| 摘要 |
PURPOSE:To obtain the excellent water running preventive material for optical fiber cables by specifying weight % of the water absorptive polymer particles of a coating layer and a rubber binder having specific characteristics. CONSTITUTION:The coating layer is formed of 50 to 90wt.% water absorptive polymer particles and 10 to 50wt.% rubber binder having >=50wt.% dislodgment rate after 60 minutes when immersed into water. Rubber binders which are soluble in org. solvents, such as, for example, toluene, methyl ethyl ketone and ethyl acetate, easily eliminate the highly water absorptive polymer particles when brought into contact with water, apply flexibility to a water shielding material and do not generate gaseous hydrogen by rotting, are preferable as the rubber binder. Then, even if water infilters the cable, the polymer particles of this point swell rapidly and dislodge from the binder and can spread into slots. The excellent preventive property for invasion of water is obtd. in this way. |
