CA1326318C - Extrudable polyester blends containing phosphate/epoxy stabilizer - Google Patents

Abstract

Abstract of the Disclosure Moldable polymer blends containing polyester(s) are described and containing a stabilizer useful to retard transesterification such polymer blends during processing of the blends at elevated temperatures, particularly at high temperatures above about 285°C. More particularly, the stabilizer comprises a phosphate-epoxy adduct. The stabilizer may optionally further comprise a reactive functionality component comprising a compound having a imide or oxazoline functionality and/or a hindered phenol component.

Description

~ 1326318 EXTRUDABLE POLYESTER BLENDS
CONTAINING PHOSPHATE/EPOXY STABILIZER

This invention is directed to a moldable polyester(s) and more particularly polymer blends containing polyesters and containing a stabilizer useful to retard transesterification in such blends containing polyester(s) during processing of the blends at elevated temperatures, particularly at temperatures above about 285C. More particularly, this stabilizer comprises a phosphate-epoxy adduct and optionally other components.
This application is a division of copending Canadian patent application Serial No. 582,151 filed November 3, 1988. That application claims a stabilizer composition.
Blending two or more plastic polymeric materials to achieve certain specific properties has become an important technology. Such polymer blends can be thought of as macromolecular plastic alloys. The polymeric materials of the blend are chosen so as to optimize the properties of the blend. For example, a high glass transition temperature (T9) polymer characterized by exceptional toughness and poor solvent resistance might be blended with a polymer which has excellent solvent resistance but a lower T9, where the latter polymer alone exhibits poor mechanical properties, e.g., tensile and flexural modulus. The resulting blend would be expected to have properties intermediate those of the individual blend constituents, the particular properties dependent on the proportions of the constituents.
Polyesters having aromatic moieties, e.g., polyarylates, are often employed as at least one of the polymers in such blends. Polyarylates are high temperature, high performance polymers which have a good combination of thermal and mechanical properties.
Additionally, polyarylates have inherent combust~on ~?
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132~318 resistancs as well as good weatherability. They also have good melt ætability at high temperature~ and good color retention. Still further, they have good processability which allows them to be molded into a variety of articles. Polyarylates have been blended with a number of other polymers, such a~ A~S resins ~U.S. Pat.
No. 3,792,118), polycarbonate resins (U.S. Pat. No.
3,792,115), polyurethane resins, methacrylate resinæ, etc. When there is an estreme of viscosity difference between a high viscosity polyarylate and the other polymer, ~overe service irregularitios (e.q., ~etting) are observea when these blands are in~ection molded.
Thi~ i5 ob~erved especially when polyarylate is blended with, for esample, ABS resins and poly(methyl methacrylate) resins. Additionally, the e~tremely high viscosity of polyarylates prevents a uniform of product from being obtained by conventional polymer tschniques, i.e., e~trusion or Banbury type melt mi~ing, when the polyarylate i8 blended with a resin having a lower viscosity. The non-uniform blend will not weather as well as the un$form bl~nd of the resins nor will it have an acceptable balance of properties. Still further, the inclusion of lower molecular weight constituents (which generally have lower melt viscosities) in order to lower the melt vi~cosity of the blend and make the blend more processable is generally at the e~pense of physical properties of the blend such as toughness. Therefore, it is preferred that the blend comprise constituents having molecular weights and melt viscosities similar to the polyarylate, e.g., polycarbonate. However, the relatively high melt visco~itie~ of such blends makes them difficult to proceas at normal processing temperature~, i.e., normally below about 285-C. It is well known that the proces~ability of such blends can be improved if the blend~ are moldod at higher , ~ . ~ . . ,:
: -temperatures. Howe~er, at such higher temperatures, eschange reactions, such as alcoholysis, acidolysis, and transesterification, among the polyester(s) generally take place. Such reactions may take place when one or two or more different polyester~ are pre~ent in the blend. The estent of such reactions effect~ the ultimate propertie~ of the blend. In tran~esterification, an esehange of the ester moiety between two similar or different polyester molecules takes plaee whieh generates new molecular configurations, and hence a new composition. Transesterification during the melt-mising of sueh blends results in poor mechanical propertie~ and 10B8 of erystallinity if the polyester is a ~emi-crystalline material. The produet becomes embrittled and loses impact strongth as compared to a product made from the same polymer blend in which tran~e~terification did not oceur.

French patent 2,567,137 to Bonum and Logeat diseloses ineorporating esterified ortho-phosphoric acids into eomposition~ eompri~ing thermoplastie polye~ter pair~ with diferent chemieal ~tructure~, such as ethyleneglycol terephthalato and butanediol polyterphthlate-1,4 to prevent transesterification during molding thereo~. It i~ also known that in blends containing ~olye~ter~, a residual catalyst generally remain~ from the polymerization which may accelerate, e.g., estor-earbonate, interchange reactions in the melt state. In 30 r~ A-, 8mith, Barlow and Paul, Journal of Appliod Polymer 8cience, Vol. 26, 4233-4245 ~1981), it is taught that lnterehang- reaetiona aro greatly suppres~ed by deaetivatlng tho r-~idual titanium eataly~t with ar~enic o~id- additive. U~ually, howe~er, rather than adding eom~ounds in an attempt to deaetivate eatalyts, .. . . . . . . ......... . .. .

. ... . . .

. . .~ .: , workers in the art add any of numerous compounds to such polymer blends to improve the physical properties thereof. For example, in U.S. Patent 4,066,611, it is taught that particular phosphorous compounds may be incorporated into a bisphenol A polycarbonate/poly-(tetramethylene terephthalate) blend to enhance the mechanical properties of the blend. U.S. patent 4,066,611 discloses that cyclic diphosphite compounds can improve the thermal-oxidative stability and hydrolytic stability of aromatic carbonate polymer compositions.
However, attempts to prevent transesterification of polymer blends containing polyester during processing at elevated temperatures above about 280C have been less than successful.
The present invention is directed towards the provision of polyester which in particular may contain polymer blends and which, according to this invention, also contain a stabilizer capable of retarding transesterification of the polyester during melt-mixing and molding, particularly at the higher temperatures generally necessary to effectively process such blends.
We have found an effective stabilizer comprising a phosphate-epoxy adduct wherein the phosphate is selected from specifically defined mono and diesters of orthophosphoric acid. Use of this stabilizer in polyester(s) and polymer blends containing polyesters allows them to be processed at higher temperatures without any deterioration in properties since it retards transesterification even at higher working temperatures (i.e., 285C and above). The stabilizer, which is claimed in the parent application, may comprise, in addition to this phosphate-epoxy adduct, an imide or oxazoline containing compound. The stabilizer may further or alternately comprise a hindered phenol which provides thermal stability to the ~ B~

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132~318 blend and is particularly useful at processing -temperatures above about 3000C.

A stabilizer useful in the present invention to retard tran~esterification in compositions comprising polyester, particularly moldable polymer blends comprising polye~ter, wherein the stabilizer comprises a phosphate-epoxy adduct which is the reaction product of:

~A) phosphate being selected from mono- and di-esters of orthophosphoric acid, said mono-and di-ester respectiv~ly ha~ing two and one ionizable hydrogen atoms; and (~) eposy; 5 wherein said phosphate and said epoxy are reacted in amounts 80 as to react at least about one of said ionizable hydrogen atoms of ~a~d phosphate with an epoxide group of said epoxy, 0 The stabilizer may further comprise, in addition to the phosphate-epoxy adduct described above, a reactive functionality component selected from compounds having (1) imide or (2) oxazoline functionality; and a hindered phenol component, when the stabilizer further comprises the reactive functionality component and/or the hindered phenol component, the phosphate-epoxy adduct component comprises at least about 51 weight percent o~ the stabilizer. Preferably, the phosphate-epoxy component comprises between about 51 and about 75 weight percent o~ the stabilizer. The reactive ~unctionality component is preferably selected from carbodiimides and ~tyrene polymer~ comprising oxazoline functionality on their backbones.

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6 ~326318 - The stabilizer disclosed herein is useful to retard transesterification of polyester containing polymer blends during their processing at elevated temperatures, particularly at temperatures above about 285C. In accordance with one aspect of this invention, there is provided a blend comprising polyester and the stabilizer described above.

In one preferred embodiment, there is provided a moldable compo6ition comprising a polymer blend comprising polyester and a stabilizer useful to retard transesterification thereof, as described above, wherein the polymer blend comprises.

(I) aromatic component ~elected from the group consisting of: polysulfone, polyarylsulfone, polyether ketone, polyester ethsr ketone and polyarylate, wherein the polyarylate is the reaction product of at laa~t one dihydric phenol and at lea~t one aromatic dicarbo~ylic ac~d: -(II) polyester being the reaction product of an aliphatic or cycloaliphatic diol, or mi~tures thereof and at least one aromatic dicarbo~ylic acid; and ~III) at least one thermoplastic polymer selected from the group con~isting of an aromatic polycarbonate, a styrene re~in, a ~inyl chloriae polymer, a poly~arylether), a copolyethere~ter block copolymer, and a polyhydro~yother.

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13263i8 Preferably, at least ~II) or (III) has the ability to crystallize upon cooling.

The above defined polymer blend composition comprises at least about 0.1 weight percent phosphate-epo~y adduct component. As disclosed above, the stabilizer may further comprise reactive functionality and~or hindered phenol component. If the stabilizer comprises reactive functional~ty component, the composition preferably comprises at least about 0.01 weight percent reacti~e functionality component. If the stabilizer comprises hindered phenol component, the composition preerably comprises at least about 0.01 weight percent hindered phenol component. The weight percent of each stabilizer component is based on the wei~ht of the polymer blend of the composition. If the stabilizer compri~e8 reactive funct~onality component and~or hindered phenol component, the phosphate-eposy component comprises, ~8 ~e8cribed above, at least 51 weight percent of the 8tabilizer. Pre~erably the polymer blend compri8e8 a blend of polyarylate, polyethylene terephthalate and polyc~rbonate.

Advantageously, the stabilizer used in thi6 invention retards transe6terficiation in polymer blends comprising polyester which allows the blends to be desirably processed at temperatures above 285C with substantially no change in physical properties. Since the polymer blend can be processed at higher temperatures, it may advantageously be compo~ed o~ polymers having higher molecular weights, which polymers generally also have more desirable physical properties, such as toughness and impact resi~tance. As pointed out above, such high molecular weight polymers have melt viscosities at normal processing temperatures which preclude their use in most ,, . : . :

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1~26318 applications. While a phosphate is somewhat useful by itself to retard transesterification of pol~ester blends at moderate temperature~ up to about 280OC, the phosphate-epoxy adduct used in this invention is capable of preventing transesterification, e~en at temperatures higher than about 285C, and even above about 300C.

The stabilizer used in this invention retards transesterification of the polyester pre~ent in the polymer blend during processing, i.e., melt-mixing and molding, of the blend. Because transesterification is substantially prevented and the polyester present in the blend does not undergo any significant change in its structure during processing, it is now possible to recycle in a second transformation, the polymer scrap produced by the first transformation. Noreover, the same mechanical and thermal properties can be obtained independent of the length of time the blend composition is maintained at the high temperature in the molding apparatus, e.g., an e~truder, which time can vary considerably depending on the type and size of the part being molded as well as the molding technique employed.
Presently, in order to somewhat limit the deterioration of compositions comprising polyester, they are maintained at elevated temperatures for relati~ely short periods of time. Incorporating the ~t~bilizer de~cribQd herein into polymer blends comprising polyester allows the composition to be proce~8ed at higher temperatures and for longer periods of time without any significant change in the phy8ical propertie8 of the polymer blend, which has dofinite commercial advantages. For esample, we have found that a polyarylate, polyethylene terephthalate, polycarbonate blend comprising an phosphate-epo~y adduct/carbodiimide/hindered phenol stabilizer has e~cellent thermal 8tability and can crystallize even : ... . ' . ;'., . .

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132~318 g after prolonged exposure to high temperatures, i.e., 30 minutes at 300C. The same blend without the stabilizer loses its individual glass transition temperature as well as ~rystallinity even after 10 minutes at 280C.

The stabilizer used in this invention comprises a phosphate-epoxy adduct (component) and, optionally, may comprise a reactive functionality component selected from compounds having (1) imide or (2) oxazoline functionality and/or hindered phenol component. If the composition is to be molded at temperatures above about 300C, it preferably includes the hindered phenol component. Each of these components as well as the polymer blend will hereinafter be discu~sed in greater detail.
The phosphate-epo~y adduct component iæ the reaction product of: ~A) phosphate and ~8) epo~y. The phosphate is selected from mono- and di~esters of orthophos~horic acid. As is known to those skilled in the art, the mono- and di-ester respectively have two and one ionizable hydrogen atoms. The phosphate and eposy are reacted in amounts 80 as to react at least about one of the ionizable hydrogen atoms of the phosphate with an eposide group of the eposy. That is, in the case of the mono- e~ter, which has two hydrogen atoms which are ionizable, at least one of the hydrogen atoms would be reacted with an eposide group of the eposy compound. The epo~y could be reactea in an amount 80 as to react more than one of the hydrogen atomg, up to an amount which would react both of the hydrogen atoms. In the case of the ~i-e~ter, whlch has one hydrogen atom which is ionizable, the eposy woula be reacted in an amount which would react this one hydrogen atom. In a reaction .

- lo 1326318 mi~ture of the phosphate/eposy reaction mi~ture, the epoxy can be present in escess. The phosphate component may be selected from any mono- or di-ester, many of which are commercially available, or mistures of any of them.
In the case when the phosphate is a misture of mono- and di-esters, the eposy and ester are reacted in amounts so as to react at least one of the ionizable hydrogens of the esters of the misture. As is known to those skilled in the art, the reaction of an eposide group of the eposy reactant with an ionizable hydrogen (i.e., an acid group) of the phosphate reactant generates a hydrosyl group.
The phosphate ester comprises ester functionality which may comprise groups selected, e.g., alkyl and aryl groups such as ethyl, propyl, butyl, pentyl, phenyl, p-methyl phenyl, and stearyl and the like. Particularly preferred of these mono- or di-esters are those which contain at least one phenyl group, since such compounds containing phenyl groups generally are relatively more stable at high temperatures. Esemplary of such mono- and di-esters are diphenyl phosphate, dibenzyl phosphate, naphthol AS
BI phosphate, with diphenyl phosphate being preferred in making the phosphate-eposy adduct f or uss in the polyarylate, polyethylene terephthalate, polycarbonate polymer blend described herein.
The eposy may be selected from monoeposides or polyeposides. Eposy material are well know to those skilled in the art and many are commercially available.
Esemplary of monoeposides are those whose carbon chain may be interrupted by osygen or be hydro~y substituted and glycidyl e8ters and glycidyl ethers. Esamples of such monoeposies which may be employed are the alkylene osides such as propylene oside, ethylene oside and 1,2-eposy decane, styrene oside, cyclohesene oside, glyc~dol acetate and glycidol. The preferred monomer ~ ' :

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preferably has no hydrosyl functionality. The epo~y may also be selected from polyeposides having two or more eposide groups. From the view of availability and cost consideration, however, two appears to be preferable.
The molecular weight of such eposies generally is between about 300 and lO,OOo. The polyeposide compounds used may be polyglycidyl ethers of polyhydric phenols, such as for esample, pyrocatechol. In particular, one class of suitable eposy compounds for the epo~y includes the lo reaction product of di or polyhydric, mono, di or polycyclic compounds with epihalohydrins of the formula X--CiH2 CY--CH2 wherein X is halogen such a chloro and Y is hydrogen or lower alky such as methyl or ethyl, which epihalohydrin reaction products are esemplified by such straight chain eposy terminated compoun8 containing glycidyl ether groups a8 bis-phenol-A-epichlorohydrin reaction products that are commercially available ~uch as, for esample, under the Epon (trademark) series, e.g., Epon 828, 832, 836, lO01, 1004 or 1007 (marketed by Shell Chemical Co.) or the Araldite ~trademark) ~eries, e.g., Araldit 6010, and 8001 (marketed by Ciba-Geigy). Included in the group of suitable polyeposide compounds containing more than two eposide groups are the novolac epo~y resins, e.g,, Epon 1138 and 1139 (trademark) and Cresol* novolac Araldite ECN 1235 and 1273 (trademark, Ciba-Geigy).
Compatible misture~ of any of the~e epo-y compounds are al~o ~uitable. Technique~ for react~ng phosphate and eposy are well known to those skilled in the art.
Selection of the optimal technigue for 8uch react~on will be apparent in view of the present disclosure.
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--`` 1326318 An optional component of the stabilizer used in this invention comprises a compound having reactive ~unctionality selected from imide and osazoline. Such functionalities are capable of reactinq with a hydrosyl or carbosyl group. This optional component comprises a compound (1) having one or more of such functionalities, ~2) which is soluble in the polymer blend and (3) which has thermal stability at the processing temperatures of the blend. This compound may thus, for esample, be lo selected from carbodiimides such as benzene,2,4,-diiso-cyanate-1,3,5-tris~l-methyl-ethyl)-homopolymer, 2,2'-dimethyl-4,4'-dinitrodiphenyl-carbodiimide, 2,2~,6,6'-tetrachloro-diphenylcarbodiimide, and 2,2'-dinitro-4,4'-dichloro-diphenylcarbodiimide. The first named carbodiimide is preferred for use in the preferred polymer blend comprising polyarylate, polyethylene terephthalate, and polycarbonate. Esemplary of compounds containing the osazoline functionality are reactive poly8tyrene, i.e., polymeric styrene having o~azoline functionality on its backbone, obtained from Dow Chemical Co., Midland, MI. The reactive functionality (optional) component of the stabilizer may also comprise mistures of any of the various suitable compounds de8cribed above. Selection of still other materials useful as this component would be apparent to tho~e skilled in the art in view of the present disclo~ure. Numerous such materials are known and many are commercially available.
The stabilizer optionally compri~e~ a hindered phenol. Numerous ~uch materials are known and are commercially available, e.g., octadecyl-3,5-di-tert-butyl-4-hydro~y-hydrocinnamate, 1,3,5-tris(4-tert-butyl-3-hy~ro~y-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(lH,-3H,5H)-trione, and 1,3,5-trimethyl-2,4,6-tris(3,5-di-., , ,, , , - . ~:
- : ` .. . ..

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tert-butyl-4-hydro~y-benzyl) benzene, the last one being preferred in the invention composition for use with the preferred polymer blend of polyarylate, polyethylene terephthalate and polycarbonate. The hindered phenol component, when employed as a component in the stabilizer, serves to improve the thermal stability of the polymer blend composition employing the ~tabilizer.
Incorporation of a hindered phenol component is particularly advantageous when the compo~ition is to be subjected to temperatures above about 300~C during processing, e.g., during the melt-mising or moldinq of the blend.

As disclosed above, if the stabilizer comprises the reactive functionality component and/or the hindered phenol component in addition to the phosphate-epoxy adduct, the stabilizer compri~es a ma~or weight proportion, i.e., greater than about 51 weight percent, of the phosphate-eposy adduct component. Preferably, the phosphate-epoxy adduct component comprises between about 51 and about 75 weight percent of the stabilizer. This stabilizer retards transe~terification in estrudable compositions containing polyester during the processings of ~uch compositions. In view of the present disclosure, it will be apparent to those skilled in the art that any composition containing polyester could benefit from the incorporation o~ the stabilizer used in this invention therein, such compo~itions being numerous and varied.
E~emplary of one embodiment of this type of composition, and one which particularly benefits from inclusion of the stabilizer since it is generally processed at the high temperatures which encourage transesterification, are tho~e compo8itions compri8ing a polyester blend of:

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13~6318 (I) aromatic component selected from the group consisting of polysulfone, polyarylsulfone, polyether ketone, polyesterether ketone and polyarylate, wherein the polyarylate is the reaction product of at least one dihydric phenol and at least one aromatic dicarbosylic acid;

~II) polyester being the reaction product of an aliphatic or cycloaliphatic diol, or `
mistures thereof, and at least one aromatic dicarbo~ylic acid; and (III) at least one thermoplastic polymer selected from the qroup consisting of an aromatic polycarbonate, a styrene resin, a vinyl chloride polymer, a poly(aryl ether), a copolyetherestic block copolymer, and a polyhe~drosy ether.

Such compositions comprise the phosphate-eposy adduct in at least about 0.1 weight percent, preferably between about 0.1 and about 3 weight percent, more preferably between about 0.4 and about 1.0 weight percent. The composition preferably compriseæ reactive functionality component wherein the composition preferably comprise~ at least about 0.01 weight percent of the reactive fu w tionality component, preferably between about 0.01 and about 1 weight percent, more preferably between about 0.1 and about 0.5 weight percent. When a hindered phenol is employed in such compositions, the eomposition preferably comprise~ at least about 0.01 weight pereent of the hindered phenol component, preferably between about 0.1 and about : - -, , " . ;. . . ~ . - ~ .

-` 1326318 1 weight percent, more preferably between about 0.1 and about O.S weight percent of this optional component. The weight percent of each stabilizer component is individually based on the wsight of the polymer blend of the composition.

The components of the stabilizer may be combined to form the system in any suitable manner according to technigues known to those skilled in the art. For esample, the stabilizer-o~ h~s-~nven~Lon may be made by dry blending the stabilizer co~ponent~s) into a powdered misture which is then available to be dusted into the polymer blend prior to loading the composition into the melt-mising apparatus. The order of com~ination of any components o the stabilizer is not critical.
Alternately, the stabilizer components can be added individually into the composition blend or pre-compounded with one of the polymer blend components. The stabilizer can also be metered into the polymer blend composition as it is being melt-mised in the appropriate apparatus, e.g., into an estruder barrel downstream port.

~Qmpone~t I

Polysulfones that may be employed in the practice of the present invention are high molecular weight polymers containing sulfone groups. The polyarylsulfones additionally contain aromatic nuclei in the main polymer chain. Polysulfones and polyarylsulfones are rigid, strong thermoplastic materials that can be molded, estruded, and thermoformed into a variety of shapes. They are highly resistant to chemicals, heat, osidation and hydrolysis. Numerous such materials are known to those skilled in the art and many are commercially available. For esample, the Amoco . ~ -.. ~ , . ~ --- ~326318 Corporation manufactures and sells polysulfones under the trademark Udel. The polyarylsulfones which may be suitably employed in the practice of this invention are commercially available from various sources, including 5 Amoco which markets a product under the trademark U~EL
polysulfone and from I.C.I. U.S. Inc. which markets such materials in various grades having different performance characteristics.

Polyether ketones and polyesterether ketones useful in the present invention as the aromatic component may be selected from any of numerous known materials of these t~rpes. Such materials are commercially available from I. C. I. U.S. Inc. under the trademark Victres.
The polyarylates suitable for use herein are derived from a dihydric phenol and an aromatic dicarbosylic acid. Esemplary of polyarylates are those made by reaction of bisphenol-A and aromatic dicarbosylic 20 acids such as terephthalic acid, isophthalic acid, naphlhalene dicarbosylic acid as well as mistures thereof. The polyarylates of the present invention can be prepared by any of the well known prior art polyester forming reactions, such as the reaction of the acid 25 chlorides of the aromatîc dicarbosylic acid with the dihydric phenol, the reaction of the diaryl ester of the aromatic dicarbosylic acids with the dihydric phenols, and the roaction of the aromatic diacids with diester derivatives of the dyhydric phenol. These processes are 30 described, for esample, in U.S. Pat. Nos. 3,317,464, 3,948,856, 3,780,148, 3,842,213.

. , . :
~.: '. ' ' . ' ' :: ' ' CQmpone~

The polyesters of the estrudable composition described herein are derived from an aliphatic or cycloaliphatic diol, or mistures thereof, containing from 2 to about 10 carbon atoms and at least one aromatic dicarbosylic acid. The polyesters as described herein can be produced by methods well known in the art.
Numerous such polyester are ~nown to thoæe skilled in the art and many are commercially available. The preferred dicarbosylic acid employed to make the polyester is terephthalic acid or mistures of terephthalic and isophthalic acid. The preferred polyesters are poly~l,4-cyclohenanedimethanol tere~iæo~-phthalate) and a lS copolyester of 1,4-cyclohasanedimethanol, ethylene glycol and terephthalic acid and poly~ethylene terephthalate).
The polyester component may also comprise in minor amounts, from about 0.5 to about 2 percent by weight, of the reaction produ~t of aliphatic acids and~or aliphatic polyols, to form copolyesters. The aliphatic polyols include glycol~ such as poly~ethylene glycol).
Copolyester~ are those derived from aliphatic dicarbosylic acids including cycloaliphatic straiqht and branched chain acids. In addition, there can be minor amounts of units derived from aliphatic glycols and polyols.

ComDonent III

The thermoplastic polymers suitable for use in this invention are selected from the group consisting o~
an aromatic polycarbonate, a styrene resin, an alkyl acrylate resin, a vinyl chloride polymer, a poly(aryl ether), a copolyetherester block polymer, a polyhydrosyether, or mistures thereof.

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, - ~ 18 1326~18 Polycarbona~

The thermoplastic aromatic polycarbonates that can be employed herein are homopolymers and copolymers and mi~tures thereof which have an intrinsic viscosity of 0.40 to 1.0 dl./g. as measured in methylene chloride at 25C that are prepared by reacting a dihydric phenol with a carbonate precursor. The polycarbonates can be prepared by methods well known to thoæe skilled in the art. Typical of some of the dihydric phenols that may be employed in the practice of this invention are bisphenol-A (2,2-bis~4-hydro~yphenyl) propane), bis(4-hydro-yphenyl) methane, 2,2-bis(4-dydro~y-3-methylphenyl) propane, 4,4-bis(4-hydro~yphenyl) heptane, 2,2-(3,5,3',5'-tetrachloro-4,4'-dihydrosydiphenyl) propane, 2,2-(3,5,5',5'-tetrabromo-4,4'-dihydro~ydiphenyl)-propane, (3,3'-dichloro-4,4'-dihydro~ydiphenyl) methane. It i8 of course, possible to employ two or more different dihydric phenols or a copolymer of a dihydric phenol with a glycol or with hydro~y or acid terminated polyester, or with a dibagic acid in the event a carbonate copolymer or inter-polymer rather than a homopolymer is dQsired for use in the preparation of the aromatic carbonate polymers of this invention.
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The carbonate precursor may be either a carbonyl halide, a carbonate ester or a haloformate. Typical of the carbonate esters which may be employed herein are diphenyl carbonate, di-(halophenyl) carbonates, and d~-(alklyphenyl) carbonates. The haloformate~ suitable for use herein include bis-haloformates of dihydric phenols or glycols. While other carbonate precursors , : . ...

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~- 13~6318 will occur to those skilled in the art, carbonyl chloride, also known as phosgene, is preferred.

Styrene Re~in The styrene resins suitable for use herein are A8S type polymers, the molecules of which consist of two or more polymeric parts of different compositions that are bonded chemically. The polymer is preferably prepared by polymerizing a conjugated diene such as butadiene or a conjugated diene with a monomer copolymerizable therewith such as styrene to provide a polymeric backbone. After formation of the backbone, at least one grafting monomer and preferably two are polymerized in the presence of the prepolymerized backbone to obtain the graft polymer.

~ he backbone polymer, as mentioned, is preferably a conjugated diene polymer such as polybutadiene polyisoprene, or a copolymer such as butadiene styrene, butadiene-acrylonitrile, or the like.
Esemplary of the monomer~ generally utilized in preparing the backbone of the polymer are butadiene; isoprene;
1,3-heptadiene; methyl-1,3-pentadiene;
~5 2,3-dimethyl-1,3-butadiene; 1,3-pentadiene;
2-methyl-3-ethyl-1,3-butadiene; 2-ethyl-1,3-pentadiene; -1,3- and 2,4-hesadienes, chloro and bromo substituted butadienes such as dichlorobutadiene, bromobutadiene, dibromobutadiene, mistures thereof, and the like. The preferred conjugated diene utilized herein i8 butadiene.

one group of monomer~ that may be polymerized in the pre~once of the prepolymerized backbone are preferably monovinylaromatic hydrocarbons. E~amples of the monovinylaromatic compounds and substituted , : ,, .

, ''``' : : ,-- ~ ., , 13263~8 monovinylaromatic compounds tha~ may be used are styrene and other vinyl substituted aromatic compounds including alkyl-, cycloal~yl-, aryl-, alkaryl-, aralkyl-, alko~y-, aryloxy-, and other substituted vinylaromatic compounds.
The preferred monovinylaromatic hydrocarbons used herein are styrene and/or ~-methylstyrene.

A second qroup of monomers that may be polymerized in the presence of the prepolymerized backbone are acrylonitrile, subætituted acrylonitrile and~or acrylic acid esters e~emplified by acrylonitrile and alkyl acrylates ~uch as methyl methacrylate. The preferred acrylic monomer used herein is acrylonitrile and the preferred acrylic acid esters are ethyl acrylate and methyl methacrylate.

In the preparation of the graft polymer, the conjugated diolefin polymer of copolymer e~emplified by 1,3-butadiene polymer or copolymer compriseæ from about 50% by weight to about 5% by weight of the total graft polymer composition and the monomers polymerized in the pre8ence of the backbone esemplified by styrene and acrylonitrile compri~e from about 40 to about 95% by weight of the total graft polymer composition.
The second group of qrafting monomers, esemplified by acrylonitrile, ethyl acrylate or methyl methacrylate, of the graft polymer composition, preferably comprise from about 10% to about 40~ by wei~ht of the total graft copolymer composition and the monovinylaromatic hydrocarbon e~emplified by styrene comprise from about 30 to about 70% by weight of the total graft polymer compo8ition.
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Optionally, the elastomeric backbone may be an acrylate rubber such 3S one based on n-butyl acrylate, ethylacrylate, 2-ethylhesylacrylate, and the like.
Additionally, minor amounts of a diene may be copolymerized in the acrylate rubber backbone to yield improved grafting with the matri~ polymer~

Alkyl Acrylat~ Re~in The alkyl acrylate resin useful in the present invention includes a homopolymer of methyl methacrylate (i.e., polymethyl methacrylate) or a copolymer of methyl methacrylate with a ~inyl monomer (e.g., acrylonitrile, N-allylmaleimide, N-vinly malemide, or an alkyl acrylate or methacrylate in which the alkyl group contains from 1 to 8 carbon atoms such as methyl acrylate, ethyl acrylate, but~l acrylate, ethyl methacrylate and butyl methacrylate). The amount of methyl methacrylate is not less than 70% by weight of this copol~mer resin.
The alkyl acrylate resin may be grafted onto an unsaturated elastomeric backbone such as polybutadiene, polyisoprene, and~or butadiene or isoprene copolymers.
In the case of the graft copolymer, the alkyl acrylate resin comprise8 greater than SO weiqht percent of the graft copolymers.

Vinyl Chloride Poly~s Vlnyl chloride polymers for the purpose of this invention are polyvinyl chloride and copolymers of vinyl chloride with olefinically unsaturated polymerisable compounds which contain at least 80 percent by weiqht of vinyl chloride incorporated therein. Olefinically unsaturated compounds which are suitable for . . ~' :~'' '.

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.

, ' t 22 ~326~18 ~opolymerization are, for e~ample, vinylidene halides such as vinylidene chloride and vinylidene flouride, vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyate, ~inyl chloroacetate, vinyl benzoate, acrylic and ~-alkyl-acrylic acids and their alkyl esters, amides and nitriles, methacrylic acid, methyl methacrylate, ethyl acrylate, 2-ethyl-hesylacrylate, butyl methacrylate, acrylamide, N-methyl acrylamide, acrylonitrile and methacrylonitrile, aromatic vinyl compounds such as styrene and vinyl naphthalene and olefinically unsaturated hydrocarbons such as ethylene, bicyclo-[2,2,1]-hepta-2-ene and bicyclo-t2,2,1i-hepta-2,5-dienes. These vinyl chloride polymers are known and can be prepared by the usual methods of emulsion, suspension, bulk or mass polymerisation. Vinyl chloride polymers which have molecular weights of 40,000 to 60,000 are preferred.

Poly~aryl et~h~ s The poly(aryl ether) resin component of the blend of this invention may be described as a linear, thermoplastic polyarylene polyether polysulfone, wherein the arylene units are interspersed with ether and sulfone linkages. These resins may be obtained by reaction of an alkali metal double salt of a dihydric phenol and a dihalobenzenoid compound, either of both of which contain a sulfone linkage -SO2-- between arylene groupings to provide sulfone units in the polymer chain in addition to arylene units and ether units.

Typical esamples are the reaction products prepared from 2,2-bis-(4-hydrosyphenyl) propane with 4,4'-dichlorodiphenylsulfone and eguivalent reaction product~ such as tho8e from 4,4'-dichlorodiphenylsulfone - - .
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with bisphenol of benzophenone (4.4'-dihydro2ydiphenyl ketone), or the bisphenol of acetophenone [l,l-bis(4-hydrosyphenyl) ethane~, or the bisphenol of vinyl cyclohesane [l-ethyl-l-(hydrosyphenyl)-3-(4-hydroxyphenylcoclohe~ane)], or 4,4'-dihydrosydiphenyl sulfone or alpha, alpha'-bist4-hydrosyphenyl)-p-diisopropylbenzene.

Co~olyetherester Block Copolymer The polyetheresters consist essentially of a multiplicity of recurrinq intralinear long chain and short chain ester units connected head-to-tail through ester linkages, said lonq chain ester units being represented by the following structure:

O O
-OGO-~R2-C-and said short chain ester units being represented by the following structure O O
-ODO-CR2-~-wherein: G is a divalent radical remaining after removal of terminal hydrosy groups from a poly(alkylene oside) gylcol having a molecular weight of about 400-3500: D is a divalent radical remaining after removal of hydrosyl groups from a low molecular weight diol having amolecular weight leæs than about 250; and R2 i8 a divalent radical remaining ater removal of carbosyl groups from a .-dicarbosylic acid having a molecular weight lsss than about 300; with the provisos that the short chain ester units constitute about 25-65~ by weight of the ~ ' .

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24 13~6318 copolyester, at least about 70% of the R2 groups must be 1,4-phenylene radicals, at least about 70~ of the D
groups must be the 1,4-butylene radicals, and the sum of the percentages of the R2 groups which are not 1,4-phenylene rsdicals and of the D groups which are not 1,4-butylene radicals cannot esceed about 30%.

Included among the low molecular weight diols (other than 1,4-butanediol) which react to form short chain ester units are acyclic, alicyclic and aromatic dihydro~y compounds.

Dicarbo~ylic acids (other than terephthalic acid) which are reacted with the foregoing long chain lS glycols or low molecular weight diols to produce the copolye~tors of this in~ention are aliphatic, cycloaliphatic or aromatic dicarbosylic acids of a low molecular weight. The term ~dicarbo~ylic acids~ as used herein, includes acid eguivalent~ of dicarbosylic acids having two functional carbo~yl groups which perform sub~tantlally like dicarbo~ylic acids in reaction with glycol~ and diols in forming copolyester polymers. These eguivalents include esters and ester-forming derivatives, such a~ acid halides and anyhydrides. ~he molecular welght roquirement portains to the acid and not to its oquivalent eJter or oster-forming deri~ati~e. Aromatic dicarbo~ylic acids are a preforred cla~ for preparing th~ copoly~ter polymers u~sful for composition~ of this in~entien. Among the aromatic acids, tho~e with 8-16 carbon atoms are preferred, particularly the phenylene dicarbo~ylic acids, i.e., terophthalic and isophthalic acid~.

Tho most preferred copolyesters of this 3S invention are tho~e prepared from dimethylterephthalate, , 1,4-butanediol and poly(tetramethylene oxide) glycol having a molecular weight from about 600-1500.

Po~Yhydr~y~the~

The thermoplastic polyhydro~yethers in the present invention ha~e the general formula ~ D-0-E ~~n wherein D is the radical residuum of a dihydric phenol, E' is a radical residuum of an epo~ide selected from mono- and diepo A des and contains from 1 to 2 hydrosyl groups and n is an integer which represents the degree of polymerization and is at least 30 and preferably is above about 80.

In general, thermoplastic polyhydro~yethers are prepared by contacting under polymerization conditions a dihydric phenol and an eposide containing from 1 to 2 eposide grOups in 8ub~tantially equimolar amounts. These polyhydro~y ether8 are prepared by methods well known in the art ~uch as those aetailed in, for esample, U.S. Pat.
Nos. 3,238,087; 3,305,528; 3,294,747, and 3,277,051.
U.S. patent 4,259,458 disclo~es the materials of Components I, II and III disclosed above.

In one embodiment of the e~trudable composition 30 blend employed with the stabilizer of the present invention, the first component (I), which is preferably a polyarylate, is preferably u~ed in amounts of from about 4 to about 80, more preferably from about 40 to about 60 , . ~ ~

13263~8 weight percent. The second component ~II), the polyester, is preferably used in amounts of from about 4 to about 60, more preferably from about lO to about 45 weight percent. The thermoplastic polymer is preferably used in amounts of from about lO to about 92, more preferably Çrom about lO to 60 weight percent.

The stabilizer may be incorporated into the composition as described above, either beore or during lo proce~sing of the composition according to any of the known technigues. It should, of course, be apparent to tho~e skilled in the art that other additi~es may be included in the present compositions. These additi~es include plasticizers; pigments; flame retardant additi~es; rein~orcing agents, such as glass fibers;
thermal stabilizers; ultraviolet light stabilizers processing aids, impact modifiers and the like. Useful flame retardant materials include decabromodiphenyl ether and triarylphosphates, such as triphenylphosphate, and halogen monomer organic compounds such as tetrafluoro-phthalic acid or tetrabromo-phthalic anhydride, bi~-(di- or pentabromophenyl) o~ide, these organic compounds e~entually being associated with compounds with synergic effect such as antimonium anhydride. Polymeric compounds especially, e.g., bromide polystyrene and bromide polycarbonate8 are also suitable as flame retardant8. The impact modifiers which can be used are described in u.S. Patent No. 4,231,921. ~hese impact modifiers are a graft copolymer of a vinyl aromatic, an acrylate, an unsaturated nitrile, or mixtures thereof, grafted onto an unsaturated elastomeric backbone and having a tensile modulus (as measured by ASTM D-638, except that the test piece is compression molded to a ~ . , " ~ .
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^ 27 1326318 20 mil thickness) of less than about 100,000 psi, and preferably from about 15,000 to less than about 100,000 psi .

The invention will be further understood by referring to the following detailed e~amples. It should be understood that the specific esamples are presented by way of illustration and not by way of limitation. Unless otherwise specified, ~parts~ is intended to mean ~parts by wei~ht~.

E~ample 1 A. A phosphate-eposy adduct according to this invention is prepared as follows:

~ o a three-neck round bottom flask equipped with a thermometer and a drying tube is charged 19.2 paxts of Epon 1001 ~trademark, Shell Chemical Co., epo~y resin) and 10 parts o diphenyl phosphate in 116.8 parts of acetone. The system is blanketed with nitrogen and stirred overnight. A light brown solution is obtained.

~. A polyester blend composition comprising the pho~phate-epo~y adduct ~A~ prepared abo~e and carbodiimide i~ made from the following materials:

Ra~ Ma~g~ials Parts ~y_~i9h~

30 Ardel (D-100) 50 Calibre2 (300-15) 20 Cleartuf3 (1006~) 30 Solution ~A~ 2.5 Carbod~imide 0.25 .
.. . . .

Trademark, Amoco Performance Products, Inc., Ridgefield, C~, polyarylate 2Trademark, Dow Chemical Co., Midland, MI, polycarbonate 3Trademark, Goodyear Tire and Rubber Co., Akron, OH, polyethylene terephthalate Solution ~A~ is added to the polyethylene terephthalate and is vacuum dried at 110 C. The ingredients are premised and dried in a vacuum oven at 110C. The above composition is melt e~truded in a Haake mini-estruder at 290C.

Different1al ScannL~g Calorimetry ~DSC) is uæed to evaluate the stability of the e~trudate. The criteria for stability are the retention of the crystalline heat of fusion and the melting point of the polyethylene terephthalate. The glass transition temperatures of polycarbonate and polyarylate may es~entially be masked by the cold crystallization esotherm of the polyethylene terephthalate.

The resulting estrudate gives e~cellent thermal stability and can crystalize after prolonged e~posure at hiqh temperature (i.e., 30 minutes at 300C).

When the solvent in part ~A~ is evaporated and 0.5 parts of the dried compound ~from ~A~) is uæed in forming the composition of ~B~, a similar result is obtained.

The same polymer blend composition without stabilizer loses its individual glass transition temperature as well as crystallinity under the same test ,, . ~
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" 1326318 conditions which is a strong indication that an estensive ester eschange reaction takes place without stabilizer.

Esa~ple 2 A polymer blend composition comprising phosphate-epo~y adduct and carbodiimide is prepared as in Esample lB and estruded in a Haake mini-estruder at 315C. The estrudate gives escellent thermal stability and can crystalize.

A similar polymer blend composition is made but without stabilizer. It is estruded in a Haake mini-estruder at 315C. This estrudate eshibits poor lS impact resistance and cannot crystallize. Its solvent resistance is also poor.

Esample 3 A. A phosphate-eposy adduct according to this invention i8 prepared as follows:

A three-neck round bottom flask i8 equipped with a thermometer, an inert ga~ tube, and a drying tube.
25 66 parts of Epon 1001 (trademark, Shell Chemical Co., eposy re~in~ is dissolved in 397 parts of acetone. The solution is ~tirred by a magnetic stirrer. 34 parts of diphenylphosphate is added incrementally. The whole stystm i~ blanketed with dried nitroqen. The solution is 8tirred for at least 24 hours. The ~olution i8 then decanted snd the acetone is dried by evaporation. The final adduct is further dried in vacuo for at least 24 hours. An infrared spectrum reveals that the eposide absorption at wave number 925 and 862 disappears at the end of the reaction.

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13~318 The following ingredients are premised and dried in a vacuum oven at 110C:

Raw Mate~ials Parts by Wei~ht Ardell (D-100) 50.0 Calibre2 (300-15) 20.0 Cleartuf3 (1006B) 28.3 XE7646 1.7 Adduct Es. 3A o.s Trademark, Amoco Perormance Products, Inc., Ridgefield, CT, polyarylate 2~rademark, Dow Chemical Co., Midland, MI, polycarbonate 3Trademark, Goodyear Tire and Rubber Co., Akron, OH, polyethylene terephthalate 4KE7646 is a concentrate of polyethylene terephthalate with 15% of Aromatic polycarbodiimide 1P-100) from Mobay Chemical Co., Rhein-Chemie Div., Mogadove, OH.

The misture is then charged into a Haake mini estruder and estruded to form a polyester blend. The masimum temperature setting for the estruder is 290C.

The estrudate is evaluated by DSC as outlined in the following isothermal test and the test results are li8ted below:

Isothermal Te~t The sample i8 first rapidly scanned at a rate of 20-C/min. and then isothermally held at the masimum temperature for a specific period of time. The sample is then cooled to ambient temperature and rescanned at a slower rate of 5C/minute from 30C to 280C.

~f~J~ Tm(C) Isothermal Test:
Original 13.6 252.4 30 min./300C 8.6 24~.3 Esample 4 A. The procedure of Esample 3A is repeated with the following changes: 28.6 parts of Epon 825 (trademark, Shell Chemical Co., eposy resin) is dissolved in 286 parts of acetone and 71.4 parts of diphenylphosphate is added incrementally into the solution with stirring. The reaction is continued for at least 24 hours at ambient temperature. The solution is used without drying.

The followi~g first four ingredients are premised and dried in a vacuum oven at 110C:

Ra~ MaterialsPar~ by Weight Ardell (D-100) 50.0 Calibre2 ~300-15)20.0 Cleartuf3 (1006~)28.3 XE7646 1.7 æolution Adduct Es. 4A 9.5 .

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: ` 1326318 Trademark, Amoco Performance Products, Inc., Ridgefield, CT, polyarylate 2Trademark, Dow Chemical Co., Midland, MI, polycarbonate 3Trademark, Goodyear Tire and Rubber Co., Akron, OH, polyethylene terephthalate 4KE7646 is a concentrate of polyethylene terephthalate with 15% of Aromatic polycarbodiimide (P-100) from Mobay Chemical Co., Rhein-Chemie Div., Mogadove, OH.

The solution from Es. 4A is added to the polymer pellet misture and the misture is further tumble-mised thoroughly. The solvent is then evaporated at ambient temperature and further dried under vacuum for at least 16 hours. The misture is then charged into a Haake mini estruder and estruded. The masimum temperature setting for the estruder is 290C. The estrudate i8 evaluated by DSC as outlined above and the test results are listed below:
~f(J/g) Tm ~-C) Isothermal Test: Original 14.0 254 30 min.~300-C 9.5 251 From the above e~amples, it can be seen that the incorporation of the stabilizer of this invention at elevated processing temperatures, i.e., above about 285 C, prevent~ transesterification and maintains the properties of the blend.

In view of the di~closure, many modifications of this invention will be apparent to those skilled in the art. It is intended that all such modificatlons which - 132631~

fall within the true scope of this invention be included within the terms of the appended claims.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A composition comprising:
I. polyester; and II. stabilizer;
wherein said stabilizer comprises a phosphate-epoxy adduct which is the reaction product of:
(A) phosphate being selected from mono- and di-esters of orthophosphoric acid, said mono and di- ester respectively having two and one ionizable hydrogen; and (B) epoxy;
wherein said phosphate and said epoxy are reacted in amounts so as to react at least about one of said ionizable hydrogen atoms of said phosphate with an epoxide group of said epoxy.

2. A composition according to claim 1, which further comprises a component selected from:
(i) reactive functionality component selected from compounds having (1) imide or (2) oxazoline functionality;
(ii) hindered phenol component; and (iii) mixtures of (i) and (ii);
wherein said phosphate-epoxy adduct comprises at least about 51 weight percent of said stabilizer.

3. The composition according to claim 2 wherein said phosphate-epoxy adduct comprises between about 51 and about 75 weight percent of said stabilizer.

4. A moldable composition comprising a polymer blend comprising polyester and a stabilizer useful to retard transesterification thereof;

the polymer blend comprising:
(I) aromatic component selected from the group consisting of: polysulfone, polyarylsulfone, polyether ketone, polyester ether ketone and polyarylate, wherein the polyarylate is the reaction product of at least one dihydric phenol and at least one aromatic dicarboxylic acid;

(II) polyester being the reaction product of an aliphatic or cycloaliphatic diol, or mixtures thereof and at least one aromatic dicarboxylic acid; and (III) at least one thermoplastic polymer selected from the group consisting of an aromatic polycarbonate, a styrene resin, a vinyl chloride polymer, a poly(arylether), a copolyethester block copolymer, and a polyhydroxyether; and the stabilizer comprising a phosphate-epoxy adduct which is the reaction product of:

(A) phosphate being selected from mono- and di-esters of orthophosphoric acid, said mono-and di- ester respectively having two and one ionizable hydrogen atoms; and (B) epoxy;
wherein said phosphate and said epoxy are reacted in amounts so as to react at least about one of said ionizable hydrogen atoms of said phosphate with an epoxide group of said epoxy and said phosphate-epoxy adduct is present in said composition in an amount of at least 0.1 weight percent based on the weight of said polymer blend.

5. The composition according to claim 4, wherein said stabilizer further comprises a component selected from:
(i) reactive functionality component selected from compounds having (1) imide or (2) oxazoline functionality;
(ii) hindered phenol component; and (iii) mixtures of (i) and (ii);
wherein said phosphate-epoxy adduct comprises at least about 51 weight percent of said stabilizer.

6. The composition according to claim 5, wherein said phosphate-epoxy adduct comprises between about 51 and about 75 weight percent of said stabilizer.

7. The composition according to claim 5, wherein said composition comprises at least about 0.01 weight percent reactive functionality component, the weight percent of the reactive functionality component being based on the total weight of said polymer blend.

8. The composition according to claim 5, wherein said composition comprises at least about 0.01 weight percent hindered phenol component.

9. The composition according to claim 5, wherein said composition comprises at least about 0.01 weight percent reactive functionality component and at least about 0.01 weight percent hindered phenol component, wherein the weight percent of each of said components of said stabilizer are based on the total weight of said polymer blend.

10. The composition according to claim 5, wherein said composition comprises between about 0.1 and about 3 weight percent said phosphate-epoxy adduct, between about 0.01 and about 1 weight percent reactive functionality component and between about 0.01 and about 1 weight percent hindered phenol component, the weight percent of each stabilizer component being based on the total weight of said polymer blend.

11. The composition according to claim 5, wherein said aromatic component (I) is present in amount between about 4 and 80 weight percent, said polyester component (II) is present in an amount between about 4 and about 60 weight percent and said thermoplastic component (III) is present in an amount between about 10 and 92 weight percent, the weight percent of each of said components (I), (II), and (III) being based on the total weight thereof.

12. The composition according to claim 5, wherein said aromatic component (I) is polyarylate, said polyester component (II) is polyethylene terephthalate, and said thermoplastic component (III) is polycarbonate.

13. The composition according to claim 5, wherein said stabilizer comprises diphenyl phosphate-epoxy adduct, benzene-2,4-diisocyanate-1,3,5-tris(1-methylethyl)-homopolymer, and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxy-benzyl) benzene.

14. The composition according to claim 5, wherein at least said component (ii) or (i) has the ability to crystallize upon cooling.