Fire retardant nylon fibers and methods for making them

Abstract

Provided are nylon fibers having fire retardant agents dispersed therein and methods for manufacturing such fibers. The fire retardant agents may comprise Tis(tribromophenyl) triazine and/or antimony trioxide. Fabrics made from such fibers are also provided.

The invention claimed is: 
     
       1. A method for making fire retardant nylon fibers comprising:
 (a) heating a mixture of solid pellets of Nylon-6 polymer, wherein said pellets having tris(tribromophenyl) triazine dispersed therein, and Nylon-6,6 polymer to form a molten mixture comprising Nylon-6 and Nylon-6,6 polymers and tris (tribromophenyl) triazine; and 
 (b) forming nylon fibers from said molten mixture. 
 
     
     
       2. The method according to  claim 1 , wherein said solid pellets of Nylon 6 polymer having tris (tribromophenyl) triazine dispersed therein are formed by dispersing tris(tribromophenyl) triazine into molten Nylon-6 polymer and subsequently cooling said molten Nylon-6 polymer to form said pellets. 
     
     
       3. The method according to  claim 2 , wherein, said step of dispersing tris(tribromophenyl) triazine into molten Nylon-6 polymer is carried out in an extruder. 
     
     
       4. The method according to  claim 1 , wherein said mixture of pellets of Nylon-6 polymer and Nylon-6,6 polymer is a physical admixture of said solid pellets of Nylon-6 polymer and solid pellets of Nylon 6,6 polymer. 
     
     
       5. The method according to  claim 1 , wherein said mixture of pellets of Nylon-6 polymer and Nylon-6,6 polymer is formed by adding said solid pellets of Nylon-6 polymer to molten Nylon 6,6 polymer. 
     
     
       6. The method according to  claim 1 , wherein said solid pellets of Nylon-6 polymer further comprise a synergist dispersed within said pellet. 
     
     
       7. The method according to  claim 1 , wherein said solid pellets of Nylon-6 polymer having tris(tribromophenyl) triazine and a synergist dispersed therein are formed by dispersing tris(tribromophenyl) triazine and a synergist into molten Nylon-6 polymer and subsequently cooling said molten Nylon-6 polymer to form said pellets. 
     
     
       8. The method according to  claim 1 , wherein a synergist is added to the molten mixture comprising Nylon-6 and Nylon-6,6 polymers and tris(tribromophenyl) triazine. 
     
     
       9. The method according to  claim 6 , wherein said synergist is antimony trioxide and said tris(tribromophenyl) triazine are present in an amount sufficient to provide a weight ratio of elemental Sb and Br (Sb:Br) of from 1:3 to about 1:10, and wherein the aggregate weight of elemental Sb and Br in said fibers is from about 0.1% to about 20% by weight of the total weight of said fibers. 
     
     
       10. The method according to  claim 6 , wherein said synergist is antimony trioxide and said tris(tribromophenyl) triazine and said antimony trioxide are present, collectively, in an amount from about 0.1% to about 20% by weight based on the weight of said fibers. 
     
     
       11. The method according to  claim 6 , wherein said synergist is antimony trioxide and said tris(tribromophenyl) triazine and said antimony trioxide are present in said fibers in a weight ratio of from about 2:1 to about 5:1. 
     
     
       12. The method according to  claim 6 , wherein said tris(tribromophenyl) triazine and said antimony trioxide are present in said fibers in a weight ratio of from about 3:1 to about 4:1. 
     
     
       13. The method according to  claim 1 , wherein said solid pellets of Nylon-6 polymer further comprise a phosphorous compound dispersed within said pellet. 
     
     
       14. The method according to  claim 1 , wherein said solid pellets of Nylon 6 polymer having tris(tribromophenyl) triazine comprises a phosphorous compound dispersed therein, and are formed by dispersing tris(tribromophenyl) triazine and a phosphorous compound into molten Nylon-6 polymer and subsequently cooling said molten Nylon-6 polymer to form said pellets. 
     
     
       15. The method according to  claim 1 , wherein a phosphorous compound is added to the molten mixture comprising Nylon-6 and Nylon-6,6 polymers and tris(tribromophenyl) triazine. 
     
     
       16. A method for making fire retardant nylon fibers comprising:
 (a) extruding Nylon-6 polymer with tris(tribromophenyl) triazine to form pellets of Nylon-6 polymer having tris(tribromophenyl) triazine dispersed therein; 
 (b) forming a physical blend of said pellets of Nylon-6 polymer with pellets of Nylon-6,6 polymer; 
 (c) heating said physical blend of pellets of Nylon-6 polymer with pellets of Nylon-6,6 polymer to form a molten mixture comprising Nylon-6 and Nylon-6,6 polymers and tris(tribromophenyl) triazine homogenously dispersed therein; and 
 (d) forming nylon fibers from said molten mixture by melt spinning. 
 
     
     
       17. A method for making fire retardant nylon fibers comprising:
 (a) extruding Nylon-6 polymer with tris(tribromophenyl) triazine to form pellets of Nylon-6 polymer having tris(tribromophenyl) triazine dispersed therein; 
 (b) adding pellets of Nylon-6 polymer to molten Nylon-6,6 polymer to form a molten mixture comprising Nylon-6 and Nylon-6,6 polymers and tris(tribromophenyl) triazine homogenously dispersed therein; and 
 (c) forming nylon fibers from said molten mixture by melt spinning. 
 
     
     
       18. A fire retardant nylon fiber having dispersed within the internal regions thereof an amount of a fire retardant composition comprising:
 (i) from about 0.1% to about 10% tris tribromophenyl)triazine; 
 (ii) from about 0.1% to about 10% tris(tribromoneopentyl)phosphate; and 
 (iii) from about 0.1% to about 10% antimony trioxide, 
 
       wherein a major portion thereof is Nylon-6 polymer and/or Nylon-6,6 polymer. 
     
     
       19. The fire retardant nylon fiber according to  claim 18 , comprising at least about 50% Nylon-6 polymer and/or Nylon-6,6 polymer. 
     
     
       20. The fire retardant nylon fiber according to  claim 18 , wherein said fiber is spun from a melt comprising molten nylon polymer homogeneous mixed with said fire retardant composition. 
     
     
       21. The fire retardant nylon fiber according to  claim 18 , wherein said fiber comprises a tensile strength within 20% of the tensile strength of an otherwise identical nylon fiber that does not comprise said fire retardant composition. 
     
     
       22. A woven fabric comprising a plurality of fire retardant nylon fibers according to  claim 18 . 
     
     
       23. The fire retardant nylon fiber according to  claim 18 , wherein the nylon fiber comprising at least about 70% Nylon-6 polymer and/or Nylon-6,6 polymer. 
     
     
       24. The fire retardant nylon fiber according to  claim 18 , wherein the nylon fiber comprising at least about 90% Nylon-6 polymer and/or Nylon-6,6 polymer. 
     
     
       25. The fire retardant nylon fiber according to  claim 18 , wherein the nylon fiber consists essentially of Nylon-6 polymer and/or Nylon-6,6 polymer.