| 摘要 |
<p>PURPOSE:To obtain a roll for VTR which has a drive characteritics equal to or better than the conventional metal roll and is capable of being manufacture by injection molding by utilizing special thermoplastic composite material. CONSTITUTION:The present roll is made of injection-moldable composite material in which 100pts.wt. of a thermoplastic resin such as nylon, polyester etc., 10- 400pts.wt. of nonmagnetic inorganic compound, 0.5-50pts.wt. of lubrication additive, and, if necessary, 0-100pts.wt. of carbon fiber are mixed. This material has a smaller coefficient of thermal contraction, excells in lubrication, and allows a smoother rotation to stabilize the travel of tape relative to temperature changes. For nonmagnetic inorganic compound, oxides, hydroxides, carbon acid salts, sulfuric acid salts, silicates, and sulfides of metal powder or metal, or kind or two of metals having a high specific gravity consisting of a compound salt are named as candidates, and they include copper, zinc, zinc white, sulfuric barium and the like. Graphite, wax and the like are named as lubrication additives.</p> |
