| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that an ink holding tube for a writing implement is cracked in the case when a writing chip, a joint member or the like is pressed into the end part of the ink holding tube which is molded in a multilayer structure. <P>SOLUTION: The ink holding tube 4 comprises a double-layer structure of an inner layer 11 and an outer layer 12. A soft resin material having a lower hardness than a resin constituting the outer layer is used for a resin constituting the inner layer and these layers are molded by utilizing a two-color molding method. The tip part of the ink holding tube 4 into which the writing chip or the joint member connecting the writing chip is pressed is molded in a single-layer structure from the resin material constituting the inner layer having the low hardness, and a press-in part 11a of the writing chip or the joint member is formed on the inner peripheral surface of the end portion of the tip part of the tube. Besides, the rear end part of the ink holding tube 4 into which a tail plug is pressed is molded in the single-layer structure from the resin material constituting the inner layer having the low hardness and a press-in part 11b of the tail plug is formed on the inner peripheral surface of the end portion of the rear end part of the tube. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
