| 摘要 |
FEP compositions are provided that provide foam insulation in coaxial cable that surpasses the return loss obtained when PFA is used to make the foamed insulation, one composition comprising a blend of tetrafluoroethylene/hexafluoropropylene copolymers, one of said copolymers exhibiting a strip force of at least about 3 lbf (13.3 N) and another of said copolymers exhibiting a strip force no greater than about 2.5 lbf (11.1 N), said blend exhibiting a strip force of at least about 3 lbf (13.3 N), each said strip force being the force necessary to break adhesion between conductor and said one of said copolymers, said another of said copolymers, and said blend, respectively, and another composition comprising tetrafluoroethylene/hexafluoropropylene copolymer having an MFR of no greater than about 16 g/10 min and containing -CF<SUB>3 </SUB>end groups and an effective amount of wire affinity end groups to exhibit a strip force of at least about 3 lbf (13.3 N), said strip force being the force necessary to break adhesion between conductor and said copolymer, the coaxial cable exhibiting an average return loss of no greater than about -26 dB at 800 MHz to 3 GHz and having a void content of about 20 to 65% and (b) forming an outer conductor over said foamed insulation.
|
