US 12,265,270 B2
Flame retardant compositions for buffer tubes and method of making same
Xiaole Cheng, Painted Post, NY (US); Dayue Jiang, Painted Post, NY (US); and Kevin Andrew Vasilakos, Painted Post, NY (US)
Assigned to CORNING RESEARCH & DEVELOPMENT CORPORATION, Corning, NY (US)
Filed by CORNING RESEARCH & DEVELOPMENT CORPORATION, Corning, NY (US)
Filed on Feb. 21, 2022, as Appl. No. 17/676,317.
Claims priority of provisional application 63/157,985, filed on Mar. 8, 2021.
Claims priority of provisional application 63/225,060, filed on Jul. 23, 2021.
Prior Publication US 2022/0283393 A1, Sep. 8, 2022
Int. Cl. G02B 6/44 (2006.01); C08L 67/02 (2006.01); C09K 21/12 (2006.01)
CPC G02B 6/4436 (2013.01) [C08L 67/02 (2013.01); C09K 21/12 (2013.01); C08L 2201/02 (2013.01)] 12 Claims
OG exemplary drawing
 
1. An optical fiber cable, comprising:
at least one buffer tube, each of the at least one buffer tube comprising a first exterior surface and a first interior surface that defines a central bore along a longitudinal axis of the optical fiber cable;
at least one optical fiber disposed within the central bore of each of the at least one buffer tube;
a cable jacket disposed around the at least one buffer tube, the cable jacket comprising a second interior surface and a second exterior surface defining an outermost surface of the optical fiber cable;
wherein each of the at least one buffer tube comprises a flame retardant composition, comprising:
at least one polybutylene terephthalate (PBT) resin;
a dialkylphosphinic salt;
an ethylene vinyl alcohol (EVOH);
an organoclay synergist; and
at least one of:
a PBT chain extender; or
a reactive compound comprising at least two functional groups selected from the group consisting of an epoxide, a maleic anhydride, an isocyanate, an acrylate, and an acetate;
wherein the dialkylphosphinic salt and the organoclay synergist comprise at least 16 wt % of the flame retardant composition.