Colored polyester compositions

Provided are novel methine colorants derived from acetaldehyde, 1,3-dihydro-7-methoxycarbonyl-1,1,3-trimethyl-2H-benz[e]indol-2-ylidine and polyester compositions and concentrates having these colorants copolymerized therein. Also provided are novel intermediates useful for making the colorants.

FIELD OF THE INVENTION 
This invention belongs to the field of polyester chemistry. More 
particularly, this invention relates to polyester compositions having 
certain methine colorants copolymerized therein. 
BACKGROUND OF THE INVENTION 
Copolymerization of yellow and red anthraquinone colorants into polyesters 
is known. See, for example, U.S. Pat. Nos. 4,267,306; 4,403,092; and 
4,359,570. However, these colorants inherently have low molar extinction 
coefficients and are expensive. Also, U.S. Pat. No. 4,617,373 describes 
certain methine colorants having the formulae 
##STR1## 
wherein Z is the residue of certain active methylene groups, and these 
colorants copolymerized within polyesters. 
DETAILED DESCRIPTION OF THE INVENTION 
Plastics, paints, printing inks, rubber, cosmetics, e.g., lipsticks, etc., 
are usually colored by organic colorants when superior brilliance and 
tinctorial strength are advantageous. Toxicity has been a chronic problem 
related to the use of these materials as some have been shown to be 
potential carcinogens and to cause contact dermatitis. (See, for example, 
Federal Register, (July 15, 1988) and ACTA Derm. VENEROL, Suppl. 1987, 
134, pp. 95-97.) Recent publications document the continued concern. 
Plastics usually consist of large macromolecules and other ingredients 
such as fillers, plasticizers, colorants, etc. Most polymers do not 
produce allergic reactions by themselves, but leachable additives are 
known to cause contact dermatitis. (See, for example, S. Fregert, Manual 
of Contact Dermatitis, Munksgard, Denmark, 2nd Ed. 1981.) 
The overall purpose of this invention is to provide colored polymeric 
compositions which have the colorants incorporated into the polymer chain 
so that the colorant will not be leachable, sublimable, extractable, or be 
exuded from the polymer composition. A further purpose is to provide 
microcrystalline polyester materials capable of being formulated into a 
wide variety of products such as cosmetics, household care products, etc., 
which will be safe to humans since exposure to toxic molecules readily 
absorbed by the body is greatly minimized. As can be envisioned, these 
polymeric compositions have utility in a wide variety of applications 
where toxicological concerns are evident. The concentrate materials may be 
used for imparting color to a wide variety of thermoplastic compositions 
including polyesters, polycarbonates, polyamides, cellulose esters, 
polyurethanes, polyolefins, etc., by conventional melt or solution 
blending techniques. When using the polymeric color concentrates of this 
invention, the colorant problems relative to toxicity concerns are 
overcome. 
The present invention provides a polyester composition having copolymerized 
therein or reacted therewith at least 0.001 weight percent of a residue of 
Formulae (I) and/or (II): 
##STR2## 
wherein R is carboxy, C.sub.1 -C.sub.8 optionally substituted 
alkoxycarbonyl, C.sub.3 -C.sub.7 cycloalkoxycarbonyl, C.sub.3 -C.sub.8 
alkenyloxycarbonyl or aryloxycarbonyl; 
A is a divalent residue of an active methylene component; 
B and B.sup.1 are the trivalent residues of an active methylene compound; 
and 
L is a C.sub.1 -C.sub.20 divalent organic residue. 
As a further aspect of the present invention, there are provided colorant 
compounds of Formulae (I) and (II). 
Preferred thermally stable colorants are those of Formulae (I) and/or (II) 
wherein A represents the divalent residue of an active methylene compound 
selected from .alpha.-cyanoacetic acid esters, .alpha.-cyanoacetamides, 
.alpha.-arylacetonitriles, 2(5H)-furanones, 
3-cyano-1,6.dihydro-4.methyl.2,6-dioxy(2H)-pyridines, 1,3-indandiones and 
benzo(b)thieno.3 (2H)-ylidenepropane-dinitrile-S, S-dioxide compounds; 
wherein B and B.sub.1 each represent a trivalent residue of an active 
methylene compound selected from those classes listed above for A; wherein 
L is a divalent organic linking group; and wherein B--L--B.sub.1 in 
combination can also be the residue of an arylene-diacetonitrile compound. 
A further preferred group of compounds are those where A is selected from 
one of the following structures: 
##STR3## 
wherein R.sub.1 is unsubstituted or substituted straight or branched chain 
alkyl of 1-8 carbons, unsubstituted or substituted cycloalkyl, 
unsubstituted or substituted aryl or alkenyl; wherein R.sub.2 and R.sub.3 
are independently selected from hydrogen or one of the groups listed for 
R.sub.1 ; R.sub.4 is selected from hydrogen, lower alkyl, lower alkoxy, 
halogen, carboxy or lower alkoxycarbonyl; R.sub.5 is an aromatic 
heterocyclic radical selected from unsubstituted or substituted 
2-benzothiazolyl, 2benzoxazolyl, 2-benzimidazolyl, pyridyl, pyrimidinyl, 
1,3,4-thiadiazol 2-yl, 1,2,4-thiadiazol-5-yl, 1,3,4-oxadiazol-2-yl, 
2-thiazolyl, thienyl or furanyl; R.sub.6 is selected from unsubstituted or 
substituted alkyl and aryl; R7 is cyano, --SO.sub.2 R.sub.1, --CO.sub.2 
R.sub.1, --CON(R.sub.2)R.sub.3, unsubstituted or substituted phenyl, or 
R.sub.5 ; and R.sub.8 is hydrogen or one of the groups represented by 
R.sub.1. 
Particularly preferred are compounds of Formula (I) wherein R.sub.1 is 
lower alkyl, R.sub.4 is carboxy or carboxylate ester, R.sub.5 is 5 
-carboxy (or ester)-2-benzothiazolyl, 5-carboxy (or ester)-2.benzoxazolyl 
and 5-carboxy (or carboxy)-2-benzimidazolyl; R.sub.6 is selected from 
phenyl or phenyl substituted with lower alkyl, lower alkoxy or halogen; 
R.sub.7 is selected from CO.sub.2 R.sub.1, wherein R.sub.1 is lower alkyl; 
and R.sub.8 is alkyl substituted with hydroxy or acyloxy and phenyl or 
benzyl substituted with carboxy or lower alkoxycarbonyl. 
Also preferred are compounds of Formula (II) wherein the active methylene 
residues B and B.sub.1 are independently selected from the following 
structures: 
##STR4## 
wherein R.sub.9 is selected from hydrogen, lower alkyl, lower alkoxy, or 
halogen; X is selected form --O--, --S--or --N(R.sub.2)--; Y is a divalent 
linking group selected from --O--, --S--, SO.sub.2, --OCO.sub.2 --, 
--CO.sub.2, --CON(R.sub.2)--, --SO.sub.2 N(R.sub.2)-- or --N(SO.sub.2 
R.sub.1)--; wherein R.sub.1 R.sub.2 and R.sub.6 are as defined above in 
the definition of A; L is a divalent organic residue selected from 
unsubstituted or substituted lower alkylene, cycloalkylene, unsubstituted 
or substituted phenylene, unsubstituted or substituted 
alkylene-phenylene-alkylene, alkylene-cycloalkylene-alkylene-, 
alkylene-Y-alkylene, alkylene-Y-phenylene-, alkylene-Y-phenylene-alkylene, 
alkylene-Y-alkylene-Y-alkylene or alkylene-phenylene-alkylene-; Y is as 
defined above in the definition of B; and wherein .dbd.B--L--B.sub.1 
.dbd.in combination has the structure .dbd.C(CN)--C.sub.6 H.sub.4 
--C(CN).dbd.. 
Particularly preferred are compounds of Formula (II) wherein B and B.sub.1 
are selected from the following structures: 
##STR5## 
wherein X is as defined above and L is selected from alkylene, 
alkylene-0-alkylene, phenylene, alkylenecycloalkylene-alkylene or 
alkylene-arylene-alkylene. 
Compounds of Formula (I) can be prepared as shown in the scheme below: 
##STR6## 
The intermediate aldehydes IV are reacted with the desired active methylene 
compounds using knoevenagel reaction conditions or in the presence of 
carboxylic anhydrides such as acetic anhydride. 
Intermediate aldehydes (IV), where R=--CO.sub.2 CH.sub.3, can be prepared 
as shown in the following scheme 
##STR7## 
As one of ordinary skill will appreciate, other esters in the 7-position 
can be introduced by using a different C.sub.1 -C.sub.8 alcohol in the 
esterification step above. Further, standard hydrolysis of intermediate 
(IV) above provides the corresponding 7-carboxy compound. 
As a further aspect of the present invention there are provided novel 
intermediates (III) and (IV) above, useful in preparing the compounds of 
the present invention. 
Compounds of Formula (II) may be prepared by reacting two molar equivalents 
of intermediate (IV) with a compound of the formula H.sub.2 B--L--B.sub.1 
H.sub.2 : 
##STR8## 
In contrast to the prior art, compounds of Formulae (I) and (II) of the 
present invention have unexpectedly high color yields (molar extinction 
coefficients) even with the carboxy or carboxylate ester group present in 
the residual aldehyde portion of the molecule. That is, the presence of 
the carboxy and carboxylate ester groups in (I) and (II) does not have an 
adverse effect on the color yield (see Table II) as noted above in the 
case of the prior art, e.g. compounds of Formulae A and B as set forth 
above, (see Table I, below). 
As a further aspect of the present invention, there is provided an 
amorphous color concentrate comprising an amorphous polyester having 
copolymerized therein or reacted therewith at least about 5.0 weight 
percent of a residue of Formula (I) and/or (II). 
As a further aspect of the present invention, there is provided a 
partially-crystalline polyester color concentrate comprised of a 
partially-crystalline polyester having copolymerized therein or reacted 
therewith at least about 5.0 weight percent of a residue of Formula (I) 
and/or (II). 
As a further aspect of the present invention, there is provided a colored 
semicrystalline powder having an average particle diameter of less than 
about 50 microns comprising a normally-amorphous polyester or a partially 
crystalline polyester which has been modified by 
dissolution-crystallization-precipitation to impart increased 
crystallinity thereto having copolymerized therein or reacted therewith at 
least about 5.0 weight percent of a residue of Formula (I) and/or (II). 
The colored polyester compositions provided by this invention comprise 
extrusion, molding and fiber grade, thermoplastic, linear polyester having 
reacted therewith or copolymerized therein a compound of Formula (I) 
and/or (II). It is apparent that the amount of residue present in the 
polyester material will vary substantially depending on several factors 
such as the particular compound being used, for example, the tint or depth 
of shade desired, and the thickness of the article, e.g., film, bottle, 
etc., to be produced from the colored polyester composition. For example, 
relatively thin film and thin-walled containers require higher levels of 
the compounds of Formula (I) and/or (II) to produce an equivalent color 
than do thicker articles such as sheet material or tubing. 
The polyesters which may be used in the preparation of the compositions of 
our invention include linear, thermoplastic, crystalline or amorphous 
polyesters produced by conventional polymerization techniques from one or 
more diols and one or more dicarboxylic acids. The polyesters normally 
have an inherent viscosity (IV) of about 0.4 to about 1.2. The preferred 
polyesters comprise at least about 50 mole percent terephthalic and/or 
2,6-naphthalenedicarboxylic 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 and/or 2,6-naphthalenedicarboxylic acid 
residues and from about 75 to 100 mole percent ethylene glycol residues. 
The 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, 
2-methyl-1,3-propanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 
1,4-cyclohexanediol, 1,2.cyclohexanedimethanol, 1,3cyclohexanedimethanol, 
X,8-bis(hydroxymethyl)-tricyclo-[5.2.1.0]-decane wherein X 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. 
The 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, 
1,3cyclohexanedicarboxylic acid, succinic acid, glutaric acid, adipic 
acid, sebacic acid, 1,12-dodecanedioic acid, 2,6.naphthalenedicarboxylic 
acid and the like. In the 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. 
The novel colored polyester compositions provided by this invention are 
useful in the manufacture of containers or packages for comestibles such 
as beverages and foods. By the use of known heat-setting techniques, 
certain of the polyesters are, in terms of color, I.V. and heat 
distortion, stable at temperatures up to about 100.degree. C. Such 
stability characteristics are referred to as "hot-fill" stability. 
Articles molded from these polyesters exhibit good thin-wall rigidity, 
excellent clarity and good barrier properties with respect to moisture and 
atmospheric gases, particularly carbon dioxide and oxygen. The colored 
polyesters are particularly useful for the fabrication of containers 
having a wall thickness of about 10 to 30 mils. Further, the color 
concentrates of the present invention may be melt-blended with other 
colored or uncolored polyesters or blended with other polymers used in 
packaging materials. Thus, as a further aspect of the present invention, 
there is provided a formed article comprising the polyester composition as 
described above. 
The linear polyesters most preferred for use in one embodiment of the 
invention comprise poly(ethylene terephthalate), poly(ethylene 
terephthalate) wherein up to 5 mole percent of the ethylene glycol 
residues have been replaced with residues derived from 
1,4-cyclohexanedimethanol and poly(ethylene 2,6-naphthalenedicarboxylate) 
and wherein the polyesters have been sufficiently heat set and oriented by 
methods well known in the art to give a desired degree of crystallinity. 
For the manufacture of blow-molded beverage bottles, the most preferred 
polyesters have an I.V. of 0.65 to 0.85, and a glass transition 
temperature (Tg) greater than 70.degree. C. The glass transition 
temperature (Tg) referred to herein is determined by Differential Scanning 
Calorimetry at a scan rate of 20 Centigrade Degrees/minutes. The inherent 
viscosities (I.V., dl/g) of the polyesters described herein are determined 
at 25.degree. C. using 0.5 g polymer per 100 mL of a solvent consisting of 
60 parts by weight phenol and 40 parts by weight tetrachloroethane. 
Colorants of Formula (I) and/or (II) are added at levels of about 1-5,000 
ppm (parts by weight) before or during the polymerization reaction. For 
example, the colorants may be added along with the initial glycol and 
diacid (or ester) reactants, immediately prior to the polycondensation 
stage or subsequently. For this end use, the colorant compound of Formula 
(I) and/or (II) may contain one or a multiplicity of reactive groups, 
since addition of the copolymerizable colorants in relatively low levels 
does not interfere substantially with the polymer preparation even if 
chain termination or cross linking do occur. 
Preferred groups which are reactive with at least one of the functional 
groups of the monomers from which the polyester is prepared, i.e., 
"polyester reactive groups", include hydroxy, carboxy, carbonyl halide, 
C.sub.1 -C.sub.10 alkoxycarbonyl, C.sub.3 -C.sub.10 alkenyloxycarbonyl, 
C.sub.3 -C.sub.8 cycloalkoxycarbonyl, or a group of the formula 
##STR9## 
wherein R.degree. is hydrogen; C.sub.1 -C.sub.10 alkyl; C.sub.1 -C.sub.10 
substituted alkyl; C.sub.3 -C.sub.8 cycloalkyl; phenyl; substituted 
phenyl; furanyl, or thienyl. 
The compounds of Formulae (I) and (II) and the reacted residues thereof 
possess the critical property of being sufficiently thermally stable to 
permit their copolymerization with polyesters by adding them at the start 
or at an early stage of the polyester preparation. Neither the colorant 
compounds nor their reacted residues sublime under polymerization 
conditions and the residues are not extractable from the polyesters. The 
thermal stability of the compounds of Formulae (I) and (II) is 
particularly important in the preparation of the color concentrates, i.e., 
polyesters containing from 1.0, especially at least 5.0, to as high as 50 
weight percent of colorant residue. The color concentrates are 
advantageous in that the colorant moiety (1) is stable to heat and 
chemicals, (2) is resistant to sublimation, heat migration, bleeding and 
leaching by solvents, (3) possesses high color value or chroma and visible 
light absorption characteristics which allows the color concentrates to be 
combined with other color concentrates to provide a range of colors, (4) 
is safe to humans and the environment, and (5) may be blended with other 
polymers. 
The colored semicrystalline powders provided by this invention may be 
derived from the color concentrates by means of a 
dissolution-crystallization-precipitation technique described in detail 
below. Various processes for the manufacture of finely-divided forms of 
polyesters have been disclosed in the prior art such as U.S. Pat. Nos. 
4,378,228, 4,254,207, 3,586,654, 3,931,082, 4,267,310, 4,305,864, 
4,451,606, 3,674,736 and 3,669,922. Some of these known processes include 
the presence of pigments such as carbon black during particle size 
reduction to produce colored polyester powders. The known procedures are 
summarized below. 
1. Comminution, as by grinding, which is difficult and expensive and 
results in highly irregular-shaped particle having a broad range of 
particle size distribution. 
2. Spray drying techniques which tend to produce "hollow shells" or porous 
particles and also are hazardous when organic solvents are used to 
dissolve the polyester. 
3. Dispersion processes which involve melting the polymer in an inert 
solvent in the presence of a non-ionic dispersing agent. Polyester, in 
contrast to other thermoplastic polymers, tend to hydrolyze (decompose) 
when melted in the presence of water and the particles thus produced have 
a strong tendency to agglomerate or coalesce. 
4. Heating under shearing agitation conditions a condensation polymer in an 
aprotic liquid which is not a solvent for the polymer and in the presence 
of a dispersing agent to form small liquid particles and cooling with 
agitation. Colorants added during this process are still extractable, 
sublimable, and may exude from the polymer. 
5. Solvent induced crystallization wherein an amorphous polymer is 
initially contacted with a crystal-inducing fluid under certain conditions 
while the polymer is subjected to physical and/or ultrasonic forces. 
Colorants added during this process are not reacted with the polymer and 
therefore are subject to removal from the polymer. 
6. Producing microcrystalline polyesters by a hydrolytic removal of 
amorphous regions of synthetic, linear polyesters followed by a mechanical 
disintegration of the resulting aggregated microcrystals. 
7. Crystallization of polyesters in the presence of nucleating agents. 
The prior art does not disclose the preparation of colored microcrystalline 
polyester powders wherein an amorphous or partially-crystalline polyester, 
having a thermally-stable, colorant compound of Formula (I) and/or (II) 
copolymerized therein, is converted to a colored, microcrystalline, 
polyester powder by means of a dissolution-crystallization-precipitation 
procedure. The prior art also fails to disclose microcrystalline, 
polyester powders containing high levels of colorant incorporated therein 
which cannot be removed by extraction or sublimation and which does not 
exude from the surface of the polymer. 
The amorphous color concentrates of this invention exhibit a glass 
transition temperature (Tg) and no, or only a trace of, crystallization or 
melting point by differential scanning calorimetry (DSC). Examples of such 
amorphous polyesters include those obtained by the polymerization of a 
colorant compound of Formula (I), terephthalic and/or 
2,6-naphthalenedicarboxylic acid and a branched-chain diol having the 
formula 
##STR10## 
wherein R.sup.20 is hydrogen or an unsubstituted or substituted alkyl, 
cycloalkyl or aryl radical, and R.sup.21 is an unsubstituted or 
substituted alkyl, cycloalkyl or aryl radical. Preferred amorphous 
polyester color concentrates have an inherent viscosity of about 0.2 to 
0.8 and are comprised of: 
(i) diacid residues comprised of at least 50, preferably at least 80, mole 
percent terephthalic and/or 2,6-naphthalenedicarboxylic acid residues; 
(ii) diol residues comprised of at least 50, preferably at least 80, mole 
percent of residues of a diol having the formula 
##STR11## 
wherein R.sup.20 is hydrogen or lower alkyl and R.sup.21 is lower alkyl; 
and 
(iii) residues of a colorant compound of Formula (I) 
and/or (II). 
The particularly preferred amorphous polyester color concentrates are 
comprised of (i) diacid residues consisting essentially of terephthalic 
and/or 2,6-naphthalenedicarboxylic acid residues; (ii) diol residues 
consisting essentially of 2,2-dimethyl-1,3propanediol residues; and (iii) 
residues of a colorant compound of Formula (I) and/or (II). 
Other amorphous polyesters, as defined above, suitable for preparing the 
colored semicrystalline powders may be obtained by employing (1) two 
dicarboxylic acids and one or more diols or (2) two diols and one or more 
dicarboxylic acids according to known procedures for obtaining amorphous 
polyesters. The polyester comprising a diacid component consisting of 75 
mole percent terephthalic acid residues and 25 mole percent 
1,4-cyclohexanedicarboxylic acid residues, a diol component consisting of 
1,4-butanediol residues and residues of a compound of Formula (I) and/or 
(II) is an example of such a polyester. 
The partially-crystalline color concentrates of this invention usually 
exhibit a glass transition temperature, a crystallization temperature and 
a melting temperature by DSC. These partially-crystalline, polyester 
concentrates are comprised of (i) diacid residues consisting of at least 
80 mole percent terephthalic acid residues, 2,6-naphthalenedicarboxylic 
acid residues, 1,3-cyclohexanedicarboxylic acid residues, 
1,4-cyclohexanedicarboxylic acid residues or a mixture thereof, (ii) diol 
residues consisting of at least 50 mole percent of residues having the 
formula --O--(CH.sub.2).sub.p --O-- wherein wherein p is 2, preferably 4, 
to 12 and (iii) residues of colorant compound (I) and/or (II). A preferred 
partially-crystalline color concentrate has a melting temperature of at 
least 110.degree. C. and is comprised of (i) diacid residues comprised of 
at least 80 mole percent terephthalic acid residues, (ii) diol residues 
comprised of at least 80 mole percent of residues of 1,4-butanediol and 
(iii) residues of a colorant compound of Formula (I) and/or (II). An 
especially preferred partially-crystalline color concentrate has a melting 
temperature of at least 110.degree. C. and consists essentially of (i) 
terephthalic acid residues, (ii) 1,4-butanediol residues and (iii) a 
colorant compound of Formula (I) and/or (II). 
The colored semicrystalline powders provided by this invention may be 
obtained by means of a dissolution-crystallization-precipitation procedure 
wherein the amorphous or partially-crystalline polyester color 
concentrates described above are dissolved in an organic solvent from 
which the polymeric color concentrate is recovered in a finely divided 
form consisting of particles of relatively uniform size, e.g., from about 
10 to 50 microns. If desired, the particle size of the colored 
semicrystalline powders may be reduced further by conventional grinding 
processes. Examples of solvents in which the amorphous and/or 
partially-crystalline concentrates may be dissolved include halogenated 
hydrocarbons such as aliphatic chlorides, e.g., methylene chloride; esters 
such as alkyl esters of carboxylic acids, e.g., ethyl acetate and methyl 
benzoate; hydrocarbons such as toluene; and ethers such as 
tetrahydrofuran. We have found methylene chloride to be a particularly 
effective solvent. 
The particular dissolution-crystallization-precipitation procedure utilized 
is not critical. The amorphous or partially-crystalline concentrate may be 
dissolved in a suitable solvent at elevated temperatures and then 
crystallized in a finely-divided state by cooling, with or without a 
reduction in the volume of solvent, i.e., either with or without a 
solution concentration step. Another useful technique involves dissolving 
the amorphous concentrate in an organic solvent, either at ambient or 
elevated temperature, and then adding to the solution another miscible 
solvent which causes crystallization of the colored semicrystalline 
powder. The use of methylene chloride as the primary solvent and an alkyl 
acetate such as ethyl acetate as the "crystallization-inducing" solvent 
has been found to be particularly efficacious. Depending on their intended 
utility, the colored semicrystalline powders may be extracted with a 
suitable organic solvent to remove relatively low molecular weight 
polyester oligomers. Examples of oligomer-extracting solvents include 
ketones such as acetone, 2-pentanone, 3-methyl-2-butanone, 
4-methyl-2-pentanone, 2.hexanone and 5-methyl-2-hexanone; hydrocarbons 
such as hexane, heptane and toluene; and ethers such as tetrahydrofuran. 
Another, but not preferred, dissolution-precipitation procedure involves 
dissolving the amorphous color concentrates in certain solvents, e.g., 
ethyl acetate, from which the polymeric color concentrate, after 
undergoing a change in morphology, precipitates. 
Some of the more crystalline polyesters such as poly(ethylene 
terephthalate) and poly(tetramethylene terephthalate) require the use of a 
high-boiling solvent in the dissolution-precipitation procedure. Examples 
of such high-boiling solvents include alkyl esters of aromatic carboxylic 
acids, e.g., alkyl benzoates, and alkyl phthalates; aliphatic dicarboxylic 
acid esters; glycol esters, e.g., ethylene glycol diacetate; diethylene 
glycol diacetate; aromatic ketones, e.g., acetophenone, and aromatic 
oxides, e.g., diphenyl oxide; and aliphatic carboxamides, e.g., 
N,N-dimethylformamide and isophorone. Methyl benzoate and ethylene glycol 
diacetate are particularly preferred high-boiling solvents since they are 
readily available, have a pleasant odor and do not cause color problems 
during crystallization which sometimes is a problem with acetophenone. 
In one variation of the process, crude polyester color concentrate is 
prepared and granulated to a very course powder which is heated with a 
high-boiling solvent (methyl benzoate) to facilitate solution. Upon 
cooling, crystallization-precipitation occurs and a diluent such as 
acetone usually is needed to permit stirring. Filtration gives the 
finely-divided powder which may require washing or reslurrying to remove 
the crystallization solvent. 
In another variation of the dissolution-crystallization-precipitation 
process, crystallization can occur as an integral part of the polyester 
color concentrate manufacturing process wherein the crystallization 
solvent is added to a melt of the concentrate to obtain a solution of the 
color concentrate which then may be obtained as a powder by precipitation. 
The polyester color concentrate powder is thus obtained in a purified form 
without the need of granulating by a means which may be used in 
conjunction with batch processing. 
The dissolution-crystallization-precipitation procedure alters the 
morphology of the amorphous and partially-crystalline polyester color 
concentrates in a number of respects. X-Ray diffraction analysis of the 
colored semicrystalline powders shows a marked increase in the 
crystallinity of the polyester and, while the amorphous polyester 
concentrates do not exhibit a melting temperature, the microcrystalline 
concentrates usually (almost always) exhibit a melting temperature by DSC. 
Although the weight average molecular weight (Mw) may increase, decrease 
or not be changed by the dissolution-crystallization-precipitation 
procedure, the number average molecular weight (Mn) always increases, the 
magnitude of the increase depending on the degree to which oligomeric 
material has been removed from the colored semicrystalline polyester 
powder. The polydispersity ratio (Mw:Mn) of the colored semicrystalline 
polyester is always less than that of the polyester concentrate from which 
it is prepared due to the increase in Mn (even when Mw increases, Mn 
increases more). Finally, the inherent viscosity of the colored 
semicrystalline powders normally is slightly higher than that of the color 
concentrate. 
The amorphous and partially-crystalline polyester color concentrates may be 
used in coloring various thermoplastic polymeric materials when 
nonextractability or non-volatility of the colorant is critical because of 
toxicity considerations, e.g., in rigid and flexible packaging materials 
for food. The concentrates and powders may be used in formulating inks, 
coatings, toners for impactless printing, and similar products. 
The polyester color concentrates may be prepared according to conventional 
esterification or transesterification and melt polycondensation procedures 
using (i) a dicarboxylic acid or, preferably, a lower alkyl ester thereof, 
(ii) a diol and (iii) a compound of Formula (I) and/or (II) bearing one to 
four, preferably about two, polyester reactive groups. Normally, at a 50 
mole percent excess of the diol is used. The colorant compound of Formula 
(I) and/or (II) preferably is added with the other monomers at the 
commencement of the color concentrate manufacture although it may be added 
subsequently, e.g., at the beginning or during the polycondensation step. 
The concentration (weight percent) of the colorant residue is determined 
by summing up the weights of all the components charged to the reactor and 
subtracting the sum of the weights of the components removed during 
transesterification and polycondensation, e.g., methanol and excess diol. 
The difference represents the theoretical yield of the color concentrate. 
The weight of the colorant of Formula (I) and/or (II) charged to the 
reactor is divided by the theoretical weight and multiplied by 100 to give 
the weight percent of colorant residue. 
The novel color concentrates and their preparation are further illustrated 
by the experimental section below. The inherent viscosities specified 
herein are determined at 25.degree. C. using 0.5 g of polymer (polyester 
color concentrate) per 100 mL of a solvent consisting of 60 weight percent 
phenol and 40 weight percent tetrachloroethane. The weight average 
molecular weight (Mw) and number average molecular weight value referred 
to herein are determined by gel permeation chromatography. The melting 
temperatures are determined by differential scanning calorimetry on the 
first and/or second heating cycle at a scanning rate of 20.degree. C. per 
minute and are reported as the peaks of the transitions. 
The color concentrates provided by this invention comprise a polyester 
composition having copolymerized therein at least 0.5 wt %, based on the 
weight of the polyester, or more of the residue of one or more of 
colorants of Formula (I) and/or (II) wherein the initial colorant contains 
about two polyester reactive groups. Normally, the color concentrates will 
not contain greater than about 30 wt % of colorant residue, with a 
concentration in the range of about 5 to 20 wt % being preferred. 
The term "substituted phenyl" as used herein refers to a phenyl group 
substituted with one or two groups chosen from the group consisting of 
halogen, hydroxy, cyano, nitro, C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.4 
alkoxy, carboxy, carboxymethyl, hydroxymethyl, amino, trihalo methyl and 
N-methylsulfonylamino. 
Examples of the term "substituted phenyl" include a mono- or di(halo)phenyl 
group such as 4-chlorophenyl, 2,6-dichlorophenyl, 2,5-dichlorophenyl, 
3,4-dichlorophenyl, 3-chlorophenyl, 3-bromophenyl, 4-bromophenyl, 
3,4-dibromophenyl, 3-chloro-4-fluorophenyl, 2-fluorophenyl and the like; a 
mono- or di(hydroxy)phenyl group such as 4-hydroxyphenyl, 3-hydroxyphenyl, 
2,4-dihydroxyphenyl, and the like; a nitrophenyl group such as 3- or 
4-nitrophenyl; a cyanophenyl group, for example, 4-cyanophenyl; a mono- or 
di(lower alkyl)phenyl group such as 4-methylphenyl, 2,4-dimethylphenyl, 
2-methylphenyl, 4-(iso-propyl)phenyl, 4ethylphenyl, 3-(n-propyl)phenyl and 
the like; a mono- or di(alkoxy)phenyl group, for example, 
2,6-dimethoxyphenyl, 4-methoxyphenyl, 3-ethoxyphenyl, 
4-(isopropoxy)phenyl, 4-(t-butoxy)phenyl, 3-ethoxy-4-methoxyphenyl and the 
like; 3- or 4-trifluoromethylphenyl; a nono- or dicarboxyphenyl group such 
as 4-carboxyphenyl or a mono- or di(hydroxymethyl)phenyl such as 
3-(hydroxymethyl)phenyl or 3,4-di(hydroxymethyl)phenyl; a mono- or 
di(aminomethyl)phenyl such as 2-(aminomethyl)phenyl or 
2,4(aminomethyl)phenyl; or a mono- or di(N-(methylsulfonylamino))phenyl 
such as 3-(N-(methylsulfonylamino))phenyl. Also, the term "substituted 
phenyl" represents disubstituted phenyl groups wherein the substituents 
are different, for example, 3-methyl-4-hydroxyphenyl, 
3-chloro-4-hydroxyphenyl, 2-methoxy 4-bromophenyl, 
4-ethyl-2-hydroxyphenyl, 3-hydroxy-4-nitrophenyl, 2-hydroxy-4-chlorophenyl 
and the like. 
The term "substituted alkyl" refers to an alkyl group substituted by one or 
more halogen, phenyl, hydroxy, amino, C.sub.1 -C.sub.6 alkoxycarbonyl, 
nitro, carboxy, 1 cyclohexyl, carbamoyl, cyano, C.sub.1 -C.sub.6 
alkylsulfonylamino or C.sub.1 -C.sub.6 alkoxy groups. The substituted 
alkyl groups may be substituted one or more times with the same or with 
different substituents. Preferably, the alkyl portion contains from one to 
ten carbon atoms, most preferably from one to six carbon atoms. 
Examples of the above substituted alkyl groups include cyanomethyl, 
nitromethyl, hydroxymethyl, trityloxymethyl, propionyloxymethyl, 
aminomethyl, carboxymethyl, allyloxycarbonylmethyl, 
allyloxycarbonylaminomethyl, carbamoyloxymethyl, methoxymethyl, 
ethoxymethyl, t-butoxymethyl, acetoxymethyl, chloromethyl, bromomethyl, 
iodomethyl, 6-hydroxyhexyl, 2,4-dichloro(n-butyl), 2-amino(iso-propyl), 
2-carbamoyloxyethyl chloroethyl, bromoethyl, fluoroethyl, iodoethyl, 
chloropropyl, bromopropyl, fluoropropyl, iodopropyl, and the like. 
The term "aryl" as used herein refers to heterocyclic aryl rings and 
carbocyclic rings. For example, aryl can be phenyl, naphthyl, phenanthryl, 
and the like. Aryl can also be 5 or 6-membered heterocyclic aryl rings 
containing one oxygen atom, and/or one sulfur atom, and up to three 
nitrogen atoms, said heterocyclic aryl ring optionally fused to one or two 
phenyl rings. Examples of such ring systems include thienyl, furyl, 
pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, 
isoxazolyl, triazolyl, thiadiazolyl, oxadiazolyl, tetrazolyl, 
thiatriazolyl, oxatriazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, 
thiazinyl, oxazinyl, triazinyl, thiadiazinyl, oxadiazinyl, dithiazinyl, 
dioxazinyl, oxathiazinyl, tetrazinyl, thiatriazinyl, oxatriazinyl, 
dithiadiazinyl, imidazolinyl, dihydropyrimidyl, tetrahydropyrimidyl, 
tetrazolo 1,5-b]pyridazinyl and purinyl, benzoxazolyl, benzthiazolyl, 
benzimidazolyl, indolyl and the like. 
Accordingly, the term "substituted aryl" refers to such aryl rings 
substituted by one or more halogen, phenyl, hydroxy, amino, C.sub.1 
-C.sub.6 alkoxycarbonyl, nitro, carboxy, cyclohexyl, carbamoy, cyano, 
C.sub.1 -C.sub.6 alkylsulfonylamino or C.sub.1 -C.sub.6 alkoxy groups. 
The term C.sub.1 -C.sub.8 alkoxycarbonyl refers to a C.sub.1 -C.sub.8 
alkoxy group bonded to a carbonyl function. In other words, the C.sub.2 
alkoxycarbonyl group is ethoxycarbonyl. The term C.sub.1 -C.sub.8 
optionally substituted alkoxycarbonyl refers to a C.sub.1 -C.sub.8 
alkoxycarbonyl group optionally substituted by one or more halogen, 
phenyl, hydroxy, amino, C.sub.1 -C.sub.6 alkoxycarbonyl, nitro, carboxy, 
cyclohexyl, carbamoyl, cyano, alkylsulfonylamino, or C.sub.1 -C.sub.6 
alkoxy groups. 
The term "alkyl" as used herein preferably refers to a C.sub.1 -C.sub.10 
straight or branched chain alkyl group. The term "lower alkyl", preferably 
refers to a C.sub.1 -C.sub.6 straight or branched-chain alkyl group. 
The term C.sub.1 -C.sub.20 divalent organic residue" (L) denotes typical 
organic linking groups bonded to the adjacent atoms through non-oxo carbon 
atoms. Thus, the C.sub.1 -C.sub.20 linking group may be selected from a 
wide variety of alkylene, alkenylene, alkynylene, cycloalkylene, 
carbocyclic and heterocyclic arylene and combinations of such divalent 
groups. The alkylene linking groups may contain within their main chain 
hetero atoms, e.g., oxygen, sulfur, sulfonyl, nitrogen, substituted 
nitrogen, and/or cyclic groups such as cycloalkylene, carbocyclic arylene, 
or divalent aryl groups.