WEIGHT COMPOSITION FOR SELF-WINDING WRISTWATCH

摘要

PURPOSE:To decrease the weight ratio of a thermoplastic org. resin and to improve the mechanical strength and moldability thereof by adding said resin and lubricant at a weight ratio within a specified range to 3 kinds of tungsten powder having different grain sizes subjected to a surface treatment. CONSTITUTION:1-3 kinds of the tungsten powders having 4-30mu grain size and different grain sizes are surface-treated by adding 0.3pt.wt. 1 or 2 kinds of a silane surface treating agent and titanate surface treating agent thereto. The thermoplastic org. resin added and mixed preliminarily with 1 or 2 kinds of the lubricant of metallic salt of higher carboxylic acid and silicone lubricant within 0.8pt.wt. is added and kneaded to and with such powders at 0.1-5pts.wt. The mixture composed thereof is pelletized by a kneading extruder.