PRIMARY COATED OPTICAL FIBER, OPTICAL FIBER CABLE, AND COATING RESIN SELECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a primary coated optical fiber with a sufficient fatigue characteristic allowing the primary coated optical fiber to have an n-value of dynamic fatigue of≥20. SOLUTION: Moisture permeability of the hard coating resin of the secondary coated layer 4 is made to 2.5g/cm3or less, which is obtained based on an increase in weight acting to a container 7 in the case of having left the container 7 for 24 hours under a wet heat environment of 60°C room temperature and 95% humidity under the condition that the opening part of the container 7 holding silica gel 6 therein is air-tightly plugged with a sample sheet 5 made of the same material as the hard coating resin. COPYRIGHT: (C)2005,JPO&NCIPI