Poly(phenylene ether) composition, method of forming same, and articles prepared therefrom

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

15 to 70 weight percent of a poly(phenylene ether);

15 to 70 weight percent of a rubber-modified polystyrene comprising polystyrene and polybutadiene;

10 to 20 weight percent of a flame retardant comprising an organophosphate ester; and

0.2 to 4 weight percent of a mold release agent comprising a polydiorganosiloxane having a kinematic viscosity of 20,000 to 5,000,000 centistokes at 23° C., measured at 23° C. according to ISO 2555:1989;

wherein the composition excludes polyolefin waxes.

2. The composition of claim 1 , wherein the poly(phenylene ether) is a poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.3 to 0.5 deciliter per gram as measured in chloroform at 25° C.

3. The composition of claim 1 , wherein the rubber-modified polystyrene comprises 80 to 96 weight percent polystyrene, and 4 to 20 weight percent polybutadiene, based on the weight of the rubber-modified polystyrene.

4. The composition of claim 1 , wherein the sum of the poly(phenylene ether) weight percent and the rubber-modified polystyrene weight percent is 75 to 89.6 weight percent.

5. The composition of claim 1 , wherein the organophosphate ester is selected from the group consisting of tris((C 1 -C 6 -alkyl)phenyl) phosphates, resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), triphenyl phosphate, t-butylphenyl diphenyl phosphates, bis(t-butylphenyl) phenyl phosphates, and combinations thereof.

6. The composition of claim 1 , wherein the organophosphate ester is selected from the group consisting of resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), and combinations thereof.

7. The composition of any one of claims 1 - 6 , wherein the flame retardant consists of the organophosphate ester.

8. The composition of claim 1 , wherein the polydiorganosiloxane comprises diorganosiloxane repeat units having the structure

wherein each occurrence of R 1 and R 2 is independently C 1 -C 12 hydrocarbyl.

9. The composition of claim 1 , wherein the polydiorganosiloxane is selected from the group consisting of polydimethylsiloxanes, trimethylsilyl-terminated polydimethylsiloxanes, vinyldimethylsilyl-terminated polydimethylsiloxanes, epoxycyclohexyldimethylsilyl-terminated polydimethylsiloxanes, glycidoxypropyldimethylsilyl-terminated polydimethylsiloxanes, p-styryldimethylsilyl-terminated polydimethylsiloxanes, methacryloxypropyldimethylsilyl-terminated polydimethylsiloxanes, acryloxydimethylsilyl-terminated polydimethylsiloxanes, aminopropyldimethylsilyl-terminated polydimethylsiloxanes, 3-isocyanatopropyldimethylsilyl-terminated polydimethylsiloxanes, 3-mercaptopropyldimethylsilyl-terminated polydimethylsiloxanes, 3-ureidopropyldimethylsilyl-terminated polydimethylsiloxanes, ethyldimethylsilyl-terminated polydimethylsiloxanes, propyldimethylsilyl-terminated polydimethylsiloxanes, hexyldimethylsilyl-terminated polydimethylsiloxanes, octyldimethylsilyl-terminated polydimethylsiloxanes, decyldimethylsilyl-terminated polydimethylsiloxanes, phenyldimethylsilyl-terminated polydimethylsiloxanes, and combinations thereof.

10. The composition of claim 1 , comprising

a continuous phase comprising the poly(phenylene ether), the rubber-modified polystyrene, and the organophosphate ester; and

a disperse phase comprising the polydiorganosiloxane;

wherein the disperse phase comprises disperse phase domains characterized by a domain length of 150 to 500 nanometers.

11. The composition of claim 1 ,

wherein the poly(phenylene ether) is a poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.34 to 0.46 deciliter per gram as measured in chloroform at 25° C.;

wherein the rubber-modified polystyrene comprises 80 to 96 weight percent polystyrene, and 4 to 20 weight percent polybutadiene, based on the weight of the rubber-modified polystyrene;

wherein the organophosphate ester comprises resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), or a combination thereof;

wherein the polydiorganosiloxane is a polydimethylsiloxane having a kinematic viscosity of 1,000,000 to 5,000,000 centistokes at 23° C.; and

wherein the composition comprises

47 to 67 weight percent of the poly(phenylene ether),

20 to 30 weight percent of the rubber-modified polystyrene,

8 to 18 weight percent of the organophosphate ester, and

0.3 to 2 weight percent of the polydiorganosiloxane.

12. A method of forming a composition, the method comprising:

melt-blending components comprising, based on the total weight of the composition,

15 to 70 weight percent of a poly(phenylene ether),

15 to 70 weight percent of a rubber-modified polystyrene comprising polystyrene and polybutadiene,

10 to 20 weight percent of a flame retardant comprising an organophosphate ester, and

0.2 to 4 weight percent of a mold release agent comprising a polydiorganosiloxane having a kinematic viscosity of 20,000 to 5,000,000 centistokes at 23° C.

to form the composition;

wherein the polydiorganosiloxane prior to melt blending is in the form of a masterbatch in polystyrene, rubber-modified polystyrene, silica, or a combination thereof;

wherein the masterbatch is a solid at 23° C. and one atmosphere; and

wherein the composition excludes polyolefin waxes.

13. The method of claim 12 , wherein the composition comprises

a continuous phase comprising the poly(phenylene ether), the rubber-modified polystyrene, and the organophosphate ester; and

a disperse phase comprising the polydiorganosiloxane;

wherein the disperse phase comprises disperse phase domains characterized by a domain length of 150 to 500 nanometers.

14. The method of claim 12 ,

wherein the poly(phenylene ether) is a poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.34 to 0.46 deciliter per gram as measured in chloroform at 25° C.;

wherein the rubber-modified polystyrene comprises 80 to 96 weight percent polystyrene, and 4 to 20 weight percent polybutadiene, based on the weight of the rubber-modified polystyrene;

wherein the organophosphate ester comprises resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), or a combination thereof;

wherein the polydiorganosiloxane is a polydimethylsiloxane having a kinematic viscosity of 1,000,000 to 5,000,000 centistokes at 23° C.;

wherein the polydiorganosiloxane prior to melt blending is in the form of a masterbatch in rubber-modified polystyrene; and

wherein the composition comprises

47 to 67 weight percent of the poly(phenylene ether),

20 to 30 weight percent of the rubber-modified polystyrene,

8 to 18 weight percent of the organophosphate ester, and

0.3 to 2 weight percent of the polydiorganosiloxane.

15. An article comprising a composition comprising, based on the total weight of the composition:

15 to 70 weight percent of a poly(phenylene ether);

15 to 70 weight percent of a rubber-modified polystyrene comprising polystyrene and polybutadiene;

10 to 20 weight percent of a flame retardant comprising an organophosphate ester; and

0.2 to 4 weight percent of a mold release agent comprising a polydiorganosiloxane having a kinematic viscosity of 20,000 to 5,000,000 centistokes at 23° C.;

wherein the composition excludes polyolefin waxes.

16. The article of claim 15 , wherein the composition comprises

a continuous phase comprising the poly(phenylene ether), the rubber-modified polystyrene, and the organophosphate ester; and

a disperse phase comprising the polydiorganosiloxane;

wherein the disperse phase comprises disperse phase domains characterized by a domain length of 150 to 500 nanometers.

17. The article of claim 15 ,

wherein the poly(phenylene ether) is a poly(2,6-dimethyl-1,4-phenylene ether) having an intrinsic viscosity of 0.34 to 0.46 deciliter per gram as measured in chloroform at 25° C.;

wherein the rubber-modified polystyrene comprises 80 to 96 weight percent polystyrene, and 4 to 20 weight percent polybutadiene, based on the weight of the rubber-modified polystyrene;

wherein the organophosphate ester comprises resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), or a combination thereof;

wherein the polydiorganosiloxane is a polydimethylsiloxane having a kinematic viscosity of 1,000,000 to 5,000,000 centistokes at 23° C.; and

wherein the composition comprises

47 to 67 weight percent of the poly(phenylene ether),

20 to 30 weight percent of the rubber-modified polystyrene,

8 to 18 weight percent of the organophosphate ester, and

0.3 to 2 weight percent of the polydiorganosiloxane.

18. The article of claim 15 , comprising a cylindrical or conical portion characterized by a length of at least 10 millimeters and a draft angle of 0 to 0.5 degree.

19. The article of claim 15 , wherein the article is a battery holder for a back-up power supply.