PLASTICIZED POLYARYLATE COMPOSITIONS

Abstract: Described herein is a plasticized polyarylate composition comprising in admixture, a polyarylate derived from a dihydric phenol and at least one aromatic dicarboxylic acid and having a reduced viscosity of from about 0.4 to greater than 1.0 dl/g and a plasticizing amount of an oligomeric poly(aryl ether) having a reduced viscosity of from about 0.10 to about 0.45 dl/g.

Description: This invention is directed to a plasticized polyarylate composition comprising in admixture, a polyarylate derived from a dihydric phenol and at least one aromatic dicarboxylic acid and having a reduced viscosity of from about 0.4 to greater than 1.0 dl/g and a plasticizing amount of¯an olgomeric polyCaryl ether) having a reduced viscosity of from about 0.10 to about 0.45 dl/g. Polyarylates are aromatic polyesters derived from a dihydric phenol, particularly 2,2-bis(4-hydroxyphenyl)propane also identified as bisphenol-A, and an aromatic dicarboxylic acid, particularly mixtures of terephthalic and isophthalic acids. These polyarylates are high temperature, high performance thermoplastic polymers with a good combination of thermal and mechanical properties. However, polyarylates are generally processed at temperatures of about 680"C. At these temperatures the mechanical properties of the polyarylate may be detrimentally effected. Additives have been proposed which lower the processing temperature of the polyarylate. However, many of these polyarylates are not stable at these processing temperatures. Thus, there is a desire to lower the processing temperature of the polyarylate without effecting the mechanical properties. Also, if an additive is used to lower the processing temperature it must be compatible with and not degrade the polyarylate. THE INVENTION It has now been discovered that by admixing a plasticizing amount of an oligomeric poly(aryl ether) having a reduced viscosity of from about 0.10 to about 0.45 dllg with a polyarylate derived from a dihydric phenol and at least- one aromatic dicarboxylic acid and having a reduced viscosity of from about 0.4 to greater than 1.0 dl/g, the polyarylate may be processed at lower temperature, thus retaining the high mechanical properties of the polyarylate. In the practice of this invention, the oligomeric polyCaryl ethers) which may be used are linear, thermoplastic polyarylene polyether polysulfone oligomers, 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 or both of which contain a sulfone or ketone linkage, i.e., -SO2- or -CO- between arylene groupings, to provide sulfone or ketone units in the polymer chain in addition to arylene units and ether units. The polysulfone polymer has a basic structure comprising recurring units of the formula: -O-E-O-E' O--E''- wherein E is the residuum of the dihydric phenol and ±' is the residuum of the benzenoid compound having an inert electron withdrawing group in at least one of the positions ortho and para to the valence bonds; both of said residua are valently bonded to the ether oxygens through aromatic carbon atoms.. Such polysulfones are included within the class of polyarylene polyether resins described in U.S. patent 3,264,536, and 4,108,837, for example. The residue of a dihydric phenol, E is derived from dinuclear phenols having the structure: EMI3.1 Wherein Ar is an aromatic group and preferably is a phenylene group, A and A1 may be the same or different inert substituent groups, such as alkyl groups having from 1 to 4 carbon atoms, halogen atoms, i.e., fluorine, chlorine, bromine or iodine, or alkoxy radicals having from 1 to 4 carbon atoms1 r and rl are integers having a value of from 0 to 4, inclusive, and R is representative of a bond between aromatic carbon atoms as in dihydroxydiphenyl, or is a divalent radical, including, for example, CO, 0, S, S-S, S02 or a divalent organic hydrocarbon radical, such as alkylene, alkylidene, cycloalkylene, cycloalkylidene, or the halogen, alkyl, aryl substituted alkylene, alkylidene, cycloalkylene, and cycloalkylidene radicals as well as alkarylene and aromatic radicals and a ring fused to both Ar groups. Typical preferred oligomers have recurring units having the following structure: EMI3.2 as described in U.S. Patent 4,108,837, supra. In the foregoing formula A and A1 can be the same or different inert substituent groups as alkyl groups having from 1 to 4 carbon atoms, halogen atoms (e.g., fluorine, chlorine, bromine or iodine) or alkoxy radicals having from 1 to 4 carbon atoms, r and rl are integers having a value of from 0 to 4, inclusive. Typically, R1 is representative of a bond between aromatic carbon atoms or a divalent connecting radical and R2 represents sulfone, carbonyl, or sulfoxide. Preferably, R1 represents a bond between aromatic carbon atoms. Even more preferred are the oligomeric polysulfones of the above formula wherein r and rl are zero, R1 is'a divalent connection radical of the formula EMI4.1 wherein R3 is independently selected from lower alkyl, aryl, and the halogen substituted groups thereof, preferably methyl and R2 is a sulfone group. The polyCaryl ether) oligomers have a reduced viscosity of from about O.lOto about 0.45 dl/g as measured in an appropriate solvent at an appropriate temperature depending on the particular polyether, such as in methyl ene chloride at 25-C. The preferred poly(aryl ether) oligomers have repeating units of the formula: EMI4.2 The polyarylates which are suitable for use in this invention are derived from a dihydric phenol and at least one aromatic dicarboxylic acid and have a reduced viscosity of from about 0.4 to greater than about 1.0, preferably from about 0.6 to about 0.8 dl/gm, as measured in chloroform C0.5 g/dl chloroform) or other suitable solvent at 25"C. A particularly desirable dihydric phenol is of the following formula: EMI5.1 wherein Y is selected from alkyl groups of 1 to 4 carbon atoms, chlorine or bromine, each z, independently, has a value of from 0 to 4, inclusive, and R4 is a divalent saturated or unsaturated aliphatic hydrocarbon radical, particularly an alkylene or alkylidene radical having from 1 to 3 carbon atoms, or a cycloalkylidene or cycloalkylene radicals having up to and including 9 carbon atoms. The preferred dihydric phenol is bisphenol-A. The dihydric phenols may be used individually or in combination. The aromatic dicarboxylic acids that may be used in this invention include terephthalic acid, isophthalic acid, any of the naphthalene dicarboxylic acids and mixtures thereof, as well as alkyl substituted homologs of these carboxylic acids, wherein the alkyl group contains from 1 to about 4 carbon atoms, and acids containing other inert substituents, such as halides, alkyl or aryl ethers, and the like. Preferably, mixtures of isophthalic and terephthalic acids are used. The isophthalic acid to terephthalic acid ratio in the mixture is about 20:80 to about 100:0, while the most preferred acid ratio is about 75:25 to about 50:50. Also, from about 0.5 to about 20 percent of aliphatic diacids containing from 2 to about 10 carbon atoms, such as adipic acid, sebacic acid, and the like may be additionally used in the polymerization reaction. 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 chlorides of thejaromatic dicarboxylic acids with the dihydric phenols; the reaction of the diaryl esters of the aromatic dicarboxylic acids with the dihydric phenols; or the reaction of the aromatic diacids with diester derivatives of the dihydric phenol. These processes are described in, for example, U.S. Patents 3,317,464; 3,948,856; 3,780,148; 3,824,213 and 3,133,898. Preferably, the polyarylates used in this invention are prepared by the process described in U.S. Patent Application Serial No. 189,561, filed September 23, 1980, in the names of L. M. Maresca, et al. and titled "Improved Process For Preparing Polyarylates". This application describes an improved prowess for preparing a polyarylate having a reduced viscosity of from about 0.5 to greater than 1.0 dl/gm which process comprises the following steps: (a) reacting an acid anhydride derived from an acid containing from 2 to 8 carbon atoms with at least one dihydric phenol to form the corresponding diester; and (b) reacting said diester with at least one aromatic dicarboxylic acid at a temperature sufficient to form the polyarylate, wherein the improvement comprises removing residual acid anhydride, after formation of the dihydric phenol diester, so that its concentration is less than about 1500 parts per million. The polyCaryl ether) oligomer is used in plas ticizing amounts, i.e. from about 5 to about 25, preferably from about 5 to about 15 weight percent, most preferably 10 weight percent. Other additives may be included in the composition of this invention. These additives include pigments, reinforcing agents, such as glass fibers; thermal stabilizers; ultraviolet light stabilizers, impact modifiers of one or more thermoplastic polymers, and the like. The compositions are prepared by blending the polyarylate, poly(aryl ether) oligomer and any other optional ingredients by any conventional mixing methods. For example, the polyarylate and poly(aryl ether) oligomer are mixed in powder or granular form in an extruder and extruding the mixture into strands, chopping the strands into pellets and molding the pellets into the desired article. EXAMPLES The following examples serve to give specific illustrations of the practice of this invention but they are not intended in any way to limit the scope of this invention. In these examples, all parts and percentages are on a weight basis unless otherwise specified. In the Examples the following designations are used: PS oligomerI EMI8.1 having a reduced viscosity of 0.42 as measured in methylene chloride at 250C. PS oligomer II EMI8.2 having a reduced viscosity of 0.34 as measured in methylene chloride at 25 C. Control A A polyarylate (prepared from bisphenol-A and a mixture of 50 mole percent of terephthalic acid chloride and 50 mole percent of isophthalic acid chloride by conventional methods) having a reduced viscosity of 0.66 dl/g as measured in p-chlorophe-i1. @t 49 C was injection molded in a 3 in. Van Dorn molding machine at the following temperatures: rear 620 F, middle 680 F. front 685 F, nozzle 644"F and stock 740"F, into an ASTM test bar. The polyarylate was injection molded into ASTM test bars at a low temperature and a high temperature. The low temperature was that temperature necessary to fill the mold while the high temperature was the highest temperature at which no appearance of degradation takes place. The medium temperature was the -difference between the two. At each of these temperatures the melt flow of the polymer was tested as well as the mechanical properties of the ASTM test bar. The ASTM test bar was tested for the following mechanical properties: tensile strength and modulus according to ASTM D-638; elongation at break according to ASTM D-256; tensile impact strength according to ASTM D-1822; heat distortion temperature according to ASTM D-635. The melt flow of the polymer was measured in a Tinius Olsen thermodyne (melt flow cell) at 3750C. The polymer was added to the preheated (375"C) chamber of the thermodyne and put under a constant pressure of 44 psi. One sample of the polymer was held at this temperature and pressure for 10 minutes (Melt Flow I) and another sample held at the temperature and pressure for 30 minutes (Melt Flow II). The results are shown in Table I. Example 1 95 weight percent of the polyarylate described in Control A was tumble mixed with 5 weight percent of PS oligomer I. The blend whs injection molded and tested by the procedure described in Control A. The results are shown in Table I. Example 2 95 weight percent of the polyarylate described in Control A was blended with 5 weight percent of PS oligomer II by the procedure as described in Example 1. The blend was injection molded and tested by the procedure described in Control A. The results are shown in Table I. Example 3 90 weight percent of the polyarylate described in Control A was blended with 10 weight percent of PS oligomer I by the procedure as described in Example 1. The blend was injection molded and tested by the procedure described in Control A. The results are shown in Table I. Example 4 75 weight percent of the polyarylate described in Control A was blended with 25 weight percent of PS oligomer by the procedure as described in Example 1. The blend was injection molded and tested by the procedure described in Control A. The results are shown in Table I. The data in the Table shows that the addition of the polysulfone oligomer to the polyarylate increases molding latitude since the low temperature is generally decreased so that heat effects on the polymer are minimized. In the above mentioned formulae alkyl with 1 to 4 carbon atoms is preferably methyl, ethyl, propyl, i-propyl, butyl, i-butyl, sec.-butyl or tert.-butyl. Alkylene is preferably methylene, ethylene, 1,3 or 1,2-propylene. A cycloalkylene residue contains preferably 3 to 8 carbon atoms like cyclo propane, cyclobutane, cyclopentane, cyclohexane, cycloheptane or cyclooctane. T A B L E I Control A 1 2 High Low Medium AT High Low Medium AT Eigh Low Medium #T Molding Temperature ( F) 750 665 710 85 770 685 715 85 770 640 700 130 Injection pressure (psi) High 825 1700 1700 975 1850 1250 800 1800 1100 Low - 700 1125 775 1800 1075 700 700 700 Properties of the resin Melt Flow I 19.2 16.0 11.7 9.1 7.8 7.8 17.0 12.7 15.8 Melt Flow II 29.5 16.6 12.9 12.4 8.4 8.7 25.9 19.1 20.7 Mechenical Properties Notched izod (ft-lb/in2) 4.50 4.50 4.96 - - - 4.4 4.4 4.7 Tensile strength (psi) 9120 9210 9610 10.500 9000 10.600 8720 8920 9310 Elongstion (%) 49.5 55.0 61.0 75.0 43.0 71.0 41.5 27.5 58.5 Tensile modulus(psi)x106 3.0 3.03 3.02 3.12 3.20 3.10 3.04 3.09 3.10 Tensile impact(ft-lb/in2) - - - 96.2 94.7 93.9 - - Heat Distortion Temp.( C) 172.9 172.5 169.9 165.3 170.6 167.1 - - -

Claims: of the formula: -O-E-O-E' wherein E is the residuum of a dihydric phenol and E' is the residuum of a benzenoid compound having an inert electron withdrawing group. 6. A compositionaa.deined in claim 5 wherein the polyCaryl ether) has recurring units having the formula: EMI13.1 A and A1 can be the s-ame or different inert substituent groups and are selected from alkyl groups having from 1 to 4 carbon atoms, fluorine, chlorine, bromine, iodine, or alkoxy radicals having from 1 to 4 carbon atoms, R1 represents a bond between aromatic carbon atoms or a divalent connecting radical, R2 is sulfone, carbonyl or sulfoxide, r and rl are integers having a value of from 0 to 4, inclusive. 7. A composition as defined in claim 6 wherein r and r1 are O,R2 is S02, and R1 is the following EMI13.2 8. A compositton as defined in claim 1 wnerein the oligomeric poly(aryl ether) is used in amounts of from about 5 to about 25 weight percent.

Inventors: DICKINSON, BARRY LEE
Applicants: UNION CARBIDE CORPORATION
Application year: 1982
Main classification: C08L67
IPC codes: C08L67