Thermoplastic compositions having low smoke, methods of their manufacture, and uses thereof

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

70 to 95 wt % of a polycarbonate copolymer comprising first repeating units and second repeating units, wherein the first repeating units are not the same as the second repeating units, and wherein

the first repeating units are bisphenol carbonate units of the formula

wherein

R a and R b are each independently C 1-12 alkyl, C 1-12 alkenyl, C 3-8 cycloalkyl, or C 1-12 alkoxy,

p and q are each independently 0 to 4, and

X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, a C 1-11 alkylidene of formula —C(R c )(R d )— wherein R c and R d are each independently hydrogen or C 1-10 alkyl, or a group of the formula —C(═R e )— wherein R e is a divalent C 1-10 hydrocarbon group; and

the second repeating units comprise a combination of

monoaryl arylate ester units of the formula

siloxane units of the formula

optionally, arylate-bisphenol ester units of the formula

and

optionally monoaryl carbonate units of the formula

wherein in the foregoing formulas

R h is each independently a halogen atom or a C 1-10 hydrocarbon group,

n is 0 to 4,

R a and R h are each independently a C 1-12 alkyl,

p and q are each independently integers of 0 to 4, and

X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 -, —C(O)—, or a C 1-13 alkylidene of formula —C(R c )(R d )— wherein R c and R d are each independently hydrogen or C 1-12 alkyl, or a group of the formula —C(═R e )— wherein R e is a divalent C 1-12 hydrocarbon group,

R is each independently a C 1-13 monovalent hydrocarbon group, and

E has an average value of 2 to 500; and

20 wt % to 30 wt % of a polyetherimide based on the weight of the composition, wherein an article molded from the composition has smoke density after 4 minutes (Ds-4) of less than or equal to 300 as measured by ISO 5659-2 on a 3 mm thick plaque.

2. The thermoplastic composition of claim 1 ,

wherein an article molded from the composition has

a multiaxial impact energy determined according to ISO 6603 on a 3.2 mm thick disc within 20% of the same composition without the polyetherimide.

3. The composition of claim 1 , wherein in the polycarbonate copolymer, the first repeating units are bisphenol-A carbonate units.

4. The composition of claim 1 , wherein the siloxane units are of the formula

or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200.

5. The composition of claim 1 , wherein the siloxane units are of the formula

or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 200.

6. The composition of claim 1 , wherein the polycarbonate copolymer comprises

1 to 20 mol % of bisphenol-A carbonate units,

60 to 90 mol % of isophthalic acid-terephthalic acid-resorcinol units, and

in an amount effective to provide 0.1 to 10 wt % of siloxane units based on the weight of polycarbonate, units of the formula

or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 80.

7. The composition of claim 3 , further comprising a second polycarbonate copolymer comprising first repeating units and second repeating units different from the first repeating units, wherein

the first repeating units are bisphenol carbonate units of the formula

wherein R a and R b are each independently C 1-12 alkyl, C 1-12 alkenyl, C 3-8 cycloalkyl, or C 1-12 alkoxy, p and q are each independently 0 to 4, and X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, a C 1-11 alkylidene of formula —C(R c )(R d )— wherein R c and R d are each independently hydrogen or C 1-10 alkyl, or a group of the formula —C(═R e )— wherein R e is a divalent C 1-10 hydrocarbon group; and

the second repeating units comprise monoaryl arylate ester units of the formula

wherein R h is each independently a C 1-4 alkyl and n is 0 to 1.

8. The composition of claim 7 , comprising, based on the weight of the polymers in the composition,

20 to 80 wt % of the polycarbonate copolymer, which comprises, based on the copolymer,

1 to 20 mol % of bisphenol-A carbonate units,

60 to 90 mol % of isophthalic acid-terephthalic acid-resorcinol units, and

in an amount effective to provide 0.1 to 10 wt % of siloxane units based on the weight of polycarbonate, units of the formula

or a combination comprising at least one of the foregoing, wherein E has an average value of 2 to 30; and

20 to 80 wt % of a second polycarbonate copolymer, which comprises, based on the second polycarbonate copolymer,

2 to 20 mol % of bisphenol-A carbonate units,

60 to 98 mol % of isophthalic acid-terephthalic acid-resorcinol ester units, and

optionally, 1 to 20 mol % resorcinol carbonate units, isophthalic acid-terephthalic acid-bisphenol-A ester units, or a combination thereof; and

wherein an article molded from the composition has a smoke density (Ds-4) value of less than 150 as determined in accordance with ISO 5659-2 on 3 mm thick plaque.

9. The composition of claim 1 , wherein the polyetherimide comprises units of the formula

wherein

R is a C 2-20 hydrocarbon group, and

Z is an aromatic C 6-24 monocyclic or polycyclic group optionally substituted with 1 to 6 C 1-8 alkyl groups, 1 to 8 halogen atoms, or a combination thereof, wherein the divalent bonds of the —O—Z-O— group are in the 3,3′, 3,4′, 4,3′, or the 4,4′ positions.

10. The composition of claim 9 , wherein

R is a divalent radical of the formula

wherein Q is —O—, —S—, —C(O)—, —SO 2 -, —SO—, or —C y H 2y — or a halogenated derivative thereof

wherein y is an integer from 1 to 5, and

Z is a divalent group of the formula

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

11. The composition of claim 10 , wherein R is m-phenylene and Q 1 is isopropylidene.

12. The composition of claim 1 , further comprising an organophosphorus compound in an amount effective to provide 0.1-1 wt % phosphorus, based on the total weight of the composition.

13. The composition of claim 12 , wherein the organophosphorus compound is of the formula

wherein

R 16 , R 17 , R 18 and R 19 are each independently C 1-8 alkyl, C 5-6 cycloalkyl, C 6-20 aryl, or C 7-12 arylalkylene, each optionally substituted by C 1-12 alkyl, and

X is a mono- or poly-nuclear aromatic C 6-30 moiety or a linear or branched C 2-30 aliphatic radical, which can be OH-substituted and can contain up to 8 ether bonds, provided that at least one of R 16 , R 17 , R 18 , R 19 , and X is aromatic,

n is each independently 0 or 1, and

q is from 0.5 to 30.

14. The composition of claim 13 , wherein

each of R 16 , R 17 , R 18 , and R 19 is phenyl,

X is of the formula

each n is 1, and

p is 1-5.

15. The composition of claim 12 , wherein the organophosphorus compound is bisphenol-A bis(diphenyl phosphate), triphenyl phosphate, resorcinol bis(diphenyl phosphate), tricresyl phosphate, or a combination comprising at least one of the foregoing.

16. The composition of claim 1 , wherein an increase in fractional concentration of polyetherimide in the composition reduces the smoke density (Ds-4) as measured in accordance with ISO 5659-2 on a 3 mm thick plaque in a non-linear manner, wherein an interaction parameter ‘k’ measured using the equation

Ds

Blend

=

w

POL

⁢

Ds

POL

pure

+

kw

PEI

⁢

Ds

PEI

pure

w

POL

+

kw

PEI

where DS Blend is the smoke density of the composition;

w POL is the fractional wt % of the non-polyetherimide polymer(s)/copolymer(s) or their blends based on the weight of the composition;

w PEI is the fractional wt % of the polyetherimide based on the weight of the composition;

Ds POL pure is the smoke density of the composition with only the non-polyetherimide polymer(s)/copolymer(s);

Ds PEI pure is the smoke density of the composition with only polyetherimide; and

k is greater than 4.0.

17. An article selected from a molded article, a thermoformed article, an extruded film, an extruded sheet, a foamed article, one or more layers of a multi-layer article, a substrate for a coated article, and a substrate for a metallized article comprising the composition of claim 1 .

18. The article of claim 17 , wherein the article is a transportation component.

19. The article of claim 18 , selected from a train or aircraft interior component, wherein the component is a partition, a room divider, a seat back, a food tray, a trim panel, an interior display panel, an interior wall, a side wall, an end wall, a ceiling panel, a door lining, a flap, a box, a hood, a louver, an insulation material, a handle, a body shell for a window, a window frame, an enclosure for an electronic device, a door, a luggage rack, a luggage container, an interior side of a gangway membrane, an interior lining of a gangway, or a component of a luggage compartment, a display unit, a television, a refrigerator door, a tray table, a food cart, a magazine rack, an air flow regulator, a door, a table, or a seat.

20. A method of manufacture of an article, comprising molding, extruding, or casting the thermoplastic composition of claim 1 to form the article.

21. The thermoplastic composition of claim 1 , further comprising a bisphenol A homopolycarbonate.

22. The thermoplastic composition of claim 8 , further comprising a bisphenol A homopolycarbonate.