is incorporated herein by reference. 
The terms substituted C.sub.1 -C.sub.6 -alkylsulfonyl, substituted C.sub.1 
-C.sub.6 -alkylthio, and substituted C.sub.1 -C.sub.6 -alkylsulfinyl 
referred to herein denote radicals wherein the alkyl portion is 
substituted with at least one polyester reactive group X which is capable 
of reaction via esterification with either an alcohol or ester, preferably 
said polyester reactive groups nonexclusively includes hydroxy, carboxy, 
amino and C.sub.1 -C.sub.6 -alkylamino or ester groups selected from any 
radical having the formula --OCOR.sub.4,--OCO.sub.2 R.sub.4,--CO.sub.2 
R.sub.4, or --OCONHR.sub.4 wherein R.sub.4 nonexclusively includes C.sub.1 
-C.sub.6 -alkyl, hydroxy-C.sub.1 -C.sub.6 -alkyl, C.sub.3 -C.sub.7 
-cycloalkyl and phenyl; or the C.sub.1 -C.sub.6 -alkyl group of R.sub.3 
may bear a substituent of the formula --Y--R.sub.5 --X, wherein Y 
nonexclusively includes--O, --S, and SO.sub.2 ; R.sub.5 nonexclusively 
includes straight or branched chain C.sub.1 -C.sub.6 -alkylene and 1,2-, 
1,3- or 1,4- phenylene, and X is a polyester reactive group as described 
above; the C.sub.1 -C.sub.6 -alkyl groups of R.sub.3 which contain 
reactive groups X or the group --Y--R.sub.5 --X, as defined above, may 
contain at least one additional substituent which nonexclusively includes 
hydroxy, halogen, --OCOR.sub.4, C.sub.1 -C.sub.6 -alkoxy and C.sub.1 
-C.sub.6 -alkylthio. 
The terms substituted phenylthio, substituted phenylsulfinyl, and 
substituted phenylsulfonyl referred to herein indicate groups wherein the 
phenyl radical contains at least one group comprising a reactive group X 
which nonexclusively includes --OCOR.sub.4 and --CO.sub.2 R.sub.4 or a 
group of the formula --Y--R.sub.5 --X, wherein R.sub.4, Y, R.sub.5 and X 
are as defined previously. The phenyl radical containing the reactive 
group X or the group --Y--R.sub.5 --X, as defined above, may contain at 
least one additional substituent which nonexclusively includes C.sub.1 
-C.sub.6 -alkyl, C.sub.1 -C.sub.6 -alkoxy, halogen, carboxy and --CO.sub.2 
R.sub.4. 
The term heteroarylthio referred to herein indicates groups wherein the 
heteroaryl radical comprises benzothiazol-2-yl, benzoxazol-2-yl, 
benzimidazol-2-yl, thiazolyl-2-yl or 1,3,4-thiadiazolyl-2-yl radical 
substituted with carboxy or --CO.sub.2 R.sub.4, wherein R.sub.4 is as 
defined above; or a substituted triazolylthio group of the Formula II: 
##STR4## 
wherein: R.sub.6 represents hydrogen or a C.sub.1 -C.sub.6 -alkyl radical 
containing at least one polyester reactive group X, wherein X is as 
previously defined; R.sub.7 represents a C.sub.1 -C.sub.6 alkyl or phenyl 
radical. The heteroarylthio groups may be substituted further with 
additional groups listed above as possible substituents for the phenyl 
group. 
The blue anthraquinone colorants of Formula I can be prepared by reacting 
the appropriately substituted leucoquinizarin 
(1,4,9,10-tetrahydroxyanthracene) compound of the Formula III: 
##STR5## 
with 2,6-dialkylaniline of the Formula IV: 
##STR6## 
preferably in the presence of acid catalysts such as boric acid as 
described in U.S. Pat. No. 3,918,976, incorporated herein by reference. 
Alternatively, the blue anthraquinone colorants of Formula I may be 
prepared by reacting dihalo- 
1,4-bis-(2,6-dialkylanilino)-9,10-anthraquinones of the formula: 
##STR7## 
with the appropriately substituted C.sub.1 -C.sub.6 -alkylmercaptan, 
C.sub.1 -C.sub.6 -alkane suifinic acid salt, benzenethiol, benzenesulfonic 
acid salt or heteroarylthiol, in the presence of base in solvents such as 
N,N-dirnethylformamide, N,N-dimethyacetamide, N-methyl-2-pyrrolidinone and 
dimethylsulfoxide. 
Preferred polyesters nonexclusively include linear, thermoplastic, 
crystalline, or amorphous polyesters produced by conventional 
polymerization techniques from at least one diol and at least one 
dicarboxylic acid. 
In the preferred embodiment, the polyesters are molding or fiber grade and 
have an inherent viscosity of from about 0.4 to about 1.2 (dL/g) measured 
at 25.degree. C. in a 60/40 ratio by weight of phenol/tetrachloroethane. 
These polyesters are more fully disclosed in U.S. Pat. No. 5,372,864, 
which is incorporated herein by reference. Suitable diol components of the 
described polyesters may be selected from ethylene glycol, 
1,4-cyclohexanedimethanol, 1,2-propanediol, 1,3-propanediol, 
1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 
1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 
1,3-cyclohexanedimethanol, 
Z,8-bis(hydroxymethyl)-tricyclo-5.2.1.0!-decane wherein Z represents 3, 
4, or 5; and diols containing one or more oxygen atoms in the chain, e.g., 
diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene 
glycol, and the like. In general, these diols contain 2 to 18, preferably 
2 to 8 carbon atoms. Cycloaliphatic diols can be employed in their cis or 
trans configuration or as mixtures of both forms. Suitable acid components 
(aliphatic, alicyclic, or aromatic dicarboxylic acids) of the linear 
polyester are selected, for example, from terephthalic acid, isophthalic 
acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 
succinic acid, glutaric acid, adipic acid, sebacic acid, 
1,12-dodecanedioic acid, 2,6-naphthalenedicarboxylic acid and the like. In 
polymer preparation, it is often preferable to use a functional acid 
derivative thereof such as the dimethyl, diethyl, or dipropyl ester of the 
dicarboxylic acid. The anhydrides or acid halides of these acids also may 
be employed where practical. Preferred polyesters comprise at least about 
50 mole percent terephthalic acid residues and at least about 50 mole 
percent ethylene glycol and/or 1,4-cyclohexanedimethanol residues. 
Particularly preferred polyesters are those containing from about 75 to 
100 mole percent terephthalic acid residues and from about 75 to 100 
percent ethylene glycol residues. The linear polyesters may be prepared 
according to polyester forming conditions well known in the art. For 
example, a mixture of one or more dicarboxylic acids, preferably aromatic 
dicarboxylic acids, or ester forming derivatives thereof, and one or more 
diols may be heated in the presence of esterification and/or 
polyesterification catalysts at temperatures in the range of about 
150.degree. C. to about 300.degree. C., and pressures of atmospheric to 
about 0.2 mm Hg. Normally, the dicarboxylic acid or derivative thereof is 
esterified or transesterified with the diol(s) at atmospheric pressure and 
at a temperature at the lower end of the specified range. Polycondensation 
then is effected by increasing the temperature and lowering the pressure 
while excess diol is removed from the mixture. 
Typical catalyst or catalyst systems for polyester condensation are 
well-known in the art. For example, catalysts disclosed in U.S. Pat. Nos. 
4,025,492; 4,136,089; 4,176,224; 4,238,593; and 4,208,572, incorporated 
herein by reference, are deemed suitable in this regard. Further, R. E. 
Wilfong, Journal of Polymer Science, 54 385 (1961) sets forth typical 
catalysts which are useful in polyester condensation reactions. A 
preferred temperature range for a polyester condensation is about 
260.degree. C. to about 300.degree. C. 
The preferred amount of copolymerizable colorant added during polyester 
manufacture depends upon the inherent tinctorial strength of the colorant 
and the end use of the polyester. For polyesters to be used in films such 
as in the blow molding of bottles for packaging usually ranges from about 
10 parts per million (ppm) to about 10,000 ppm, preferably from about 10 
ppm to about 1,000 ppm, more preferably from about 100 ppm to about 750 
ppm, and most preferably from about 100 ppm to about 400 ppm. For 
polyester fibers, the usual amount of colorant would normally range from 
about 500 ppm to about 10,000 ppm. In another embodiment of the invention, 
a polyester color concentrate may be prepared by copolymerizing higher 
levels of the colorant usually in the range of about 0.1% to about 30% by 
weight based on the weight of the final polyester. Cyan colorants may be 
combined with magenta or yellow colorants to produce blue or green, 
respectively, thus allowing a wide range of colors to be produced. 
When the colorants are added at high levels, it is preferred that the 
copolymerizable colorants have only two polyester reactive groups to avoid 
crosslinking of the polymer during the polycondensation reaction. At low 
levels of addition, e.g. below about 1,000 ppm, the colorant may have only 
one or more than two reactive groups without affecting the desirable 
polymer properties of the linear polyesters. 
These polyester color concentrates may be blended with thermoplastics, 
specifically polyesters to impart the desired level of color by melt 
blending followed by extrusion. The colored thermoplastic compositions 
thus produced are useful as thick and thin plastic films, extruded 
coatings and lamination layers, plastic sheeting, molded plastic articles 
and fibers. Useful thermoplastic polymers non-exclusively include 
polyesters, polyurethanes, polycarbonates, polyethers, polystyrenes, 
polyolefins, acrylics, vinyls, cellulosics, epoxies, phenolics, 
polyamines, polyamides and mixtures thereof The amount of colored 
polyester useful in blends with thermoplastic polymers may be readily 
determined by those skilled in the art. When blended with thermoplastic 
polymers to form thermoplastic compositions, the amount of colored 
polyester copolymer may range from about 10 ppm to about 10 weight % 
preferably from about 100 ppm to about 5 weight % by weight of the 
thermoplastic composition.