| 摘要 |
PURPOSE:To suppress, in addition to an increase in a lead grasping force at an initial time, a decrease in a lead grasping force due to repetitive use to a small value and design to manufacture at a low cost and hold the same chuck as metal chuck by forming it of a liquid crystalline aromatic polyester resin. CONSTITUTION:A chuck of a mechanical pencil is formed of liquid crystalline aromatic polyester resin. As a result, various characteristics of the resin can be sufficiently reflected to advantages of a chuck. That is, it has, for example, high surface hardness, excellent wear resistance, high mechanical strength, a more increase in a mechanical strength particularly as made in a thinner molded form, a high elastic modulus, excellent heat resistance and chemical resistance, small molding shrinkage rate, excellent dimensional stability, and excellent vibration absorptive characteristics. Further, high fluidity, excellent moldability such as burr is scarcely produced, and hence it can be molded with a conventional thermoplastic resin injection molding facility. |
