| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a sliding bearing for an oral cavity hygienic instrument such as an electric toothbrush in such a way that a friction coefficient is not fluctuated by environmental change with the lapse of time such as temperature change and that rotational torque is stabilized as small as possible for many hours. SOLUTION: A sliding bearing 9 for holding a shaft 8 fitted with a cleaning instrument such as a toothbrush or a massaging instrument and axially vibrated or rotated around its axis by the driving force of an electric motor is formed of a polyolefin-based resin such as polyethylene resin, or a polyamide-based resin as an essential component and containing 0.1-20wt% polymer type synthetic lubricating oil such as silicone oil without a functional group or non-polymer type synthetic lubricating oil such as ester type synthetic oil. In such a sliding bearing for an oral cavity hygienic instrument, lubricating oil is dispersedly held in the resin in fine dispersion units, the exudation speed of lubricating oil is stabilized, and a friction coefficient is hardly fluctuated by a temperature change of the bearing.</p> |
