摘要 |
An optical cable [100] having one or more optical fibers [11] that are surrounded by an improved filling material [10] is disclosed. The filling material includes one or more synthetic oil(s) that are present in an amount, which is 80 to 95 percent by weight of the filling material and which have an average molecular weight that is greater than about 350. The filling material further includes an organic gelling agent, which is a diblock copolymer that is present in an amount of about 5 to 20 percent by weight. However, no more than 1.5 percent by weight of inorganic gelling agents may be used without impairing the long-term stability of the viscosity and the yield stress of the filling material. Preferably, a blend of two different polyalphaolefin oils are used while inorganic gel ling agents are completely avoided. Critical-yield stress is kept appropriately low (i.e., less than 0.01 psi) by the use of diblock copolymers. Together, these factors cooperate to provide a filling material whose yield stress and viscosity have excellent stability over time.
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