Document 6RY7nXNQMYjbR5DY4dbO5m8r3

United States Patent [i9] Deyrup [li] Patent Number: [45] Date of Patent: 4,753,980 Jun. 28, 1988 [54] TOUGHENED THERMOPLASTIC POLYESTER COMPOSITIONS [75] Inventor: Edward J. Deyrup, Northeast, Md. [73] Assignee: E. I. Du Pont de Nemours & Company, Wilmington, Del. [21] Appl. No- 9304>97 [22] Filed: Not. 14,1986 Related U.S. Application Data [63] Continuation of Ser. No. 704,533, Feb. 22, 1985, aban doned, which is a continuation-in-part of Ser. No. 582,988, Feb. 24, 1984, abandoned. [51] Int. Cl.4............................................ C08L 67/02 [52] U.S. a..................................... 524/369; 524/378; 524/394; 524/424; 524/427; 524/444; 524/449; 524/452; 524/513; 525/166; 525/173; 525/174; 525/176 [58] Field of Search .............. 525/166, 173, 176, 174; 524/378, 375, 372, 513, 369, 394, 427, 424, 444, 449, 452 [56] References Cited U.S. PATENT DOCUMENTS 3,591,659 3,793,262 3,925,326 4,022,748 4,034,013 4,172,859 4,275,180 4,284,540 4,317,764 4,322,335 7/1971 Brinkmann et al................... 260/873 2/1974 Logothetis .......................... 260/86.7 12/1975 Logothetis.......................... 260/78.5 5/1977 Schlichting et al..................... 260/40 7/1977 Lane...................................... 260/835 10/1979 Epstein.................................. 428/402 6/1981 Clarke.................................. 525/173 8/1981 Iida et al.................................. 260/22 3/1982 Sheer..................................... 524/449 3/1982 Nield .................................. s523/522 FOREIGN PATENT DOCUMENTS 0055473 57-123251 1241168 2015014 7/1982 7/1982 7/1971 9/1979 European Pat. Off. . Japan . United Kingdom . United Kingdom . Primary Examiner--Patricia Short [57] ABSTRACT Toughened thermoplastic polyester compositions com prising 60-97 weight % of a polyester matrix resin and 3-40 weight % of an ethylene copolymer such as ethylene/methylacrylate/glycidyl methacrylate. 28 Claims, No Drawings 4,753,980 12 This invention relates to certain polyester molding TOUGHENED THERMOPLASTIC POLYESTER compositions characterized by extraordinary toughness, COMPOSITIONS especially at low temperatures. More specifically, it has been found that when certain ethylene copolymer CROSS-REFERENCE TO RELATED 5 tougheners are blended into a polyester matrix such that APPLICATION the ethylene copolymer is dispersed throughout the This application is a continuation of application Ser. No. 704,533 filed Feb. 22, 1985, now abandoned, which is a continuation-in-part of U.S. Application Ser. No. 582,988, filed Feb. 24, 1984, now abandoned. 10 polyester matrix as a discrete phase or discrete particles, which particles have a number average particle size of less than 3 micrometers, then such compositions possess extraordinary low temperature toughness, as measured by a standard notched Izod test (ASTM D-256) with DESCRIPTION the samples at temperatures of 0" C. or lower. This is 1. Technical Field This invention relates to certain polyester molding compositions characterized by extraordinary toughness. 15 particularly unexpected, because polyester molding compositions made with certain ethylene copolymers known as tougheners for polyester molding composi tions are markedly inferior with respect to low tempera The most common polyester molding compositions are ture toughness, even as compared to the polyester based on polyethylene terephthalate homopolymers, molding compositions of the present invention contain polybutylene terephthalate homopolymers, polyethyl ing an ethylene copolymer toughener which is an adja ene terephthalate/polybutylene terephthalate copoly 20 cent homolog to the known ethylene copolymer tough mers, polyethylene terephthalate/polybutylene tere ener. phthalate mixtures, and mixtures thereof, although The term "polyester" as used herein includes poly other polyesters can be used as well, alone, in combina mers having an inherent viscosity of 0.3 or greater and tion with each other, or in combination with those poly which are, in general, linear saturated condensation esters listed above. Such other polyesters include copo- 25 products of glycols and dicarboxylic acids, or reactive lyetheresters, such as described in U.S. Pat. Nos. derivatives thereof. Preferably, they will comprise con 3,651,014; 3,763,109; and 3,766,146. In any event, com densation products of aromatic dicarboxylic acids hav positions based on such polyesters are useful in prepar ing 8 to 14 carbon atoms and at least one glycol selected ing semi-finished and finished articles by any of the from the group consisting of neopentyl glycol, cyclo techniques commonly used with thermoplastic materi 30 hexane dimethanol and aliphatic glycols of the formula als, e.g., compression molding, injection molding, extru HO(CH2)OH where n is an integer of 2 to 10. Up to 50 sion, blow molding, rotational molding, melt spinning, stamping and thermoforming. Finished products made mole percent of the aromatic dicarboxylic acids can be replaced by at least one different aromatic dicarboxylic from such compositions possess extremely desirable acid having from 8 to 14 carbon atoms, and/or up to 20 physical properties, including strength and flexural 35 mole percent can be replaced by an aliphatic dicarbox modulus. However, in certain applications, it would be ylic acid having from 2 to 12 carbon atoms. desirable to have greater toughness, particularly at low Preferred polyesters include polyethylene terephthal temperatures, than has heretofore been possible with ate; poly(l,4-butylene)terephthalate; and 1,4- conventional polyester molding compositions. cyclohexylene dimethylene terephthalate/isophthalate 2. Background Art 40 copolymer and other linear homopolymer esters de U.S. Pat. No. 4,172,859, granted Oct. 30, 1979 to B. rived from aromatic dicarboxylic acids, including iso- N. Epstein, discloses multiphase thermoplastic molding phthalic, bibenzoic, naphthalene-dicarboxylic including compositions where one phase contains 60-99 weight the 1,5-; 2,6-; and 2,7-naphthalenedicarboxylic acids; percent of the matrix resin and is a polyester matrix 4,4'-diphenylenedicarboxylic acid; bis(p-carboxy- resin, and the remaining phase or phases contain 1-40 45 phenyl)methane; ethylene-bis-p-benzoic acid; 1,4-tet- weight percent of the matrix resin and is a random ramethylene bis(p-oxybenzoic) acid; ethylene bis(p- copolymer having particle size in the range of 0.01-3.0 oxybenzoic) acid; 1,3-trimethylene bis(p-oxybenzoic) microns, which copolymer is adhered to the matrix acid; and 1,4-tetramethylene bis(p-oxybenzoic) acid, resin, has a tensile modulus of 1.0-20,000 psi, and has a and glycols selected from the group consisting of 2,2- tensile modulus of less than l/10th the tensile modulus 50 dimethyl-1,3-propane diol; neopentyl glycol; cyclohex of the matrix resin. Among the random copolymers ane dimethanol and aliphatic glycols of the general disclosed and exemplified by Epstein in such composi formula HO(CH2)nOH where n is an integer from 2 to tions are poly(ethylene/methylacrylate/glycidyl/me- 10, e.g., ethylene glycol; 1,3-trimethylene glycol; 1,4- thacrylate) and poly(ethylene/vinyl acetate/glycidyl tetramethylene glycol; 1,6-hexamethylene glycol; 1,8- methacrylate). Such compositions are characterized as 55 octamethylene glycol; 1,10-decamethylene glycol; 1,3- toughened as compared with unmodified polyester propylene glycol; and 1,4-butylene glycol. Up to 20 compositions. mole percent, as indicated above, of one or more ali U.S. Pat. No. 4,284,540, granted Aug. 18, 1981 to Iida phatic acids, including adipic, sebacic, azelaic, et al., discloses impact-modified polyethylene tere dodecanedioic acid or 1,4-cyclohexanedicarboxylic phthalate molding compositions which include a co 60 acid can be present. polymer of a-olefins and glycidyl esters of a,/3-ethyleni- The most common polyester molding compositions cally unsaturated carboxylic acids and barium salts of are based on polyethylene terephthalate homopoly fatty acids. mers, polybutylene terephthalate homopolymers, poly Neither of these references disclose the particular ethylene terephthalate/polybutylene terephthalate co compositions of the present invention or the unexpected 65 polymers, polyethylene terephthalate/polybutylene superior low temperature toughness that characterizes terephthalate mixtures and mixtures thereof, although the particular compositions of the present invention. other polyesters can be used as well, alone, in combina 3. Disclosure of the Invention tion with each other, or in combination with those poly- 4,753,980 34 esters listed above. Such other polyesters include copo- dred parts of the matrix resin (such as disclosed in co lyetheresters such as described in U.S. Pat. Nos. pending U.S. Application Ser. No. 582,991, filed Feb. 3,651,014; 3,763,109 and 3,766,146. 24,1984 by W. E. Garrison, Jr.), 0-16 parts by weight of The inherent viscosity of the polyesters is measured a crystallization promoter per hundred parts by weight at a concentration of 0.32 grams/100 ml. in trifluoroace- 5 of the matrix resin, and up to 80% by weight of rein tic acid (25)/metbylene chloride (75) at 250.10 C. It is computed by the formula forcing or filling material. Additional ingredients which can be incorporated into the compositions of the present invention include epoxy compounds, lubricants, pig Inherent viscosity natural log elution rime of solution elution of solvent C ments, flame retardants, antioxidants, mold-release 10 agents, ultraviolet light and heat stabilizers, nucleating agents and polymers used for convenience of processing where C is the concentration expressed in grams of polymer per 100 ml of solution. The polyester will comprise the matrix resin and to prepare concentrates. Plasticizers can be any known in the art (see, e.g. U.K. Pat. Nos. 2,015,013 and 2,015,014) to be useful in further will comprise 60-97 weight % of the composi *5 polyester molding compositions. However, particularly tions of the present invention based on the total weight useful plasticizers for polyethylene terephthalate and of the polyester and the ethylene copolymer toughener polyethylene terephthalate/polybutylene terephthalate to be described below. The polyester will preferably molding compositions are compounds of the formula comprise 65-95% by weight, and most preferably, 20 70-85% by weight of the composition. The compositions of the present invention will also contain 3-40 weight %, preferably 5-35 weight %, and most preferably, 15-30 weight % of an ethylene copoly CH-(CH2), -0x B mer toughener, each of the above percentages being based on the total of the polyester and the ethylene 25 where copolymer only. The ethylene copolymer is a copoly m is an integer from 1 to 3, inclusive, mer of the formula E/X/Y where n is an integer from 4 to 25, inclusive, E is the radical formed from ethylene and comprises X is CH3, C2H5 or H, 40-90 weight percent of the ethylene copolymer, A is alkyl, acyl or aroyl of 1 to 10 carbon atoms, and X is the radical formed from 30 B is alkyl, acyl or aroyl of 1 to 10 carbon atoms, Preferred plasticizers for use in the compositions of the R2 O I II CHj=CH--C--O--R| present invention are those described above where m is one, or where n is 4 to 14, or where 35 X is H, where R; is an alkyl group with 2-8 carbon atoms, and especially where m is one, n is 4 to 14, and X is H. preferably 4-6 carbon atoms, and most preferably 4 More preferred plasticizers for use in the compositions carbon atoms, and of the present invention are those described above R.2 is H, CH3 or C2H5, preferably H or CH3, and most 40 where preferably H, and X comprises 10-40 weight per cent, preferably 15-35 wt %, most preferably 20-35 wt % of the ethylene copolymer, and Y is selected from the group consisting of glycidyl methacrylate and glycidyl acrylate and Y com prises 0.5-20 weight percent, preferably 2.0-10 wt %, most preferably 3-8 wt % of the ethylene co 45 m is one, or where n is 7 to 13, or where X is H, or where A is acyl of 8 carbon atoms or methyl, or where B is acyl of 8 carbon atoms, and especially where m is one, n is 7 to 13, X is H, A is polymer. acyl of 8 carbon atoms or methyl, and B is acyl of 8 Additional comonomers, e.g. CO and methyl acry carbon atoms. Polyethylene glycol 400 bis(2-ethylhex- late, can also be present in minor amount, provided that anoate), methoxy polyethylene glycol 550 2-ethylhex- the essential characteristics of the ethylene copolymer 50 anoate and tetraethylene glycol bis(2-ethylhexanoate) are not substantially altered. are especially preferred. Polyethylene glycol 400 bis(2- The ethylene copolymers used in the compositions of ethylhexanoate) is most preferred. the present invention can be prepared by direct copoly The polyalkylene oxide "soft segment" is especially merization, for example, copolymerization of ethylene, preferred for use with compositions of the present in- glycidyl methacrylate or glycidyl acrylate, and the 55 vention based on polyethylene terephthalate and on above-defined acrylate or methacrylate, X, in the pres polyethylene terephthalate/polybutylene terephthalate ence of a free-radical polymerization initiator at ele copolymers and/or mixtures. The polyalkylene oxide is vated temperatures, preferably 100-270 C., and most preferably predominantly or all polyethylene oxide and preferably 130-230 C., and at elevated pressures, pref preferably is introduced into the polymer chain as a erably at least 70 MPa, and most preferably 140-350 60 copolymer of polyethylene glycol terephthalate (op MPa. tionally containing a minor proportion of other alkylene In addition to the polyester matrix resin and the eth units) and polyethylene terephthalate or is introduced ylene copolymer toughener, the compositions of the into the polymer chain by reaction in the melt of poly present invention can contain a variety of additional ethylene glycol (optionally containing a minor propor- ingredients, including 0-15 parts by weight of a plasti 65 tion of other alkylene units) with polyethylene tere cizer per hundred parts of the matrix resin, 0-15 parts phthalate. When the matrix resin is a mixture and/or by weight of polyalkylene oxide "soft segments" incor copolymer of polyethylene terephthalate and polybu porated into the matrix resin polymer chain per hun- tylene terephthalate, the polyalkylene oxide can be 4,753,980 56 incorporated into the polymer chain by direct copoly throughout the polyester resin matrix as separate parti merization of polyethylene terephthalate, polybutylene cles, such that the ethylene copolymer particles have a terephthalate and polyalkylene glycol, by let-down of number average particle size of less than 3 microns. polybutylene terephthalate/polyalkylene oxide copoly Temperature and pressure conditions are not critical. mer with polyethylene terephthalate, or by direct addi 5 Mixing equipment and shear conditions can vary tion of polyalkylene oxide to polyethylene tereph- widely, however, high shear equipment and conditions thalate/polybutylene terephthalate copolymer. The are preferred to insure number average particle size of molecular weight of the polyalkylene oxide should be in the ethylene copolymer toughener will be as small as the range of 200 to 3250, preferably 600 to 1500. The possible, and in any event, below 3 microns. total weight proportion of the soft segment plus the 10 Particle size is measured by preparing slices 200 nano plasticizer in the compositions of the present invention meters thick of sample composition by microtoming should be from 9-20 parts by weight per hundred parts molded test bars in the center of the bar, perpendicular of the matrix resin, preferably 9-18% parts by weight to the long axis of the bar using a Sorvall MT-2B ultra- and most preferably, 12-18% parts by weight. The microtome, Christensen cryogenic cell, diamond knife, relative quantities of soft segment and plasticizer in the 15 operating at --90' C., using ethanol as a knife lubricant. compositions of the present invention can vary from 85:15 to 15:85, but preferably will be between 75:25 and After cutting, the slices were floated on water, picked up on 200 mesh copper grids, an photographed without 40:60, most preferably between 65:35 and 40:60. staining with a Zeiss EM10A TEM operating at 80 KV. The crystallization promoter can be one which is The 70 mm camera was loaded with Eastman fine grain derived from 20 release positive film type 5302. Using standard dark (a) hydrocarbon acids containing between about 7 room procedures, 8" X10" photographs were produced and 54 carbon atoms or organic polymers having at using a Durst enlarger at a magnification of 4.3 X, giv least one carboxyl group attached thereto, and ing a net magnification of 11.800X. (b) sodium and/or potassium ion sources capable of The photographs were analyzed with a "Quantimet" reacting with the carboxyl groups of the acids or 25 900 image analyzer (Cambridge Instruments, Inc.). Par polymers of (a). ticle differentiation was accomplished by means of an The crystallization promotor should be such that it automatic detection level cut-off modified by editing contains the sodium and/or potassium ion source in with a light pen. Tiny particles of matrix resin (dark) sufficient quantity such that the sodium and/or potas inside of toughener particles (light) were ignored. The sium concentration in the matrix resin is greater than 30 light pen was used to separate particles that touched 0.01 weight percent. Preferably, the crystallization and were not separated in the automatic "detect" mode. promotor is an organic ionic hydrocarbon copolymer of Enough photographs were analyzed in each area to an -olefin of 2-5 carbon atoms and an a,/3-ethylenically count at least 750 particles greater than 0.04 microme unsaturated carboxylic acid of 3-5 carbon atoms in ters. Particles less than 0.04 micrometers wide were which the carboxyl groups have been at least partially 35 ignored as photometric noise. Width and length were neutralized with sodium or potassium cations. Other measured by 8 ferets and distributed into 48 logrithmi- suitable crystallization promotors include materials de cally distributed bins from 0.04 to 40.0 micrometers. rived from (a) polyethylene terephthalate and/or poly The measured length and width are of two-dimensional butylene terephthalate oligomer and (b) sodium and/or images and have not been stereologically corrected to potassium ion sources capable of reacting with the car 40 estimate the true maximum and minimum diameters of boxyl groups on the oligomer(s) of (a). Further, it is the three-dimensional particles. Number average and preferred that the crystallization promoter be present in standard deviation for each distribution was calculated an amount sufficient to provide AH///AHC ratio to the composition of less than 0.25. It has been found that the by standard procedures. Accordingly, the compositions of the present inven AH/j/AHc ratio is a convenient method of measuring 45 tion consist essentially of: the degree of crystallization. Procedures for measuring A. 60-97 weight % based on the total of components A this ratio and further details concerning the crystalliza and B of a polyester matrix resin having an inherent tion promoter are described, for example, in U.K. Pat. viscosity of at least 0.3, and Nos. 2,015,013 and 2,015,014. B. 3-40 weight % based on the total of components A The reinforcing and filling material can be glass, 50 and B of an ethylene copolymer of the formula graphite or aramid fibers, glass beads, aluminum silicate, E/X/Y where asbestos, mica, calcium carbonate and the like, and E is the radical formed from ethylene and comprises combinations of such materials. Glass fibers are pre 40-90 weight % of the ethylene copolymer, ferred. The compositions of the present invention can X is the radical formed from contain up to 80% by weight of reinforcing or filling 55 material, preferably 0-50%, and most preferably 0-45%. Compositions containing polyoxyalkylene oxide "soft segments" and ethylene/butyl acrylate/- ch2=ch--c--o--R, glycidyl methacrylate elastomeric toughener and 2-8% glass fibers have shown surprisingly good Gardner 60 where impact and are especially preferred for certain end uses. Ri is alkyl of 2-8 carbon atoms, and R2 is H, CH3 or Other compositions containing 25-45% glass fibers C2H5, and have shown remarkable good over-all balance of prop X comprises 10-40 weight percent of the ethylene erties and are especially preferred for certain end uses. copolymer, and The compositions of the present invention can be 65 Y is selected from the group consisting of glycidyl prepared by blending the various ingredients together methacrylate and glycidyl acrylate, and Y com by any convenient means to obtain an intimate blend in prises 0.5-20 weight percent of the ethylene co which the ethylene copolymer toughener is dispersed polymer, 4,753,980 78 said composition optionally also containing above except the cycle was 20, 20, 3; and the mold C. 0-15 parts by weight of a plasticizer per hundred cavity temperature was ~ 110' C. A control containing parts of the matrix resin A, all ingredients above was also evaluated. The notched D. 0-15 parts by weight of a polyalkylene oxide soft Izod was 3.63 ft-lbs/in as compared with 2.10 ft-lbs/in segment incorporated into the matrix resin polymer 5 for the control. chain per hundred parts of the matrix resin A, E. 0-16 parts by weight of a crystallization promoter EXAMPLES 2-17 per hundred parts of the matrix resin A, and In the following Examples, 18% of each was the F. 0-80 weight percent based on the total of compo 10 ethylene copolymer toughener described in Example 1, nents A, B and F of at least one material selected from 81.5% was polyethylene terephthalate of an inherent the group consisting of reinforcing and filling materi viscosity of approximately 0.6, or polybutylene tere als. phthalate of an inherent viscosity of approximately In the following Examples, there are shown specific 0.8-0.9, and 0.5% was "Irganox" 1010 a hindered phe embodiments of the present invention demonstrating 15 nolic antioxidant These ingredients were dry blended the extraordinary low temperature toughness of the together by tumbling in a polyethylene bag. The mix compositions of the present invention, even as com ture was then blended in a 28 mm Werner and Pfleid pared to a composition containing an ethylene/methyla- erer extruder which had two sets of kneading blocks crylate/glycidyl methacrylate toughener. All parts and and reverse sections in which the hopper is blanketed percentages are by weight, and all temperatures are in 20 with nitrogen and the vacuum port maintained at about degrees Celsius unless otherwise specified. Measure 28 inches vacuum. Extruder barrel temperatures were ments not originally in SI units have been so converted set at 270' C. except for the first zone which was set at and rounded where appropriate. 200' C. Melt temperatures were approximately EXAMPLE 1 25 290-300 C. The melt exiting the extruder was quenched in water and then cut. The cut strands were A polymer containing normal butyl acrylate, ethyl dried overnight at 110' C. and then molded into ene and glycidyl methyl acrylate was produced by a "X5"X|" thick test bars in a 6 oz. injection molding free-radical polymerization carried out at a reactor machine. With PET, barrel temperatures were approxi temperature of 190' C. and 190 MPa (27,000 psi). Mono 30 mately 285 C.t melt was 295' C. With PBT, the barrel mer addition was adjusted to give a polymer containing temperatures were 240' C. and melt was --240' C. approximately 6% of glycidyl methacrylate (GMA), Mold temperatures were 50' C. The cycle was 20 sec 31% of n-butyl acrylate (BA) and 63% of ethylene. A onds injection forward, 20 seconds additional mold blend was prepared from 20.4% of this polymer (E/31- close and 2 seconds mold open. The bars were then /BA/6GMA-20 melt index) with 79.6% PET of 0.6 35 annealed at 150' C. overnight in order to come to a inherent viscosity (1) by dry blending these ingredients constant level of crystallinity. The notched Izod was together by tumbling in a polyethylene bag, (2) melt evaluated in approximate accord to ASTM D-256-56. blending in a 28 mm Werner and Pfleiderer extruder The reported values represent the average of tests on 6 which had two sets of kneading blocks and reverse samples--3 from near the gate end of the bar and 3 from bushings. The hopper was blanketed with nitrogen and 40 near the other end. the vacuum port on the extruder was maintained at 27.5 In Table I below, the column labeled "polyester" inches vacuum. Extruder barrel temperatures were set designates the type of polyester matrix resin: PET is at 270' C. except for the first zone which was set at 240" polyethylene terephthalate i.v. 0.6, PBT is polybutylene C. Extruder RPM was 200. Feed was ~ 19 lbs/hr. Melt 45 terephthalate i.v. 0.8-0.9. The column labeled "X" des temperature was approximately 305" C. The melt exit ignates the weight percent and type of monomer X in ing the extruder was quenched in water and then cut. the ethylene copolymer toughener as defined above, The cut strands were dried overnight at 110' C. and BA is butyl acrylate; MA is methyl acrylate; VA is then molded into j" X 5" X i" thick test bars in a 6 oz. vinyl acetate; CO is carbon monoxide. The column injection molding machine with the following condi 50 labeled "% GMA" is the weight percent of glycidyl tions: barrel temperatures=285 C.; cycle=30 second methacrylate monomer in the ethylene copolymer injection forward time, 20 seconds additional mold toughener. The column labeled "M.I." is the approxi close, and 3 seconds mold open; melt=305 C.; mold mate melt index (measured according to ASTM-D-1238 cavity=50' C. The bars were then annealed at 150' C. Condition E) of the ethylene copolymer toughener; overnight in order to come to a constant level of crys 55 Example 3 used a 50/50 blend of the ethylene copoly tallinity. The notched Izod according to ASTM D-256- mers from Examples 2 and 4; Example 5 used a 50/50 56 was 20.1 ft-lbs/in at 23' C., as compared with 0.5-0.6 blend of the ethylene copolymers from Examples 2 and ft-lbs/in for a control without any ethylene copolymer 7; Example 8 used a 50/50 blend of an E/19 MA/4.4 toughener. 61.4% of this blend was dry blended with GMA (melt index=29) copolymer and an E/22 30% of a commercial glass, 3.8% of a sodium neutral 60 MA/12.7 GMA (melt index=68) copolymer. The last ized ethylene methacrylic acid copolymer, 0.6% of a three columns report average notched Izod values for condensation product of epichlorohydrin and bisphenol tests run at 23' C., 0 C. and --20 C., respectively. A, 3.9% dibenzoate of neopentyl glycol and 0.3% of a It can be seen from the data in Table I that as temper hindered phenolic antioxidant. This was melt blended in 65 ature decreases the E/BA/GMA tougheners are clearly a 2-inch single screw extruder with a barrel temperature superior to the E/MA/GMA and E/VA/CO/GMA of approximately 270' C. This was then molded in a 6 copolymers, especially at --20 C., all other parameters oz. injection molding machine at similar conditions to being equal. example 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 9 POLY ESTER X PET 35BA PET 33BA PET 31 BA PET 31 BA PET 24BA PET 28BA PET 18.6MA PET 20MA PET 27VA/ 4.3CO PET 71VA PBT 35BA PBT 31BA PBT 28BA PBT 19MA PBT 27VA/ 4.3CO PBT 21VA 4,753,980 TABLE I Izod 23' C. % GMA M.I. (J/m) 0.00 34.0 35.2 2.25 81.7 4.50 9.1 472.1 4.50 435.2 4.50 8.0 351.4 8.40 11.0 1105.4 4.40 12.0 351.4 8.60 844.8 Izod 0* C. (J/m) 31.8 71.8 97.2 91.8 92.6 699.5 86.2 103.3 4.10 12.0 4.60 40.0 0.00 34.0 4.50 9.1 8.40 11.0 4.40 29.0 179.4 157.0 49.1 192.8 453.9 100.4 86.8 74.2 38.7 94.8 101.5 53.4 4.10 12.0 4.60 40.0 136.7 120.7 83.3 61.9 Izod -20' C. (J/m) 21.9 52.3 66.2 56.1 59.0 98.3 46.5 45.9 45.1 50.5 29.6 58.2 65.1 40.6 46.7 39.5 10 Examples 18-4-3 In the following Examples, various quantities of eth ylene copolymer toughener (as indicated in Table II) were blended with polyethylene terephthalate of an inherent viscosity of approximately 0.6 substantially as 25 described for Examples 2-17 above. Test bars were prepared and tested, also as described for Examples 2-7, above, and the results are reported in Table II, below, where the column headings are the same as for Table I, except the weight % of the ethylene copolymer tough- 30 ener (E/X/GMA) is also indicated. It can be seen from the data in Table II that, espe ter consists essentially of a linear saturated conden sation product of at least one glycol selected from the group consisting of neopentyl glycol, cyclohex ane dimethanol and aliphatic glycols of the formula HO(CH2)nOH where n is an integer of 2 to 10 and at least one aromatic dicarboxylic acid having 8 to 14 carbon atoms, or reactive derivatives thereof, and (B) 3-40 weight % based on the total of components A and B of an ethylene copolymer of the formula cially at low temperatures, the compositions containing E/X/Y E/BA/GMA and E/EA/GMA (EA is ethyl acrylate) generally have superior toughness, even as compared 35 where with the adjacent homolog E/MA/GMA toughener. E is the radical formed from ethylene and comprises EX AM WT. % TABLE II Izod Izod 23' C.' O' C. Izod 20* C. 40-90 weight percent of the ethylene copolymer, X is the radical formed from PLE E/X/GMA X % GMA (J/m) (J/m) (J/m) 18 3 28BA 8.4 33.6 31.2 27.3 19 3 31BA 4.5 53.4 88.6 21.1 20 3 31BA 4.5 35.2 34.7 20.8 21 3 28BA 4.5 32.0 23.0 48.1 22 3 21MA 4.4 37.4 22.2 30.2 23 10 28BA 8.4 104.1 61.1 42.2 24 10 31BA 4.5 113.7 103.9 45.9 25 10 28EA 4.5 105.2 77.7 15.2 26 to 21MA 4.4 105.2 43.0 40.9 27 12 31 BA 4.5 139.9 86.5 56.1 28 12 31BA 4.5 130.8 143.6 61.4 29 18 28BA 8.4 -- 180.2 145.5 30 18 28BA 8.4 738.5 186.9 99.3 31 18 31BA 4.5 767.9 512.9 126.0 32 25 31BA 4.5 891.8 512.6 176.8 33 25 28EA 3.0 891.8 376.7 143.1 34 25 28EA 4.5 955.9 852.5 134.6 35 25 28EA 4.5 -- 503.8 105.2 36 25 28EA 6.0 1003.4 911.0 145.5 37 25 31EA 4.5 -- 612.2 111.3 38 25 21MA 4.4 791.4 199.4 108.1 39 40 3 [BA 4.5 887.0 919.0 937.7 40 40 31BA 4.5 828.8 820.8 909.1 41 40 28EA 4.5 692.6 932.4 1025.3 42 40 21MA 4.4 834.6 214.4 117.5 43 40 2 IMA 4.4 720.9 672.3 86.5 ch2=ch--c--o--R, where Ri is alkyl of 2-8 carbon atoms and R2 is H, CHj or C2H5, and X comprises 10-40 weight per cent of the ethylene copolymer, and Y is selected from the group consisting of glycidyl methacrylate and glycidyl acrylate, and Y com prises 0.5-20 weight percent of the ethylene co polymer. 2. The compositions of claim 1 wherein the ethylene copolymer is dispersed throughout the polyester matrix resin as separate particles having a number average particle size of less than 3 micrometers. 3. The compositions of claim 1 where the polyester also contains >0-20 mole % of units derived from aliphatic dicarboxylic acids having 2 to 12 carbon atoms. 4. The compositions of claim 1 where the polyester is selected from the group consisting of polyethylene tere phthalate homopolymer, polybutylene terephthalate homopolymer, polyethylene terephthalate/polybuty- lene terephthalate copolymers, polyethylene tereph- I claim: thalate/polybutylene terephthalate mixtures and mix 1. A polyester molding composition comprising 65 tures thereof. (A) 60-97 weight % based on the total of components 5. The compositions of claim I where the polyester A and B of a polyester matrix resin having an in matrix resin comprises 65-95% by weight of the com herent viscosity of at least 0.3, wherein the polyes position, based on the total of components A and B. 4,753,980 11 12 6. The compositions of claim 1 where the polyester 22. The compositions of claim 21 where the relative matrix resin comprises 70-85% by weight of the com quantity of soft segment and plasticizer is from 85:15 to position, based on the total of components A and B. 15:85. 7. The compositions of claim 1 where Ri is alkyl of 23. The compositions of claim 1 which also contains 4-6 carbon atoms. 5 0-16 parts by weight of a crystallization promoter per 8. The compositions of claim 1 where Ri is alkyl of 4 hundred parts of the matrix resin. carbon atoms. 24. The compositions of claim 23 where the crystalli 9. The compositions of claim 1 where R2 is H or CH3. zation promoter is derived from 10. The compositions of claim 1 where R2 is H. (a) hydrocarbon acids containing 7-54 carbon atoms 11. The compositions of claim 1 where X comprises 10 or organic polymers having at least one carboxyl 15-35 weight % of the ethylene copolymer. group attached thereto, and 12. The compositions of claim 1 where X comprises 20-35 weight % of the ethylene copolymer. 13. The compositions of claim 1 where X is butyl 15 (b) sodium and/or potassium ion sources capable of reacting with the carboxyl groups of the acids or polymers of (a), where the concentration of said sodium and/or potassium in said polyester matrix acrylate. resin (A) is at least 0.01 weight percent. 14. The compositions of claim 1 where Y is glycidyl 25. The compositions of claim 1 which also contains methacrylate. 0-80% by weight of a material selected from the group 15. The compositions of claim 1 which also contain consisting of reinforcing and filling materials. 0-15 parts by weight of plasticizer per hundred parts of 20 26. The compositions of claim 25 where the reinforc the matrix resin. ing and filling materials are selected from the group 16. The compositions of claim 15 where the plasti consisting of glass fibers, graphite fibers, aramid fibers, cizer is a compound of the formula glass beads, aluminum silicate, asbestos, mica and cal cium carbonate. 25 27. Molded articles made from the composition of claim 1. x _ J/| 28. Molded articles comprising (A) 60-97 weight % based on the total of components where m is an integer from 1 to 3, inclusive, A and B of a polyester matrix resin having an in 30 herent viscosity of at least 0.3, and (B) 3-40 weight % based on the total of components n is an integer from 4 to 25, inclusive, A and B of an ethylene copolymer of the formula X is CH3, C2H5 or H, A is alkyl, acyl or aroyl of 1-10 carbon atoms, and B E/X/Y is alkyl, acyl or aroyl of 1-10 carbon atoms. 35 17. The compositions of claim 15 where the plasti cizer is polyethylene glycol 400 bis(2-ethylhexanoate). 18. The compositions of claim 1 where the polyester also contains >0-15 parts by weight of polyalkylene oxide soft segments incorporated into the backbone of 40 where E is the radical formed from ethylene and com prises 40-90 weight percent of the ethylene co polymer, X is the radical formed from the polyester per hundred parts of the polyester. 19. The compositions of claim 18 where the polyal kylene oxide is polyethylene oxide, optionally contain ing a minor proportion of alkylene oxide units other than ethylene oxide units. 45 20. The compositions of claim 18 which also contains 0-15 parts by weight of plasticizer per hundred parts of the matrix resin. 21. The compositions of claim 20 where the total weight proportion of the plasticizer and the soft seg 50 ch2=ch--c--0--Ri where Ri is alkyl of 2-8 carbon atoms and R2 is H, CH3 or C2H5, and X comprises 10-40 weight percent of the ethylene copolymer, and Y is selected from the group consisting of glycidyl methacrylate and glycidyl acrylate, and Y com prises 0.5-20 weight percent of the ethylene ment is 9-20 parts by weight per hundred parts of the matrix resin. copolymer. ***** 55 60 65