Flame retarded fibers and filaments and process of production therefor

1. A fiber or filament formed from ingredients comprising

(a) at least one polybrominated anionic styrenic polymer, wherein the polybrominated anionic styrenic polymer has a bromine content of at least about 50 wt %, and a GPC weight average molecular weight of at least about 600,000; and

(b) at least one fiber-forming thermoplastic polymer, wherein when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is present in a flame resistant or a flame retardant amount, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 2 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, at least one synergist is present and the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament.

2. A fiber or filament as in claim 1 wherein when said fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament, when said fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 5 wt % of the fiber or filament, when said fiber-forming thermoplastic polymer is a polyolefin, the polybrominated anionic styrenic polymer is no more than about 10 wt % of the fiber or filament.

3. A fiber or filament as in claim 1 wherein when said fiber-forming thermoplastic polymer is a polyester, said polyester is polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethanol terephthalate, polycyclohexanedimethanol terephthalate/isophthalate, or polytrimethylene terephthalate; wherein when said fiber-forming thermoplastic polymer is a polyamide, said polyamide is nylon-6 (polycaprolactam), nylon-6,6, nylon-6,12, nylon-12 (polylauryllactam), or a high temperature nylon; and wherein when said fiber-forming thermoplastic polymer is a polyolefin, said polyolefin is polypropylene.

4. A fiber or filament as in claim 1 wherein said fiber-forming thermoplastic polymer is a polyolefin, wherein said polyolefin is polypropylene, and wherein the synergist is at least about 0.5 wt % of the fiber or filament.

5. A fiber or filament as in claim 1 wherein said bromine content of said polybrominated anionic styrenic polymer is at least about 60 wt %, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

6. A fiber or filament as in claim 1 wherein said fiber-forming thermoplastic polymer is a polyester, wherein said polyester is polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethanol terephthalate, polycyclohexanedimethanol terephthalate/isophthalate, or polytrimethylene terephthalate, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

7. A fiber or filament as in claim 1 wherein said fiber-forming thermoplastic polymer is a polyamide, wherein said polyamide is nylon-6 (polycaprolactam), nylon-6,6, nylon-6,12, nylon-12 (polylauryllactam), or a high temperature nylon, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

8. A fiber or filament as in claim 1 wherein said polybrominated anionic styrenic polymer is produced by bromination of an anionic styrenic polymer, which anionic styrenic polymer is produced by a batch process, which process comprises charging a liquid saturated hydrocarbon diluent and an ether promoter into a reactor; and then

A) (i) charging a saturated hydrocarbon solution of organolithium initiator into the reactor, in an amount to provide in the range of about 1 to about 10 mol % of organolithium initiator based on the total amount of a styrenic monomer to be added followed by (ii) the controlled addition of the styrenic monomer such that the temperature of the resultant reaction mixture is maintained at or below about 55° C.,

or

B) concurrently feeding separate feeds of (i) a styrenic monomer and (ii) a saturated hydrocarbon solution of organolithium initiator into the reactor, the feeds being maintained at rates to provide for the addition of an amount of organolithium initiator in the range of about 1 to about 10 mol % based on the total amount of styrenic monomer to be added, the temperature of the resultant reaction mixture being maintained at or below about 55° C. and feed (ii) being of a shorter duration than feed (i).

9. A fiber or filament as in claim 8 wherein when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 5 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, the polybrominated anionic styrenic polymer is no more than about 10 wt % of the fiber or filament.

10. A fiber or filament as in claim 8 wherein said bromine content of said polybrominated anionic styrenic polymer is at least about 60 wt %, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

11. A fiber or filament as in claim 9 wherein when said fiber-forming thermoplastic polymer is a polyester, said polyester is polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethanol terephthalate, polycyclohexane-dimethanol terephthalate/isophthalate, or polytrimethylene terephthalate; wherein when said fiber-forming thermoplastic polymer is a polyamide, said polyamide is nylon-6 (polycaprolactam), nylon-6,6, nylon-6,12, nylon-12 (polylauryllactam), or a high temperature nylon; and wherein when said fiber-forming thermoplastic polymer is a polyolefin, said polyolefin is polypropylene.

12. A process for producing a fiber or filament, which process comprises melt spinning

(a) at least one fiber-forming thermoplastic polymer; and

(b) at least one polybrominated anionic styrenic polymer, wherein the polybrominated anionic styrenic polymer has a bromine content of at least about 50 wt %, and a GPC weight average molecular weight of at least about 600,000;

in proportions such that when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is present in a flame resistant or flame retardant amount, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 2 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, at least one synergist is present and the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament.

13. A process as in claim 12 wherein, when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 5 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, the polybrominated anionic styrenic polymer is no more than about 10 wt % of the fiber or filament.

14. A process as in claim 12 wherein when said fiber-forming thermoplastic polymer is a polyester, said polyester is polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethanol terephthalate, polycyclohexane-dimethanol terephthalate/isophthalate, or polytrimethylene terephthalate; wherein when said fiber-forming thermoplastic polymer is a polyamide, said polyamide is nylon-6 (polycaprolactam), nylon-6,6, nylon-6,12, nylon-12 (polylauryllactam), or a high temperature nylon; and wherein when said fiber-forming thermoplastic polymer is a polyolefin, said polyolefin is polypropylene.

15. A process as in claim 12 wherein said bromine content of said polybrominated anionic styrenic polymer is at least about 60 wt %, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

16. A process as in claim 12 wherein said fiber-forming thermoplastic polymer is a polyester, wherein said polyester is polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethanol terephthalate, polycyclohexane-dimethanol terephthalate/isophthalate, or polytrimethylene terephthalate, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

17. A process as in claim 12 wherein said fiber-forming thermoplastic polymer is a polyamide, wherein said polyamide is nylon-6 (polycaprolactam), nylon-6,6, nylon-6,12, nylon-12 (polylauryllactam), or a high temperature nylon, and wherein said polybrominated anionic styrenic polymer is a brominated anionic polystyrene.

18. A masterbatch which comprises

(a) at least one polybrominated anionic styrenic polymer, wherein the polybrominated anionic styrenic polymer has a bromine content of at least about 50 wt %, and a GPC weight average molecular weight of at least about 600,000; and

(b) at least one fiber-forming thermoplastic polymer, wherein when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is present in a flame resistant or a flame retardant amount, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 2 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, at least one synergist is present and the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament.

19. A masterbatch as in claim 18 wherein said polybrominated anionic styrenic polymer is at least about 25 wt % of said masterbatch.

20. A masterbatch as in claim 18 wherein the weight ratio of (b):(a) is in the range of about 30:60 to about 90:10.

21. A process for producing a fiber or filament, which process comprises melt spinning

(a) at least one fiber-forming thermoplastic polymer, and

(b) at least one masterbatch of claim 18 ,

in proportions such that when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is present in a flame resistant or flame retardant amount, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 2 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, at least one synergist is present and the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament.

22. A process as in claim 21 wherein said thermoplastic fiber-forming polymer and said polybrominated anionic styrenic polymer are simultaneously mixed and melted.

23. A process as in claim 21 wherein, when the fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is no more than about 15 wt % of the fiber or filament, when the fiber-forming thermoplastic polymer is a polyamide, the polybrominated anionic styrenic polymer is at least about 5 wt % of the fiber or filament, and when the fiber-forming thermoplastic polymer is a polyolefin, the polybrominated anionic styrenic polymer is no more than about 10 wt % of the fiber or filament.

24. A fiber or filament as in claim 1 wherein when said fiber-forming thermoplastic polymer is a polyester, the polybrominated anionic styrenic polymer is no more than about 5 wt % of the fiber or filament.

25. A fiber or filament as in claim 1 wherein when the fiber-forming thermoplastic polymer is a polyolefin, the polybrominated anionic styrenic polymer is no more than about 5 wt % of the fiber or filament.