Filled composition containing polyphenylene sulphide (PPS) and polyamide 6 (PA6)

Abstract

The present invention relates to a polymer composition (C) comprising: —a polyphenylene sulfide (PPS), —at least 3 wt. % of polyamide 6 (PA6), —25 to 60 wt. % of reinforcing agents, —3 to 8 wt. % of a functionalized, non-aromatic elastomer, wherein the weight ratio PPS/PA6 is at least 4 and wherein wt. % are based on the total weight of the composition. The present invention also relates to articles incorporating the polymer composition and the use of polyamide 6 (PA6) as a heat-aging stabilizer in a polymer composition.

Claims

1. A polymer composition comprising: a polyphenylene sulfide (PPS), at least 3 wt. % of polyamide 6 (PA6), from 25 to 60 wt. % of reinforcing agents, from 3 to 8 wt. % of a functionalized, non-aromatic elastomer, wherein the weight ratio PPS/PA6 is at least 4 and less than about 18, and wherein wt. % are based on the total weight of the composition.

2. The polymer composition of claim 1, wherein the PPS comprises at least about 50 mol. % of recurring units (R.sub.PPS) of formula (L): ##STR00004## wherein R.sub.1 and R.sub.2, equal to or different from each other, are selected from the group consisting of hydrogen atoms, halogen atoms, C.sub.1-C.sub.12 alkyl groups, C.sub.7-C.sub.24 alkylaryl groups, C.sub.7-C.sub.24 aralkyl groups, C.sub.6-C.sub.24 arylene groups, C.sub.1-C.sub.12 alkoxy groups, and C.sub.6-C.sub.18 aryloxy groups, and substituted or unsubstituted arylene sulfide groups, the arylene groups of which are also linked by each of their two ends to two sulfur atoms forming sulfide groups via a direct C—S linkage thereby creating branched or cross-linked polymer chains, wherein mol. % is based on the total number of moles in the PPS.

3. The polymer composition of claim 1, wherein the PA6 comprises at least about 50 mol. % of recurring units (R.sub.PA6) of formula (N):
—NH—(CH.sub.2).sub.5—CO— wherein mol. % is based on the total number of moles in the PA6.

4. The polymer composition of claim 1 comprising from 35 to 60 wt. % of PPS.

5. The polymer composition of claim 1 comprising from 5 to 12 wt. % of PA6.

6. The polymer composition of claim 1, wherein the elastomer is functionalized with maleic anhydride.

7. The polymer composition of claim 1, wherein the elastomer is EPDM grafted with maleic anhydride (EPDM-g-MAH).

8. The polymer composition of claim 1, wherein the weight ratio of PA6/elastomer is at least 1.

9. A method of making the polymer composition of claim 1, said method comprising melt-blending PPS, PA6, the reinforcing agents, and the functionalized, non-aromatic elastomer, and optionally any other components or additives.

10. An article comprising the polymer composition of claim 1.

11. The article of claim 10, wherein the article is a film, a laminate, an automotive part, an engine part, an electrical part, or an electronic part.

12. A method of heat-stabilizing the polymer composition of claim 1 comprising adding the polyamide 6 (PA6) as a heat-aging stabilizer in the polymer composition.

13. The method of claim 12, wherein the polymer composition comprises: from 35 to 70 wt. % of a polyphenylene sulfide (PPS), from 25 to 60 wt. % of reinforcing agents, with the proviso that the composition either does not comprise an elastomer or comprises an elastomer in an amount not exceeding 1 wt. %, wherein wt. % are based on the total weight of the composition.

14. The method of claim 12, wherein the PA6 comprises at least about 50 mol. % of recurring units (R.sub.PA6) of formula (N):
—NH—(CH.sub.2).sub.5—CO— wherein mol. % is based on the total number of moles in the PA6.

15. The method of claim 12, wherein the PA6 in the composition ranges from 5 to 15 wt. %, based on the total weight of the composition.

16. The polymer composition of claim 1, wherein the weight ratio PPS/PA6 is less than about 16.

Description

EXAMPLES

(1) Raw Materials

(2) PPS Ryton® QA281 N (Solvay)

(3) PA 6 AK270 (Shaw Industries)

(4) PA 66 Stabamid®27AE1 (Solvay)

(5) Glass Fibers T779H (Nippon)

(6) Lotader® AX8840 (Arkema), copolymer of ethylene and glycidyl methacrylate (epoxy functionalized)

(7) Exxelor® VA1801 (Exxon Mobil), ethylene copolymer functionalized with maleic anhydride (EPDM-g-MAH)

(8) Kraton® FG-1901 (Kraton), triblock copolymer based on styrene and ethylene/butylene functionalized with maleic anhydride (SEBS-g-MAH)

(9) Irganox® 1010 (BASF), an antioxidant

(10) HDPE (High Density Polyethylene) 6007G (Chevron Phillips), a lubricant

(11) Compounding

(12) Compounding that involved the incorporation of glass fibers was performed on a Coperion ZSK-26 R&D twin-screw extruder (26 mm extruder). The neat PPS resin was fed into barrel 1. Glass fibers were fed at barrel 7. Optional ingredients when present were also included into barrel 1, possibly pre-mixed before being fed into barrel 1.

(13) Barrel conditions were specified in order to achieve a melt temperature between 310° C. and 340° C. Screw speeds were set at 200 RPM. Feed rates were set according to the desired composition of each formulation.

(14) The molten strands were cooled and crystallized in a water bath before being pelletized for further processing.

(15) Molding

(16) All compounds were molded into ISO Type IA tensile bars.

(17) Testing

(18) Tensile properties were tested according to ISO 527-2 using the ISO Type IA tensile bars.

(19) Impact properties were tested using ISO Unnotched Izod (ISO 180), at room temperature, using ISO Type IA tensile bars.

(20) Heat aging was performed by exposing test samples in an air oven regulated at 200° C. and removed after designated time intervals, to be subsequently tested at room temperature for tensile and impact properties.

(21) The components and their respective amounts in the compositions (according to the present invention or comparative) and the mechanical properties of the same are reported in Tables below.

Example 1

(22) TABLE-US-00001 TABLE 1 1 C1 C2 Components (wt. %) PPS 54.12 58.39 48.98 PA6 9.13 9.86 8.27 Glass fibers 30 30 30 Lotader ® AX8840 6 1 12 HDPE 6007G 0.25 0.25 0.25 Irganox ® 1010 0.5 0.5 0.5 Impact and Tensile properties Unnotched Izod 51.2 ± 2.45 30.9 ± 2.36 53.7 ± 3.17 Impact resistance (KJ/m.sup.2) Tensile stress  163 ± 0.91  168 ± 1.99  147 ± 1.06 at break (MPa)

(23) Example 1 provides a good compromise in tensile strength and impact resistance that is not achievable when the concentration of elastomer Lotader® AX8840 is lower than 3 wt. % or higher than 8%.

Example 2

(24) TABLE-US-00002 TABLE 2 2 3 C3 C4 PPS 51.75 54.12 45.18 49.19 PA6 11.5 9.13 18.07 14.06 Glass fibers 30 30 30 30 Lotader ® AX8840 6 6 6 6 HDPE 6007G 0.25 0.25 0.25 0.25 Irganox ® 1010 0.5 0.5 0.5 0.5 PPS/PA6 ratio 4.5 5.9 2.5 3.5 Unnotched Izod 42.7 ± 4.05 51.2 ± 2.45 34.2 ± 1.1  33.2 ± 2.21 Impact resistance (KJ/m.sup.2) Tensile stress  158 ± 2.13  163 ± 0.91  150 ± 2.89  152 ± 0.78 at break (MPa)

(25) Example 2 demonstrates that better impact resistance and tensile stress at break are obtained when the PPS/PA6 weight ratio is greater than 4 (examples 2 & 3). When the weight ratio of PPS/PA6 is less than 4 (examples C3 & C4), impact resistance and tensile stress at break have lower values.

Example 3

(26) TABLE-US-00003 TABLE 3 4 C5 Components (wt. %) PPS 54.12 69.52 PA6 9.13 11.73 Glass fibers 30 12 Lotader ® AX8840 6 6 HDPE 6007G 0.25 0.25 Irganox ® 1010 0.5 0.5 Impact and Tensile properties Unnotched Izod Impact 51.2 ± 2.45 29.7 ± 2.58 resistance (KJ/m.sup.2) Tensile stress at break (MPa)  163 ± 0.91  107 ± 2.26

(27) Interestingly, the composition providing the highest impact resistance and tensile strength is the one having a concentration of glass fibers greater than 25 wt. %

Example 4

(28) TABLE-US-00004 TABLE 4 5 C6 6 C7 Components (wt. %) PPS 54.8 54.8 54.8 54.8 PA6 9.25 — 9.25 — PA66 — 9.25 9.25 Glass fibers 30 30 30 30 Lotader ® AX8840 5.2 5.2 — — Exxelor ® VA1801 — — 5.2 5.2 HDPE 6007G 0.25 0.25 0.25 0.25 Irganox ® 1010 0.5 0.5 0.5 0.5 Impact and Tensile properties Unnotched Izod 45.6 ± 1.91 33.8 ± 1.61 41.4 ± 2.14 32.4 ± 3.34 Impact resistance (KJ/m.sup.2) Tensile stress  150 ± 1.89  141 ± 0.71  146 ± 2.07  138 ± 2.23 at break (MPa)

(29) Surprisingly, the combination of elastomer (Lotader® AX8840 or Exxelor® VA1801) and PA6 provides better results in terms of impact resistance and tensile strength at break than the combination of elastomer and PA66.

Example 5

(30) TABLE-US-00005 TABLE 5 C8 C9 Components (wt. %) PPS 54.25 64.25 PA6 10 — Glass fibers 30 30 Kraton ® FG-1901 5 5 HDPE 6007G 0.25 0.25 Irganox ® 1010 0.5 0.5 Impact and Tensile properties Unnotched Izod Impact 32.4 ± 4.13 36.4 ± 1.46 resistance (KJ/m.sup.2) Tensile stress at break (MPa)  141 ± 3.16  128 ± 2.01

(31) An aromatic-containing elastomer (Kraton® FG-1901) does not provide good impact resistance to the PPS glass-filled compounds (example C8). The addition of PA6 to this formulation (example C9) further does not improve the impact resistance. This example demonstrates that aromatic-containing elastomers are not suitable in combination with PPS glass-filled compounds or upon further addition of PA6.

Example 6

(32) TABLE-US-00006 TABLE 8 7 C9 Components (wt. %) PPS 54.25 64.25 PA6 10 — Glass fibers 30 30 Lotader ® AX8840 5 5 HDPE 6007G 0.25 0.25 Irganox ® 1010 0.5 0.5 Impact and Tensile properties Unnotched Izod Impact resistance 43.9 ± 0.82 35.9 ± 3.92 (KJ/m.sup.2) T0 Unnotched Izod Impact resistance 28.2 ± 2.63 18.7 ± 0.81 (KJ/m.sup.2) T1 = 1000 hours heat aging at 200° C. Heat aging - Impact Resistance 64.2 52.1 Retention (%) Tensile stress at break (MPa)  144 ± 1.73  141 ± 2.71 T0 Tensile stress at break (MPa)  133 ± 2.05  114 ± 3.11 T1 = 1000 hours heat aging at 200° C. Heat aging - Tensile Strength at 92.4 80.9 break Retention (%)

(33) Surprisingly, the addition of PA6 to the composition comprising PPS/elastomer/glass fibers shows an unexpected increase in the long-term high-temperature resistance.