CA2030616A1 - Composition - Google Patents

Abstract

COMPOSITION
ABSTRACT OF THE DISCLOSURE
A composition comprising a copolyestercarbonate derived from a dihydric phenol, a carbonate precursor, and an aliphatic alpha omega dicarboxylic acid or ester precursor wherein the dicarboxylic acid or ester precursor has from 10 to about 20 carbon atoms, inclusive, and is present in the copolyestercarbonate in quantities of from about 2 to 30 mole percent of the dihydric phenol.

Description

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COMPOSITION
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8ACKGROUND OF T~E INVENTION
Polycarbonates are well known as a tough, clear, highly impact resistant thermoplastic resin. However the polycarbonates are also possessed of a relatively high melt viscosity. Therefore in order to prepare a ~ molded a~ticle from polycarbonate, relatively high extrusion and molding temperatures are required.
Various efforts throughout the years to reduce the melt viscosity while also maintaining the desired physical properties of the polycarbonates have been attempted.
These methods include the use of plasticizer~, ~he use of aliphatic chain stoppers, reduc~ion of mslecular weight, the preparation of bisphenols having long chain aliphatic substituents and various polycarbonate copolymers as well aq blends of polycarbonate with other polymers.
With respect to plasticizers, the~e are generally used with thermoplastics to achieve higher melt flow.
Hswever usually accompanying the plasticizer incorporation into polycarbonate co~positions are undesirable features such as embrittlement and fugitive characteristics of the plasticizer.
I~creased flow can be fairly readily obtained with the use of aliphatic chain stoppers, however impact reqistance as measured by notched izod drops significantly. Embrittlement may also be a problem.
When utilizing a bisphenol having a lengthy aliphatic chain thereon, increases in flow can be observed. However these are usually accompanied by substantial decreases in the desirable property of impact strength.

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~ educing the molecular weight of poLycarbonate has also been useful to increase flow ~or applications requiring thin wall sections. However, molecular weight reduction is limited in the extent that it can be practiced before properties such as ductility and impact streng~h are severely hampered.
Blends of polycarbonate with other polymers are useful to increase melt flow, however the very useful property of transparency is generally lost.
With respect to polycarbonate copolymers it has been well known that a reduced glass transition temperature Tg, can be obtained by introducing aliphatic ester fragments into the polycarbonate backbone. Examples of this work go back as early as the original copolyestercarbonate patent of Goldberg, USP 3,169,121 wherein at column 3, line ~4 to column 4, lin~ 41 various aliphatic dibasic acids are disclosed as being appropriate for usage in making copolyester-carbonates. Reduced softening points axe noted. At column 4, line 11, a2elaic and sebacic acids are disclosed. At column 7, example 4, a 50 mole percent ester con~ent bisphenol-A copolyestercarbonate based on bisphenol-A using azelaic acid as the ester linkage is disclased. Various other patents since that time have broadly disclosed the use of aliphatic acids in the preparation of copolyestercarbonate for example USP
3,030,331, 4,238,596, 4,238,597, 4,504,634, 4,487,896 and 4,252,922. Kochanowski USP,4,286,083, specifically refers to the making of a copolyestercarbonate utilizing bisphenol-A, azelaic acid and phosgene in example 6 at column 9. 25 mole percent of the azelaic acid, based on the moles of bisphenol-A, was contacted with the bisphenol-A together with phenol as a chain stopper, and triethylamine as a catalyst in an inter-facial reaction with phosgene wherein the pH was main-tained at 6 over a period of 35 minutes and then raised to 11.4 for a period of 3~ m~nutes. Generally ~hese , - . i , :

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copolyestercarbonates with aliphatic linkages have sig-nificantly lowered Tgs than the polycarbonate and there-fore are processable at lower temperature. However, these polymers as in Kochanowski do not have other physical properties reported, in particular impact resistance or impact resistance under various environ-mental conditions such as heat aging and/or reduced temperature.
- Chain stoppers have been utilized in making polymers for many decades. ~he function of the chain stopper in the preparation of the polymer is to control the molecular weight. Generally these chain stoppin~
compounds are monofunctional compounds similar to the functionality of a repeating unit of the polymer. For quite some time scant at~ention was dixected to the structure of the chain stopping agent o~her than it be reactive with the monomer unit during the praparation o~
the poLymer and be compatible with the polymer. In the la~t few years more attention has been directed to the struc~ure of the chain stopper. It has been found that the structure of the chain stopping compound can signi-ficantly effect the property spectrum o~ the polymer.
Fcr many years, phenol had been the standard chain stopping agent used in the preparation o~ polycarbonate.
At times paratertiarybutylphenol was employed as a chain stopping agent. Lately more attention has been focused on other materials for preparation of the polycarbonate.
USP 4,269~964 , disclosed the usage of isooctyl and isononyl substituted phenols as chain stoppers for poly-carbonate. Additionally paracumylphenol and chromanylcompounds have been utilized to chain stop poly-carbonates. Both the paracumylphenol and chromanyl compounds have been utilized to chain stop copolyester-carbonates wherein there is a totally aromatic molecule with hi~h ester content, see USP 4,774,315 and ., ' ,' '' '' , ' ' ,' ' . ' ~ ' 2 ~

4,788,275. Accompanying the usage of the larger sized endgroups has been t~e ability to obtain the same or essentially the same physical characteristics of the polycarbonate but at a lower molecular weight. This lower molecular weight provides better flow than a polycarbonate of a hig~er molecular weight. However these ~ystems reach a point wherein the chain stopping agent cannot solve the problems caused by utilizing a shorter chain length i.e. lower molecular weight polycarbona~e. Embrittlement occurs, therefore ~here still exists a need for a polymer having lower processing temperature but which i5 accompanied by substantially increased flow and essentially the full spectrum of polycarbonate properties.
A new polymer system has now been discoverecl which manages to combine excellent processability due to its extremely high me}t flow with essentially maintained physicaL properties such as toughness, ~ransparency, and impact resistance.
SU~MARY OF T~E INVENTION
In accordance with the inventicn there is a com-position comprising a copolyestercarbonate polymer derived from a dihydric phenol, a carbonate precursor a~d an aliphatic alpha omega dicarboxylic acid or ester precursor wberein the ~icarboxylic acid has from ten to about ~wenty carbon atoms, inclusive and the dicar-boxylic acid is present in the copolyestercarbonate in quantities of from about 2 to 30 mole percent of the dihydric phenol.
A further aspect is the copolyestercarbonate of the invention extended to include dicarboxylic acids of 8 and 9 carbon atoms, which is endcapped with a monophenolic compound which provides the copolyester-carbonate with better Notched Izod impact resistance and ductility after aging than the phenol endcapped copolyestercarbonate.

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Dihydric phenols which are useful in preparing the copolyestercarbonate of the invention may be represented by the general formula n ~7~)n~ Figure 1 ~O ~ ~ OH

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wherein:
R is independently selected from halogen, monovalent hydrocarbon, and monovalent hydrocarbonoxy radicals, Rl is independently selected from halogen, monoYalent hydrocarbon, and monovalent hydrocarbonoxy radicals;
N is selected rom divalent hydrocarbon O O O
radicals, -S-, -S-S-, -0-, -S-, -S~, and -C-;
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n and nl are independently selected from integers having a value of from 0 to 4 in d usive; and b is either zero or one.
The monovalent hydrocarbon radicals represented by R and Rl include the alkyl, cycloalkyl, aryl, aralkyl and alkaryl radicals. The preferred alkyl radicals are those containin~ from 1 to about 12 carbon atoms. The preferred cycloalkyl radicals are those containing from 4 to about 8 ring carbon atoms. The preferred aryl radicals are those containing from 6 to 1~ ring carbon atoms, i.e., phenyl, naphthyl, and biphenyl. The preferred alkaryl and aralkyl radicals are those containing from 7 to about 14 carbon atoms.

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The preferred halogen radicals repre~ented by R and Rl are chlorine and bromine.
The divalent hydrocarbon radicals represented by W
include the alkylene, alkylidene~ cycloaLkylene and cycloalkylidene radicals. The preferred alkylene radicals are those con~aining from 2 to about 30 carbon atoms. The preferred alkylidene radicals are those containing from 1 to about 30 carbon atoms. The preferred cycloaLkylene and cycloalkylidene radicals are those containing from 6 to about 16 ring carbon atoms.
The monovalent hydrocarbonoxy radicals represented by R and Rl may be represented by the formula - oR2 wherein R is a monovalent hydrocarbon radical of the type described hereinafore. Preferred monovalent hydrocarbonoxy radicals are the alkoxy and aryloxy radicals.
Some illustrative non-limiting examples of the dihydric phenols falling within the scope of Formula II
include:
2,2-bi 9 ~ 4-hydroxyphenyl)propane ~bisphenol-A);
2,2-bis~3,5-dibromo-4-hydroxyphenyl)propane;
2,2-bis~3,5-dimethyl-4-hydroxyphenyl~propane 1,1-bis~4-hydroxyphenyl)cyclohexane:
1,1-bis~3,5-dimethyl-4-hydroxyphenyl)cyclohexane;
1,1-~is~4-hydroxyphenyl)decane;
1,4-bis~4-hydroxyphenyl)propane:
1,1-bis54-hydroxyphenyl~cyclododecane;
1,1-bis~3,5-dime~hyl-4-hydroxyphenyl)cyclododecar.e;
4,4 -dihydroxydiphenyl ether;
4,4 -thiodiphenol;
4,4 -dihydroxy-3,3 -dichlorodiphenyl ether; and 4,4 -dihydroxy-2,5-dihydroxydiphenyl ether.

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Other useful dihydric phenols which are alsosuitable tor use in the preparation of the above polycarbonates are disclosed in U.S. Patent Nos.
2,999,835; 3,028,365; 3,334,154; and 4,131,575.
s The carbonate precursor utilized in the invention can be any of the standard carbonate precursors such a~
phos~ene, diphenyl carbonate and the llke. When using ~ - an in~erfacial process or a bischloroformate process it is also preferred to use a standard cataLyst system well known in the synthesis of polycarbonates and copoly-estercarbonates. A typical catalyst system is that of an amine system such as tertiaryamine, amidine or guanidine. Tertiaryamines are generally employed in such reactions. ~rialkylmines such as triethylaminQ are generally preferred.
The monomer which supplie~ the ester units in the copolyestercarbonate is a~ aliphatic alpha omega dicarboxylic acid ~rom 10 to about 20 carbon atoms preferably 10 to 12 carbon atoms. The aliphatic system is normal, branched or cyclic. Examples of the system include sebacic acid, dodecanedioic acid, Cl~, C18 and C20 diacids. The normal saturated aliphatic alpha omega dicarboxylic acids are preferred. Sebacic and dodecane-dioic acid are most preferred; Mixtures of the diacid~can also be employed. It should be noted that although referred to as diacids, any ester prècursor can be employed such as acid halides, preferably acid, chloride, diaromatic ester of the diacid such as diphenyl, for example the diphenylester of sebacic acid.
With reference to the carbon atom number earlier mentioned, this does not include any carbon atoms which may be included in the ester precursor portion, for example diphenyl.

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The copolyestercarbonates of the invention can be prepared by the known methods, for example those appearing in Quinn 4,238,596 and Quinn and Markezich 4,238,597. Examples of such processes include the formation of acid halides prior to the reaction of the es~er forming group with the dihydric phenol and then followed by phosgenation. Still further, the basic solution process of Goldberg in the 3,169,121 reference utilizing a pyridine solvent can also be employed while also using the dicarboxylic acid per se. A melt process utilizing the diesters of the alpha ome~a dicarboxylic acids can also be employed. An example of such a compound is the diphenyLester of sebacic acid.
After substantial experimentation~ it has been found that a preferred pracess for making the copoly-estercarbonates of this invention exists. The process o~ Kochanowski, USP 4,286,083 tn83) was inLtially utilized and then improved upon. It was found that lower diacids such a~ adipic acid were not incorporated into the polymer backbone to any great extent. Rather, - one had to go up to higher carbon atom dicarboxylic acids before any sig~ificant incorporation of diacid into the backbone was observed. We have found that the dihydric phenol and alpha omega diacid should be phos-genated at a pH of at about 8 to 9 for about 70 to 95 of the p~osgenation. Following that, the pH of the reaction should be raised to a level of about 10 to 12 preferably 10O2 to 11.2 for the remainder of the phos-genation. A preequilibration of the reactants, other than phosgene, at the initial reaction pH, 8 to 9, preferably 8 to 8.5, for a period of time, for example 3 to 10 minutes, seems to improve the incorporation of the diacid into the polymer. On a lab scale wherein the mixing is not as effective as in a resin reactor, dodecanedioic acid appears to incorporate better when it is used in fine particle size, for example abou~ 50 to :

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_g_ 300 mesh. In performing- this interfacial reaction, the reactor should also contain a catalytic quantity of an amine, preferably triethylamine. Amine catalyst with a range of about 0.75 to about 3 mole percent based on the dihydric phenol content can be employed.
Further experimentation has shown that reaction time can be substantially reduced and the diacid totally or substantially incorporated within the copolyester-carbonate as well by utilizing in the interfacial reaction a solution of the dicarboylic acid salt. That is, a solution of the dicarboxylic acid salt is charged to the reactor rather than the dicarboxylic acicl per se.
Acids of 10 carbon atoms or greater are preferred. I~
is o course, preferred to prepare a solution of the same dicarboxylic acid salt as is being utilized as the aqueous medium in the interfaoial reaction. For example when aqueous sodium hydroxide is used as the aqueous phase in the interfacial reaction a~ well as control the pH of the reaction, the sodium salt of the dicarboxylic acid i5 prepared. Other salts can be used such as prepared from potassium, calcium and the like. This is simply done by contacting the diacid, usually in its solid form, with aqueous sodium hydroxide and pumping that solution into the reactor. The dihydric phenol can 2S be already present toget~er with the aqueous base and endcapping agent. The carbonate precursor such as phosgene is added and the reaction allowed to proceed.
Interestingly with the use of tbe diacid salt soLution the aforementioned pH periods are substan-tially changed. A period of ~ime at a high pH, about 10to 12, should still be used to obtain the desired product. However the quantity of time at the lower pH, 8 to 9 can be significantly reduced. For example when the entire reaction was run at pH10 with previously prepa.ed sodium dodecanedioate for a period of only -- ~ :

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twenty minutes, 99 percent of the acid was incorporated into the copolyestercarbonate. When only 25% of the twenty minute reaction period was held at pH8, ~he remaining 15 minutes at pHlO, and utilizing the previously prepared sodium dodecanedioate lO0~ of the acid was incorporated into the copolyestercarbonate.
Therefore, anywhere from about 0 to about 95% of the carbonate precursor addition time should be run at about pH8 to 8.5 with the remainder of the carbonate precursor addition time being at a pH of about lO to 12.
Preferably the intitial period of carbonate precursor addition is from about 5 to aS%.
In order to control molecular weight, it is standard practice to utilize a chain stopping agent lS which is a monofunctional compound. This compound when reacting with the appropriate monomer provides a non-reactive end. Therefore the quantity of chain stopping compound controls the molecular weight of the polymer.
Bulkier chain terminators than phenol should provide substantially better physical properties such as low temperature impact. Examples of these bulkier substituents include paratertiarybutylphenol, isononyl phenol, isooctyl phenol, cumyl phenols such as meta and paracumyl phenol, preferabIy paracumyl phenol, as well a chromanyl compounds such as Chroman I.
The copolyestercarbonate of this invention with the standard endcapping reagent posseses a substantially lowered glass transition temperature, Tg, therefore providing processability at a lower temperature. Sur-prisingly accompanying this lower temperature processa-bility are substantially equivalent physical properties as a standard polycarbonate of the same intrinsic viscosity as the inventive composition and very high flow rates. When utilizing the bulkier endgroups, it is possible to achieve even lower molecular weight copoly-estercarbonate while maintaining excellent physical . . . : . : , .:
, properties such as aged impact re3istance and/or low temperat~re impact resistance while having a very high ~low ra~e. This allows the copolyestercarbonates of this invention to be utilized where the characteristics of polycarbonates such as clari.y, impact resistance, modulus, and overall toughness are req~ired but mu~t also be present in increas~d processability through an enhanced flow rate. Such applica~ions include opticalLy pure materials such as audio discs, digital discs, other media storage devices, pac~aging materials, other thin walled parts and films, optical discs including fiber optics and the like.
The aliphatic aLpha omega dicarboxylic acid ester is present in the copolyestercarbonate in qua~titie-~
from about 2 to 30 mole per~ent, based on the dihydricphenol. Ge~era}ly with quantitie~ below about 2 mole percent the Tg is in~ufficien~ly lowered and signifi-cantly altered flow rate is not observed. Above about:
30 mole percent, the physical properties o the copoly-e~teroarbonate are signiicantly hindered in comparison~o the polycarbona~e without the aliphatic e~ter linkages. Preferred mole percents of a}iphatic alpha omega dicarboxylic acid ester are from about 5 to 25 and more preferably about 7 to 15 mole percent of the dihydric phenol.
The weight average molecular weight of the copoly-estercarbonate can generally vary from about 10,000 to about 100,000 as measured by GPC using a polystyrene standard, corrected for polycarbonate. A preferred molecular weight is from about 18, noo to about 40,000.

A. PreDaration of Cooolvestercarbonate with Sebacic Acid and Ste~ Wi~ L~ es~
To a lOO~liter, gLass vessel wa~ added deionized water (30 L~, methylen~ chloride (35 L~, bisphenol-A
(BPA) (11.34 Kg, 49.63 mol~, P-cumyl phenol (319 g, 1.50 mol), triethylamine (70 mL, 0.90 mol), sebacic acid .

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tlO05 g, 4.97 mol), and sodium gluconate (1~5 g).
Phosgene was introduced to the reaction mixture at a rate of 150 g/min for 34 min (660~ g, 66.73 mol) while maintaining a pH range of 8.0-8.5. The pH was adjusted to 10.0 and the phosgenation continued for 10 min.
The phosgene free solution was diluted to 10~
solids with ~he addition of methylene chloride (ca. ~5 L) and the polymer solution was extracted untiL solution organic chloride levels wexe non-d~tectable and triethylamine content was less than 1 ppm~
The extracted polymer solution was isolated by steam precipitation at a 1. 9 L/min eed rate and 100 p~ig stream feed pressure. The water wet, coarse powder was chopped in a Fitzmill to achieve a more uniform particle size and dried in a hot nitro~en fed fluid bed 15 drier with the ~emperature at 110C maximum.
The copolyestercarbonate resin bad a Tg of about 128Co Standaxd polycarbonate has a Tg of 150C.
Extrusion at 230C and molding at 275C yielded a transparent material which exhibited improved flow and at 3Q0C (g/10 min) processability, MFI = 15, as well as excellent mechanical propertie~. The 1/8" notched izod was 880 J/M, the DTUL measured at 1.8s MPa was B. Preparation of CoDolYes~ercarbonate with the Earlier Pre~_red Salt of DDDA
The disodium salt of dodecanedioic acid (DDDA~ was generated by dissolving the free acid (7.2 g, 31 mmol) and NaOH pellets (2.7 g, 68 mmol) in water ~180 mL~.
A 2000 mL five neck Morton flask equipped with a bottom outlet was ~itted with a mechanical stirrer, a pH
probe, an aqueous sodium hydroxyde (50~) inlet tube, a Claisen adapter to which dry ice condenser was attached, and a gas inlet tube. The ~lask was charged .
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with bisphenol A (71 g, 311 mmol), triethylamine (0.9 mL), p-cumylphenol (2.0 g t 9 mmol), methylene chloride (220 mL), and the disodium salt solution of DDDA
described above. Then phosgene was introduced at a rate of 2 g/min, while the pH was maintained at 8 by addition of caustic for 10 minutes; the pH was then raised and maintained at around 10.5 while phosgene addition continued for 10 additional minutes. The total anount of phosgene added was 40 g (400 mmol). The pH was adjusted to 11-11.5 and the organic pha~e wa~ separated from the brine layer and washed with 2~ hydrochloric acid t3 x 300 m~), and with deionized water (5 x 300 mL).
The brine layer was acidified to pH 1 with concentrated HCl and no unreacted DDDA precipitated.
The solution was dried (MgSO4), filterad, and then precipitated into methanol (1500 mL)~ The resin was washed with me~hanoL (1 x 500 mL) and deionized water (4 x S00 mL), and dried at 100C for lS hours.

To a 100-liter, glass vessel was added deionized water (30 L), methylene chloride (35 L), BPA (11~34 ~g, 49.68 mol), ~-cumyl phenol (319 g, 1.50 mol), triethyl-amine (70 mL, 0.90 mol), dodecanedioic acid (1155 g, 4.97 mol), and sodium gluco~ate (17.5 g). Phosgene wa introduced to the reaction mixture at a rate of 150 g/min for 34 min (6600 g, 66.73 mol) while maintaining a pH range of 8.0-8.5. The pH was adjusted to 10.0 and the phosgenation continued for 10 min.
The phosgene free solution was diluted to 10~
solids with the addition of methylene chloride (ca. 45L) and the polymer solution wa3 extracted until solution or~anic chloride levels were non-detectable and triethylamine content was less than 1 ppm.

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'- ' : ' ' ' 2 ~ 6 The extracted polymer solution was isolated by steam precipitation at 1~9 L/m n feed rate and 100 psig stream feed pressure. The water wet, coarse powder was chopped in a Fitzmill to achieve a more uniform particle size and dried in a hot nitrogen fed fluid bed drier with ~he temperature at 110C maximum.
The copolyestercarbonate resln had a Tg of about 12$~C. Extrusion at 250C and molding at 275C
yielded a transparent ma~erial which exhibited improv~d flow and processability, MFI = 13 at 300C (g/10 min), compared to standaxd polycarbonate of similar or same molecular weiqht, as well as excellent mechanical properties. The 1/8" Notched Izod was 880 J/M, the DTUI
measured at 1.82 MPa was 119C.
Copolymers of various intrinsic viscosities containing 10 mol~ dodecanedioyl e~ter were prepared according to this procedure. The copolyestercarbonateq were paracumylphenol-endcapped. The copolyester-carbonates were compared to standard commercial grade BPA polycarbonates, Lexan 125, 145, and 135 prepared by GE Plastics, all of which were phenol end-oapped, a~
well as stearic acid endcapped polycarbonate (SAPC) of a similar intrinsic viscosity. All materials were stabilized with 0.05 weight percent of a phosphite.

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In general the copolyestercarbonates of the invention have substantially lower glass transition temperatures and heat deflection temperatures than the standard polycarbonates. In fact they were very similar S to the stearic acid endcapped polycarbonate comparative examples. However these stearic acid endcapped materials were extremely embrittled in comparison to the normal polycarbonate and the copolyestercarbonates o~
the invention. The invention materials demonstrated outs~anding flow relative to the standard poly-carbonates while achieving equivalent impact resistance.
In the Table below, Example 4 of the invent:ion is compared to a standard BPA polycarbonate but containing either 7 weight percent of a diphosphate plasticizer or in admixture with a LO wt.~ of polybutylene terephthalate~

Example IV Tg MFI (g/lOminj 125 ~I Transmi~ion 300C ~J/M) 4 0.48 124 46 883(D~* 90 7% C~733S 0.50 128 45 50(B)~ 90 10~ P8T BLEND 0 . 49 126 45 50 ~B) * 89 * D is a ductile break, B is a brittle break As is clearly observed from the above data, the presence o~ the plasticizer or the polyester brings about similar flows and transparancies but seriously e~brittles the polycarbonate in comparlson to the copoLyester-carbonate of the invention.
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2~3~16 . E~AMPLES 7-9 FolLowiny procedures similar to Example 2, bisphenol-A copolyestercarbonates incorporating various quantities of dodecanedioic acid were prepared. The properties of these paracumyl-endcapped copolyester-carbonates were compared to a paracumylphenol endcappedbisphenol-A polycarbonate control. The results are provided below wherein there is 10 mole percent dodecane-dioic acid ester in the copolyestercarbonate, I.V. is intrinsic viscosity measured at 25C in methyLene chloride, Mw is wei~ht average moLecular weight measured by GPC. MFI is Melt Flow Index at 300~C ~g/10 min). Y.I. is yellowness index measured according to AgTM D1925, and N.I.
is notched izod impact strength measured according to ASTM
D256 at room temperature (RT) and -lO~C.
All break~ were 100% ductile of all five samples except for control at -10C which wa~ 100~ brittle.
Example I.V. MW MF~ Tq C Y.I. N.I.~J/M) Control .439 22,000 22 149 - 623 156 7 .495 27,766 16 130 1 9 831 779 8 .488 26,363 25 125 1.7 831 779 9 .456 21,717 48 L25 1.9 623 675 As is observed from the above results, standard "high flow" paracumylphenol endcapped polycarbonate9 the control, exhibited reasonable flow, M~I= 22, at a molecular weight of about 22,000. However, the No~ched Izod at -10C
is low and completely brittle. The copolyestercarbo~ates of the invention, however, have literally more than ~wice the flow, MFI=48 at almo~t the same molecular weight and are accompanied by high impact strength with complete ductility, even at the reduced temperature of -L0C.

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2~3~6 The essence of the invention is the insertion of the aliphatic alpha omega dicarboxylate unit into the polycarbonate, thereby providing a copolyestercarbonate having repeating units of the structure t ~o e I c t`~ o o where R, Rl, n, nl, W and b have been previously described and X is an aliphatic grouping of about 7 to about 18 carbon atoms, inclusive. The d repeating unit i5 pre~ent in the copolyestercarbonate in from about 2 to 30 mole percent of the total of the repeating units c+d, X is pre~erably about 10 to 18 carbon atoms, inclusive. The aliphatic system is preferably saturated and is normal, branched, cyclic or alkylene substituted cyclic. The mole percent of d is preferably about 5 to 25 and more preferably about 7 to 15 mole percent.
As shown in this specification, the copolyester carbonates of this invention essentially maintain a signi-ficant portion of the physical properties of polycarbonate of similar or same molecular weight but achieve these, except those related to Tg such as HDT~ with reduced processing requirements since the Melt Flow Index for these new materials is substantially raised. Perhaps the most significant property maintained and in some cases even improved is the 1/8 inch Notched Izod impact strength.
SimilarLy, copolyestercarbonates of this invention which have the same processability as standard polycarbonates can have , ~3~

significantly higher molecular weights and resulting property enhancements.
Thus, a further aspe~t of this invention is a method for using the above identified invention campositions. This is a method for processing resins which comprises processing a copolyestercarbonate of the above invention wherein the copolyestercarbonate is processed at a temperature significantly lower and with less work, as shown by a hlgher melt flow index ~han the same aromatic polycarbonate without ~ ester units and of the same weight average molecular w~ight~
Any type of processing operation is included for example, injection molding, rotary molding, blow molding, compression molding and extrusion processes such as sheet and film extrusion, profile extrusion, coextrusion and general compounding. Injection moldin~ and extrusion are preferred.
When referrin~ to the "poLycarbonate of same or qimilar molecular weight" or '~standard polycarbonate" re~erence.is made to the polycarbonate made from the same dihydric`phenol but without aliphatic ester repeat units.

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Claims (15)

1. A composition comprising a copolyestercarbonate derived from a dihydric phenol, a carbonate precursor, and an aliphatic alpha omega dicarboxylic acid or ester precursor wherein the dicarboxylic acid or ester precursor has from 10 to about 20 carbon atoms, inclusive, and is present in the copolyestercarbonate in quantities of from about 2 to 30 mole percent of the dihydric phenol.

2. The composition in accordance with claim 1 wherein the dicarboxylic acid or ester precursor has from 10 to about 14 carbon atoms, inclusive.

3. The composition in accordance with claim 2 wherein the dicarboxylic acid has 10 carbon atoms.

4. The composition in accordance with claim 2 wherein the dicarboxylic acid has 12 carbon atoms.

5. The composition in accordance with claim 1 wherein the mole percent is from about 8 to 15 mole percent.

6. The composition in accordance with claim 2 wherein the mole percent is from about 8 to 15 mole percent.

7. A composition comprising a copolyestercarbonate derived from a dihydric phenol, a carbonate precursor, and an aliphatic alpha omega dicarboxylic acid or ester precursor wherein the dicarboxylic acid or ester precursor has from 8 to about 20 carbon atoms.
inclusive, and is present in the copolyestercarbonate in quantities of from about 2 to 30 mole percent of the dihydric phenol, wherein the copolyestercarbonate is endcapped with a monophenolic compound which provides the copolyestercarbonate with better notched izod impact resistance and ductility after aging than a phenol endcapped copolyestercarbonate.

8. The composition in accordance with claim 7 wherein the dicarboxylic acid or ester precursor has from 8 to about 14 carbon atoms, inclusive.

9. The composition in accordance with claim 7 wherein the mole percent is from about 8 to 15 mole percent.

10. The composition in accordance with claim 7 wherein the copolyestercarbonate is endcapped with a compound selected from the group consisting of isooctylphenol, isononylphenol, cumylphenol or a chromanyl compound.

11. The composition in accordance with claim 10 wherein the compound is paracumnylphenol.

12. The composition in accordance with claim 7 wherein the diacid is azelaic.

13. A method for processing are in having similar molecular weight to a standard polycarbonate resin which comprises processing a copolyestercarbonate having repeat units of the structure wherein:
R is independently selected from halogen, monovalent hydrocarbon, and monovalent hydrocarbonoxy radicals;
R1 is independently selected from halogen, monovalent hydrocarbon, and monovalent hydrocarbonoxy radicals;
W is selected from divalent hydrocarbon radicals, -S-, -S-S-, -O-, -?-, , and -?-;
n and n1 are independently selected from integers having a value of from 0 to 4 inclusive;
b is either zero or one;
X is an aliphatic group of about 6 to 18 carbon atoms, inclusive;
c is from about 2 to 30 mole percent of the total units c+d; and with less work than required for the said standard polycarbonate.

14. A copolyestercarbonate comprising repeating units of the structure wherein:
R is independently selected from halogen, monovalent hydrocarbon, and monovalent hydrocarbonoxy radicals;
R1 is independently selected from halogen, monovalent hydrocarbon, and monovalent hydrocarbonoxy radicals;
W is selected from divalent hydrocarbon radicals, -S-, -S-S-, -O-, -?-, , and -?-;
n and n1 are independently selected from integers having a value of from 0 to 4 inclusive;
b is either zero or one;
X is an aliphatic group of about 8 to 13 carbon atoms, inclusive:
c is from about 2 to 30 mole percent of total units c+d.

15. The invention as defined in any of the preceding claims including any further features of novelty disclosed.