High flow, high ductility poly(arylene sulfide) resin blends

Information

  • Patent Grant
  • 5723542
  • Patent Number
    5,723,542
  • Date Filed
    Tuesday, May 28, 1996
    28 years ago
  • Date Issued
    Tuesday, March 3, 1998
    26 years ago
Abstract
A poly(arylene sulfide) resin composition is provided which contains a low molecular weight poly(arylene sulfide) resin, a high molecular weight poly(arylene sulfide) resin and impact modifiers. The compositions exhibit enhanced levels of low temperature impact properties. The compositions are useful in the manufacture of molded articles. Preferably the compositions utilize an elastomeric block copolymer as the impact modifier, and further comprise an epoxy functional alpha-olefin elastomer.
Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to impact modified poly(arylene sulfide) resin compositions, and more particularly relates to impact modified poly(arylene sulfide) resin compositions comprising blends of poly(arylene sulfide) resins.
2. Description of the Related Art
Impact modified poly(arylene sulfide) resin compositions are generally known. Compositions utilizing a high molecular weight poly(arylene sulfide) resin as the sole poly(arylene sulfide) resin generally lack desired levels of flowability and have poor low temperature impact properties. Compositions utilizing a low molecular weight poly(arylene sulfide) resin as the sole poly(arylene sulfide) resin lack the desired levels of certain properties, for example, impact properties at low temperatures. Compositions utilizing a mid-molecular weight poly(arylene sulfide) resin can exhibit higher than desired melt viscosities.
Accordingly, there is a need for impact modified poly(arylene sulfide) resin compositions which exhibit relatively low melt viscosities while also exhibiting desired levels of impact resistance and ductility at low temperatures.
SUMMARY OF THE INVENTION
The compositions comprise a low molecular weight poly(arylene sulfide) resin, a high molecular weight poly(arylene sulfide) resin, an impact modifier and additional optional components. The compositions unexpectedly exhibit the combined properties of relatively low melt viscosities and desired levels of impact resistance and ductility at low temperatures. The compositions are useful for making molded articles.
DETAILED DESCRIPTION OF THE INVENTION
The poly(arylene sulfide) resin (hereinafter referred to as PPS) used in the present invention is a polymer comprising at least 70 molar %, preferably at least 90 molar %, of recurring units of the structural formula (I): ##STR1## When the amount of recurring units of formula (I) is less than 70 molar %, the heat resistance is insufficient.
The remaining 30 molar % or less, preferably 10 molar % or less, of the recurring units of the PPS polymer can be those of the following structural formulae (II): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 can be independently selected from the group consisting of hydrogen, halogen, alkyl, phenyl, alkoxy, aryloxy, nitro, amino, and carboxy groups.
The PPS may be unfunctionalized or functionalized. If the PPS is functionalized, the functional groups may include, but are not limited to, amino, carboxylic acid, metal carboxylate, disulfide, thio and metal thiolate groups. Some of the available methods to prepare PPS with functional groups can be found in U.S. Pat. No. 4,769,424, which is incorporated herein by reference. One method for incorporation of functional groups into PPS utilizes the incorporation of substituted thiophenols into halogen substituted PPS. Another method involves incorporation of chlorosubstituted aromatic compounds containing the desired functionality reacted with an alkali metal sulfide and chloroaromatic compounds. A third method involves reaction of PPS with a disulfide containing the desired functional groups, typically in the melt or in a suitable high boiling solvent such as chloronaphthalene.
The PPS includes generally those having a relatively low molecular weight prepared by, for example, the process disclosed in the specification of U.S. Pat. No. 3,354,129 and those having a relatively high molecular weight such as the essentially linear polymers prepared by, for example, a process disclosed in the specification of U.S. Pat. No. 3,919,177, both of which U.S. Patents are incorporated herein by reference. The degree of polymerization of the polymers prepared by the process of U.S. Pat. No. 3,354,129 can be further increased by heating the same in an oxygen atmosphere or in the presence of a crosslinking agent such as a peroxide after the polymerization. Though PPS prepared by any process can be used in the present invention, an essentially linear polymer having a relatively high molecular weight prepared by the process of U.S. Pat. No. 3,919,177 is preferably used.
The low molecular weight PPS (hereinafter referred to as "LMWPPS"), is preferably a low molecular weight poly(p-phenylene sulfide) resin, and preferably has a number average molecular weight of between about 2,000 and about 10,000, more preferably between about 5,000 and about 9,000, and most preferably between about 7,000 and about 8,500. Additionally, the LMWPPS preferably has a weight average molecular weight of between about 2,000 and about 40,000, more preferably between about 20,000 and about 35,000, and most preferably between about 30,000 and about 34,000.
The high molecular weight PPS (hereinafter refered to as "HMWPPS") is preferably a high molecular weight poly(p-phenylene sulfide) resin, and preferably has a number average molecular weight of between about 11,000 and about 100,000, more preferably between about 25,000 and about 50,000, and most preferably between about 27,000 and about 35,000. Preferably the HMWPPS has a weight average molecular weight of between about 55,000 and about 150,000, more preferably between about 80,000 and about 120,000, and most preferably between about 85,000 and about 100,000.
Suitable impact modifiers include various eIastomeric copolymers, examples of which are ethylene-propylene-diene polymers (EPDM's) that may be either unfunctionalized or functionalized with, for example, epoxy, anhydride, ortho-ester, oxazoline, sulfonate or phosphonate groups; carboxylated ethylene-propylene rubbers; polymerized cycloalkenes; block copolymers of alkenylaromatic compounds, such as for example styrene, with polymerizable olefins or dienes, such as for example butadiene, isoprene, chloroprene, ethylene, propylene and butylene; and core-shell polymers, including those containing a poly(alkyl acrylate) core attached to a polystyrene shell via interpenetrating network, and more fully disclosed in U.S. Pat. No. 4,681,915, which is incorporated herein by reference.
The preferred impact modifiers are block (typically diblock, triblock or radial teleblock) copolymers of alkenylaromatic compounds and dienes. Most often, at least one block is derived from styrene and at least one other block from at least one of butadiene and isoprene. Especially preferred are the triblock copolymers with polystyrene end blocks and diene-derived midblocks. It is preferable to remove or decrease the aliphatic unsaturation in the block copolymers by selective hydrogenation. The weight average molecular weight of the block copolymers are typically in the range of about 50,000-300,000. Block copolymers of this type are commercially available from Shell Chemical Company under the trademark KRATON, and include KRATON D1101, G1650, G1651, G1652 and G1702.
Preferably the compositions further comprise an epoxy functional .alpha.-olefin elastomer. The term .alpha.-olefin as used herein means ethylene, propylene, butene-1, etc. Among them, ethylene is preferred. The addition of an epoxy functional .alpha.-olefin elastomer provides the composition with enhanced physical properties. The epoxy functional .alpha.-olefinic elastomer is preferably an olefinic copolymer containing from about 60% to about 99.5% by weight of an .alpha.-olefin and from about 0.5% to about 40% by weight of a glycidyl ester of an .alpha.,.beta.-unsaturated carboxylic acid.
The glycidyl esters of the .alpha.-.beta.-unsaturated acids are compounds of the general formula (III): ##STR3## wherein R.sup.5 represents a hydrogen atom or a lower alkyl group. Examples of the glycidyl esters of .alpha.,.beta.-unsaturated acids include glycidyl acrylate, glycidyl methacrylate and glycidyl ethacrylate. The amount of the glycidyl ester of the .alpha.,.beta.-unsaturated acid in the olefinic copolymer is from about 0.5% to about 40% by weight, preferably from about 3% to about 30% by weight; based on the weight of the total composition. When it is less than about 0.5% by weight, no intended effects can be obtained and, when it exceeds about 40% by weight, gelation occurs during melt-blending with PPS, resulting in degradation of the extrusion stability, moldability and mechanical properties of the product. Suitable epoxy functional .alpha.-olefin elastomers include: ethylene-glycidyl acrylate copolymers, ethylene-glycidyl methacrylate-vinyl acetate terpolymers, ethylene-glycidyl methacrylate-methyl acrylate terpolymers, ethylene-ethyl acrylate-glycidyl methacrylate terpolymers. The preferred epoxy functional .alpha.-olefin elastomers are Bondfast.RTM. E from Sumitomo and Lotader.RTM. AX from Elf Atochem.
The preferred compositional ranges of the present invention, all of which are expressed as percentages by weight of the total composition, are as follows: the LMWPPS is preferably present in the composition at a level of about 10% to about 85%, more preferably of about 50% to about 70%, and most preferably of about 55% to about 65%; the HMWPPS is preferably present in the composition at a level of about 10% to about 85%, more preferably of about 10% to about 30%, and most preferably of about 15% to about 25%; the impact modifier is preferably present at a level of about 2% to about 20%, more preferably of about 5% to about 15%, and most preferably of about 7% to about 10%. The epoxy functional alpha-olefin elastomer, if present, is preferably present in the composition at a level of about 2% to about 25%, more preferably of about 5% to about 20%, and most preferably of about 10% to about 15%.
Compositions of the present invention can also include effective amounts of at least one additive selected from the group consisting of flame retardants, drip retardants, dyes, pigments, colorants, stabilizers, antistatic agents, plasticizers and lubricants. These additives are known in the art, as are their effective levels and methods of incorporation. Effective amounts of the additives vary widely, but they are usually present in an amount from about 0.1% to about 50% by weight, based on the weight of the entire composition.
The preparation of the compositions of the present invention is normally achieved by blending the ingredients under conditions for the formation of an intimate blend. Such conditions often include mixing in single or twin screw type extruders or similar mixing devices which can apply a shear to the components. It is often advantageous to apply a vacuum to the melt through a vent port in the extruder to remove volatile impurities in the composition. The compositions of the present invention are useful for making molded articles such as housings for electrical connectors in under-the-hood automotive applications, and are useful for making various other molded articles.
It should also be clear that improved molded articles prepared from the compositions of the present invention represent an additional embodiment of this invention.
All patents and references cited herein are incorporated by reference.
The following examples are provided to illustrate some embodiments of the present invention. They are not intended to limit the invention in any aspect. All percentages are by weight based on the total weight of the entire composition, unless otherwise indicated.





EXAMPLES
The illustrative compositions of the Tables, all of which components are expressed as percentages by weight based on the total composition weight, were extruded on a Werner-Pfleiderer twin-screw extruder at a temperature of about 600.degree. F. with a vacuum of 10-20 inches Hg applied to at least one vent port and were molded using a Toshiba injection molding machine using a barrel temperature of about 600.degree. F. and a mold temperature of about 250.degree. F. The molded samples of the compositions were subjected to measurement of notched Izod impact strength according to ASTM D256 (employing a sample size of 2.5 inch by 0.5 inch by 0.125 inch), Dynatup (energy to fracture falling dart test) strength according to ASTM D3763 (using 4 inch diameter by 0.125 inch disks), flexural modulus and flexural strength according to ASTM D790 (employing a samples size of 6 inch by 0.5 inch by 0.25 inch), heat deflection under loads of 66 and 264 psi according to ASTM D648 (employing a sample size of 6 inch by 0.5 inch by 0.25 inch) and tensile yield and tensile elongation at break according to ASTM D638. The viscosities (MV) were measured under the described conditions using an Instron capillary rheometer.
The PPS used in the examples was poly(p-phenylene sulfide) resin. The LMTVPPS was commercially available from Hoechst Celanese sold under the trademark FORTRON W203 (Mn=8400, Mw=3300), the HMWPPS1 was commercially available from Hoechst Celanese sold under the trademark FORTRON W214 (Mn=12,000, Mw=59,000), and the HMWPPS2 was also commercially available from Hoechst Celanese sold under the trademark FORTRON W300 (Mn=27500, Mw=90000). The melt flow indices of LMWPPS and HMWPPS were determined by ASTMD D1238, at 300.degree. C. under a load of 2.16 kilogram (shear stress of 19400 pascals), and had the corresponding values of 378 and 12 gram/10 minutes. The epoxy functional .alpha.-olefin elastomer (EAO) was a polyethylene-co-glycidyl methacrylate copolymer sold under the trademark Bondfast.RTM. E. The impact modifier (IM) was a styrene-(ethylene-butylene)-styrene triblock copolymer sold under the trademark Kraton.RTM. G1651.
TABLE 1______________________________________ BLENDSProperty A B C D E______________________________________LMWPPS (wt %) 80 60 40 20 0HMWPPS2 (wt %) 0 20 40 60 80EAO (wt %) 12 12 12 12 12IM (wt %) 8 8 8 8 8MV @ 300.degree. C., 100s.sup.-1, 1900 6900 12300 20600 23800poiseMV @ 300.degree. C., 1800s.sup.-1, 1090 2100 3300 5040 5841poiseHDT @ 264 psi, .degree.F. 208 211 210 209 208Room Temp. NII, ft-lb/in 1.5 12.6 13.6 14.5 13.5-20.degree. F./NII, ft/lb./in 1.2 4.2 5.3 4.2 3.0Room Temp. Dynatup 30B 33D 35D 34D 27DEnergy*, ft-lb-20.degree. F. Dynatup Energy, 5B 19D 28D 29D 3Bft-lbFlex Modulus, kpsi 276 275 284 298 295Flex Strength, psi 9950 9930 10000 10600 10400Tensile Elongation at 18 65 51 63 71break, %Tensile Yield Strength, 6490 6460 6830 7169 7000psiTensile Ultimate 6510 6160 6290 6560 6300Strength, psi______________________________________ *D and B refer to Ductile and Brittle failure modes, respectively.
Table 1 illustrates compositions that utilize both the EAO and IM with PPS. Physical property data of comparative blends made from the compositions of Examples A and E, each utilizing only a single molecular weight PPS, show the deficiency in low temperature impact strength, as represented by -20.degree. F. Dynatup impact strength. Comparison of the comparative blends Examples A and E to the physical property data of blends made from the compositions of Examples B, C and D, each of which utilizes a mixture of LMWPPS and HMWPPS2, illustrates the unexpected results of superior low temperature impact strength and ductility, again represented as -20.degree. F. Dynatup impact strength, of the present invention. Other physical properties are maintained in the compositions made with the mixture of PPS resins.
TABLE 2______________________________________ BLENDSProperty F G H I J______________________________________LMWPPS (wt %) 90 67.5 45 22.5 0HMWPPS2 (wt %) 0 22.5 45 67.5 90EAO (wt %) 6 6 6 6 6IM (wt %) 4 4 4 4 4MVI, 300.degree. C., 2.16 kg, 154 40 13 4 1g/10'HDT @ 264 psi, .degree.F. 214 222 218 212 212Room Temp. NII, ft-lb/in 0.7 2 6.3 6.6 15.8-20.degree. F./NII, ft/lb./in 0.8 1.4 2.6 2.6 2.3Room Temp. Dynatup 3 30 39 29 40Energy*, ft-lb-20.degree. F. Dynatup Energy, 2 23 38 36 46ft-lbFlex Modulus, Kpsi 391 384 379 378 358Flex Strength, Kpsi 14.2 14.3 14.3 14.0 13.0Tensile Elongation at 7 20 16 28 62break, %Tensile Yield Strength, 8742 8950 8829 8835 7431psiTensile Ultimate 8742 8053 7054 7103 5221Strength, psi______________________________________
Table 2 further illustrates compositions that utilize both the EAO and IM with PPS and demonstrate the utility at a lower overall level of EAO and IM than utilized in the compositions of Table 1. As seen by these data, a better overall balance in physical property data is obtained by utilization of a high molecular weight PPS and a low molecular weight PPS than with either PPS alone.
TABLE 3__________________________________________________________________________ BLENDSProperty K L M N O__________________________________________________________________________LMWPPS (wt %) 80 60 40 20 0HMWPPS2 (wt %) 0 20 40 60 80EAO (wt %) 20 20 20 20 20MV @ 300.degree. C., 100s.sup.-1, poise 1685 3668 10787 15945 28937MV @ 300.degree. C., 1800s.sup.-1, poise 641 1271 2919 4827 6765HDT @ 264 psi, .degree.F. 217 214 207 208 215Room Temp. NII, ft-lb/in 2.35 9.88 12.21 12.67 11.48-20.degree. F./NII, ft/lb./in 1.71 2.37 3.63 6.7 8.64Room Temp. Dynatup Energy*, 15.5B 22.3B 27D 31.1D 32.4Dft-lb-20.degree. F. Dynatup Energy, ft-lb 1.5B 29.3B 17.1B 34.8B 35.2BFlex Modulus, kpsi 281 282 285 275 246Flex Strength, psi 10400 10240 10270 9839 9274Tensile Elongation at break, % 19 31 38 44 85Tensile Yield Strength, psi 6800 7027 7091 7061 6040Tensile Ultimate Strength, psi 6825 6385 6484 6353 5878__________________________________________________________________________ *D and B refer to Ductile and Brittle failure modes, respectively.
The data in Table 3 relates to samples made utilizing a single modifier, in these examples the epoxy functional .alpha.-olefin elastomer (EAO). Physical property data of comparative blends made from the compositions of Example K utilizing only a single molecular weight PPS, show the deficiency in low temperature impact strength, as represented by -20.degree. F. Dynatup impact strength. Comparison of the comparative blends Examples K and O to the physical property data of blends made from the compositions of Examples L, M, and N, each of which utilizes a mixture of LMWPPS and HMWPPS2, illustrates the unexpected results of superior impact strength and flow of the present invention. Other physical properties are maintained in the compositions made with the mixture of PPS resins.
TABLE 4______________________________________ BLENDSProperty P Q R S T______________________________________LMWPPS (wt %) 90 67.5 45 22.5 0HMWPPS2 (wt %) 0 22.5 45 67.5 90EAO (wt %) 10 10 10 10 10MVI, 300.degree. C., 2.16 kg, 147 33 9 3 1g/10'HDT @ 264 psi, .degree.F. 226 219 217 210 207Room Temp. NII, ft-lb/in 1.0 1.4 2.3 10 11.7-20.degree. F./NII, ft/lb./in 0.8 1.8 1.8 2.1 1.9Room Temp. Dynatup 5 31 41 39 34Energy*, ft-lb-20.degree. F. Dynatup Energy, 2 9 25 36 23ft-lbFlex Modulus, kpsi 403 386 375 366 341Flex Strength, kpsi 15.1 14.4 14.0 13.6 12.6Tensile Elongation at 8 17 20 28 29break, %Tensile Yield Strength, 936 9714 9241 8613 7369psiTensile Ultimate 9386 8593 6996 6592 5458Strength, psi______________________________________
The data in Table 4 relates to additional samples made utilizing a single modifier, in these examples the epoxy functional .alpha.-olefin elastomer (EAO). As seen by these data, a better overall balance in physical property data is obtained by utilization of a high molecular weight PPS and a low molecular weight PPS than with either PPS alone.
TABLE 5__________________________________________________________________________ BLENDSProperty U V W X Y__________________________________________________________________________LMWPPS (wt %) 80 60 40 20 0HMWPPS2 (wt %) 0 20 40 60 80IM (wt %) 20 20 20 20 20MV @ 300.degree. C., 100s.sup.-1, poise 2477 2222 2405 3932 4050MV @ 300.degree. C., 1800s.sup.-1, poise 579 836 1190 1505 1780HDT @ 264 psi, .degree.F. 217 214 210 220 212Room Temp. NII, ft-lb/in 0.67 1.12 1.5 1.83 2.76-20.degree. F./NII, ft/lb./in 0.66 0.89 0.96 1.1 1.05Room Temp. Dynatup Energy*, 1.4 10 13 35.3 31.1ft-lb-20.degree. F. Dynatup Energy, ft-lb 1.2B 2.5B 1.3B 3B 23BFlex Modulus, kpsi 298 296 287 276 307Flex Strength, psi 9550 9663 9522 9212 10410Tensile Elongation at break, % 9.2 33.1 22.3 24 17.9Tensile Yield Strength, psi 5762 6103 6036 5881 6634Tensile Ultimate Strength, psi 5762 6311 6043 5600 5684__________________________________________________________________________ *D and B refer to Ductile and Brittle failure modes, respectively.
The data in Table 5 relates to samples made utilizing a single modifier, in these examples the styrene-(ethylene-butylene)-styrene triblock copolymer. Physical property data of comparative blend made from the composition of Examples U utilizing only a single molecular weight PPS, show the deficiency in impact strength, as represented by notched Izod. Comparison of the comparative blends Examples K and O to the physical property data of blends made from the compositions of Examples L, M and N, each of which utilizes a mixture of LMWPPS and HMWPPS2, illustrates the unexpected results of superior impact strength and flow of the present invention. Other physical properties are maintained in the compositions made with the mixture of PPS resins.
TABLE 6______________________________________ BLENDSProperty Z AA BB CC DD______________________________________LMWPPS (wt %) 90 67.5 45 22.5 0HMWPPS2 (wt %) 0 22.5 45 67.5 90IM (wt %) 10 10 10 10 10MVI, 300.degree. C., 2.16 kg, 172 61 27 16 8g/10'HDT @ 264 psi, .degree.F. 232 215 211 208 212Room Temp. NII, ft-lb/in 0.6 1.0 1.5 2.0 1.8-20.degree. F./NII, ft/lb./in 0.5 0.8 1.3 1.2 0.9Room Temp. Dynatup 2 15 30 40 35Energy*, ft-lb-20.degree. F. Dynatup Energy, 1 3 6 16 34ft-lbFlex Modulus, Kpsi 417 406 407 393 381Flex Strength, Kpsi 14.1 14.6 14.7 14.0 13.5Tensile Elongation at 7 17 11 13 11break, %Tensile Yield Strength, 8688 9008 8870 8772 8269psiTensile Ultimate 8688 7688 7141 6853 6534Strength, psi______________________________________
The data in Table 6 relates to samples made utilizing a single modifier, in these examples the styrene-(ethylene-butylene)-styrene triblock copolymer. As seen by these data, a better overall balance in physical property data is obtained by utilization of a high molecular weight PPS and a low molecular weight PPS than with either PPS alone.
TABLE 7__________________________________________________________________________ BLENDSProperty EE FF GG HH II__________________________________________________________________________LMWPPS (wt %) 80 60 40 20 0HMWPPS1 (wt %) 0 20 40 60 80EAO (wt %) 20 20 20 20 20MV @ 300.degree. C., 100s.sup.-1, poise 1685 4249 6243 11183 18690MV @ 300.degree. C., 1800s.sup.-1, poise 641 1307 1853 3045 4711HDT @ 264 psi, .degree.F. 217 213 212 220 212Room Temp. NII, ft-lb/in 2.35 3.45 9.94 11.8 13.24-20.degree. F./NII, ft/lb./in 1.71 1.76 2.57 5.22 6.11Room Temp. Dynatup Energy*, 15.5B 32.5D 35D 31.9D 36.5Dft-lb-20.degree. F. Dynatup Energy, ft-lb 1.5B 25.2B 36.9B 28.5B 38.7DFlex Modulus, kpsi 281 299 292 285 280Flex Strength, psi 10360 11140 10940 10690 10430Tensile Elongation at break, % 19 29.3 34 33.8 41.9Tensile Yield Strength, psi 6800 7496 7341 7207 7184Tensile Ultimate Strength, psi 6825 7142 6579 6668 6548__________________________________________________________________________ *D and B refer to Ductile and Brittle failure modes, respectively.
The data in Table 7 relates to samples made utilizing a single modifier, in these examples the epoxy functional .alpha.-olefin elastomer (EAO). Physical property data of comparative blends made from the composition of Example EE utilizing only a single molecular weight PPS, show the deficiency in low temperature impact strength, as represented by -20.degree. F. Dynatup impact strength. Comparison of the comparative blends Examples EE and II to the physical property data of blends made from the compositions of Examples FF, GG, and HH, each of which utilizes a mixture of LMWPPS and HMWPPS1, illustrates the unexpected results of superior impact strength and flow of the present invention. Other physical properties are maintained in the compositions made with the mixture of PPS resins.
TABLE 8__________________________________________________________________________ BLENDSProperty JJ KK LL MM NN__________________________________________________________________________LMWPPS (wt %) 80 60 40 20 0HMWPPS1 (wt %) 0 20 40 60 80IM (wt %) 20 20 20 20 20MV @ 300.degree. C., 100s.sup.-1, poise 2477 2245 1896 2406 3520MV @ 300.degree. C., 1800s.sup.-1, poise 579 709 881 1111 1364HDT @ 264 psi, .degree.F. 217 215 208 220 217Room Temp. NII, ft-lb/in 0.67 1.07 1.51 1.6 1.62-20.degree. F./NII, ft/lb./in 0.66 0.91 1.08 1.16 1.07Room Temp. Dynatup Energy*, 1.4B 5.6B 9.4B 26.8B 18.8Bft-lb-20.degree. F. Dynatup Energy, ft-lb 1.2B 1.2B 2.3B 3.3B 9.2BFlex Modulus, kpsi 298 295 293 295 290Flex Strength, psi 9550 9662 9829 9959 9882Tensile Elongation at break, % 9.2 26.2 38.7 50.5 34.4Tensile Yield Strength, psi 5762 5285 5944 6079 6336Tensile Ultimate Strength, psi 5762 5503 6215 6055 6064__________________________________________________________________________ *D and B refer to Ductile and Brittle failure modes, respectively.
The data in Table 5 relates to samples made utilizing a single modifier, in these examples the styrene-(ethylene-butylene)-styrene triblock copolymer. Physical property data of comparative blend made from the composition of Examples JJ utilizing only a single molecular weight PPS, show the deficiency in impact strength, as represented by notched Izod. Comparison of the comparative blends Examples JJ and NN to the physical property data of blends made from the compositions of Examples KK, LL, and MM, each of which utilizes a mixture of LMWPPS and HMWPPS1, illustrates the unexpected results of superior impact strength and flow of the present invention. Other physical properties are maintained in the compositions made with the mixture of PPS resins.
The compositions of the present invention may contain additional thermoplastic materials, but preferably are free of such additional thermoplastic materials. Thermoplastic materials which either may be added or may be absent from the present compositions include, for example, polyphenylene ethers, polyamides, polyimides, polyetherimides, polycarbonates, and polyesters.
Claims
  • 1. A composition comprising:
  • (a) a low molecular weight poly(arylene sulfide) resin, wherein said low molecular weight poly(arylene sulfide) resin is present at a level of from about 10% to about 85% by weight based on the total weight of the composition, and wherein said low molecular weight poly(arylene sulfide) resin has a number average molecular weight of between about 2,000 and about 10,000;
  • (b) a high molecular weight poly(arylene sulfide) resin, wherein said high molecular weight poly(arylene sulfide) resin is present at a level of between about 10% by weight and about 85% by weight percent based on the total weight of the composition, and wherein said high molecular weight poly(arylene sulfide) resin has a number average molecular weight of between about 11,000 and about 100,000; and
  • (c) at least one impact modifier selected from the group consisting of:
  • (i) a block copolymer of alkenyl aromatic compounds and dienes, wherein the block copolymer is a triblock copolymer comprising polystyrene endblocks and a selectively hydrogenated diene-derived midblock;
  • (ii) an epoxy functional alpha-olefin elastomer comprising about 60% to about 99.5% by weight of an .alpha.-olefin and about 0.5% to about 40% by weight of a glycidyl ester of an .alpha.,.beta.-unsaturated carboxylic acid; and
  • (iii) a mixture of (i) and (ii);
  • wherein said impact modifier is present at a level of from about 2% to about 20% by weight based on the total weight of the composition.
  • 2. The composition as claimed in claim 1, wherein said composition consists essentially of said low molecular weight poly(arylene sulfide) resin, said high molecular weight poly(arylene sulfide) resin, and said epoxy functional alpha-olefin elastomer.
  • 3. The composition as claimed in claim 1, wherein said composition consists essentially of said low molecular weight poly(arylene sulfide) resin, said high molecular weight poly(arylene sulfide) resin, and said block copolymer.
  • 4. The composition of claim 1 further comprising at least one additive selected from the group consisting of flame retardants, drip retardants, dyes, pigments, colorants, stabilizers, antistatic agents, plasticizers and lubricants.
  • 5. An article molded from the composition of claim 1, least one additive selected from the group consisting of flame retardants, drip retardants, dyes, pigments, colorants, stabilizers, anti-static agents, plasticizers, and lubricants.
  • 6. A composition consisting essentially of:
  • (a) a low molecular weight poly(arylene sulfide) resin, wherein said low molecular weight poly(arylene sulfide) resin is present at a level of from about 10% to about 85% by weight based on the total weight of the composition, and wherein said low molecular weight poly(arylene sulfide) resin has a number average molecular weight of between about 2,000 and about 10,000;
  • (b) a high molecular weight poly(arylene sulfide) resin, wherein said high molecular weight poly(arylene sulfide) resin is present at a level of between about 10% by weight and about 85% by weight percent based on the total weight of the composition, and wherein said high molecular weight poly(arylene sulfide) resin has a number average molecular weight of between about 11,000 and about 100,000; and
  • (c) at least one impact modifier selected from the group consisting of:
  • (i) a block copolymer of alkenyl aromatic compounds and dienes, wherein the block copolymer is a triblock copolymer comprising polystyrene endblocks and a selectively hydrogenated diene-derived midblock;
  • (ii) an epoxy functional alpha-olefin elastomer comprising about 60% to about 99.5% by weight of an .alpha.-olefin and about 0.5% to about 40% by weight of a glycidyl ester of an .alpha.,.beta.-unsaturated carboxylic acid; and
  • (iii) a mixture of (i) and (ii);
  • wherein said impact modifier is present at a level of from about 2% to about 20% by weight based on the total weight of the composition.
  • 7. An article molded from the composition of claim 6.
  • 8. A composition consisting of:
  • (a) a low molecular weight poly(arylene sulfide) resin, wherein said low molecular weight poly(arylene sulfide) resin is present at a level of from about 10% to about 85% by weight based on the total weight of the composition, and wherein said low molecular weight poly(arylene sulfide) resin has a number average molecular weight of between about 2,000 and about 10,000;
  • (b) a high molecular weight poly(arylene sulfide) resin, wherein said high molecular weight poly(arylene sulfide) resin is present at a level of between about 10% by weight and about 85% by weight percent based on the total weight of the composition, and wherein said high molecular weight poly(arylene sulfide) resin has a number average molecular weight of between about 11,000 and about 100,000; and
  • (c) at least one impact modifier selected from the group consisting of:
  • (i) a block copolymer of alkenyl aromatic compounds and dienes, wherein the block copolymer is a triblock copolymer comprising polystyrene endblocks and a selectively hydrogenated diene-derived midblock;
  • (ii) an epoxy functional alpha-olefin elastomer comprising about 60% to about 99.5% by weight of an .alpha.-olefin and about 0.5% to about 40% by weight of a glycidyl ester of an .alpha.,.beta.-unsaturated carboxylic acid; and
  • (iii) a mixture of (i) and (ii);
  • wherein said impact modifier is present at a level of from about 2% to about 20% by weight based on the total weight of the composition.
Parent Case Info

This application is a continuation in part of Ser. No. 08/288,518, filed Aug. 10, 1994, now abandoned.

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Number Name Date Kind
3354129 Edmonds, Jr. et al. Nov 1967
3354757 Grimm et al. Nov 1967
3919177 Campbell Nov 1975
4528346 Sugie et al. Jul 1985
4681915 Bates et al. Jul 1987
4769424 Takekoshi et al. Sep 1988
4889893 Kobayashi et al. Dec 1989
5122578 Han et al. Jun 1992
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Number Date Country
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0368413 May 1990 EPX
02252761 Oct 1990 JPX
04198268 Jul 1992 JPX
Continuation in Parts (1)
Number Date Country
Parent 288518 Aug 1994