CA1250692A - Polyarylates having improved hydrolytic stability - Google Patents

Abstract

POLYARYLATES HAVING IMPROVED
HYDROLYTIC STABILITY
Abstract This invention relates to moldable polyarylates and in particular to moldable polyarylate compositions which have repeating units derived from bis-(3,5-dimethyl-4-hydroxyphenyl) sulfone (TMBS), optionally a dihydric phenol such as 2,2-bis-(4-hydroxyphenyl)-propane (Bisphenol A) and a mixture of isophthalic acid and terephthalic acid or derivatives thereof. Such polyarylates exhibit improved hydrolytic stability.

Description

PQLYA~YLATES H~VING IMRR~VED
HYD~OLYTIC ~TABIL TY

Brief Su~marY o~ the InvenSion chnical Field Thifi inYention rel~te~ in genera1 ~o ~oldable po1yarylates, a1~o k~own as aro~atic polye~ter6, and ~n particular to ~oldalble po1yarylate ~o~position~ whi~h ~on~ain repeating units derived fro~ bi -~3,5-di~ethyl-4-hydroxyphe~yl) ~ulfone (TMBS), optional1y a dihydric phenol ~u~h as ~,2-bi~-(4-hydroxyphe~yl)~ opane (~ispheno1 A) and a ~ix~uce of i~ophthalic acid and terephthalic acid or deri~atives ~her~of. Such palyarylate~ exhibit improved hydroly~ic 6tability.
Backqround of the Invention Po1yarylates are aro~atic polye6ters derived fro~ a dihydric phenol, particu1arly

2,2~bi~-(4-hydroxyphenyl)propane (Bi~phenol A), and an aro~atic dicarboxylic acid, particu1ar1y mixtures of teLephtha1ic and isophthalic acids. Illustrative polyarylate~ are de~crib~d, for example, i~ V.V.
Korshak and S. V. Vinogrado~a, Po1ye~ters, 1965, Pergamon P~e66, ~ew Yor~, Chapter I~. Polyary1~tes are high te~peratu~e, high perfor~ance thermop1a6tic po1y~ers with a go~d combina~lon of ~herm~1 and ~chanical properties. Polyary1ate6 al60 have good prQ~e~abili~y ~ch al10ws them to be molded in~o a variety of artic1e~.
~ owever, ~hen po1yarr1ates are exposed to a hydrolytic environ~e~t unde~ ~ce~6ive time and/or ,177 .. ,.,,, ~

~2~

~emperature conditions, the hydrolytic ~tabili~y of ~he polyarylates i~ ~enerally poor which resul~s in poor mechanical propertie6. Poor hydroly~ic stability is reflected by a rapid decrea~e in reduced viscosity of the polyarylates resulting from exposure to the hydrolytic environment. T~is deficiency also reguires careful drying procedures of the polya~ylates prior to ~elt proces~ing.
U.S. Pa~ent 3,652,499 (Bo~man3 de~crib~s linear polyester6 having recurring s~ruc~ural units derived from, for example, a 4,4'-Eulfonyl diph~nol such as bis-(3,5-dimethyl-4-hydroxyphenyl)sulfone ~TM~53 and an alip~atic polycarboxylic acid halide selected from substituted and un~ub~ituted malonic, glutaric and pimelic acid h~lides. The polymers are characterized as being extremely resistant to organic solventfi and have substantially t~e 6ame or better physical properties than polye6te~6 of the prior art.
Characterized in the Borman patent as polyesters of the prior art are the aroma~ic polye~ters of U.S. Paten~ 3,234,167 (Sweeney). The Sweeney patent de~cribes a~omatic polyesterfi having recurring structural units derived from a bi6phenolic ~ompound and an 3romatic dicarboxylic acid such as terephthalic and isophthalic acids.
From the o~nibu~ formula depicted in column 1, lines 52-60, of the Sweeney paten~, one can incidentally portray bis-(3,5 dime~hyl-4-oxyphenyl) sulfone derived f~om T~BS. According to U.S. Patent

3,652,~99 (Borman~, the aromatic polyeG~er~ of U.S.
Patent 3, ~34,167 ~Sweeney) are reporeed ~o be 601uble in organic 601v2n~s.

~-14,~7 36~

V.S. Paten~ 4,390,682 (~yo et al.) de~cribe6 aromatic polye~er~ containing terephthaloyl ar.d isophthaloyl repeatinq units and dioxyarylene unit~ derived from aromatic diols such as Biphenol A. From the omnibu~ formula~ depicted in column 3, line6 5-34, of the Kyo et ~l. pa~ent, one can incidentally portray bis-(3,5-dlimethyl-4-oxyphenyl)~ulfone derived from TMB5. The aromatic polyester~ are characterized as having high durabili~y under dry and moi~t heat a6 well a6 high resi6tance to water crazing. As illustrated in the working exa~ples hereinbelow, polyarylate~ having repeating unit~ derived from ~MBS and a dihydric phenol 6uch as Bi6phenol A exhibit greater hydrolytic ~tability than polyarylates w~ich contain repeating units derived only fom bi~phenol compound6 æuch as ~i~phenol A (no TMBS)as exemplified in Kyo et al.
It has been ~ound a6 a result of thi~
invention that polyarylate~ which contain repea~ing unit6 deri~ed from bi6(3,5-dimethyl-~-hydroxyphenyl) fiulfone (TMBS) exhibit improved hydrolytic 6tability. Such improved hydrolytic ~tability is a~tributable to the ~olecular configuration of repeating unit6 derived from TMBS in which t~e ~our ~ethyl group~ att~ched to the aromatic rings of TMBS
~ct to sterically hinder hydrolytic a~tack againæt the carbonyl-ether oxy~en linkage6 vicinally po~itioned in the polymer ~hain.
Disclosure of tbe Invention This invention relate~ t~ moldable polyarylate~ which have good proces6ability and ~eehanical propertie~ and whieh exhiblt improved D-14,177 hydrolytic tability. In particular, this inven~ion relates to a composition compri~ing a polyarylate containin~ rep9ating units (I) having t~e formula ~3 ~ .
~ ~~CX

in an a~ount 6ufficient to enhance hydrolytic stabili~y of the polyarylate, and optionally repeating unit~ (II) haviDg the formula - ~1~1~ ~

in which repeating unit6 (I) and optionally repeating unitC t II) are connected by interbonding unit~ ~III) having the f ormula O O
-- C - Ar - C - (III) w~erein Y i~ sel~cted ~ro~ alkyl group~ of 1 to 4 carbon a~om~, chlorine or bror~ine, each z, independently, has a ~r~lue of from O to 4 inclu~ive, n ha a value of O or 1, Rl i~ a divalent 6~urated or un~aturated aliphatic hydrocarbon V-1~,177 ,~

radical, particularly an alkylene or alkylidene rad;cal having from 1 to 6 carbon ato~s; or a cycloalkylidene or cycloalkylene radicall having up to and including 9 carbon atoms, O, CO. 52~ S or a direct bond, with the provi~o that when Rl is SO2, then repeating unit (II) i~ not the same as repeating unit ~ r is a subs~i~u~ed or unsub~tituted mesa- or para-p~enylene group, and wherein the polyarylate ha~ a reduced viscosity of dt least abou~ 0.3 dl/g as measured in chloroform at a concentration of 0.5 gtlOO ml at 25C.
The improved hydrolytic ~tability exhibited by ~he polyarylates of this invention can be attributable to ~he incorporation of repeating unit~
(I) above into the polymer chain. The molecular confiquration of repeating unit6 (I) is important in this regard. In particular, the four methyl groups attached to the aromatic rings of repeating unit~
(I) are believed to act to sterically hinder hydrolytic attack against She carbonyl-ether oxygen linkages vicinally poitioned in the polymer chain.
In contras~, carbonyl-~ther oxygen linkages in vi inal posisions to, for example, Bisphenol A have no sterically hindering methyl groups, and such is believed to explain w~y such a polymer would be more su~ceptible to hydrolytic attack. In ~eneral, tho~e polyarylates containing a higher concentration of repeating unit6 (I) will have the preferred enhanced hydrolytic ætability.
Detailed Descri~tion The polyarylate~ of shi6 invention can be prepared by a~y of the polyester forming reaction6 known to tho~e skilled in the art. Differe~t ~-14,177 ~5~

additive equence6 of reactant~ c~n be used. For example, a diacid which gives interbonlding uni~s (III) hereinabove and ~he diphenol rea~ant~ which give repeating unit~ (I) and (II) hereinaboYe are charged and polymerized 6imul~aneously. In another ~equence, one of the diphenol reactant's which give either repeating unit~ II) or ~II) hereinabove is charged with ~he acid reactant which gi~es interbonding units (III) hereinabove, poly~erization is initiated, and then the other diphenol reactant which qive6 either repeating unit~ (I3 or (II) hereinabove is added and the reaction i~ allowed to progre~6. Other additive ~equences of reactant6 are also plau6ible.
Illustrati~e of known polye6ter forming reactions which can be used to make the polyarylates of this invention include:
(1) The redction of the acid chlorides of the isophthalic and terephthalic acid~ which gi~es interbonding unit6 ( I I I ) hereinabove with the diphen~l~ which give repeating units ~I) and (II) hereinabove;
(2~ The reaction of the aromatic diacids which gives interbonding unit~ ( I I T ) hereinabove with d ie~t~r derivative~ of the diphenol6 having the f ormul as R C - O ~ ~ ~ ~2 ~IV) CH3 ~H3 D-14,177 ~2~ ii9;~

and gY3 (~) R2~--t~t~R~o -Dc-P~2 (V) where Y, z, n and Rl are a~ defined hereinabo~e and where R2=C1 ~ ~2~ aliphatic skeletons, hereinaf~er referred to as the Diacetate Proces6 and (3) The reaction of the diaryl e~ers of ~he aroma~ic diacids having the formula Arl-o- e ~ C -O-Arl ~VI~

where Arl can ~e a phenyl, o-tolyl, m-tolyl, p-tolyl, or like re6idues, with the diphenols w~ich give repeating units (I) and (II~ hereinabove, hereinafter referred to as the Diphenate Proces~.
TWO procedures can be u~ed for the preparation of the polyarylates of thi6 invention via the acid chloride route. One is carried ou~ at low temperature and the other at high temperature.
In the low temperature technique, polycondensation of the acid chloride6 derîved from terephthalic and isophthalic acid which give interbonding unit~ ~III) hereinabove with t~e dihydric p~enol~ which qive repeati~g units (I~ and (II) hereinabove is effected ~t ambient temperature6 in an i~ert 601vent, 6uch as methylene chloride, in the presence of a basic eataly6t and an acid acceptor. A 6econd immiscible ~olvent, e.g., water, ~ay be present. In the high te~perature technique, polycondens~tion of acid chloride6 which give interbo~ding u~its ~III) 14,177 hereinabove wîth ~he dihydric phenols which give repeating uni~s (I) and ~II) hereinabove i6 effected in a high boiling ~olvent, ~uch a~
1,2c4-~richlorobenzene, a~ temperatures above about 150C, and preferably at about 200~ to about 220C.
Other suitable inert organic ~olvents u~eful for low temperature polycondensation include halogenated aliphatic compound~, such a~, chloroform, methylene bromide, 1,1,2-trichloroethane as well a~ methylene chloride mentioned aboYe and the like; and cy~lic ether~ ~uch as tetrahydrofuran, dioxane, and t~e like. For the hi~h temperature polyconden~ation, 6uitable 601vent6 include halogena~ed aroma~ic compound6 ~uch as, o-dichlorobenzene, 1,2,4-trichlorobenzene ~r diphenyl ether, diphenyl 6ulfone, ben~oic acid alkyl e~ter~ wherein the alkyl group contains 1 to about 12 carbon atoms, phenolic ether6, such a~, ani601e and the like.
Preferred acid acceptor6 for u6e in the low temperature polyconden6ation are alkali metal and alkaline earth metal hydroxides including sodium, potas6ium, barium, calcium, ~trontium, magnesiu~, and beryllium hydroxide.
U~eful ba~ic cataly6t~ for u~e in the low temperature polyconden6ation include ~ertiary amine~
6uch as alkyl amine~, including trimethyla~ine, triethylamine, tripropylamine, tributylamine, and th~ 8: where the alkyl group contain~ from 1 ~o about 10 carbon a~om6; alkaryl amine~ ~uch a~
N,N-dimethylaniline, N,N-aiethyl~nillne, N,N-di~ethylnaph~hylamine~ benzyl dimethylamine, D-1~,177 , .

- g alpha-methylbenzyl dimethylamine, pyridine, cyclic diazo compounds, such a~, diazobicyclooctane IDABCo), diazobicyclononene (DBN) and diazo~icycloundecene (VBU) and the like.
PolymerizatioD~ using the Diacetate Proce~s can be carried out in ~he melt at between 260GC and 340C, preferably between 275C and 320~C. They can also be carried out either a~ a solution reac~ion at those temperatures or a su~pen~ion reac~ion al80 at those temperatures. The solvent(s) or suspending agent(s) can be one of any number of organic compounds boiling between 140C and 3qO~C. They can be chosen from hydrocarbons, ketones, ethers, or sulfones which are inert under the reaction conditions. These polymerizaeion6 may or may not be run in the presence of a catalyst. Typical solvents are ~etramethylene ~ulfone, diphenyl ether, substituted diphenyl ether, and the like. Typical catalysts include Na, Li, K 6alts (organic and inorganic), transi~ion metal salts, alkaline earth metal ~alts, e.g., Mg acetate, and the like. They may be performed at atmospheric pressure, ~uper atmo~pheric prefi~ure, or ~ubatmospheric pressure.
Polymerizations using the Diphenate Proce~s can be carried ou~ in the mel~ at be~ween 250C and 350C. The preferred temperature range i~ about 275~C to 320C. In general, reduced pressure for th~ inal poreions of the rea~tion is u6ed. The polymerizations can also be carried out ei~e~ as a 601ution reaction or ~u~pen~ion reaction under those soDditio~. The 801vent(&~ or su pending agen~
~re the same a~ t~o~e describe~ aboYe. Typical ,177 ca~alyst~ include tin compo~nds and generally tho~e mentioned above for the Diacetate Proce~s.
Particularly preferred cataly~tfi are Ti and tin sal~, Mg acetate, and alkali metal ~alt~, alkoxide6 and phenoxides.
If desired. a chain stopper can be u~ed to control the ~oleculaL weigh~ of the polyarylates obtained. Suitable chain xtoppers a~en~ include monohydric phenol~ or their derivatives, 6uch as, p-phenylphenol, and the like and monofunctional carboxylic acid or their deriva~i~es, such as benzoic or naphtholic acids, and ~he like, The diphenol reactant bi6 (3,5-dimethyl-~-hydroxyphenyl)sulfone (TMaS) whi~h give~ repeating UDits ~I) hereinabove can be prepared according to the process de~cribed in U.S.
Patent ~,383,q21. Die~ter derivatives of TMBS as describ~d in Formula (IV) hereinabove can also be prepared accordinq to known proce~es.
Suitable dihydric phenols other ~han bi~- ( 3, 5-d imethyl-4-hydroxyphenyl)~ulfone (TMBS) which give repea~ing unit~ (II) hereinabove include the following: 2,2-bis~4-hydroxyphenyl)propane (Bi6phenol A); bis-(2-hydroxyphenyl)me~hane bi (4-hydroxyphenyl)methane;
bi~-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)-methane;1,1-bi~-(4-hydroxyphen~l)ethane;
1,2-bis-~4-hydroxyphenyl)ethane:
1,1-bi~-~4-hydroxy-2-clhlorophenyl)ethdne;
l,l-bi~ -methyl-4-hydroxyphenyl3ethane:
1,3-bis-(3-methyl-4-hydroxyphenyl)propane;

D-14,177 . .

2,2-bi~-(3-methyl-4~hydroxyphenyl)propane:
2,2-bi~-(3-isopropyl-~-hydroxyphenyl~propane;
2,2-bis-(2-i~opropyl-4-hydroxyphenyl)propane:
2,2-bi~-(4-hydroxyphenyl)pentane;
~,3 bi~-(4-hydroxyphenyl)pentan~:
2,2-bis-(4-hydroxyphenyl)heptane;
1,2-bi~-(4-hydroxyphenyl)1,2-bi~-(phenyl)-propalle:

4,4'-~dihydroxyphenyl)ether:
4,4'-(dihydroxyphenyl)sulfide;
4,4'-(dihydroxyphenyl)sulfoxide: hydroquinone; and naph~halene diols. Other bisphenol compounds suitable for u e in this invention 3re d;~clo~ed in U.S. Patent~ 2,999,8~5, 3,028,365 and 3,339,154.
Preferred dihydric phenols include 2,2-bis-(4-hydroxyphenyl)propane ~Bi6phenol A) and bi6-(4-hydroxyphenyl)6ulfone (Bi~phenol S). Glycols and aliphatic dihydroxy compounds other than bisphenol~ in amount~ typicdlly not greater than about 10 weight percent of the total weight of repeating unit6 (I) and (II) in the polyarylate can also be u~eful in preparing the polyaryla~e~ of ~his invention. Die~ter derivatives of these dihydric phenol~ as described in Pormula (V) hereinabove can also be prepared accordinq to known proce~ses.
Suitable aromatic difunctional acids and acid halide6 whic~ gi~e interbonding unit6 tTlI~
bereinabove include i~ophthaloyl acid and chloride, terephthaloyl acid and chloride, mixture6 of i~ophthaloyl and terephthaloyl acid~ and chloride~, 2,5-dic~loroterephthaloyl acld and chloride,

5-tert-butyl-i~oph~haloyl acid and chloride, 2-chloroi60phthaloyl acid and c~loride, D-1~,177 g~

4-chloroi60phthaloyl acid and c~loride, 5-chloroi~ophthaloyl acid and chloride, any of the naphthalene dicarboxylic acid~ and acid halide~ and the like. The aromatic ring ~ay be sub~ti~uted with ~ub~tituents 5uch a~ al~yl group~ eontaining from 1 to 4 ca~bon atoms, alkoxy group~ containing from 1 to 4 carbon atoms, aryl, halogen and the like.
O~her ~uitable aromatic difunctional acids and acid halide6 which can be used in preparing the polyarylate~ o~ this invention include the 6ub6tituted and unsub~ti~uted ~,4'-biphenyl dicarboxylic acid, ~,4'-diphenyloxide dicarboxylic acid, halide derivative~ thereof and the like.
~oreover, hydroxyaromatic æcid~ and derivative~
thereof such a6 4-hydroxybenzoic acid and the like can be used in thi~ invention~ Diaryl e6ters of these aromatic difunctional acid6 and deriv~tives theeeof can al60 be u~eful in preparing the polyarylate6 of this invention.
The preferred aromatic difunctional acids or derivative~ for u~e in preparing the polyarylate~
of this invention include ieo~hthalic acid, terephthalic acid and mixture6 of isophthalic and terephthalic acid.
The reaction for preparing the polyarylates of thi~ invention proceeds on a ~toichiometric basi6 ~uc~ that the desired polyarylate i6 formed.
&toichiometry i6 not critical and the only requirement i~ that the amount6 employed are 6ufficient to form the polyarylate of the de6ired ~olecular weight having enbanced hydrolytic ~tability. The preferred polyarylate of ~his inv~ntion h~ ~he following ~tructural formula D-14,177 _ 13 --CH3 ~W3 -E ~ C D -~,~ 0~ ; C113 ~:H3 _ wherein the polyarylate has a reduced vi~eosity of at leas~ about 0.3 dl/g as mea~ured in chloroform at a concen~ra~ion of 0.5 g/100 ml at 25C. Another preferred polyarylate of tbi6 invention has the following structural formula E_~C~~ ~C~ ~ c~3~

wherein the polyarylate ha~ a reduced vi~cosity of at least about 0.3 dl/g as mea~ured in chloroform at a concentration of 0.5 g ~100 ml at 25C.
By varying t~e amounts of reactants, one can vary the polyarylate polymer ulti~ately produced and it~ properties. For example, in general, the polyaryla~e polymer~ of this invention conta;ning ~he greater weight percentages of repea~ing units (I) will preferably h~ve the better hydrolytic stability. Thi~ i6 attributable to the molecular configuration of repeating unit~ (I) in which the four me~hyl groups attached to the aro~atic rings of repeati~g uni~ (I) a~t to 6terically ~inder hydrolytic at~ack aga~6t the carbonyl-ether oxygen ~ a~es vicinally po6itioned in the polymer ~hain.

D-1~,177 . ~ ... . . .. .

6~2 A6 ~ydrolytlc ~tability can be enhancecl by even minor amoun~s of repeating units (I), 1:he concentration of repeating uni~ (I) in the polyarylate6 of thi6 inv0ntion i~ not narrowly cri~ical and can be varied over a wide range. The only requirement is that the polyarylat:e~ of t~i~
invention contain a sufficient amount of repeating unit~ (I) to enhance hydrolytic ~tability t~ereof.
In particular, the polyarylate~ of this invention can preferably contain from about 5 weight percent or le~6 to about 95 weight percent or greater of repea~ing units (I) ~ereinabove, together with interbonding unit~ ~III) hereinabove, more prefer~bly from about 25 weight percent to ~bout 75 weight percent, and mo~t preferably from about 40 weig~t percent to about 60 weight percent. The polyarylates of this invention can preferably contain from about 95 weight percent or greater to about S weight percent or le6s of repeating unit~
(II) hereinabove, together with interbonding units (III) hereinabove, more preferably from about 75 weight percent to about 25 weight percent, and mo~t preferably from about 60 weight percent to about 40 weigh~ pereent. In general, those polyarylates con~aining the higher weight percentage~ of repeating units tI) w~ll preferably have the better hydrolytic 6tability, and those poly~rylates containing t~e higher weight percentages of repeating unitfi (II) ~ill preferably hav~ the better proce~6ability.
The ~tructure of ~he polyarylate polymers of th~ invention can be ~odified to ~ome extent by including in the polymer;zation reaction other D-14,177 ..~. .. .

dihydroxy compounds, typically not mor~ than abo~lt 10 weight percent of t~e total weight of t~e repea~ing units (I~ and (II) in the po].yarylate.
~or example, one might in~lude along wi.th Bisphenol-~ and bis-~3~5-di~ethyl-4-hydroxyphenyl)-6ulfone (TMBS), other dihydroxy compound~ either as ~uch or in the die~ter form, as a partial ~ubstitute and modifier of the po1ymeric structure, without adversely affecting the overall propereies of the polymeric ~tructure of ~his invention. For example, such dihydroxy compound~ as ethylene glycol, propylene glycol, 1,4-butylene glycol, and the like can be included in the polymerization reactions to ~anufacture the polyarylate polymers of this invention.
Additionally, tbe preparation of the polyarylate6 of this invention via the Diace~ate Proce~ or Diphenate Proce~ may be carried out in the presence of from about 10 to about 60 weight percent, based on the weight of ~he polyaryla~e produced, of a processing aid. The preferred proces~ing aid~ are diphenyl ether compounds, a cycloaliphatic, sub6tituted aromatic, or heteroaromatic compound, and a halogena~ed andJor etherated 6ubstitu~ed aromatic or heteroaromatic compound, or mixture~ of these. ~uch a proces~ing a~d ~ay be useful in con~rolling and/or modifying vi~co~ity, reaction time, color, ~tability and the like.
Poly~er recovery can be achie~ed by proce~e~ W~ no~n in ~he art to recover a ~oldable polydrylate ~uch a~ by ~oagulation and filtra~ion.

D-14,177 . .

In addition. the polyarylate~ of this invention exhibit excellent compatibili.~y wi~h polye~hersulfones 6uch a~ ~ho~e which alre de~cribed in U.S. Patent 3,264,536 and U.S. Pa~sn~ 4,175,175, as well a~ with poly(aryl@thsr~s, poly(e~ter-carbonate)s, polye6~er6, po}ycarbonate~, poly(ether imide)s. 6 tyrenic polymers, vinyl chloride containing polymer~ and the like. In ~ome instances, it may be desirable to blend the polyarylate6 of the inven~ion with other polymers exhibiting mechanical compatibility with ~he polyarylate polymer~. Mechanical compatibility refers to a balance of mechanical properties, e.g., ~treng~h, toughnes6 and the like, in miscible blend ~ystems which is generally an average of the mechanical propertie6 of ~he particular blend constituents. Such moldable and compatible blends may typically contain feom about 5 weight percent to about 9S weight parcent of the polyarylates oP thi~
invention and from about 95 weight percent to about S weight percent of a polymer exhibiting mec~anical compatibility with the polyarylate. The weight percent ratio of the polymer~ may vary widely depending upon the propertie~ ~ought from the molded products made from ~he blend.
Blending may be done in the u~ual fa~hion, 6ucb a~ by ~i~ple mixing of powder~ of t~ poly~ers, though u~ually in an extruder mixer. The extruded product will typically be a ~elt mixture of the polyarylate and tbe polymer blended therewith. Such an extruded product ~an be pelleted and u~ed a6 ~uch in ~aking molded ar~iele~ of co~meree.

D-14,177 _ 17 -The polyarylates of thi~ invention utili2ed in manufacturing ~olded article6 may be optionally used wit~ other ingredlen~ ~uch a~ ~tabilizers, i.e., ~etal oxides ~uch a6 zinc oxide, an~ioxidant~, flame retardants, pigment~, and the like. The polyarylates may be optionally u~ed with reinforcing fi~ers and/or inorganic fillers. The reinfQrcing fiber include~ fiberglas~, carbon fiber~, and the like, and mixture~ thereof. The carbon fibers include ~ho6e ~aving a high Young's ~odulu~ of ela6~icity and high ten6ile ~erength. These carbon fiber~ may be produced rom pitch, as described in U.S. Pa~ents 3,976,729: 4,005,183 and 4,026,788, for exa~ple. The particulate inorganic fillers which ~ay be used include wollastonite, calcium oarbonate, glas~ bead~, ~alc, mica, clay, quartz and the l~ke, or mixture~ thereof.
The ~iber reinforcement, filler or combinations thereof, can be utilized in amount6 of from O to about 50 weight percent, preferably from about 10 to about 35 weight percent, of the total weight of ~he molded arti~le.
The polyarylate6 of thi6 invention utilized in manufacturing molded articles in combination wi~h one or more other ingredients can be prepared by any conYentional ~ixing method~. For example, the polyarylate6 and other optional ingredien~s in powder or granular fo~ can be blended in an extruder ~nd tbe mixture can be extruded into ~trand6 and the ~trands can be chopped into p~ t6. The pellets can then be molded into ~he desired ar~icle by ~onven~ional techniques ~uch a~

D-14,177 , . ~ .. . .

compre~ion molding, thermoforming, blow molding and injection molding.
The ~olecular weight of these polyarylate polymers i~ indicated by reduced vi6co~ity in indicated ~olvent~. As well understood in the art, ~he vi~cosity of a re~in ~olution bear~ a direct relation~hip to the weight average molacula~ ~ize of the polymer chains, and i6 ~ypically the mo6t important ~ingle property that can be u~ed to characterize the degree of polymerization. The reduced vi~co~ity as6igned to the polymeric ~aterial6 of this invention i~ there~ore to be under6tood as significant in reflecting molecular 6ize rather than consideration concerning the visco~ity per 6e. Most of these polyarylate polymer~ have indicated ready solubility in N-methylpyrrolidinone, chloroform, or tetrachloroethane or other 6imilar ~olvent.
Reduced vi~cosity (R.V.) as u~ed herein wa~
determined by di6~01ving a 0.2 or 0.5 gram sample of .
polyarylate polymer in the ind;~ated solven~, i.e., chloroform, contained in a 100 mill;liter volumetric fla~k ~o tha~ the re~ultant 601ution ~easured ~xactly 100 milliliter~ at 25C. in a con~tant tempera~ure b~th. The vi~cosity of 3 millili~ers of ~e ~olution which had been filtered throuqh a 6intered glas6 funnel wa~ ~etermined in an Ostwald or similar type viscome~er at 25C. Reduced visco~i~y val~es were obtained from the eguation:
t~ - to Reduced Visco61ty - _ _ C-to ~-14~177 3~

w~erein:
~ he ef f lux ti~e of the pure solven~;
t~ i6 ~he e~flux ~i~e of t~e poly~er solution: and C i~ t~e concentration of ~e polymer ~olution expre~sed in ~er~ of gram~ of polymer per lO0 millili~ers of 601ution.
Tbe polyarylates of tbis invention are characterized as linear ~hermopla~tic structure~
which have a relatively high molecular weight, that is, a rsduced vi~co~ity determined at a concentration of 0.5 g/lO0 ml in chloroform at 25C
of at leas~ 0.3 dl/g, preferably at lea6t 0.5 dl~g and, typically not exceeding about 1. 5 dl/g. T~e~e polymer6 are exceptionally tough and po6se6s ~uperior hydrolytic 6tability in compari~on with conventional Bi~phenol A polyarylates of the pr;or art.
Although thi~ invention has been described with re~pect to a number of detail~, it i6 not intended tha~ thi~ invention 6hould be limited thereby. The example6 which follow are intended fiolely to illu~trate the embodiment~ of this invention which to date have be~n determined and are not intended in any way to limit the ~cope and intent of t~i6 invention.
Example_l To a 4-necked 500 ~llliliter fla6k fitted wi~h a nitrogen inlet pore, ~echanical stirrer, ~flu~ ~onden6er, ~lai~en head. thermometer and a 20~ s~dium hydroxide trap wa~ ~dded 14.27 gra~s ~0.0625 ~ole~) o~ 2,2-bis-~4-hydroxyphenyl)propane ~-14,177 -- ~o --(Bisphenol A). 19.14 grams (0.0625 mole~) of bi~(~,5-dimethyl-ql-hydroxyphenyl~sulfone (T~SBS), 12.69 grams (0.0625 mole~) of i~ophthaloyl chloride, 12.69 qrams ~0.0625 moles) of ~ereph~aloyl chloride, and 175 ~illiliter6 of 1,2,4-trichlorobenzene. The con~ents of the fla6k were then hea~ed to a temperature of 210C and maintained at this temperature for a period of 16 hours with con~inuou~ stirring. A sample removed from the flask after this reaction period had a reduced visc06ity of 0.157 at 25C in O.S~
chloroform ~olution. An additional 0.507 grams (0.0025 moles) of terephthaloyl chloride was added to ~he flask, and the contents in the flask were reacted for another 16 hour period at a temperature of 210C with continuous stirring. A sample removed from the flask after this second 16 ~our reaction period had a reduced visc06ity of 0.35 at 25C in 0.5% chloroform solution. An additional 0.57 grams (0.0028 mole6) of terephthaloyl chloride and 0.57 grams (0.0025 ~oles) of 2,2-bis-(4-hydroxyphenyl)propane ~Bisphenol A) were then added to the fla~ over a period of 24 hours at a t~mperature of 210C with continuous stirring.
The resulting mixture was ~en coagula~ed in ~ethanol, filtered ana washed with methanol. The polymer wa6 dried under vacuum at a temperature o~
100C. T~e reduced visc061ty at 25C in 0.5%
chl~roform solution was 0.46.
Co~parative ~xample A
A 6ample of Bi~phe~ol A polyarylate ~ommercially available from Union Carbide D-14,177 Corporation, Danbury, Connecticut a~ Ardel D-100 prepared from Bisphenol A and a mixture of 50 mole percent each of terephthaloyl and isopht~aloyl chlorides by conventional methods) wa~ compres~ion molded into a plaque in a 4 inch ~ 4 inch ~ 0.020 inch cavity mold at 300C u~ing a South Bend hydraulic pres6 with heated platens. T~e reduced viscosity of the polymer co~position of the plaque was determined and. after placing ~he plaque in boili~g di6tilled water, t~e reduced viscosi~y of the polymer composition of the plague was again detecmined at various period~ of time (boiling di~tilled water immersion) 2~ 6pecified in Table A
hereinbelow. All reduced viscosity values in Table A were determined at a tempera~ure of 25C in a 0.
chloroform solution. The re6ults in Table A
indicate the ratio of the reduced visco6ity of the polymer compo~ition at the 6pecified time to the initial reduced vi6c06ity of the polymer composition determined before placing the plaque in boilinq water.
Exam~le 2 A æample of ehe Bi6phenol A/TMBS
polyarylate prepared in Example 1 wa6 compression moldsd into a plaque in a ~ inch ~ 4 inch X 0.020 inch cavity mold at 300C using a South Bend hydraulic pre~s with heated pldtens. The reduced vi~co~ity of the pvlymer composition of the plaque ~a~ deter~ined and, after placing e~e plaque in boiling di~tilled water, the r@duced vi6cosity of the polymer composition of the plaque wa~ again determined at variou6 psriod~ of time (boilinq D 1~,177 ~t~%

di~tilled water immer~i~n) as ~pecified in Table A.
All reduced vi6c06ity value~ in Table A wer2 de~ermined at a temperature of 25~C in a 0.2%
chloroform solueion. The re6ults in T,able A
indicate the ratio of the reduced visc~ity of the polymer composition at the ~pecified time to the initial reduced viscosity of the polymer composition determined before placing the plaque in boiling water.
TP.BLE A
Ra~io of Reduced Viscosity at Indicated Ti~e to Initial Reduced Viscosity a~ a Function of Time in Boilinq Distilled Water Plaque Sample ~oiling Di6~illed Water Immersion (Hours) Identification 0 100 _308_ 316 580 Compara~ive 1 0.89 0.64 - 0.42 Exa~ple A
Example 2 1 0.93 - 0.84 Table A illu6~rates ~hat the reduced visco~ity of the polymer composition of the plaque prepared in Comparative Exampl0 A (control Bi~phenol A polyarylate) decrea~es ~uch more rapidly upon p~olonged expo~ure in boilin~ distilled water t~an the reduced vi~co~ity of ~he polymer compo6ition of the plaque prepared in Example 2 ~Bisphenol A/TMBS
polyarylate) at ~imilar expo~ure time. The polymar ~ompo~ition of the plaque prepared in ~xample 2 ~how~ improved hydroly~ic ~tability in compari~on ~ith ~e polymer co~posi$ion of the plaque prepared ~n Comparative ~xample A. A~ reduced visco~ity i6 D-14,177 J

- ~3 -an indication of polymer ~olecular weig~t, Bi~phenol ~/TM~S polyarylate~ are ~ore hydrolytically ~table than comparable Bi6phenol A polyarylat,e6 which do not contain TMBS.

D-1~,177 ~.. . . .. , . .... . . ~. , .. . . . ~ . . . . . .

Claims (15)

- 24 -

1. A composition comprising a polyarylate containing repeating units (I) having the formula (I) in an amount sufficient to enhance hydrolytic stability of the polyarylate and repeating units (II) having the formula (II) in which repeating units (I) and repeating units (II) are connected by interbonding units (III) having the formula (III) wherein R1 is a divalent saturated or unsaturated aliphatic hydrocarbon radical, O, CO, S or a direct bond, Ar is a substituted or unsubstituted meta- or para-phenylene group, wherein the substituents are selected from the group comprising alkyl groups containing from 1 to 4 carbon atoms, alkoxy groups containing from 1 to 4 carbon atoms, aryl, and halogen, and wherein the polyarylate has a reduced viscosity of at least about 0.3 dl/g as measured in chloroform at a concentration of 0.5g/100 ml at 25°C.

2. A composition as defined in claim 1 wherein repeating units (II) of the polyarylate have the formula

3. A composition as defined in claim 1 wherein interbonding units (III) of the polyarylate have the formula

4. A composition as defined in claim 1 wherein the polyarylate contains repeating units having the formula

5. A composition as defined in claim 1 in which the polyarylate contains from about 5 weight percent to about 95 weight percent of repeating units (I) and from about 95 weight percent to about 5 weight percent of repeating units (II).

6. A composition as defined in claim 1 in which the polyarylate has a reduced viscosity of at least about 0.5 dl/g as measured in chloroform at a concentration of 0.5g/100 ml at 25°C.

7 A composition as defined in claim 1 which contains a polymer having mechanical compatibility with the polyarylate, and wherein the polymer is selected from a polyethersulfone, a poly(aryl ether), a poly(ester carbonate), a polyester. a polycarbonate, a poly(ether imide), a styrenic polymer and a vinyl chloride containing polymer.

8. A composition as defined in claim 1 which contains a mineral filler.

9. A composition as defined in claim wherein the mineral filler is selected from wollastonite, calcium carbonate, glass beads, talc clay and quartz.

10. A composition as defined in claim 1 which contains a reinforcing fibers.

11. A composition as defined in claim 10 wherein the reinforcing fiber is selected from fiberglass and carbon fibers.

12. A molded article prepared from the composition of claim 1.

13. A molded article prepared from the composition of claim 7.

14. A molded article prepared from the composition of claim 8.

15. A molded article prepared from the composition of claim 10.