Polycarbonate compositions, articles formed therefrom, and methods of manufacture thereof

A composition comprising, based on the weight of the composition,

• 65 to 95 wt. % of a polycarbonate copolymer comprising
• bisphenol A carbonate units, and
• units of the formula
• wherein R5 is hydrogen, phenyl optionally substituted with 1 to 5 C1-6 alkyl groups, or C1-4 alkyl;
• and
• 5 to 35 wt. % of a poly(carbonate-siloxane) comprising
• bisphenol A carbonate units, and
• siloxane units of the formula
• or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200;
• wherein the poly(carbonate-siloxane) comprises 0.5 to 55 wt. % of siloxane units based on the total weight of the poly(carbonate-siloxane);
• wherein no or substantially no brominated polycarbonate is present in the composition;
• wherein an article molded from each of the polycarbonate copolymer and the poly(carbonate-siloxane) has a smoke density after 4 minutes (DS-4) of greater than 600 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2;
• and
• wherein an article molded from the composition comprising the polycarbonate copolymer and the poly(carbonate-siloxane) has a smoke density after 4 minutes (DS-4) of less than or equal to 480 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2.

A composition comprising, based on the weight of the composition,

• 70 to 99 wt. % of a poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) comprising 75 to 85 wt. % of the ester units, wherein the ester units have a molar ratio of isophthalate to terephthalate of 98:2 to 88:12;
• and
• 1 to 30 wt. % of a poly(carbonate-siloxane) comprising
• bisphenol A carbonate units, and
• siloxane units of the formula
• or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200;
• wherein the poly(carbonate-siloxane) comprises 0.5 to 55 wt. % of siloxane units based on the total weight of the poly(carbonate-siloxane);
• wherein an article molded from each of the poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) or the poly(carbonate-siloxane) has a smoke density after 4 minutes (DS-4) of greater than 900 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2;
• and
• wherein an article molded from the composition comprising the poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) and the poly(carbonate-siloxane) has a smoke density after 4 minutes (DS-4) of less than or equal to 480 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2.

A composition comprising, based on the weight of the composition,

• 95 to 99.5 wt. % of a poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) comprising 75 to 85 wt. % of the ester units, wherein the ester units have a molar ratio of isophthalate to terephthalate of 98:2 to 88:12;
• and
• 0.5 to 5 wt. % of polydimethylsiloxane;
• wherein an article molded from the poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) has a smoke density after 4 minutes (DS-4) of greater than 900 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2;
• and
• wherein an article molded from the composition comprising the poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) and the polydimethyl siloxane has a smoke density after 4 minutes (DS-4) of less than or equal to 480 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2.

A composition comprising, based on the weight of the composition,

• 50 to 93 wt. % of a poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) comprising 75 to 85 wt. % of the ester units, wherein the ester units have a molar ratio of isophthalate to terephthalate of 98:2 to 88:12;
• 4 to 30 wt. % of a poly(carbonate-siloxane) comprising
• bisphenol A carbonate units, and
• siloxane units of the formula
• or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200;
• wherein the polycarbonate-siloxane) comprises 0.5 to 55 wt. % of siloxane units based on the total weight of the poly(carbonate-siloxane);
• and
• 3 to 20 wt. % of bisphenol A bis(diphenyl phosphate);
• wherein an article molded from each of the poly(bisphenol A carbonate)-co-(bisphenol phthalate ester) or the poly(carbonate-siloxane) has a smoke density after 4 minutes (DS-4) of greater than 900 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2;
• and
• wherein an article molded from the composition has a smoke density after 4 minutes (DS-4) of less than or equal to 300 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2, and a maximum average heat release (MAHRE) of less than or equal to 90 kW/m2 determined according to ISO 5660-1 on a 3 mm thick plaque at 50 kW/m2.

A composition comprising, based on the weight of the composition,

• 45 to 92 wt. % of a polycarbonate copolymer comprising
• bisphenol A carbonate units, and
• units of the formula
• wherein R5 is hydrogen, phenyl optionally substituted with 1 to 5 C1-6 alkyl groups, or C1-4 alkyl;
• 5 to 35 wt. % of a poly(carbonate-siloxane) comprising
• bisphenol A carbonate units, and
• siloxane units of the formula
• or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200;
• wherein the poly(carbonate-siloxane) comprises 0.5 to 55 wt. % of siloxane units based on the total weight of the poly(carbonate-siloxane);
• and
• 3 to 20 wt. % of bisphenol A bis(diphenyl phosphate);
• wherein an article molded from each of the polycarbonate copolymer and the poly(carbonate-siloxane) has a smoke density after 4 minutes (DS-4) of greater than 600 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2;
• and
• wherein an article molded from the composition comprising the polycarbonate copolymer, the poly(carbonate-siloxane), and the bisphenol A bis(diphenyl phosphate) has a smoke density after 4 minutes (DS-4) of less than or equal to 300 determined according to ISO 5659-2 on a 3 mm thick plaque at 50 kW/m2, and a maximum average heat release (MAHRE) of less than or equal to 90 kW/m2 determined according to ISO 5669-1 on a 3 mm thick plaque at 50 kW/m2.