Electrical tracking resistance compositions, articles formed therefrom, and methods of manufacture thereof

1. A composition comprising, based on the total weight of the composition,

70 to 90 wt % of a poly(siloxane-etherimide); and

an additive comprising a polyester, a filler, or a combination thereof;

wherein the filler comprises talc, calcium carbonate, or a combination comprising at least one of the foregoing; and

wherein the polyester is a poly((C 2-6 )alkylene terephthalate), and the composition has a number of drops to tracking at 250 volts of greater than or equal to 50 drops determined according to ASTM D-3638-85.

2. The composition of claim 1 comprising, based on the total weight of the composition:

75 to 90 wt % of the poly(siloxane-etherimide);

5 to 18 wt % of the filler; and

5 to 20 wt % of the polyester.

3. The composition of claim 1 , wherein the composition has:

a tensile strength greater than or equal to 20 MPa determined according to ASTM D638;

a tensile modulus of greater than or equal to 600 GPa determined according to ASTM method D638;

an unnotched Izod impact of greater than or equal to 400 J/m, determined at room temperature on 3.2 millimeter thick bars as per ASTM D256; and

a melt flow rate of greater than or equal to 35 g/10 min, measured in accordance with ASTM D1238 at 337° C., using a 6.7 kilogram (kg) weight.

4. The composition of claim 1 comprising, based on the total weight of the composition:

75 to 80 wt % of the poly(siloxane-etherimide); and

20 to 25 wt % of the polyester.

5. The composition of claim 4 , wherein the composition has:

a tensile strength greater than or equal to 25 MPa determined according to ASTM D638;

a tensile modulus of greater than or equal to 800 GPa determined according to ASTM method D638;

an unnotched Izod impact of greater than or equal to 800 J/m, determined at room temperature on 3.2 millimeter thick bars as per ASTM D256; and

a melt flow rate of greater than or equal to 60 g/10 min, measured in accordance with ASTM D1238 at 337° C., using a 6.7 kilogram (kg) weight.

6. The composition of claim 1 comprising, based on the total weight of the composition:

75 to 92 wt % of the poly(siloxane-etherimide); and

12 to 18 wt % of the filler.

7. The composition of claim 1 , wherein the poly(siloxane-etherimide) comprises etherimide units of the formula

wherein

R is the same or different, and is a substituted or unsubstituted divalent organic group,

T is —O— or a group of the formula —O—Z—O— wherein the divalent bonds of the —O— or the —O—Z—O— group are in the 3,3′, 3,4′, 4,3′, or the 4,4′ positions; and wherein Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof, provided that the valence of Z is not exceeded; and

siloxane units of the formula

wherein each R′ is independently a C 1-13 monovalent hydrocarbyl group, and E has an average value of 2 to 100.

8. The composition of claim 7 , wherein the poly(siloxane-etherimide) comprises units of the formula

wherein

each R 4 is independently a C 2 -C 20 hydrocarbon moiety,

each R′ is independently a C 1-13 monovalent hydrocarbyl group,

E has an average value of 2 to 100,

R is the same or different, and is a substituted or unsubstituted divalent organic group, and

Z is an aromatic C 6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof, provided that the valence of Z is not exceeded, and n is greater than or equal to 1.

9. The composition of claim 8 , wherein R is a divalent group of the formula

or a combination comprising at least one of the foregoing, wherein Q 1 is —O—, —S—, —C(O)—, —SO 2 —, —SO—, —C y H 2y —wherein y is an integer from 1 to 5 or a halogenated derivative thereof, or —(C 6 H 10 ) z —wherein z is an integer from 1 to 4, and

Z is a divalent group of the formula

wherein Q is —O—, —S—, —C(O)—, —SO 2 —, —SO—, or —C y H 2y — wherein y is an integer from 1 to 5 or a halogenated derivative thereof.

10. The composition of claim 9 , wherein R is m-phenylene; R′ is methyl; and Z is

wherein Q is isopropylidene, E is 2 to 31, and R 4 is n-propyl.

11. The composition of claim 1 , wherein the poly(siloxane-etherimide) has a siloxane content of 20 to 45 wt. %, based on the total weight of the poly(siloxane-etherimide).

12. The composition of claim 1 , wherein the polyester comprises poly(ethylene terephthalate), poly(butylene terephthalate), or a combination comprising at least one of the foregoing.

13. The composition of claim 1 , further comprising an additive, wherein the additive is a processing aid, a heat stabilizer, an ultraviolet light absorber, a colorant, a flame retardant, or a combination comprising at least one of the foregoing.

14. The composition of claim 13 , comprising, based on the total weight of the composition, from 0.0001 to 20 wt % of each additive present in the composition.

15. An insulating material comprising the composition of claim 1 .

16. An article, wherein the article is a molded article, a thermoformed article, an extruded film, an extruded sheet, one or more layers of a multi-layer article, a substrate for a coated article, or a substrate for a metallized article made from the composition of claim 1 .

17. An article comprising the composition of claim 1 , wherein the article is a solar apparatus, an electrical junction box, an electrical connector, an electrical vehicle charger, an outdoor electrical enclosure, a smart meter enclosure, a smart grid power node, a photovoltaic frame or a miniature circuit breaker.

18. A method of controlling the tracking of an electrical current of an article of manufacture, the method comprising providing a composition of claim 1 , and processing the composition to form an article of manufacture.

19. The method of claim 18 , wherein the article is a solar apparatus, an electrical junction box, an electrical connector, an electrical vehicle charger, an outdoor electrical enclosure, a smart meter enclosure, a smart grid power node, a photovoltaic frame or a miniature circuit breaker.