Flame retardant thermoplastic polymer composition, method of manufacture, and articles formed therefrom

1. A sheet having a thickness of 2-3 mm, comprising a thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises:

a branched cyanophenyl endcapped polycarbonate having:

repeating structural carbonate units of the formula:

wherein at least 60 percent of the total number of R 1 groups contain aromatic organic groups and the balance thereof are aliphatic, alicyclic, or aromatic groups;

branching groups derived from reaction with a branching agent; and

cyanophenyl endcapping groups derived from reaction with a cyanophenol;

0.01 wt. % to 0.6 wt. % of an aromatic sulphone sulphonate;

a brominated polycarbonate, in an amount such that the composition comprises 0.26 wt. % to 5.2 wt. % bromine,

wherein, said sheet has smoke density and flammability properties such that a 3 mm thick extruded sheet has a smoke density of less than 200 at an exposure period of 240 seconds in accordance with the smoke density test as set forth in ASTM E662-06, and has no burning drips on the sheet for a duration of 10 minutes in accordance with the flammability test as set forth in NF-P-92-505.

2. The sheet of claim 1 , having a thickness of 3 mm.

3. An aircraft interior component comprising the sheet of claim 2 .

4. The component of claim 3 , in the form of a partition wall, cabinet wall, sidewall panel, ceiling panel, floor panel, equipment panel, light panel, window molding, window slide, storage compartment, galley surface, equipment housing, seat housing, speaker housing, duct housing, storage housing, shelf, tray, or a combination comprising at least one of the foregoing.

5. A method for the manufacture of a sheet having a thickness of 2-3 mm, comprising

extruding a thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises:

a branched cyanophenyl endcapped polycarbonate having:

repeating structural carbonate units of the formula:

wherein at least 60 percent of the total number of R 1 groups contain aromatic organic groups and the balance thereof are aliphatic, alicyclic, or aromatic groups;

branching groups derived from reaction with a branching agent; and

cyanophenyl endcapping groups derived from reaction with a cyanophenol;

0.01 wt. % to 0.6 wt. % of an aromatic sulphone sulphonate;

a brominated polycarbonate, in an amount such that the composition comprises 0.26 wt. % to 5.2 wt. % bromine;

wherein, said sheet has smoke density and flammability properties such that a 3 mm thick extruded sheet has a smoke density of less than 200 at an exposure period of 240 seconds in accordance with the smoke density test as set forth in ASTM E662-06, and has no burning drips on the sheet for a duration of 10 minutes in accordance with the flammability test as set forth in NF-P-92-505.

6. The method of claim 5 , wherein the sheet has a thickness of 3 mm.

7. The sheet of claim 1 , wherein the sheet has a percent transmission of greater than 85%, a % haze of less than 2.0 and a yellowness index of 2.5 YI units or less, when tested according to ANSI/ASTM D1003-00, Procedure A, illuminant C.

8. The sheet of claim 1 , wherein the aromatic sulphone sulphonate is potassium diphenysulphone sulphonate, present in an amount from 0.25 to 0.35 wt. % based on the total weight of the thermoplastic polymer composition.

9. The sheet of claim 1 , wherein the branching agent is

a triacid trichloride of formula:

wherein each Z is independently a hydrogen, halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and z is 0 to 3;

a tri-substituted phenol of formula:

wherein T is a C 1-20 alkyl group, C 1-20 alkeneoxy group, C 7-12 arylalkyl group, or alkylaryl group, each S is independently a hydrogen, halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and each s is independently 0 to 4;

a benzimidazole of formula:

or a combination comprising at least one of the foregoing branching agents, and further wherein

the cyanophenol is of the formula:

wherein Y is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, y is 0 to 4, and c is 1 to 5, provided that y+c is 1 to 5.

10. The sheet of claim 1 , wherein the branching agent is trimellitic acid, trimellitic anhydride, trimellitic trichloride, tris-(p-hydroxyphenyl)ethane, isatin-bis-phenol, 1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene), 4(4(1,1-bis(p-hydroxyphenyl)-ethyl) alpha,alpha-dimethyl benzyl)phenol), 4-chloroformyl phthalic anhydride, trimesic acid, benzophenone tetracarboxylic acid, or a combination comprising one or more of the foregoing branching agents.

11. The sheet of claim 1 , wherein

the branching agent is trimellitic trichloride, tris-(p-hydroxyphenyl)ethane, or a combination comprising both of the foregoing branching agents, and

the cyanophenol is p-cyanophenol, 3,4-dicyanophenol, or a combination comprising both of the foregoing phenols.

12. The sheet of claim 1 , wherein the branching groups are present in an amount of 0.1 to 10 branching units per 100 R 1 units, and the cyanophenyl endcapping groups are present in an amount of 1 to 20 cyanophenyl carbonate units per 100 R 1 units.

13. The sheet of claim 1 , wherein the brominated polycarbonate is present in an amount such that the composition comprises 0.26 wt. % to 3.1 wt. % bromine.

14. The sheet of claim 1 , wherein the branched cyanophenyl endcapped polycarbonate comprises about 2.5 to 3.5 tris-(p-hydroxyphenyl)ethane units and about 7 to 11 cyanophenyl carbonate units per 100 R 1 units, and has a weight average molecular weight of about 25,000 to 35,000 grams per mole as measured by gel permeation chromatography.

15. The sheet of claim 1 , wherein the aromatic sulphone sulphonate comprises an alkali metal aromatic sulphone sulphonate.

16. The sheet of claim 1 , wherein the alkali metal aromatic sulphone sulphonate comprises potassium diphenylsulphone sulphonate.

17. The sheet of claim 1 , wherein the brominated polycarbonate comprises 24 wt. % to 28 wt. % bromine, based on the total weight of the brominated polycarbonate.