| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide machine parts composed of a biodegradable resin composition having an excellent heat resistance and hardly being lowered in mechanical properties with time, and to provide a roller bearing having an excellent heat resistance together with a long duration of life, hardly being lowered in mechanical properties with time. <P>SOLUTION: The machine parts are composed of the biodegradable resin composition containing a resin component comprising at least two polyvinyl alcohol compounds each having a different saponification degree. Wherein the difference between the saponification degrees of (A), a polyvinyl alcohol compound having the highest saponification degree and (B) a polyvinyl alcohol compound having the lowest saponification degree is ≥5 mol%, and the weight ratio of the compounds A to B is 5:95-95:5. The roller bearing whose constitutional member is composed of the biodegradable resin composition, is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
