REINFORCED POLYESTER COMPOSITIONS WITH HIGH IMPACT MELT VISCOSITY FOR BLOW MOLDING

Abstract: The addition of copolymers or interpolymers comprising glycidyl 2-alkenoates and alpha-olefins to reinforced thermoplastic polyester compositions results in improved impact strength if the weight ratio of polyester to reinforcement is equal to or below about 2.25. The melt viscosity of such compositions also is unexpectedly high, making them very useful in extrusion and injection blow molding applications.

Description: REINFORCED POLYESTER COMPOSITIONS WITH HIGH IMPACT MELT VISCOSITY FOR BLOW MOLDING This invention relates to impact modified reinforced thermoplastic compositions having high viscosity in the melt, and to articles and methods for their production. More par¬ ticularly, it pertains to articles blow molded from rein- forced poly(l,4-butylene terephthalate) compositions having improved impact strengths and high melt viscosities. BACKGROUND OF THE INVENTION High molecular weight linear polyesters and copoly- esters of glycols and terephthalic or isophthalic acid have been available for a number of years. These are described inter alia in Whinfield et al., U.S. 2,465,319, and in Pengilly, U.S. 3,047,539. These patents disclose that the polyesters are particularly advantageous as film and fiber formers. With the development.of molecular weight control, the use of nucleating agents and two-step molding cycles, poly(ethylene terephthalate) or PET has become an important constituent of injection moldable compositions. Further, poly(l,4-butylene terephthalate) or PBT, because of its very rapid crytallization from the melt, is uniquely useful as a component in such compositions. Work pieces molded from such polyester resins, in comparison with other -έhermoplastics, offer a high degree of surface hardness and abrasion resist¬ ance, high gloss and lower surface friction. Furthermore, in particular, poly(l,4-butylene tere¬ phthalate) is much simpler to use in injection molding tech¬ niques than poly(ethylene terephthalate). For example, it is possible to injection mold poly(l,4-butylene terephthalate) at low mold temperatures of from about 30° to 60 β C. to pro- duce highly crystalline, dimensionally stable moldings in short cycle times. Because of the high rate of crystalliza¬ tion, even at low temperatures, no difficulty is encountered in removing the moldings from the molds. Additionally, the dimensional stability of poly(l,4-butylene terephthalate) in¬ jection moldings is very good even at temperatures near or well above the glass temperature of poly(l,4-butylene tere¬ phthalate) . The impact resistance of unmodified polyesters, e.g., PBT, is, however, relatively low at room temperature and below. Thus for many * applications, it is desirable to have polyesters which are impact resistant at relatively high and relatively low ambient temperatures. It is known to add (co-)polyolefins or polyethylenes to polyesters such as PBT to improve impact strength. Used for this purpose are ethylene-vinyl acetate (EVA) , linear low density polyethylene (LLDPE) and polyethylene itself. Alpha-olefin-glycidyl methacrylate copolymers and alkenyl ester terpoly ers have also been employed to improve the impact resistance of PBT. Epstein, U.S. 4,172,859, discloses the use of ran¬ dom copolymers containing various polar monomers and glass fibers, up to 50 weight percent are claimed as fibrous reinforcement. Ξe also alludes to the use of materials grafted with various polar monomers, e.g., glycidyl meth¬ acrylate (GMA) to impact modify thermoplastic polyesters including PBT and PET. This patent does not teach, however, any criticalness with respect to the ratio of polyester to the polar monomer. Moreover, melt viscosity is not mentioned as a property. In Japanese Patent Publication 57/123251, published July 31, 1982, abstracted as CA 98{4) :17571h, the impact strength of aromatic polyesters is said to be improved by blending with copolymers of olefins and glycidyl (meth)- acrylate. There is no suggestion that glass can be used in critical amounts relative to the polyester without diminish¬ ing impact resistance nor is there any mention of improved processability, e.g., enhanced melt viscosity of the poly- ester blend. In Japanese Patent Publication 55/137155, published October 25, 1980, abstracted as CA 94(14):1044029, it is reported that glass reinforced compositions of poly(tetra- methylene terephthalate), i.e., PBT, give moldings with i - proved Izod impact strength.but diminished gloss when com¬ bined with ethylene-glycidyl methacrylate copolymers. This patent further discloses that if one adds an additional in¬ gredient, namely polyepoxides, polyisocyanates or polycarb- oxylic anhydrides to such reinforced PBT blends, both impact strength and surface appearance are improved in comparison to a composition, i.e., control, which does not include the additional ingredient. The drawback in this teaching is the requirement for an additional reactive ingredient or component. It has now been.unexpectedly discovered that in the absence of such additional reactive components, impact strength is in fact rendered improved over the control compo¬ sition of JP 55/137155 if the ratio of polyester resin to re¬ inforcing agent, e.g., PBT to glass is carefully controlled. For example, if the amount of PBT resin is not permitted to exceed 2.25 parts by weight per part of reinforcing agent, impact strengths are nearly double those of the control composition in JP 55/137155 which were formulated with about between 3 and 3.5 parts of polyester resin per part of glass. This development is entirely unexpected because one skilled in the art would expect the contrary and opposite result, it being a matter of common knowledge and experience that to add reinforcement such as glass to PBT resins di ishes impact resistant properties although it does improve the strength of the composition. As will be seen, the reinforced compositions provided herein, nevertheless return high strength and excellent impact resistant properties. It is also known that plastics fabrication tech- niques, such as extrusion blow molding, injection blow mold- ing, profile extrusion, pipe extrusion, blown film extrusion, co-extrusion (with a second plastic material) , extrusion coating, foam molding, foam extrusion, thermoforming, and the like, all require the plastic composition to have a high melt viscosity and melt strength (melt elasticity) during pro¬ cessing. Linear polyesters have low melt viscosities and are, therefore, not suitable for these applications. Especially difficult to blow mold is PBT. The compositions provided by this invention unex¬ pectedly achieve high melt viscosities which make them uniquely adaptable to blow molding, injection blow molding and the like. A principal aspect of this invention is to pro- vide shaped articles blow-molded from impact modified rein¬ forced PBT compositions and to methods for their production. SUMMARY OF THE INVENTION Provided in accordance with the -present invention are impact modified reinforced thermoplastic compositions comprising: (a) 100 parts by weight of a high molecular weight thermoplastic poly(l,4-butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer, for example, of an alpha-olefin and a glycidyl 2-alkenoate, or a ter- polymer or interpolymer thereof with an alkenyl ester? and (c) . from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25. Also provided in accordance with this invention are compositions, above-defined wherein the melt viscosity of said composition is greater than about 30,000 poise when measured at a temperature of about 250°C. and at a shear stress of about 6.6 psi. In their broadest aspects, the terms "copolymer" and "interpolymer" when used herein and in the appended claims contemplates random and block copolymers, terpolymers and higher types, as the case may be, depending of course on the total number of different units derived from the respec¬ tive monomers. Furthermore interpolymers contemplates and includes grafts and interpenetrating network type polymers which can be made by those skilled in this art. An example of the graft interpolymer would be one comprising an ethylene-propylene backbone to which glycidyl(meth)acrylate is grafted. Also provided herein are hollow shaped articles and thermoformable polymer films extrusion and injection blow molded from compositions, above-described. Contemplated by this invention are processes for the preparation of hollow ' shaped articles and thermoformable polymer films comprising: (a) providing a composition comprising 100 parts by weight of a high molecular weight thermoplastic poly(1,4- butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer of an alpha- olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with an alkenyl ester; (c) from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25; and thereafter (d) blow molding said composition to form the hollow shaped article or thermoformable polymer films. DESCRIPTION OF THE DRAWINGS Figure 1 illustrates in semi-schematic fashion, an extrusion-blow molding technique which is one means for preparing the articles and practicing the method of this invention. Figure 2 also illustrates in semi-schematic fashion, an injection blowing technique which represents another means for preparing the articles and practicing the method of this invention. DETAILED DESCRIPTION OF THE INVENTION The high molecular weight, polymeric 1,4-butylene glycol terephthalates useful herein as component (a) have repeating units of the general formula: Also contemplated are mixtures of such esters with minor amount, e.g., from 0.5 to 2% by weight, of units derived from aliphatic or aromatic dicarboxylic acids and/or aliphatic polyols, e.g., glycols, i. * e., copolyesters. These can also be made following the teachings ' outlined in Whin-field et al., ϋ.S. Pat. No. 2,465,316 and Pengilly, ϋ.S Pat. No. 3,047,539, for example. Poly(1,4-butylene terephthalate) is commercial¬ ly available, e.g., under the tradename Valox, General Electric Company. Especially preferred polyesters for use as compon- ent (a) are poly(1,4-butylene terephthalate) resins. Special mention is made of this polyester because it crystallizes at an especially rapid rate. Among the units which can be present in the copoly¬ esters are those derived from aliphatic dicarboxylic acids, e.g., of up to about 50 carbon atoms, including straight and branched chain acids, such as adipic acid, dimerized c 16 -C-ιg unsaturated acids (which have 32 to 36 carbon atoms) , tri- merized such acids, and the like. Among the units in the co- polyesters can also be minor amounts derived from aromatic dicarboxylic acids, e.g., of up to about 36 carbon atoms, such as isophthalic acids and the like. In addition to the 1,4-butylene glycol units, there can also be minor amounts of units derived from other aliphatic glycols and polyols, e.g., of up to about 50 carbon atoms, including ethylene glycol, propylene glycol, glycerol and the like. Such copolyesters can be made by techniques well known to those skilled in the art. These polymeric 1,4-butylene glycol terephthalates have an intrinsic viscosity of at least 0.4 and preferably about 0.7 deciliters/gram as measured in o-chlorophenol, a 60/40 phenol tetrachloroethane mixture or a similar solvent at 25°-30 β C. The upper limit is not critical, but it will generally be about 2.5 dl./g. Especially preferred polyesters will have an intrinsic viscosity in the range of 0.7 to 1.6. Preferred as component (b) in this invention are impact modifiers comprising copolymers or interpoly ers of an alpha-olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with-an alkenyl ester. This impact modifier- in preferred embodiments will comprise a polymer of from about 80 to about 99 parts by weight of an alpha-olefin, from about 1 to about 20 parts by weight of glycidyl methacrylate or acrylate, and from about 0 to about 19 parts by weight of vinyl acetate. Preferred as the alpha-olefin is ethylene. Especi¬ ally preferred as component (b) is an ethylene glycidyl meth¬ acrylate copolymer available under the tradename BONDFAST*E, Sumitomo Chemical Company, Ltd., Japan. The copolymer or interpolymer or terpolymer useful as component (b) may be prepared by standard copolymerization reactions or by grafting reactions. By way of illustration, the alpha-olefin, e.g., ethylene may be copolymerized or grafted with a glycidyl 2-alkenoate, e.g., glycidyl meth¬ acrylate or glycidyl acrylate. Terpoly ers may also be employed as component (b) and can be made by techniques known to those skilled in the art. For example, in Epstein, U.S. 4,172,859, a terpolymer of ethylene-vinyl acetate-glycidyl methacrylate is made by high ' pressure free radical polymer- ization. See Example 6, TABLE 1-B. Component (b) will comprise in preferred features of this invention, a polymer of from about 80 to about 99 parts by weight of an alpha-olefin, from about 1 to about 20 parts by weight of glycidyl methacrylate or acrylate, and from about 0 to about 19 parts by weight of vinyl acetate, based on a total composition of 100 parts by weight of component (b) alone. The reinforcing agents useful as component (c) in the practice of this invention comprise a range of materials including but not limited to glass, graphite, wollastonite, carbons, metals, e.g., aluminum, iron, nickel, stainless steel and the like, titanates, e.g., titanate whiskers, quartz, clay, -mica, talc, mixtures of the foregoing and the like. In particular, the preferred reinforcing fillers are of glass and it is preferred to use fibrous glass fila¬ ments comprised of lime-aluminum borosilicate glass that is relatively soda free. This is known as "E" glass. However, other glasses are useful where electrical properties are not so important, e.g., the low soda glass known as "C" glass. Special mention is made of glass filaments known as G- filaments.. The filaments are made by standard processes, e.g., by steam or air blowing, flame blowing and mechanical pulling. The preferred filaments for plastics reinforcement are made by mechanical pulling. The filament diameters range from about 3 to 19 microns, but this is not critical to the present invention. The length of the glass filaments and whether or not they are bundled into fibers and the fibers bundled in turn to yarns, ropes or rovings, or woven into mats, and the like, are also not critical to the invention. However, in preparing the present compositions, it is convenient to use the filamentous glass in the form of chopped strands of from about 1/8 inch to about 1 inch long, preferably less than 1/4 inch long. In articles molded .from the compositions, on the other hand, even shorter lengths will be encountered because, during compounding, considerable fragmentation will occur. This is desirable, however, because the best properties are exhibited by thermoplastic injection molded articles in which the filament lengths lie between about 0.0005 inch and 0.125 (1/8) inch. In general, best properties will be obtained if the sized filamentous glass reinforcement comprises from about 17.7 to about 80% by weight based on the combined weight of glass, impact modifier and polyesters and preferably from about 20 to about 50% by weight. Especially preferably the glass will comprise from about 25 to about 40% by weight based on the combined weight of glass and resins. Generally, for direct molding use, up to about 60% of glass can be present without causing flow problems. These concentrates can then be custom blended with blends of resins that are not glass reinforced to provide any desired glass content of a lower value. Also preferred as the reinforcing agent (c) of this invention is clay including treated clay. The quantities of components (a), (b) and (c) can vary widely but in all cases the weight ratio of (a) to (c) should not exceed, i.e., be substantially greater than about 2.25. For example, 100 parts by weight of PBT (a), from about 1 to about 100 parts by weight of the impact modifier (b) , and from about 44 to about 150 parts by weight of the rein¬ forcing agent, (c), e.g., glass can be blended provided that the weight ratio of PBT (a) to the reinforcing agent (c), e.g., glass is not substantially greater than 2.25. On the basis of a total composition of 100 parts by weight of (a), (b) and (c) combined, PBT can comprise an amount of from about 40 to about 80 parts by weight, the impact modifier (b) can comprise an amount of from about 1 to about 20 parts by weight; and component (c) can comprise an amount of from about 17.7 to about 40 parts by weight. Again, the weight ratio of PBT (a) to the reinforcing agent (c) should not substantially exceed 2.25. Compounding of the impact modifier, thermoplastic resin and reinforcing agent is carried out by standard tech- niques, for example, by simple melt blending or dry mixing and melt extruding at an appropriate elevated temperature for any given thermoplastic matrix. Conventional equipment temp¬ eratures will be employed, e.g., 400 β -600 β F. The resultant admixture is then molded into a thermoplastic piece of spec- ific dimensions or further extruded into a film or sheet product or blow molded into suitable articles. The conven¬ tional mold temperatures, e.g., 50 β -250°F. are useful. Compounding can be carried out in conventional equip¬ ment. For example, after pre-drying the thermoplastic poly- ester resin, e.g., at 125°C. for 4 hours, a single screw extruder is fed with a dry blend of the polyester, impact modifier, reinforcing " agent and the additive ingredients, if any, the screw employed having a long transition and metering section to insure melting. On the other hand, a twin screw extrusion machine, e.g., a 28 mm Werner Pfleiderer machine, can be fed with resin and additives at the feed port. In either case, a generally suitable machine temperature will be about 400 β F. to 600 β F. The compounded composition can be extruded and cut up into molding components such as conventional granules, pellets, etc., by standard techniques. Alternatively, the compounded composition can be blow molded or injection blow molded or extrusion blow molded into articles, e.g., hollow shaped articles. The compositions of this invention can be molded in any equipment conventionally used for thermoplastic composi¬ tions. With poly(1,4-butylene terephthalate) good results will be obtained in an injection molding machine, e.g., of the Newbury type or Van Dorn with conventional cylinder temperature, e.g., 450-550°F. and conventional mold temperatures, e.g., 50-250 β F. The reinforced impact modified molding compositions of this invention may be used as molding pellets, or blow molded into hollow shaped articles, or thermoformable polymer films. It is to be understood that the foregoing composi¬ tions may contain other additives known in the art, including, but without limitation, antioxidants, mold release agents, flow promoters, coloring agents, coupling agents, stabilizers and flame retardants. The compositions of this invention may also contain pigments, dyes, stabilizers, plasticizers, and the like. One may readily determine which are necessary and suitable for a particular application. Blow molding is used to make hollow shaped plastic articles in a variety of commonly encountered forms, such as milk bottles, auto windshield washer tanks, street light globes, arms and legs on toy dolls, and a multitude of others. There are two basic types of blow molding processs, both being fundamentally related, but technologically dissimilar. Ex¬ trusion blow molding typically comprises extruding a tube of plastic into a water-cooled mold, inflating the tube by internally introducing air or another gas until the walls of the molten tube assume the shape of the mold, allowing the shaped tube to cool to structural rigidity, and removing the extrusion blow molded part from the mold. Extrusion blow molding is illustrated in Figure 1 which depicts a horizontal rotary wheel system upon which up to 12 clamping stations can be mounted and continuous extrus- ion carried out. The wheel is rotated past a single head extrusion station where the parison, a round hollow tube is captured, as shown in Figure 1. At a given moment in time, a parison is being captured, a part is being molded, a molded part is being cooled, and a cooled part is being removed. Other extrusion-blow molding processes can also be employed in addition to the above-described continuous extru¬ sion horizontal wheel system. These are well-described in "Modern Plastics Encyclopedia", McGraw-Hill Publications Company, 1982, pp. 212-217. Another major technique, injection blow molding, involves, instead of extrusion, injection molding the plastic around core pins in an injection mold, then transferring to the blow mold. The fundamental difference between injection blow molding and extrusion blow molding is that with the former, two complete sets of molds are required-as injection mold for molding the preform and a blow mold for the final form. Injection blow molding is illustrated in Figure 2. At position "A", the hot plastic is injected into a hot mold around a pin, the preform, being called a "parison". The outer mold is removed, and the- "parison", still molten, is rotated to position "B", where it is surrounded by a mold in the shape of the final part. The molten plastic is now inflated (e.g., by air) to fill this mold, and is cooled to solidify. Inflation of the polymer melt is the critical step, requiring good melt elasticity for its successful completion. Linear polyesters, e.g., polybutylene tereph¬ thalate, in such an application, tend to run, droop, and/or "burst", making it very difficult, if not impossible, to obtai a useful part. After an additional 120° rotation, position "C, the final part, is removed from the mold (step C). Obviously, this technique is distinct from ordinary injection molding, in which a molten plastic is injected into a mold and cooled without further processing. There is no concern at all there with the need for self-support in the molten perform. Other "blow" techniques have in common with the in¬ jection blow molding process that the molten polymer is in¬ flated (by air, or a suitable inert gas) to assume its final desired shape. In extrusion blow molding an extruded tube is inflated inside a mold; in blown film extrusion an extruded tube is continuously inflated to a large diameter tube of low wall thickness, which is subsequently collapsed and further processed to yield film, (grocery) bags, etc., and in foam molding or foam extrusion applications a cellular structure is introduced in the plastic through expansion of an inert gas, again requiring high melt elasticity to prevent collapse of the foam before the part has solidified. In extrusion of profiles of closely controlled shape and dimensions it is important that the molten plastic upon leaving the extruder die does not sag or drool until it has hardened or solidified. The impact modified reinforced polyesters described herein have been unexpectedly discovered to have a high melt viscosity under the low sheer forces acting on the extrudate, preventing sagging and drooling; at the same time, they exhibit significantly lower melt viscosities under the high shear rate conditions existing in the extruder die, facili¬ tating the passage of the melt through the die without re- quiring excessive pressures in the extruder barrel. The impact modified reinforced PBT compositions of this invention are, therefore, uniquely suited for precision extrusion applications such as are required for profile and tubing extrusions, extrusion coatings and coextrusions. In thermoforming, a sheet of plastic is suspended horizontally over a suitable mold and heated, usually by radiant heat,. until melted. The sheet is then brought into contact with the mold and collapsed onto it by suction. After cooling, the plastic, which has assumed the shape of the mold is lifted off, trimmed and decorated as desired. Thermoforming polymer films likewise call for a high melt viscosity or a high degree of elasticity of the polymer melt to prevent premature sagging and running of the material. Shaped articles having excellent appearance and physical properties can be obtained if the impact modified reinforced high molecular weight PBT resins are used as the thermoplastic. The articles can be produced in equipment convention- ally used for shaping of thermoplastic compositions by extrusion blow molding, injection blow molding, profile extrusion, pipe extrusion, co-extrusion, extrusion coating, foam molding, foam extrusion, thermoforming, and the like. In extrusion blow molding, for example, they can be made on continuous extrusion ' transfer equipment in which a single manifold die head forms the hollow tube for continuous intro¬ duction, after cutting the proper length, into a number of blowing molds. Also useful is a continuous extrusion preform transfer process calling for the extruded tube to be deposit- ed in a shaping or preforming mold where the bottom is closed and sealed while the neck is held open around a mandrel and the neck configuration (threads, etc.) is preformed. The still molten, but preshaped hollow shape is then removed from the shaping mold and placed in a blow mold where it is expanded to its final configuration. Still another process is called continuous extrusion, ferris wheel, which uses equipment having a vertical wheel or endless belt located next to the die of the continuous tube extruder on which a series of split blowing molds are mounted. Each of the molds is independently operated, hydraulically or pneumatically. While the wheel turns, one mold at a time passes under the extruder die to receive and close around the molten tube. Rotation of the mold carrier is set to provide ample time for an open mold to receive the tube and then to blow, cool and eject the hollow molded piece. Other conventional equipment may also be used. Injection blow molding techniques are well-described in Borman et al., ϋ.S. 4,419,485 as well as in Modern Plas¬ tics Encyclopedia, McGraw-Hill Publications Company, 1982, pp. 217-219. The compositions produced herein are also useful for their high melt viscosities which enhances their process- ability in fabrication techniques, notably extrusion blow molding, injection blow molding and the like. As will be seen from the examples which follow, the melt viscosity of these compositions will, preferably, measure at 482°F. and about 6.6 psi shear stress greater than 30,000 poise, especially preferably greater than 40,000 poise, and most especially preferably greater than 65,000 poise. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following examples illustrate the compositions and the preparation of certain articles within the scope of this invention. They are not to be construed to limit the invention in any manner whatsoever. All parts except as otherwise indicated are by weight. In Examples 1-3; the following designations are used PBT — poly(l,4-butyle e terephthalate), VALOX*, General Electric Company- EGM — ethylene glycidyl methacrylate copolymer; BONDFAST*E, Sumitomo Chemical Co. Ltd. EVA — ethylene-vinyl acetate copolymer; ELVAX*462, DuPont LLDPE — linear low density polyethylene; DOWLEX"2952, Dow Chemical Co. EXAMPLES 1-3 Impact modified glass reinforced PBT compositions and impact-modified clay reinforced PBT composition were prepared and suitable workpieces were molded for testing. The compositions with PBT were tumble-mixed and extruded one time through a Prodex 2 J s" single-screw extruder at a tempera¬ ture of 500°C. The material was subsequently dried and mold¬ ed on a Van Dorn injection molding machine into workpieces. The composition and results are set forth in Table 1. TABLE 1: Impact Modified Glass Reinforced PBT Compositions Example 1A IB 1C ID 1 2 3 Compositions (parts by weight) PBT 61.3 — 98.35 98.35 64.8 61.8 — PBT/EGM Concentrabe 3 — — — — — — 70.0 PBT/EVA Concentrate 15 — 70.0 Glass fiber 33.0 — — — 30.0 33.0 Clay — 29.8 — — — — 29.8 LLDPE 5.0 — 1.5 EGM — — — 1.5 5.0 5.0 Epoxy 0.5 Antioxidant 0.2 — 0,15 0.15 0.2 0.2 Amino siloxane — 0.2 — ' — — — 0.2 Ratio/PBTsGlass fiber 1.86 — — — 2.11:1 2.16:1 Properties Melt Viscosity, poise at 250°C. 14,000 14,000 7,800 9,400 Notched Izod,ft.lbs./in. 2.1 2.1 Unnotched Izod,ft.lbs./in. — 38/4NB — Tensile Strength, psi 15,400 — — — 15,900 17,140 Tensile Elongation, % — — 241 222 Flexural. Modulus, psi 938,000 — — ~ 914,000 1,064,000 — Specific Gravity 1.52 1.48 — — 1.53 1.50 1.53 a An extruded blend of 89.85% PBT, 10% EGM and 0.15% antioxidant b An extruded blend of 89.85% PBT, 10% EVA and 0.15% antioxidant. Japanese Patent Publication 57/137155 describes com¬ positions comprising PBT 100 parts by weight; EGM, 10 parts by weight, and glass fibers, 30 parts by weight. These have a ratio of PBT to glass of 3.31:1, but the reported impact strength is only 8.8 kg-cm/cm or 1.61 ft.lbs./in. The results above indicate that glass reinforced PBT compositions that are modified with ethylene glycidyl meth¬ acrylate copolymers in which the PBT-glass ratio is below about 2.25 to 1 demonstrate unexpectedly high impact strengths in accordance with the present invention. Moreover, their high melt viscosities are very high and entirely unexpected. EXAMPLES 4-5 If the compositions of Examples 2 and 3 above were to be injection blow molded, shaped articles in accordance with this invention would be provided. EXAMPLES 6-7 If the compositions Of Examples 2 and 3 above were to be extrusion blow molded, shaped articles in accordance with this invention would be provided. EXAMPLES 8-9 If the compositions of Examples 2 and 3 above are to be extruded as blown films, shaped articles in accordance with this invention will be obtained. The examples above indicate that impact modified polyester compositions can be prepared in accordance with this invention, and that they have unexpectedly high impact strength. The above patents, applications and publications are incorporated herein by reference. Many variations will suggest themselves to those skilled in the art in light of the above, detailed descrip¬ tion. For example, instead of using poly(l,4-butylene tere¬ phthalate) as component (a), other polyester resins, such as copolyesters derived from one or more aliphatic and/or aromatic dicarboxylic acids and one or more straight or branched chain aliphatic or cycloaliphatic glycols including random or block copolyesters. Instead of glycidyl meth¬ acrylate, glycidyl acrylate alone, or a mixture of glycidyl acrylate and glycidyl methacrylate can be used in the impact modifier (b). Furthermore polyethylene, ethylene propylene copolymer, and ethylene, propylene norbornadiene terpolymer (EPDM), each of which is grafted, e.g., about 2 to 5 parts per hundred by weight of glycidyl methacrylate can also be used as the impact modifier (b). Instead of glass or clay, chopped graphite and wollastonite can be used as the reinforcing agent (c). Furthermore, other additives known to those skilled in the art may be added in conventional amounts to the impact modified compositions herein including but without limitation, nucleating agents, mold release agents, flow promoters, coloring agents, flame retardants, coupling agents and stabilizers, dyes and pigments. All such obvious variations are within the full intended scope of the appended claims.

Claims: CLAIMS: 1. An impact modified reinforced thermoplastic composition comprising: (a) 100 parts by weight of a high molecular weight thermoplastic poly(l,4-butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer of an alpha- olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with an alkenyl ester; and (c) from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25. 2. A composition as defined in Claim 1 wherein the melt viscosity of said composition is greater than about 30,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 3. A composition as defined in Claim 2 wherein the melt viscosity of said composition is greater than about 40,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 4. A composition as defined in Claim 3 wherein the melt viscosity of said composition is greater than about 60,000 poise when measured at a temperature of about 250 β C. and a shear stress of about 6.6 psi. 5. A composition as defined in Claim 1 wherein the intrinsic viscosity of the polyester is within the range of from about 0.7 to about 1.6 deciliters per gram, as measured as a solution in a 60:40 mixture of phenol and tetrachloro- ethane at 30 β C. 6. A composition as defined in Claim 1 wherein component (b) comprises a polymer of from about 80 to about 99 parts by weight of an alpha-olefin, from about 1 to about 20 parts by weight of glycidyl (meth)acrylate and from about 0 to about 19 parts by weight of vinyl acetate. 7. A composition as defined in Claim 6 wherein in component (b) said apha-olefin is ethylene. 8. A composition as defined in Claim 6 wherein component (b) comprises an ethylene glycidyl methacrylate copolymer. 9. A composition as defined in Claim 1 wherein said reinforcing agent (c) is selected from the group consisting of glass, metals, ceramics, silicates, quartz, carbons and clay. 10. A composition as defined in Claim 9 wherein said reinforcing agent (c) is glass. 11. A composition as defined in Claim 9 wherein said reinforcing agent (c) is clay. 12. A composition as defined in Claim 1 wherein said component (a) comprises an amount of from about 40 to about 80 parts by weight; component (b) comprises an amount of from about 1 to about 20 parts by weight; and component (c) comprises an amount of from about 17.7 to about 40 parts by weight, based on a total composition of 100 parts by weight of (a), (b) and (c) combined. 13. A hollow shaped article blow molded from a composition comprising: (a) 100 parts by weight of a high molecular weight thermoplastic poly(1,4-butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer of an alpha- olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with an alkeπyl ester; and (c) from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25. 14. A hollow shaped article as defined in Claim 13 wherein the melt viscosity of said composition is greater than about 30,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 15. A hollow shaped article as defined in Claim 14 wherein the melt viscosity of said composition is greater than about 40,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 16. A hollow shaped article as defined in Claim 15 wherein the melt viscosity of said composition is greater than about 60,000 poise when measured at a temperature of about 250 β C. and a shear stress of about 6.6 psi. 17. A hollow shaped article as defined in Claim 13 wherein the inrinsic viscosity of the polyester is within the range of 0.7 to 1.6 deciliters per gram, measured as a solution, in a 60:40 mixture of.phenol and tetrachϊoroethane at 30 β C. 18. A hollow shaped article as defined in Claim 13 wherein component (b) comprises a polymer of from about 80.to about 99 parts by weight of an alpha-olefin, from about 1 to about 20 parts by weight of glycidyl (meth)acrylate and from about 0 to about 19 parts by weight of vinyl acetate. 19. A hollow shaped article as defined in Claim 18 wherein in component (b) said alpha-olefin is ethylene. 20. A hollow shaped article as defined in Claim 19 wherein component (b) comprises an ethylene glycidyl methacrylate copolymer. 21. A hollow shaped article as defined in Claim 13 wherein said reinforcing agent (c) is selected from the group consisting of glass, metals, ceramics, silicates, quartz, carbons and clay. 22. A hollow shaped article as defined in Claim 21 wherein said reinforcing agent (c) is glass. 23. A hollow shaped article as defined in Claim 21 wherein said reinforcing agent (c) is clay. 24. A hollow shaped article as defined in Claim 13 wherein said component (a) comprises an amount of from about 40 to about 80 parts by weight; component (b) comprises an amount of from about 1 to about 20 parts by weight; and component (c) comprises an amount of from about 17.7 to about 40 parts by weight, based on a total composition of 100 parts by weight of (a), (b) and (c) combined. 25. A hollow shaped article as defined in Claim 13 blow molded by injection blow molding. 26. A hollow shaped article as defined in Claim 13 r blow molded by extrusion blow molding. 27. A thermoformable polymer film blow molded from a composition comprising: (a) 100 parts by weight of a high molecular weight thermoplastic poly(l,4-butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer of an alpha- olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with an alkenyl ester; and (c) from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25. 28. A film as defined in Claim 27 wherein the melt viscosity of said composition is greater than about 30,000 poise when measured at a temperature of about 250 β C. and a shear stress of about 6.6 psi. 29.- A film as defined in Claim 28 wherein the melt viscosity of said composition is greater than about 40,000 poise when measured at a temperature of about 250 β C. and a shear stress of about 6.6 psi. 30. A film as defined in Claim 29 wherein the melt viscosity of said composition is greater than about 60,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 31. A film as defined in Claim 27 wherein the in¬ trinsic viscosity of the polyester is within the range of from about 0.7 to about 1.6 deciliters per gram, as measured as a solution in a 60:40 mixture of phenol and tetrachloroethane at 30°C. 32. A film as defined in Claim 27 wherein compon¬ ent (b) comprises a polymer of from about 80 to about 99 parts by weight of an alpha-olefin, from about 1 to about 20 parts by weight of glycidyl (meth)acrylate and from about 0 to about 19 parts by weight of vinyl acetate. 33. A film as defined in Claim 32 wherein in component (b) said alpha-olefin is ethylene. 34. A film as defined in Claim 33 wherein compon¬ ent (b) comprises an ethylene glycidyl methacrylate copolymer. 35. A film as defined in Claim 27 wherein said re¬ inforcing agent (c) is selected from the group consisting of glass, metals, ceramics, silicates, quartz and carbons, and clay. 36. A film as defined in Claim 35 wherein said reinforcing agent (c) is glass. ' 37. A film as defined in Claim 35 wherein said reinforcing agent (c) is clay. 38. A film as defined in Claim 27 wherein said component (a) comprises an amount of from about 40 to about 80 parts by weight; component (b) comprises an amount of from about 1 to about 20 parts by weight; and component (c) comprises an amount of from about 17.7 to about 40 parts by weight, based on a total composition of 100 parts by weight of (a), (b) and (c) combined. 39. A process for the preparation of a hollow shaped article comprising: (1) providing a composition comprising: (a) 100 parts by weight of a high olecu- lar weight thermoplastic poly(l,4-butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer of an alpha-olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with an alkenyl ester; and (c) from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25; and thereafter (2) blow molding said composition to form the hollow shaped article. 40. A process as defined in Claim 39 wherein the melt viscosity of said composition is greater than about 30,000 poise when measured at a temperature'of about 250°C. and a shear stress of about 6.6 psi. 41. A process as defined in Claim 40 wherein the melt viscosity of said composition is greater than about 40,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 42. A process as defined in Claim 41 wherein the melt viscosity of said composition is greater than about 60,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 43. A process as defined in Claim 39 wherein the intrinsic viscosity of the polyester is within the range of from about 0.7 to about 1.6 deciliters per gram, as measured as a solution in a 60:40 mixture of phenol and tetrachloro- ethane at 30 β C. 44. A process as defined in Claim 39 wherein com¬ ponent (b) comprises a polymer of from about 80 to about 99 parts by weight of an alpha-olefin, from about 1 to about 20 parts by weight of glycidyl (meth)acrylate and from about 0 to about 19 parts by weight of vinyl acetate. 45. A process as defined in Claim 44 wherein in component (b) said acyclic hydrocarbon is ethylene. 46. A process as defined in Claim 45 wherein component (b) comprises an ethylene glycidyl methacrylate copolymer. 47. A process as defined in Claim 39 wherein said reinforcing agent (c) is selected from the group consisting of glass, metals, ceramics, silicates, quartz, carbons and clay. 48. A process as defined in Claim 47 wherein said reinforcing agent (c) is glass. 49. A process as defined in Claim 47 wherein said reinforcing agent (c) is clay. 50. A process as defined in Claim 39 wherein said component (a) comprises an amount of from about 40 to about 80 parts by weight; component (b) comprises from about 1 to about 20 parts by weight; and component (c) comprises an amount of from about 17.7 to about 40 parts by weight, based on a total composition of 100 parts by weight of (a), (b) and (c) combined. 51. A process as recited in Claim 39 wherein the article is blow molded by injection blow molding. 52. A process as recited in Claim 39 wherein the article is blow molded by extrusion-blow molding. 53. A process for the preparation of a thermoform¬ able polymer film comprising: (1) providing a composition comprising: (a) 100 parts by weight of a high molecu- lar weight thermoplastic poly(l,4-butylene terephthalate); (b) from about 1 to about 100 parts by weight of an impact improving copolymer or interpolymer of an alpha-olefin and a glycidyl 2-alkenoate, or a terpolymer or interpolymer thereof with an alkenyl ester; and /(c) from about 44 to about 150 parts by weight of a reinforcing agent, the weight ratio of (a) to (c) in said composition being not substantially greater than about 2.25; and thereafter (2) extrusion blow molding said composition to form a polymer film. 54. A process as defined in Claim 53 wherein the melt viscosity of said composition is greater than about 30,000 poise when measured at a temperature of about 250 β C. and a shear stress of about 6.6 psi. 55. A process as defined in Claim 54 wherein the melt viscosity of said composition is greater than about 40,000 poise when measured at a temperature of about 250 β C. and a shear stress of about 6.6 psi. 56. A process as defined in Claim 55 wherein the melt viscosity of said composition is greater than about 60,000 poise when measured at a temperature of about 250°C. and a shear stress of about 6.6 psi. 57. A process as defined in Claim 53 wherein the intrinsic viscosity of the polyester is within the range of from about 0.7 to about 1.6 deciliters per gram, as measured as a solution in a 60:40 mixture of phenol and tetrachloro- ethane at 30 β C. 58. A process as defined in Claim 53 wherein com¬ ponent (b) comprises a polymer of from about 80 to about 99 parts by weight of an acyclic hydrocarbon having one double bond, from about 1 to about 20 parts by weight of glycidyl (meth)acrylate and from about 0 to about 19 parts by weight of vinyl acetate. 59. A process as defined in Claim 58 wherein in component (b) said acyclic hydrocarbon is ethylene. 60. A process as defined in Claim 59 wherein component (b) comprises an ethylene glycidyl methacrylate copolymer. 61. A process as defined in Claim 53 wherein said reinforcing agent (c) is selected from the group consisting of glass, metals, ceramics, silicates, quartz, carbons and clay. 62. A process as defined in Claim 61 wherein said reinforcing agent (c) is glass. 63. A process as defined in Claim 61 wherein said reinforcing agent (c) is clay. 64. A process as defined in Claim 53 wherein said component (a) comprises an amount of from about 40 to about 80 parts by weight; component (b) comprises from about 1 to about 20 parts by weight; and component (c) comprises an amount of from about 17.7 to about 40 parts by weight, based on a total composition of 100 parts by weight of (a), (b) and (c) combined.

Inventors: BORMAN WILLEM FREDERIK HENDRIK, BORMAN, WILLEM, FREDERIK, HENDRIK
Applicants: GEN ELECTRIC, GENERAL ELECTRIC COMPANY
Application year: 1988
Main classification: C08L67
IPC codes: C08K3, C08L23, C08L67