Reinforced polyestercarbonate, polycarbonate-polydiorganosiloxane, poly(butylene-terephthalate) blend, and article comprising same
A composition includes specific amounts of a poly(butylene terephthalate), a reinforcing filler, and a polycarbonate that includes a copolyestercarbonate and a polycarbonate-polydiorganosiloxane block copolymer. The copolyestercarbonate includes aliphatic ester groups. The composition, which exhibits a desirable balance of melt flow and ductility, is especially useful for forming thin plastic parts of consumer electronic devices, including mobile phones.
1. A composition, comprising:
45 to 85 weight percent of a polycarbonate comprising
35 to 75 weight percent of a copolyestercarbonate comprising
ester units of the formula
wherein, independently in each ester unit, R 1 is an unsubstituted or substituted divalent C 6 -C 30 aromatic group; and T is an unsubstituted or substituted C 4 -C 18 aliphatic divalent group; and
carbonate units of the formula
wherein, independently in each carbonate unit, R 2 is a radical of the formula
* A 1 -Y 1 -A 2 *
wherein each of A 1 and A 2 is independently a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 ; and
10 to 30 weight percent of a polycarbonate-polydiorganosiloxane block copolymer;
10 to 30 weight percent of poly(butylene terephthalate); and
5 to 20 weight percent reinforcing filler;
wherein all weight percents are based on the total weight of the composition.
2. The composition of claim 1 , exhibiting a melt volume flow rate of at least 15 centimeter 3 /10 minutes measured at 300° C. and 1.2 kilogram load according to ASTM D1238; a notched Izod impact strength of at least 200 joules/meter measured at 23° C. according to ASTM D256; a tensile stress at yield of at least 50 megapascals measured at 23° C. according to ASTM D638; and a Vicat softening temperature of at least 115° C. measured at a load of 50 Newtons and a heating rate of 120° C./hour according to ASTM D1525.
3. The composition of claim 1 , wherein T is —(CH 2 ) 8 —.
4. The composition of claim 1 , wherein R 1 and R 2 are
5. The composition of claim 1 , wherein T is —(CH 2 ) 8 —, and R 1 and R 2 are
6. The composition of claim 1 , wherein the copolyestercarbonate comprises 1 to 13 mole percent of the ester units, and 87 to 99 mole percent of the carbonate units.
7. The composition of claim 1 , wherein the polycarbonate-polydiorganosiloxane block copolymer comprises 3 to 30 weight percent of diorganosiloxane units.
8. The composition of claim 1 , wherein the polycarbonate-polydiorganosiloxane block copolymer comprises a polydiorganosiloxane block comprising diorganosiloxane units of the formula wherein each occurrence of R 4 is independently C 1 -C 13 hydrocarbyl.
9. The composition of claim 1 ,
wherein the polycarbonate-polydiorganosiloxane block copolymer comprises, based on the weight of the polycarbonate-polydiorganosiloxane block copolymer, 10 to 30 weight percent of dimethylsiloxane units;
wherein the polycarbonate-polydiorganosiloxane block copolymer comprises, based on the weight of the polycarbonate-polydiorganosiloxane block copolymer, 70 to 90 weight percent of carbonate units of the formula
and
wherein the polycarbonate-polydiorganosiloxane block copolymer has a melt volume flow rate of 3 to 20 centimeter 3 /10 minutes measured at 300° C. and 1.2 kilogram load according to ASTM D1238-04.
10. The composition of claim 1 , wherein the reinforcing filler comprises glass fibers.
11. The composition of claim 1 , wherein the polycarbonate comprises 0 to 5 weight percent total of all polycarbonates other than the copolyestercarbonate and the polycarbonate-polydiorganosiloxane block copolymer.
12. The composition of claim 1 , wherein the polycarbonate consists of the copolyestercarbonate and the polycarbonate-polydiorganosiloxane block copolymer.
13. The composition of claim 1 , comprising 0 to 1 weight percent of particulate filler.
14. The composition of claim 1 , comprising 0 to 1 weight percent of impact modifier other than the polydiorganosiloxane blocks of the polycarbonate-polydiorganosiloxane block copolymer.
15. The composition of claim 1 , comprising 0 to 5 weight percent of any component other than the polyestercarbonate, the polycarbonate-polydiorganosiloxane block copolymer, the poly(butylene terephthalate), and the reinforcing filler.
16. The composition of claim 1 ,
wherein T is —(CH 2 ) 8 —, and R 1 and R 2 are
wherein the composition comprises 40 to 60 weight percent of the copolyestercarbonate;
wherein the polycarbonate-polydiorganosiloxane block copolymer comprises, based on the weight of the polycarbonate-polydiorganosiloxane block copolymer, 10 to 30 weight percent of dimethylsiloxane units;
wherein the polycarbonate-polydiorganosiloxane block copolymer comprises, based on the weight of the polycarbonate-polydiorganosiloxane block copolymer, 70 to 90 weight percent of carbonate units of the formula
wherein the polycarbonate-polydiorganosiloxane block copolymer has a melt volume flow rate of 3 to 20 centimeter 3 /10 minutes measured at 300° C. and 1.2 kilogram load according to ASTM D1238-04;
wherein the composition comprises 15 to 25 weight percent of the polycarbonate-polydiorganosiloxane block copolymer;
wherein the composition comprises 15 to 25 weight percent of the poly(butylene terephthalate);
wherein the reinforcing filler comprises glass fibers; and
wherein the composition comprises 5 to 15 weight percent of the reinforcing filler.
17. An article comprising a composition comprising:
45 to 85 weight percent of a polycarbonate comprising
35 to 75 weight percent of a copolyestercarbonate comprising
ester units of the formula
wherein, independently in each ester unit, R 1 is an unsubstituted or substituted divalent C 6 -C 30 aromatic group; and T is an unsubstituted or substituted C 4 -C 18 aliphatic divalent group; and
carbonate units of the formula
wherein, independently in each carbonate unit, R 2 is a radical of the formula
* A 1 -Y 1 -A 2 *
wherein each of A 1 and A 2 is independently a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 ; and
10 to 30 weight percent of a polycarbonate-polydiorganosiloxane block copolymer;
10 to 30 weight percent of poly(butylene terephthalate); and
5 to 20 weight percent reinforcing filler;
wherein all weight percents are based on the total weight of the composition.
18. The article of claim 17 , wherein the article comprises a thickness less than or equal to 2 millimeters.
19. The article of claim 17 , wherein the article is or is part of a mobile phone front cover or a mobile phone battery cover.
20. The article of claim 17 ,
wherein T is —(CH 2 ) 8 —, and R 1 and R 2 are
wherein the composition comprises 40 to 60 weight percent of the copolyestercarbonate;
wherein the polycarbonate-polydiorganosiloxane block copolymer comprises, based on the weight of the polycarbonate-polydiorganosiloxane block copolymer, 10 to 30 weight percent of dimethylsiloxane units;
wherein the polycarbonate-polydiorganosiloxane block copolymer comprises, based on the weight of the polycarbonate-polydiorganosiloxane block copolymer, 70 to 90 weight percent of carbonate units of the formula
wherein the polycarbonate-polydiorganosiloxane block copolymer has a melt volume flow rate of 3 to 20 centimeter 3 /10 minutes measured at 300° C. and 1.2 kilogram load according to ASTM D1238-04;
wherein the composition comprises 15 to 25 weight percent of the polycarbonate-polydiorganosiloxane block copolymer;
wherein the composition comprises 15 to 25 weight percent of the poly(butylene terephthalate);
wherein the reinforcing filler comprises glass fibers; and
wherein the composition comprises 5 to 15 weight percent of the reinforcing filler.